Subject: The Carbon Bomb: Climate Change and the Fate of the Northern Boreal Forests
From: "Saved by Windows Internet Explorer 8"
Date: Sun, 28 Nov 2010 20:32:55 -0500

Home

The Carbon Bomb: Climate Change and the Fate of the Northern
Boreal Forests
by GREENPEACE INTERNATIONAL
(GP)

Acknowledgments

This report was researched and written by Kevin Jardine and edited by Lyn
Goldsworthy, Abbie Thomas and Michael Szarbo for Greenpeace International.

Greenpeace International would like to acknowledge the work and assistance of
the many people who reviewed various drafts. We would especially like to thank
Robert Stewart, Ole Hendrickson, David Price, Michael Apps and Tim Lynham from
Forestry Canada. H.H. Shugart from the University of Virginia, G.M. MacDonald
from McMaster University in Ontario and S. Nilsson from the International
Institute for Applied Systems Analysis in Austria also provided helpful advice.
The ecology sections are much stronger as a result.

Within Greenpeace, we would like to thank Patrick Anderson, Bill Barclay,
Francesco Martone and Christoph Wiedmer from the Forests Campaign; Kalle
Hesstvedt, Marcus Rand, Jeremy Leggett and Erwin Jackson from the Climate
Campaign; Bob Lyons and Donna Greenley from Greenbase; and Andrea Imada from
Greenpeace Canada.

Designed by Wendy Farley. Produced by Social Change Media, Sydney, Australia
and Lyn Goldsworthy.

Printed by MPH Graphics Inc Ontario, Canada

Published in 1994 by Stichting Greenpeace Council, Keizersgracht 176, DW1016,
Amsterdam, The Netherlands.

ISBN 90-73361-14-1

A dragon of fire, running wild through the forest, Setting every
tree ablaze and touching off bright torches.
Like a monster starved for a
century, Destroying everything;
Like a rocket, the fire raced everywhere,
Giving vent to rage - rage pent up for thousands of years.

"An Ode to the Heroes of the Fire-Fighting" In a collection published by the
Popular Art Centre of the Hinggan prefecture, Jiagedaqi,
Chia.[1]

Executive Summary

THE NORTHERN BOREAL FORESTS make up almost a third of the Earth's forests,
covering about 15 million square kilometres, and ranging across Russia, Canada,
the United States, Scandinavia, and parts of the Korean Peninsula, China,
Mongolia and Japan.

Drawing on the latest research on forest ecology, the impacts of recent
climate change, and studies on projected future climate change, this report
shows that between 50 and 90 percent of the existing boreal forests are likely
to disappear as a result of a doubling of atmospheric levels of carbon dioxide
and other greenhouse gases. This doubling is expected to take place over the
next 30-50 years, and is likely to create abrupt changes in the Earth's climate
that would result in severe forest decline. The rate of decline is still
uncertain, but is likely to be rapid in many regions, and driven by massive
fires, insect outbreaks and storms.

There is growing and alarming evidence that this decline is already beginning
and is driven by a level of greenhouse gases in the Earth's atmosphere that is
currently higher than has been seen in over 150,000 years.

The projected decline could contribute to the rapid release of hundreds of
billions of tonnes of additional carbon dioxide into the atmosphere,
accelerating the rate of climate change.

The emerging and potential impacts of climate change threaten the more than
one million indigenous people who live in the boreal forest, as well as a loss
of wildlife and plant diversity through the destruction of habitat. Key
endangered species living in the boreal forest, such as the Siberian tiger, are
already on the brink of extinction. Climate change and current logging practices
further threaten such species.

Current logging practices are aggravating forest decline by decreasing the
ability of the boreal forest to withstand disturbances, increasing stress by
changing moisture and temperature regimes, and releasing greenhouse gases.

Serious disturbance of the boreal forest ecosystem can be traced back to an
abrupt shift in the global climate in 1976. Since then higher temperatures have
sparked larger and more frequent fires throughout the boreal forest, and the
number of storms and damaging insect outbreaks has increased. These disturbances
have been accompanied by a decline in conifer populations in the southern part
of the boreal forest.

Unless atmospheric concentrations of greenhouse gases are quickly stabilized
climate-vegetation models predict that large areas of boreal forest will be
reduced to patchy open woodland and grassland, resulting in lowered biological
diversity and a reduced ability to store carbon.

Studies of the global carbon cycle suggest that boreal forests are not
absorbing as much carbon as they did before 1976. As a result, the atmosphere
already appears to contain 10-15 billion tonnes of carbon more than it would
have if forests had continued to absorb carbon at the pre-1976 rate.

If boreal forests continue to decline, estimates suggest that burning and
rotting of boreal forests could contribute to the release of up to 225 billion
tonnes of extra carbon into the atmosphere, increasing current levels by a
third. This would accelerate the rate of climate change.

While it is possible that the boreal forest could expand into the frozen
tundra as temperatures increase, such an expansion would likely be delayed by
slow tree migration rates and the adverse effects of increased ultraviolet
radiation on trees from ozone depletion.

Even in the long term, the boreal forest is not expected to expand enough to
compensate for the deterioration in the southern part of the forest.

This report calls on policy and decision makers to radically rethink and
change energy policies and logging practices in boreal forest countries in order
to protect and preserve the climate and biodiversity. Such changes are
consistent with their obligations under the Climate Convention and Biodiversity
Treaty established by the 1992 UN Earth Summit in Rio de Janeiro, Brazil.

GREENPEACE BELIEVES that climate change and severe forest decline can only be
halted by:

* A planned and orderly global phase-out of fossil fuels and their
replacement by the efficient use of renewable and clean energy sources,
including the immediate reduction of greenhouse gas levels by at least 20
percent by 2005.

* An end to global deforestation and the introduction of a programme of
ecologically-based reforestation.

* The immediate phase-out of CFCs, HCFCs and HFCs, and their replacement by
chemicals which do not damage the ozone layer or contribute to the human-induced
greenhouse effect.

Chapter 1 -- Rigging the Bomb: The Carbon Crisis

The Greenhouse Effect

FOR MILLIONS OF YEARS, the naturally-occurring greenhouse effect has played a
crucial role in determining the Earth's climate. Greenhouse gases such as carbon
dioxide and methane have trapped the Sun's heat near the Earth's surface,
helping to evaporate surface water into clouds which later return the water to
Earth.

Without the greenhouse effect, the Earth's average temperature would be 18
degrees Celsius below zero. The Earth would be a lifeless frozen wasteland.
Instead, the greenhouse effect raises the Earth's average temperature by a full
33 degrees Celsius.[2]

Rain and the sun' s warmth trapped by the greenhouse effect allow plants to
grow and soils to form, and sustain the diversity of life. Plants and soils
absorb carbon dioxide and other greenhouse gases from the air. For millions of
years, a complex mixture of biological and hydrological systems released just
enough carbon dioxide to maintain a fairly stable balance of these gases in the
air.

Until now.

Climate Catastrophe

IN A MONITORING STATION at the Mauna Loa volcano in Hawaii, scientist Charles
David Keeling has been patiently measuring atmospheric levels of carbon dioxide
since 1957. The results of his research, which have been confirmed and extended
by scientists around the world, have profound implications.[3]

Keeling discovered an enormous disruption in the global carbon cycle. His
measurements showed that carbon dioxide levels were rising rapidly. Subsequent
research has shown that the levels of most greenhouse gases have risen
dramatically since the last century. Carbon dioxide levels have increased by
about 25 percent since 1850, methane levels by 100 percent, and nitrous oxide
levels by 15 percent. Next to water vapour, carbon dioxide is the most plentiful
and important greenhouse gas.[4]

For at least 160,000 years before the start of the Industrial Revolution,
atmospheric concentrations of carbon dioxide never exceeded 300 parts per
million. In 1992, carbon dioxide levels reached 355 parts per million, meaning
that some climate change is already inevitable.[5] Some scientists fear this is
already happening.

A recently released Greenpeace review of extreme weather events suggests that
the world's climate is, indeed, being disrupted in a manner consistent with the
increased level of greenhouse gases in the Earth's atmosphere.[6]

In the absence of urgent action by the governments of the world, this level
may rise even higher, to more than 600 parts per million in less than fifty
years. At this concentration. the world faces a very real and dangerous risk of
catastrophic climate change. The United Nations' Intergovernmental Panel on
Climate Change (IPCC) is made up of the world' s leading climate scientists.
Their 1990 and 1992 reports estimated that some of the possible effects of rapid
global warming could include:

* large-scale disruption of forestry, agriculture and fisheries;

* extinction of many plant and animal species on land and in the oceans;

* changing rainfall patterns;

* loss of huge tracts of coastal land under rising seas as the oceans
expand;

* less access to less reliable water supplies in many parts of the world;

* serious adverse effects on human health.[7]

Writing about the impacts on forests, the IPCC said: "It is possible that
many tree species will not be able to change their geographic distribution as
fast as the projected shifts in suitable climate and extinctions may
occur."[8]

The reality could be even worse. The IPCC has warned that its calculations do
not include climate "feedbacks" such as biomass reactions to a warming climate,
which could have the effect of accelerating global warming. This could include
the release of huge quantities of heat-trapping methane from tundra regions
north of the boreal forest. Compared to the amounts of carbon dioxide and
methane currently in the atmosphere, natural reservoirs of these gases trapped
in Arctic tundra, permafrost, and the world's oceans, are huge.

In a warming world these gases could be released to the atmosphere, feeding
into the warming process and increasing its impact. A runaway greenhouse effect
is therefore a possibility. A significant minority of scientists think it a
probability. This would result in rapidly accelerating and unstoppable increases
in global temperatures, with serious climate change and ecological
impacts.[9]

"The rate of change of temperature predicted by the IPCC is 15-30 times
faster than any global temperature change ever known
before."[10]

Fossil Fuels and Deforestation

HUMANS ARE ALMOST entirely responsible for this disruption of the global
carbon cycle, mainly through burning fossil fuels which increase the level of
carbon dioxide in the atmosphere, and removing forests which act as "carbon
sinks" by absorbing carbon dioxide. Approximately 7.6 billion tonnes of carbon
are currently released into the atmosphere each year. Six billion tonnes is from
fossil fuels, and an estimated 1.6 billion from deforestation.[11]

The burning of fossil fuels such as coal, oil and natural gas - themselves
largely the remains of ancient forests - has expanded rapidly since the late
19th century. Carbon emissions from fossil fuels have increased around 4.3
percent each year since then, only declining when industrial production slowed
during the Great Depression and the two World Wars.[12]

Carbon dioxide is also released into the atmosphere when forests are cleared
using fire in tropical countries such as Brazil and Indonesia, and as exposed
forest soil decomposes. The agricultural crops which usually replace tropical
forests have a far lower capacity to store carbon.[13]

Significant amounts of carbon are also released by the logging of temperate
and boreal forest, especially by the logging of old-growth temperate forest of
the Pacific Northwest and British Columbia[14], but also by the rapidly
increasing logging operations in the boreal forest.[15]

Deforestation does more than release carbon to the atmosphere; it also
reduces the ability of forests to store carbon and act as a carbon sink by
destroying them.

Chapter 2 -- Setting the Mechanism: Climate and Boreal
Ecology

A Vast Natural Resource

THE NORTHERN BOREAL forest, also called the taiga, is a vast ecosystem that
encircles the northern hemisphere and covers 1.5 billion hectares. or 11 percent
of the Earth's land surface.[16]

The forest ranges from Alaska in the far west, through most of Canada, across
the Atlantic to Norway, Sweden and Finland, through vast areas of Russia, and
into parts of China, Mongolia, the Korean Peninsula and northern Japan.[17]

Small fragments also exist in mountainous areas south of the main forest.
This mountain or alpine ecosystem is sometimes called "oroboreal", from the
Greek word "oro", or mountain. Oroboreal forest is found throughout the Rocky
Mountains and in alpine regions of Europe.

About 40 percent of the Earth's land surface is covered by dense forest,
shrubland and wooded grassland.[18] The northern boreal forest, the temperate
forest of the mid-latitudes and the tropical forest that grows near the equator
are the three great forest ecosystems.

Forests have three vital functions. They help to regulate the Earth's
climate, are home for millions of indigenous people and most of the Earth's
terrestrial animals and plants, and they are the basis of a major global
industry.

Thermostat For The Planet

FORESTS AFFECT THE CLIMATE in several ways. They have a profound effect on
the local, or microclimate. Trees provide shade which lowers summer temperatures
and prevents soil from drying out. They reduce heat loss from the ground in
winter, and provide shelter from wind, preventing storm damage that might
otherwise occur in more exposed areas. By regulating the global carbon cycle,
forests also have a profound effect on the global climate.

The carbon cycle is one of the major systems that drives the Earth's
biosphere and climate, and is, in a sense, the way the Earth breathes. The
complex interaction between the boreal forest and climate is best understood by
tracing the path of carbon through the biosphere and atmosphere.

Forests influence the global climate by taking in carbon dioxide and
releasing it back into the atmosphere. Trees extract carbon from the atmosphere
through photosynthesis which is driven by sunlight. The carbon is combined with
water and nutrients from the soil to create the materials trees need for
survival. Trees and animals also release carbon dioxide back into the atmosphere
through a process called respiration.

The carbon stored in trees is eventually returned to the atmosphere via
decomposition. Trees drop debris onto the forest floor, and eventually die,
becoming part of the litter and soil. bacteria and insects break down this
organic material, releasing carbon back into the atmosphere in the form of
carbon dioxide where it can be used again. Animals also consume the carbon
extracted from the air in the form of plants and other animals, and so it makes
its way through all life on the planet.

"The boreal forest makes up a third of the Earth's forests"
[19]

A Treasure Chest of Carbon

A VAST AMOUNT OF CARBON is locked up in the world's forests. While the
atmosphere currently contains about 750 billion tonnes in the form of carbon
dioxide, forests contain about 2,000 billion tonnes of carbon. Roughly 500
billion tonnes is stored as trees and shrubs and 1,500 billion tonnes as peat
bogs, soil and forest litter.[20]

Each year about 5 percent of this amount, or 100 billion tonnes, is cycled
through the atmosphere. This cycle is in rough balance, with about 100 billion
tonnes absorbed through photosynthesis, 60 billion tonnes released by
decomposition, and 40 billion released by respiration.[21]

Until recently, the level of carbon dioxide in the atmosphere has remained
almost constant for 6,000 years, suggesting a remarkable system of ecological
checks and balances.[22] Even a small change in photosynthesis, decomposition or
respiration rates could, over a few decades, cause a major shift in carbon
dioxide levels and global climate. And yet this has not happened.

Until now.

HOW CLIMATE SHAPES THE BOREAL FOREST

BOREAL FORESTS, LIKE ALL forests, play an important role in regulating the
world's climate. In return, climate has a profound effect on the forest.

Boreal forests are complex ecological communities supporting a wide diversity
of people, animal and plant life, and habitats. More than one million indigenous
people live in the boreal forest. Tribes including the Dene and Cree of Canada,
the Sami or Lapplanders of Norway, Sweden and Finland, the Ainu of northern
Japan, and the Nenets, Yakut, Udege and Altaisk of Siberia have lived in balance
with the forest for thousands of years.

The boreal forest is probably as widely known for its wildlife and endangered
species. Its beautiful native bird species are well known around the world and
include hawks and owls; crows, ravens and jays; ptarmigan and grouse;
woodpeckers and seed- eaters such as finches, chickadees, and crossbills.

Apart from the seed dispersing function they perform, birds also eat forest
insects such as mosquitos and black flies, and control caterpillar and beetle
populations capable of devastating tree stands. Insects such as the North
American mountain pine bark beetle and Siberian silkworm can periodically
explode and kill off trees over millions of hectares.

The boreal forest is also home to a rich diversity of native mammals ranging
from moose, deer, beavers and wolverines, to porcupines, squirrels, lemmings,
fishes and martens. Caribou or reindeer live in the northern part of the forest
and the tundra beyond. The large predators of the forest include black and
grizzly bears, wolves, cougar, and Iynx. The habitat of the highly endangered
Siberian tiger includes the southern extent of the boreal forest in the Russian
far east.

The Forest Climate

TO THE NORTH the boreal forest is bounded by the tundra, a mostly treeless
expanse of shrubs, grass and lichen that stretches to the ice packs of the polar
desert and the Arctic Ocean. At its southern edge are grassland and remnants of
the surviving maple and oak temperate broadleaf forests.

For much of the year the forest is locked in a cold winter freeze down to
minus 40 degrees Celsius during which boreal life almost comes to a halt. The
short boreal summer brings long, warm periods of daylight that lead to rapid
boreal growth. The northern parts of the forest are dominated by permafrost or
permanently frozen soil. In these areas, summer warmth only melts a thin layer
of soil, and in winter there are only very short periods of
daylight.

Forest Habitats

MUCH OF THE FOREST consists of stands of evergreen conifers. In North America
the forest changes from pine to spruce and then to fir from west to east. Scots
pine and Norway spruce are common in Scandinavia, while the deciduous larch is
dominant in much of Russia. Several less abundant broad-leaved deciduous species
also live in the boreal forest, including aspen, poplar, birch, willow and
alder.

A variety of shrubs and grasses grow beneath the forest canopy, and the
forest floor is usually cloaked in a rich mantle of moss or lichen. Fallen
leaves and twigs form a forest litter that decays over centuries to create a
deep and long-lasting forest soil which contains more organic matter than the
trees.

Peatlands

APPROXIMATELY 2.6 MILLION hectares - almost a fifth of the forest - is
covered by deep layers of decomposing peat moss.[23] These peatlands form an
ecosystem as important as the tree stands. Covered by hundreds of thousands of
shallow lakes and fens, peatlands are among the most ecologically important
wetlands. During the short boreal summer, these wetlands are a breeding ground
for many migratory ducks and geese.

CLIMATE CONTROLS

THE CLIMATE MAINLY DETERMINES where boreal forest grows. In Canada, for
example, the extent of the forest is determined by growing degree-days or the
number of days each year above 5 degrees Celsius multiplied by the average daily
temperature.[24] This means that grassland or deciduous hardwood species replace
boreal forest in southern areas with too many growing degree- days, while the
forest is replaced by tundra in northern areas with too few growing degree-days.
A similar correlation between climate and the boreal forest is found in Europe
and Asia.[25]

Past Patterns

PAST PATTERNS SHOW THAT specific climatic conditions are necessary for
healthy boreal forest growth. If conditions change, so does the forest. For
example, the boreal forest responded rapidly and dramatically to the ending of
the last ice age. At their fullest extent, some 18,000 years ago, huge ice
sheets covered most of Canada, northern Europe, and western Siberia, reaching
down into Ohio in North America and as far as northern Poland in Europe. The
boreal forest was located much further south than today. Pockets survived in icy
shelters on the peaks of mountains that rose above the ice sheets, and at the
foot of glaciers in regions such as Kansas and Nebraska.[26]

As the Earth warmed between 17,000 and 8,000 years ago, the boreal forest
shifted northwards. In Kansas and Nebraska, as the climate became hotter and
drier, the forest was replaced by grassland. In eastern Siberia, which was
largely not covered by glaciers, the cool mixture of forest and tundra gave way
to bands of vegetation, with boreal forest bounded to the south by temperate
broad-leaved forest and grassland. The boreal forest also grew onto land left by
retreating glaciers, and in some places reached the shores of the Arctic
Ocean.[27]

Can It Adapt?

PAST CHANGES IN the Earth's climate have caused profound changes in the
location and extent of the boreal forest. These changes, though immense when
measured over millennia, happened at a far slower rate than the climatic change
expected over the next few decades. Can the forest adapt in
time?

DISTURBANCE AND SUCCESSION

THE CLIMATE ALSO CONTROLS the location and distribution of tree species in
the boreal forest by shaping the two opposing forces that drive boreal ecology:
disturbance and succession. Disturbance by fire, insect and storm activity
creates openings in the forest and occasionally removes tree stands over a large
area. This natural process benefits the forest by preserving diversity, and
removing ageing stands.

Once an opening is created, a second process called succession takes place,
in which pioneer species such as grasses, herbs and shrubs move in. Depending on
the local climate and terrain, these pioneer species may later be replaced by
broad-leaved trees such as aspen and birch, and these may in return be replaced
by spruce and fir. If left undisturbed for several centuries, coniferous boreal
forest in cool lowlands can be replaced by peatlands through a process called
paludification.

Boreal species form a natural spectrum ranging from grasses to spruce and fir
to peatlands. Species on the right of the spectrum are long lived, slow growing,
and tolerant of the deep shade found in old-growth coniferous forest. Species on
the left are shorter lived, faster growing, and need more sunlight.

Disturbances that create sunlit openings in the forest often push the species
in a boreal stand further to the left of the spectrum. In the absence of new
disturbances, succession gradually moves the forest back to the right, towards a
dense old-growth forest of spruce and fir.

The boreal processes of disturbance and succession may have played a
significant role in exaggerating changes in the Earth's past climate. As the
Earth approached an ice age, the frequency of disturbances was likely reduced
throughout most of the boreal forest, and the forest tended towards peatlands
and old-growth coniferous forests - the right side of the boreal spectrum. These
ecosystems stored large amounts of carbon, reducing the level of carbon dioxide
in the Earth's atmosphere and further cooling the Earth.

On the other hand, as the Earth warmed at the end of an ice age, the
frequency of disturbances likely increased, releasing large amounts of carbon
dioxide from the forest, and moving the boreal spectrum more towards the less
carbon-intensive left side of the boreal spectrum. Warming the frozen peatlands
also released huge quantities of methane, a greenhouse gas more than 20 times
more powerful than carbon dioxide. These emissions would have contributed to the
natural greenhouse effect, further warming the Earth.[28]

Creative Disturbance

UNDERSTANDING THE interaction of disturbance and succession gives clues about
how the boreal forest might respond to climate change. Disturbance by fires,
insects and storms largely determines the distribution of species within the
boreal forest. The frequency of disturbance is closely linked to climate and can
increase dramatically during warm, dry weather. On the other hand, the rate of
succession can be significantly reduced by temperature, moisture or reproductive
stress.

FIRE

FIRE IS THE MOST important driving force in boreal ecology. It plays a
crucial role in determining the distribution of boreal species, and improves
forest vitality by removing trees weakened by age, drought, storm, insect
infestation or extreme cold. Forest fires are frequently sparked by lightning,
and usually only burn a small area of forest. Fires lead to increased diversity
in the age and type of vegetation by opening up spaces in the forest. Fires also
clear debris, expose the soil, improve the availability of nutrients and clear
space for seedlings to grow.[29]

[chart showing "Analysis of air trapped in Antarctic ice cores shows that
methane and carbon dioxide contributions were closely correlated with the local
temperature over the last 160,00 years. Present-day concentrations of carbon
dioxide are indicated." omitted here.]

May, June and July are the main fire months in most boreal forests. Snow and
cooler winter temperatures make fires less likely prior to this time, while
autumn rains in August and September usually dampen fire activity
afterwards.

Investigation of past fire frequency indicates that fire burns through tree
stands about once every 50-100 years in Alaska and western Canada, once every
130 years in eastern Siberia, and once every 200 years in eastern Canada.[30]
Before fire suppression began in Sweden, fire occurred once every 80 years.[31]
In the last 200 years, Swedish fire suppression programmes have eliminated
almost all fires.

The global area of boreal forest burned each year is highly variable,
depending largely on the weather and the amount of fuel available in the form of
litter and drought-stressed or otherwise weakened trees. Fires are most common
during warm, dry weather.[32]

Fire frequency plays a critical role in determining the distribution of
species in the boreal forest. In cooler, moister areas with more than an average
of 100 years between fires, fir and spruce tend to dominate. When fires occur
more frequently - between every 50 and 100 years the faster growing, more fire-
tolerant pines prosper. More frequent fires give the edge to aspen and birch.
When fire returns more often than once every 10 years, no tree species can
sustain itself, and the area becomes grassland.[33]

Fire plays an important role in maintaining the limits of the forest. The
cooling climate of the Little Ice Age, which lasted from 1250 to 1850, resulted
in huge forest fires in northern Quebec. Most of the trees destroyed did not
grow back and the result was the mixture of tundra and scattered trees that now
characterize northern Quebec.[34]

The grassy prairies on the southern limits of the boreal forest in western
Canada covered an area significantly further north than today before European
colonisation.

However, constant fire suppression has since allowed the forest to invade the
northern grasslands and spread further south than would have naturally
occurred.[35]

Increased temperatures caused by climate change could lead to fire occurring
well above natural frequencies, resulting in rapid shifts in boreal species and
forest decline.

INSECTS

INSECTS PLAY A VITAL role in boreal ecology, decomposing litter and serving
as a food supply for birds and small mammals. The forest usually benefits from
insect outbreaks, because they reduce the likelihood of catastrophic fire by
helping to eliminate older stands and diseased trees. However, populations of
insects such as bark beetles, the Siberian silkworm and the spruce budworm can
explode and devastate millions of hectares of forest. The life cycles of the
spruce budworm (Choristoneura fumiferana) and the spruce bark beetle (Ips
typographus) are strongly influenced by climate, with both species likely to
increase in numbers during the kind of warmer, drier weather predicted in a
global warming world.

[Chart showing "Fire Frequency and Species Distribution in the Boreal Forest"
omitted here.]

The Spruce Budworm

THE SPRUCE BUDWORM is found throughout the southern boreal forest in North
America. Its traditional range stretches from the Atlantic coast to the southern
Yukon. A similar species, the western spruce budworm (Choristoneura
occidentalis) can be found in the oroboreal forest throughout the Rocky
Mountains. The spruce budworm is misnamed. It is not a worm, but the caterpillar
larva of a moth. Its favourite food is fir, but it will also feed on spruce.

Major budworm outbreaks have occurred at thirty year intervals in eastern
North America, which contains much of the continent's balsam fir. The most
recent outbreak, which lasted from 1970 to the mid 1980s, resulted in the
defoliation of 55 million hectares of forest - an area larger than
France.[36]

[Chart showing "North American Spruce Budworm Outbreaks" omitted here.]

The budworm attacks mature stands of fir. Budworm populations grow
exponentially from year to year, and usually collapse only when every accessible
tree has been defoliated. This often leads to the death of the trees. Although
budworms normally attack fir, occasionally outbreaks will also occur in pure
spruce areas of the forest.

Climate plays a major role in the size and duration of a budworm outbreak.
Over several days, female moths can fly up to 600 kilometres to lay their eggs.
Flights normally happen in the early evening in July and only occur if the
evening temperature is above 18 degrees Celsius.[37]

Cool evening temperatures discourage flights and lead to egg laying in a
relatively small area of the forest. The hatched larvae may soon deplete their
food supply and the outbreak would then collapse. On the other hand, warm summer
nights may cause the outbreak to spread the following year.

The number of eggs laid by a budworm moth is determined by the average
temperature. At 25 degrees Celsius, 50 percent more eggs are laid than at 15
degrees Celsius.[38]

The development rate of the larvae is closely tied to temperature. Feeding
rarely occurs at all if the temperature is less than 10 degrees Celsius.[39] One
of the major restrictions on the budworm's range may be that cool temperatures
in the northern boreal forest do not allow the larvae to develop into moths fast
enough to escape the autumn freeze.

The Spruce Bark Beetle

ONE OF THE MOST aggressive of boreal forest insects is the spruce bark beetle
(Ips typographus). This insect is found throughout the boreal and temperate
forests of Eurasia - from western Europe through to Korea and Japan. It normally
attacks Norway spruce, but can also attack pine and larch.[40]

Adult bark beetles hibernate in forest litter or in the bark of wind-fallen
trees. Emergence is determined by temperature. Growing degree-days (the number
of days above five degrees Celsius multiplied by the average temperature) must
reach 50 to 130 before the beetles are able to emerge. The actual temperature
must be above 20 degrees Celsius on the day of emergence. For this reason,
beetles in northern Europe do not emerge until late May or early June.[41]

In warmer areas of Europe, bark beetles are able to emerge earlier from
hibernation and two or sometimes three generations of beetles can develop in a
single season. In northern Europe, cooler temperatures normally constrain the
beetles to a single generation.[42]

Bark beetles normally exist at a low level in the boreal forest, living in
trees that have been weakened by lightning strikes or disease.[43] Large
outbreaks are usually sparked by an increase in weakened trees. This can be
caused by windstorms, forest fires, drought, or an attack by defoliating
insects. Logging operations that leave waste wood behind in the forest can also
cause outbreaks.

For example, a huge bark beetle outbreak in Europe at the end of World War II
was caused by drought and poor logging practices.[44] Large outbreaks in Japan
on the northern island of Hokkaido followed extensive storm damage caused by
typhoons in 1954 and 1981.[45]

Once bark beetle populations grow to a critical size, they are able to
overwhelm almost every mature tree, healthy or otherwise. Outbreaks can last for
many years and normally collapse only when every tree within reach has been
killed, or cold weather suppresses populations.[46]

Like most other insects, bark beetles help maintain the long- term health of
the forest. Their normal role in attacking diseased trees helps to improve
forest vitality. Even during outbreaks, they can help promote the long-term
growth of a forest by removing the overstory and allowing for the growth of the
younger seedlings beneath.

STORMS AND LIGHTNING

WARMER TEMPERATURES CAN increase the frequency and intensity of storms and
lightning.[47]

Storms play an important role in shaping maritime boreal forests in
northeastern Asia and North America. Typhoons are capable of destroying large
areas of forest in northern Japan.[48] Storms in both of these maritime regions
create "wave forests" - strips of mature forest alternating with strips of
underbrush or young forest developing in the aftermath of severe windstorms.
Wave forests are also common in Newfoundland and the Appalachian mountains.[49]
Tornado activity plays a lesser role in disturbing boreal forests. In Ontario,
storms destroyed approximately 10 percent of the forest area burned out by
forest fires between 1950 and 1980.[50] However, tornado activity has increased
dramatically in North America since 1980.[51]

Wind plays a critical role in magnifying the impact of other disturbances.
Small forest fires can become larger conflagrations when fanned by gale-force
winds. Windstorms can lead to blowdowns and generate large amounts of fuel for
future fires or enough dead wood and damaged trees to encourage a bark beetle
outbreak. Wind can also spread insects over long distances and so help to
rapidly expand an outbreak. Conversely, fires and insect outbreaks can help
increase the impact of a windstorm by creating exposed breaks in the forest.
Lightning is the major cause of large forest fires, and plays a crucial role in
driving fire and insect disturbances.[52] Lightning is responsible for 38
percent of forest fires in Alaska, which in turn account for 80 percent of the
total area burned.[53]

SUCCESSION IN THE BOREAL FOREST

THE RATE OF SUCCESSION and recovery from disturbances depends on the level of
stress. Stress comes from three main sources: temperature, moisture levels, and
reproduction. Each of these are profoundly influenced by climate. In particular,
high temperatures and dry soil can slow down or halt successions converting a
disturbed forest to shrubs or grassland.

Temperature Stress

TEMPERATURE AFFECTS THE rate of respiration and photosynthesis. Healthy trees
grow by accumulating carbon through photosynthesis at a rate faster than they
lose carbon through respiration and other processes. In the absence of other
factors, increasing the air temperature accelerates the rate of both. However,
at high temperatures, the rate of respiration surpasses the rate of
photosynthesis, causing a tree to lose carbon and eventually
die.

Moisture Stress

TREES EXTRACT WATER and nutrients through roots, and lose water through
transpiration. A similar process, evaporation, can dry forest soils. Evaporation
and transpiration are strongly dependent on temperature. If a tree loses more
water than it can absorb through its roots, it will dehydrate and die. Night
temperatures also play a crucial role in relieving moisture stress. If night
temperatures are too high, trees can die.[54]

Spruce, pine and fir respond to moisture stress by closing tiny pores on
their leaves or needles called stomates. With most transpiration taking place
through the stomates, this can significantly reduce moisture stress. However,
the stomates are also the pores which absorb carbon dioxide during
photosynthesis. If the stomates are closed, photosynthesis stops and the tree
may starve.

Reproductive Stress

MANY BOREAL SPECIES are dormant during the autumn, and require a long period
of winter chilling before warmer temperatures trigger budburst and new growth.
Reduced chilling can significantly increase the time required for
budburst.[55]

Pollen and seed cones both develop very rapidly under high spring
temperatures. However, this development may lead to abnormal and incomplete
cones, with little pollen and infertile seeds. As a result, high spring
temperatures can lead to reproductive failure.[56]

Boreal seeds germinate within a specific range of soil temperatures. For
example, black spruce seeds germinate between 15 and 28 degrees Celsius. If the
soil temperature falls below 15 degrees, the processes that cause germination
come to a halt. If soil temperatures rise above 28 degrees, bacteria and fungi
can attack and consume seeds. The probability of germination also declines
rapidly for higher temperatures.[57]

Climate affects the boreal forest in many ways. In particular, warmer weather
increases the frequency of disturbances and may decrease the rate of succession
by creating temperature, moisture or reproductive stress. In a changing climate,
the natural balance of the boreal forest would be expected to undergo profound
disruption, with parts eventually reverting to grassland, some areas becoming
more vulnerable to large-scale wildfires and insect outbreak, while some species
could decline in the face of increasing stress.

Chapter 3 -- Lighting the fuse: The Impact of Recent Climate Change on
the Boreal Forest

The Heat is On

SCIENTIFIC EVIDENCE ALREADY shows that the climate is changing: average
global temperatures have risen about 0.5 degrees over the last century, and the
seven hottest years since records began 140 years ago all occurred after
1980.[59] These temperature increases have been most dramatic at high latitudes.
Summer temperatures on Ellesmere Island, in Canada's High Arctic, are higher
than they have been for more than 1,000 years.[60]

Weather patterns have changed at the closely monitored Experimental Lakes
Area in the boreal forest of northwestern Ontario. Since the late 1960s, the
average air temperature has risen by two degrees Celsius.[61]

Increasing Fires

MAJOR FIRES HAVE recently disrupted the boreal forest. An area of boreal
forest larger than France (56 million hectares) was destroyed between 1980 and
1989.[62] Since 1976, the area burned in Canada has soared to six times the
century trend, and to more than nine times the century trend in the alpine and
temperate forest of the western US.[63] Russian researchers have reported a
sharp increase in the area of forest burned since 1985.[64]

In 1989 the worst fires on record scorched western Canada, and the area east
of James Bay in Quebec. Fire frequency has increased since 1975 in Alaska, and
increased over several decades in Sweden at least until fire statistics were
discontinued in 1980. Only in Finland has there been a decrease in the frequency
and area of boreal fires.[65]

[Three charts showing "Global Temperatures", "Canadian Temperatures", and
"Western U.S. Forests Fires" omitted here]

In For The Kill

UNUSUALLY LARGE OUTBREAKS of the tree-eating insect, the spruce budworm, have
devastated the Canadian boreal forest in recent years. A Canadian government
study released in 1987 showed that conifers were growing on average up to 65
percent slower than in the 1940s and 1950s, because of budworm outbreaks, and
possibly acid rain.[66]

Spruce budworm outbreaks have grown exponentially throughout North America
this century, with each outbreak doubling in size. The outbreaks following 1910,
1940 and 1970 affected 10, 25 and 55 million hectares respectively.[67] The next
outbreak, due by the year 2000, could affect 100 million hectares of forest.
Such a huge infestation could dramatically accelerate the decline of spruce and
fir in the southern boreal forest.

[Two charts "Russian Forest Fires" and "Tornado Trends for Canada" omitted
here.]

Growing Storms

METEOROLOGISTS REPORT A recent sharp increase in tornados in the U.S. and
Canada. Canadian tornado frequency was four or five times higher than two
decades earlier.[68] Average wind speed in the Experimental Lakes Area in the
central boreal forest of northwestern Ontario has increased by 50
percent.[69]

1987, China: The Black Dragon Fire

WHEN THE FIRE CAME to Eastern Siberia, it was late April, 1987. Spring rain
was light that year, and there had been little snow. Snow cover disappeared by
early April, and much of the vast larch forest of eastern Siberia was tinder
dry. The fires, mostly sparked by lightning, began east of Lake Baikal in the
rugged Yablonovyy mountains and soon reached record size. Blown by gale-force
winds, the fire reached the Amur river that separates Russia from China. Fires
accidentally started by Chinese loggers were already raging to the south of the
river.

After a fire was reported near Gulian on May 6, workers moved in to put it
out. By 1:30 am on May 7, officials asked the Chinese Army for help. Despite an
all-night effort, the fire spread towards the administrative centre of Xilinji.
Soldiers raced gale-force winds to try to stop the fire from reaching the town's
munitions depot. The flames leapt past the depot and consumed the town's lumber
yard containing 100,000 cubic metres of wood. The soldiers did what they could
to fight the inferno, but it was too late. Xilinji, a town housing twenty-two
thousand people and largely built from wood, was destroyed by the flames.

More than 40,000 fire fighters battled the flames over the next 32 days until
they were finally extinguished by rain in early June. In total, about 1.1
million hectares of Chinese forest was burned. North of the Amur, a much larger
part of the Siberian forest was burned - at least 10 million hectares. It was
one of the largest fires in recorded history.

It was not the forestry workers who were primarily to blame for starting the
fires, and fire fighters weren't primarily responsible for putting them out. It
was the weather.[70]

Burning down the house -- 1988, USA: Yellowstone Forests
Burn-out

WHEN THE FIRE CAME TO the US in the summer of 1988, Yellowstone National Park
was gripped by the worst drought in its 112 year recorded history. Virtually no
rain had fallen in June, July or August. Located high in the Rocky Mountains in
northwestern Wyoming, Yellowstone is the oldest and most famous US national
park. The Greater Yellowstone Area, which includes Yellowstone Park itself,
Teton National Park, and six national forests, covers 2.9 million hectares. The
peaks of the Rocky Mountains, large forests of lodgepole pine, and abundant
moose, deer and bear, make it one of the US's most popular tourist
attractions.

Strict fire suppression in the early days of the park had left Yellowstone
with numerous old stands of lodgepole pine, many of which were now severely
stressed by the drought. Many trees had already been killed by mountain pine
bark beetle infestation.[71]

There were 249 fires in the Greater Yellowstone Area in 1988 - about double
the normal number. Most of these fires burned over a small area and extinguished
themselves quickly. This kind of fire plays an essential ecological role in
forest vitality by renewing the vegetation and eliminating dead forest litter.
However, 50 of the fires spread much more quickly and with more intensity than
normal. The situation was made worse because many of the big fires were
accompanied by windstorms of hurricane intensity.

When Yellowstone Park officials realized how dangerous the situation was,
they launched the largest forest fire suppression effort in US history. More
than 25,000 fire fighters joined the battle. A squadron of airplanes and
helicopters was used to fight the fires. Pilots from all over North America flew
more than 100 aircraft to transport supplies and bombard the flames with water
and chemical retardants.

As the fires approached Old Faithful, the famous Yellowstone geyser, the US
Army was called in to help. Soldiers and civilian workers dug large fire lines
through the forest removing trees and soil to deprive the flames of fuel and
prevent spreading. Despite the best efforts of the US Park Service and the Army,
more than 411,000 hectares of forest in the Greater Yellowstone Area were
damaged by the fires. Almost half of the forest in Yellowstone National Park
itself was scorched or consumed by the flames. The tourist industry directed
their anger at the Park Service. Don Edgarton, manager of the photo shop at the
Old Faithful tourist complex said "We've got ten million trees that are gone ...
They ain't saving none of them ... We're sick about what's happened to the
forest ..."

Park officials protested that they did everything that could have been done.
Nothing could stop the roaring 60 metre wall of flame driven by windstorms of
hurricane intensity. The winds sometimes blew embers and burning branches 2
kilometres in advance of the fire. No fire fighters could halt that kind of
conflagration. It was not park officials or the US Army that determined the
course of the Yellowstone fires. It was the weather.[72]

1989, Canada: Worst Forest Fires on Record

WHEN THE FIRE CAME to the Canadian Province of Manitoba in 1989, it struck in
more than a thousand places. Fires erupted from the shores of Lake Manitoba, and
spread northward for 800 kilometres. High temperatures and drought over the
previous two years had dried out many of the peat bogs and wetlands that served
as natural barriers to fires. As a result, fires spread much more widely than
usual. The inaccessibility of the area and sheer number of the fires made it
difficult to deal with most of them. At the start of the season, the Manitoba
government had only four people to handle fire management programs for an area
of boreal forest the size of Germany. By the end of the season, more than 3,000
people were involved in a coordinated response to the flames. Specially
constructed water tanks scooped up tonnes of water from northern lakes to dump
on the flames - and still the fires grew. More fires were set off by lightning
from thunderstorms generated by the huge clouds of smoke. Most affected were the
indigenous Cree who have lived in Canada's boreal forest for thousands of years.
Cree trap lines that had provided a living for decades were destroyed. Roaring
flames leapt a kilometre across the Nelson River, forcing the evacuation of
4,000 people from the northern community of Norway House. As Air Force Hercules
planes lifted thousands to safety, white and indigenous communities joined
together to fight the fires. Rail and road transport links were cut off by the
flames. By the time the autumn rains came, Manitoba had been hit by 1,140 fires,
over six times more than usual. About 2.7 million hectares, or 5 percent of
Manitoba's land area, had been consumed. More than 25,000 people from dozens of
northern towns became refugees. Similar huge fires raged east of James Bay in
Quebec and smaller fires struck Saskatchewan and Ontario. By the end of the
year, about 6.4 million hectares of forest was destroyed. Amir Shabbar, a
meteorologist with the Canadian Climate Centre, pointed out that there had been
high tornado activity on the Canadian prairies and that the Arctic had been hit
by an unprecedented heat-wave. The cause of the worst forest fires in Canadian
history was clear. It was the weather. [73]

The 1990s: A Fiery Tempest

THE FIRES AND STORMS which ravaged the boreal forests in the late 1980s
continue into the 1990s:

1990: MONGOLIA: On May 10, a huge fire destroyed more than 600,000 hectares
of forest. [74]

RUSSIA: Eastern Siberia exploded into flames again. Gale-force winds of more
than 100 kilometres per hour spread hundreds of fires over thousands of hectares
of Siberian forest. Fires threatened the cities of Ulan Ude and Chita. [75]

USA: The worst forest fire in more than 50 years struck central Oregon.
[76]

CANADA: The small town of Webequie, Ontario, was evacuated twice in one
summer when fires burned through more than 60,000 hectares of forest. [77]

1991: CANADA: Fires in Quebec burn hundreds of thousands of hectares and
cloak Atlantic Canada with thick smoke. [78]

RUSSIA: A state of emergency was declared in the southern Urals after a
heat-wave sparked huge forest fires and widespread drought. [79]

1992: CIS: The worst drought in a century withered the new republics of the
Commonwealth of Independent States. More than 19,000 forest fires flared across
Russia. The sky over Moscow and St Petersburg was choked in smoke. Freak weather
killed crops and destroyed tens of thousands of hectares of forest east of Lake
Baikal. "In my whole life I can never remember such a thing happening," said one
old peasant farmer. Inhabitants up to five kilometres away were evacuated when a
forest fire caused the explosion of a huge weapons depot near Vladivostok in
eastern Siberia. Fires burning in the contaminated forest near the Chernobyl
nuclear power station created huge plumes of radioactive smoke that sent
radiation levels soaring in parts of Belarus. [80]

USA: More than 150,000 hectares of forest were destroyed by mountain fires
that spread to California, Nevada, Idaho, Oregon and Utah. The worst fire struck
near Boise, Idaho. Cliff Wilcox, a spokesperson for the Boise National Forest,
called it "a total ecological disaster". [81] One fire scorched 14,000 hectares
at Burnt Mountain in Alaska's Arctic National Wildlife Refuge. When the threat
forced the US Air Force to reveal the existence of ten nuclear-powered
electricity generators, the public demanded their removal. [82]

1993: SIBERIA: July: 20,000 hectares blaze in the far northeast, fires burn
around Khabarovsk on Siberia's Pacific coast and more than 50,000 hectares are
destroyed near Irkutsk. [83]

USA: President Clinton declared a major disaster in November after 26
wildfires burnt out of control for over two weeks across 90,000 hectares of land
stretching from the Mexican border to the northern suburbs of Los Angeles. A
ten-kilometre-long wall of fire advanced through the LA suburb of Laguna Beach,
destroying more than 600 homes. Damage was estimated at $950 million.
[84]

Chapter 4 -- Packing the Gunpowder: Destabilizing the Boreal
Forest

OVER THE LAST CENTURY, research suggests that about one hundred billion
tonnes of carbon released into the atmosphere by human activity has been
reabsorbed by the world's forests. A significant amount of this carbon likely
went into the boreal forest. This carbon absorption has helped to slow down the
rate of climate change.

Many reasons have been put forward to explain why this carbon was absorbed.
Regardless of the reason, there are alarming signs that this "carbon sink" is in
decline, or has vanished altogether. In particular, increased stress caused by
climate change and inappropriate forest management practices may be about to
turn the boreal forest from one of the world's largest carbon sinks into one of
the world's largest carbon sources.

THE MISSING CARBON

FOSSIL FUEL USE GREW rapidly after the mid-19th century. Carbon emissions
from burning fossil fuels increased from half a billion tonnes in 1900, to one
billion tonnes (1923), two billion tonnes (1955), four billion tonnes (1970),
and are now approaching six billion tonnes. Between 1860 and 1988, fossil fuel
burning released about 200 billion tonnes of carbon.[85]

For much of the 19th century, temperate deforestation contributed more than
500 million tonnes of carbon dioxide to the atmosphere each year. Logging is now
consuming some of the few scattered remnants of old-growth temperate forest. At
the same time, logging and land clearing for agriculture continues to expand in
the tropical and boreal forests, releasing more carbon into the atmosphere.

More forest is being cleared today than ever before. Most recent estimates
say that roughly 1.6 billion tonnes of carbon were released from deforestation
on average between 1980 and 1990. Between 1850 and 1990, around 120 billion
tonnes of carbon were released into the atmosphere as a result of
deforestation.[86]

The total amount of carbon released from deforestation and fossil fuel use
between 1850 and 1990 was therefore approximately 320 billion tonnes. However,
less than half of this, about 130 billion tonnes, remained in the
atmosphere.[87] It is unclear what happened to the remaining 190 billion
tonnes.

According to a recent analysis by Jorge Sarmiento from Princeton, about 90
billion tonnes of carbon was absorbed through general diffusion into the oceans.
This is a natural process in which carbon dioxide in the oceans reaches a
natural equilibrium with the atmosphere. Sarmiento estimates that this oceanic
sink has been growing with the increase in carbon dioxide in the atmosphere, and
now absorbs about 2 billion tonnes of carbon a year.[88]

The remaining unaccounted-for 100 billion tonnes of carbon is the subject of
scientific controversy. Much of this missing or residual carbon is likely to
have been absorbed by forests. Some may also be stored in the oceans in other
ways.

ESTIMATED TOTAL CARBON BALANCE:
1850-1990

SOURCES

Fossil Fuels:

200 billion
tonnes

Deforestation:

120 billion
tonnes

TOTAL:

320 billion
tonnes

SINKS

Atmosphere:

130 billion
tonnes

Ocean
Diffusion:

90 billion
tonnes

Residual Sink:

100 billion
tonnes

TOTAL:

320 billion
tonnes

ESTIMATED ANNUAL CARBON BALANCE: 1980-1989
AVERAGE

SOURCES

Fossil Fuels:

5.4 billion tonnes

Deforestation:

1.6 billion tonnes

TOTAL:

7.0 billion tonnes

SINKS

Atmosphere:

3.2 billion tonnes

Ocean Diffusion:

2.0 billion tonnes

Residual Sink:

1.9 billion tonnes

TOTAL:

7.0 billion
tonnes

Note: The actual annual carbon budget varies from year to year. [89]

A recent literature survey concluded that the boreal forest absorbed about
0.7 billion tonnes of carbon on average each year during the 1980-1990
period.[90] This suggests that the boreal forest makes up more than a third of
the residual sink, and may be the largest single net terrestrial carbon sink.
Although there is controversy over where and what it is, the size of the
residual carbon sink can be estimated each year. It began to grow rapidly in the
mid-1930s. However, detailed data from Charles David Keeling's research shows
that the sink fluctuates dramatically from year to year, and has almost
disappeared several times. Moreover, the running average sink size reacted a
peak in the mid-1970s and has since been shrinking.[91]

A recent abrupt increase in the size of the residual sink from 1992-93 is
believed to be caused by the increased uptake of carbon dioxide by the oceans,
most likely due to the temporary fertilization of aquatic plant life by iron
from the Mt. Pinatubo volcano. It is not expected to continue.[92]

If the shrinking of the residual carbon sink continues, it would have serious
consequences because carbon dioxide levels would be much higher today if the
residual sink had not absorbed 100 billion tonnes in the period since 1850.

The atmosphere already contains 10-15 billion tonnes more carbon than it
would have if the residual sink had continued to grow after the mid-1970s
instead of shrinking.[93] The disappearance or substantial further reduction of
the residual sink would cause a parallel accelerated build-up of carbon dioxide
and more rapid climate change.

The Residual Sink

Many scientists find it surprising that there is a residual sink at all. Why
would forests suddenly start to absorb increasing amounts of carbon after the
1930s? Three major theories have been put forward: carbon dioxide fertilization,
nitrogen fertilization, and forest management practices.

Carbon Dioxide Fertilization

One common theory is that because carbon dioxide can act as a fertilizer
promoting plant growth, forests are now growing faster because of the increased
levels of carbon dioxide in the atmosphere. Most experiments on well-watered
individual tree seedlings in laboratory conditions have shown that doubling
carbon dioxide levels leads to an initial increase in growth of from 20-120
percent, with an average increase of 40 percent.[94] Boreal tree species in
laboratory conditions have shown an average short-term increase in growth of 38
percent.[95]

In some cases, however, increasing carbon dioxide levels only promote
temporary growth, and can even reduce growth if the concentration gets too high.
For example, sweet gum and loblolly pine exposed to elevated carbon dioxide over
four months were absorbing less carbon than control trees receiving normal
levels of carbon dioxide.[96] The decreased growth may have been caused by a
build-up of starch in leaves and a reduction in photosynthesis.[97] So it seems
that increased carbon dioxide does not necessarily increase growth rate in all
instances.

Moreover, increased levels of carbon dioxide may make some vegetation more
vulnerable to insects.[98]

Drought Resistance

Increased levels of carbon dioxide may also make vegetation more
drought-resistant. Boreal trees other than larch normally respond to drought by
cutting water loss by partially closing the stomates on the surface of leaves
and needles. Since trees also absorb carbon Dioxide through these pores, severe
drought can seriously reduce the level of photosynthesis and starve the tree.
Increased levels of carbon dioxide might make it easier for plants to continue
photosynthesizing, even with their stomates only partially open.[99]

However, increased levels of carbon dioxide have also been shown to increase
stomatal opening, which makes the plant vulnerable to moisture stress.[100]
Closing stomates will not necessarily make a tree more drought-resistant if
increased levels of carbon dioxide have resulted in the growth of more or larger
leaves or needles, and hence the growth of more water-losing
stomates.

Nutrient Levels

The response of vegetation to increased levels of carbon dioxide is strongly
influenced by the abundance of other nutrients, particularly nitrogen. Boreal
soils are nitrogen deficient, meaning that increased levels of carbon dioxide
are likely to have little influence on tree growth. As a result, if carbon
dioxide fertilization is having any real effect, it would largely be in
temperate and tropical forests.[101]

No studies have yet been published on the long-term effects of increased
carbon dioxide on natural forests.[102] This is unfortunate, because laboratory
experiments leave out one of the most influential factors: competition between
species. A review of the literature suggests that conifers, among other forest
species, are least affected by increased levels of carbon dioxide. Most affected
are underbrush shrubs and grasses.[103] Faster growing underbrush could have a
profound effect on the boreal forest. Underbrush can prevent conifer germination
and crush or overshade seedlings. Grass can rapidly reduce soil moisture,
especially for shallow-rooted species like spruce.[104]

There is still no scientific consensus on whether increased levels of carbon
dioxide have or could lead to increased long- term growth or increased
resistance to moisture stress in natural boreal ecosystems. No studies have been
conducted in natural ecosystems. There are, however, other explanations for the
apparent increase in carbon absorption besides carbon dioxide
fertilization.

Nitrogen Fertilization

Finnish researchers Kauppi, Mielikainen and Kuusela argue that nitrogen
oxides in acid rain, although having many negative affects on trees, may have a
temporary fertilizing effect, leading to at least a short-term carbon gain. They
estimate that European forests, despite clear signs of decline, are still a net
carbon sink absorbing from 85 to 120 million tonnes of carbon each year.
However, they warn that continued acid rain and climate change may alter this
situation.[105]

Forestry Management

The forest products industry sees natural forest disturbance as competition
that consumes trees that could otherwise be logged. In response, industry and
government have worked to replace the natural ecological dynamic of disturbance
and succession with the artificial dynamic of forest management. Immense effort
has gone into programs to suppress disturbances, including satellite
surveillance, water bombing airplanes, toxic pesticides and sophisticated
biological warfare. These programs have reduced the natural diversity of the
forest and led to large areas of ageing coniferous forest.[106] As a result,
boreal and temperate forests have, over the last century, absorbed more carbon
and released less carbon than they would have under normal conditions. However,
this artificial carbon sink may now be gradually coming to an end as many ageing
stands are no longer able to absorb more carbon, become more susceptible to
blowdown from storms, and fire and insect outbreaks become increasingly
difficult to suppress.[107]

"Although the circumpolar boreal forest is presently believed to be a sink
for atmospheric carbon, the mechanisms believed responsible for this sink are
not likely to be sustained."[108]

Combined Forces

Much of the residual carbon sink can be explained by a combination of these
causes. However, these causes also point to an unstable sink. Carbon dioxide
fertilization, if it exists, has natural limits. Nitrification may cause
temporary fertilization, but increased acid rain is likely to lead to severe
forest decline. Fire and insect suppression simply leads to ageing forests that
are more fire and insect prone. There is clearly no guarantee that the residual
sink will continue to expand, or even exist at all, in the
future.

VANISHING FORESTS

Although natural forces may even now be reducing the ability of the world's
forests to absorb carbon dioxide and slow the rate of climate change, human
intervention may destroy the global carbon sink even more rapidly. The world's
forests are vanishing at an accelerating rate.

Tropical forests are disappearing at the rate of 17 million hectares a year,
an area the size of the Netherlands every ten weeks.[109]

The mid-latitude temperate forest has been reduced to a fragment of its
original size, and now makes up only about one-eighth of the Earth's forest.
Much of the temperate forest was destroyed with the expansion of Europe and
subsequent European colonization of North America.

Human suppression of fire and insect outbreaks, and the creation of tree
plantations have increased the area covered by temperate forest species since
the late 19th century. However, much of this new forested area lacks the
biodiversity of old-growth temperate forest. The few remaining areas of
old-growth forest are now under extreme pressure from intensive logging
operations.

Boreal Forest Under Siege

The boreal forest is now under attack by enormous clear-cut logging
operations which remove the entire forest over huge areas. Corporations such as
Mitsubishi, Daishowa, Weyerheuser, Noranda, and Repap have rights to clear-cut
large areas of Canada's boreal forest. Some of these companies, including
Hyundai, have begun logging operations in Siberia, which has the most boreal
forest on the Earth.

Tree stands that have been clear-cut, even if replanted, will contain less
carbon than old-growth stands. Consequently there is a net release of carbon to
the atmosphere. Exposed soil on clear-cut land may decompose more rapidly,
releasing more carbon.[110]

A recent detailed analysis of the 1986 Canadian forest carbon balance by
government researchers found that logging companies are cutting more than the
net increase in forest biomass. The shrinking Canadian forest was reduced by 28
million tonnes from 1986-87.[111] Nevertheless, the amount of logging continues
to grow.

Reduced Recovery

Clear-cut logging creates profound changes in the local forest climate, or
microclimate. The barren area left behind by clear- cut logging is exposed to
far more solar radiation than the floor of an old-growth forest.

A comprehensive study by the US Forest Service at a clearcut site in Montana
found that clear-cutting exposed the forest floor to more than three times as
much solar radiation as an uncut site, and almost twice as much as a site that
had been partially cut with smaller trees left in place. Exposure sent surface
temperatures soaring and dried out the soil. As a result, seedlings were exposed
to intense temperature, moisture and reproductive stress.[112] Survival was
drastically reduced. Clear-cut logging also creates breaks in the boreal forest
and can lead to more extensive wind damage during storms.

Shade-loving seedlings like spruce and fir do not often survive in clear-cut
sites. As a result, tree planting programmes can fail and the site can revert to
grass and shrubs. Eventually the area may be colonised by windblown seeds of
sun-loving trees like aspen, birch and pine.

As a result of clear-cut logging operations, spruce and fir are rapidly
disappearing from the many areas of the southern boreal forest. A recent Ontario
study found that logging converted almost all former spruce and fir stands into
stands dominated by broad-leaved species like aspen and birch.[113] Global
climate change will further contribute to the enormous stress clear-cut logging
places on the boreal forest, accelerating the rate of forest
decline.

Industry Argument False

The forest products industry often uses the argument that clear- cut logging
mimics the natural fire disturbance common to boreal forests. This is a false
argument. The vast majority of boreal fires are small fires that burn in the
vegetation of the forest understory or remove only small areas of forest.
Catastrophic fires that destroy large areas of forest are much rarer. Canadian
fire statistics show that 50 percent of fires are less than 0.1 hectares in
size, and 97 percent are less than 200 hectares.[114]

Even the rare catastrophic fires do not often destroy all the trees in a
stand, and can leave more than 30 percent of the trees still alive.[115] Dead
trees, or snags can be left standing for many years before they collapse.[116]
As a result, there is far more shade in a burnt site than in a clear-cut,
lowering temperatures and sharply increasing the probability of seedling
survival.

Plantations At Risk

Even when tree planting is successful on a clear-cut site, it does not
recreate the original old-growth forest, but instead produces monoculture tree
plantations. These plantations tend to be more prone to disturbances than more
diverse old-growth.

Old-growth forests contain natural poisons and inedible species which resist
insect attack. Forest entomologist Tim Showalter explains, "Old-growth forests
with their very complex variety of different plant species are internally
resistant to most problem insects."[117] Plantations do not contain these
repellents. The identical age stands in plantations create a dense even canopy
which allows fires to spread rapidly. In contrast, a more diverse old-growth
forest is likely to contain a more uneven canopy and scattered forest openings
that reduce the likelihood of a large-scale fire.[118]

Plantation trees may also be more affected by blowdown due to storms.
According to plant physiologist Richard Tinus, "One of the risks in planting a
tree is a deformed root system. We know that planted trees will not have the
same configuration as trees grown from seed...".[119] Poor root structures can
lead to slower growth and blowdown in storms.

Because they are more susceptible to disturbances than natural forests, tree
plantations and climate change may be an explosive combination.

Clear-cut logging leads to a net carbon release, produces forest areas which
are under enormous temperature, moisture and reproductive stress, and often
leads to the replacement of natural forest with disturbance-prone tree
plantations. For all of these reasons, clear-cut logging makes a significant
contribution to climate change and may contribute to rapid forest decline with
the continued emissions of greenhouse gases.

Chapter 5 -- The Explosion: Computing a nightmare
future

THE RECENT DRAMATIC changes in the boreal forest are associated with an
average global warming of a fraction of a degree Celsius. Yet the IPCC predicts
that temperatures three to nine times higher than this are expected in the next
few decades if the levels of carbon dioxide in the atmosphere reach double pre-
industrial concentrations. How will this enormous change affect the boreal
forest?

The Earth's climate is an extremely complex system with wind, cloud,
temperature, ocean current, vegetation, terrain, and the polar ice caps all
interacting to determine the weather. Higher temperatures alter air and ocean
circulation, the location and frequency of clouds, the distribution and vitality
of terrestrial and marine ecosystems, and the area of glaciers and sea ice
cover.

Fortunately, it is usually easier to forecast general climate trends than it
is to make specific predictions about the next day's weather. Climate forecasts
can be made using computer simulations of the atmosphere, called global
circulation models or GCMs. Because GCMs require a long period of time and
rapid, expensive supercomputers to make their calculations, there are very few
in existence.

Certainly GCMs are not infallible. Currently they can only deal effectively
with large areas of land and water, and cannot yet realistically simulate the
ocean. "Feedbacks" are implemented differently in each GCM, and so temperature
and precipitation predictions sometimes differ, especially on a regional
basis.

Despite these difficulties, GCMs are still the best tool available for
predicting the impact of increased levels of greenhouse gases. Their success in
simulating current and past Earth climates is growing, and there is increasing
confidence in their predictions. In the absence of a second Earth-like planet to
experiment with, they offer the only method available for predicting the effects
of climate change.

Catastrophic Decline Predicted

ONE OF THE MORE comprehensive GCM studies was published in 1992 by Shugart
and Smith from the University of Virginia, and Leemans from the International
Institute for Applied Systems Analysis in Austria.[120]

"There seems to be a clear consensus... that both structure and functions of
boreal regions will be drastically altered by the climate changes projected by
present global circulation models."[121]

Comparing results using climate-vegetation models tied to the outputs of four
different GCMs, these researchers assumed a doubling of atmospheric carbon
dioxide levels. The results derived from all four GCMs predicted massive decline
in the existing boreal forest. The OSU GCM results projected a 50 per cent
decline; others projected more extreme impacts, with the GFDL GCM implying a 90
percent decline.[122]

While the models predicted that some new forest would move into the northern
tundra, this new growth would cover a smaller area than the forest displaced to
the south, reducing the total size of boreal forest and its capacity to act as a
carbon sink.[123]

Mapping the Climate

SEVERAL DECADES AGO, L.R. Holdridge observed a close correlation between
climate and vegetation distribution.[124] Based on temperature and
precipitation, he developed a system of 37 global life zones. Holdridge's life
zones system is a useful tool for predicting the impact of climate change
because it can describe the distribution of a wide variety of vegetation based
on simple variations in temperature and precipitation.

[Four maps with the following caption are omitted here:

"THESE MAPS SHOW the expected response of the boreal forest to the climate
change projected by general circulation models as a result of doubled levels of
carbon dioxide. The original maps have been simplified to focus only on the
boreal forest, and have been adapted to show how the existing forest is
projected to change.

General circulation models are not yet accurate at the regional level. These
maps are intended to show the scale of potential impacts on the forest, and are
not likely to be accurate in detail within specific regions. We have chosen two
substantially different models to show the range of potential impacts.

The OSU model projects the disappearance of 50% of the existing forest. The
GFDL model projects the disappearance of over 90% of the existing forest."
][125]

The boreal forest forms a unified ecosystem with a distribution determined by
climate. However, each species of vegetation found in the forest responds
slightly differently to changes in temperature and precipitation. E.O. Box
recognized this and developed a modification of Holdridge life zones that
allowed for several species in each life zone. Cramer and Leemans used Box's
model and the OSU GCM to compare the impact of doubled levels of carbon dioxide
on evergreen conifers such as spruce and pine, which dominate in North America
and Europe, and deciduous conifers such as larch, which dominate in Siberia.
This research projected a 66 percent decline in existing evergreen conifers, and
a 31 percent decline in existing deciduous conifers. Most notably, spruce and
pine disappear almost entirely in Scandinavia.[126]

Succession Models

STATIC VEGETATION models such as the Holdridge life zones do not provide
detailed information on how the forest will change or decline. Instead, a number
of more complex succession simulation models have been developed to examine
this. These succession models include the impact of soils, drainage,
inter-species competition, shading, and other factors. The models must deal with
the fact that the projected climate change is at least 15-30 times faster than
any previously known.[127] In many cases, seedlings that sprout in one kind of
climate will come to maturity in an entirely different climate, putting great
stress on the forest.

Succession models are complex and require an enormous amount of computation.
For this reason, most published results look at a few specific sites. One
exception is a series of maps produced by Overpeck and Bartlein showing changes
in the distribution of various species in eastern North America under doubled
levels of carbon dioxide. The results are consistent with predictions from
static vegetation models and show a severe decline in conifers, especially
spruce, coupled with some forest growth into the tundra.[128]

Fire

THE DECLINE OF MUCH of the southern boreal forest may be driven by increases
in drought and fire frequency. For example, the soil in many parts of the boreal
forest may dry out because increased temperatures will lead to more evaporation.
This is likely to happen even if there is more snow, as some GCMs project.
Warmer winters may lead to earlier springs with longer periods of warm weather
giving more time for snow to melt and evaporate, leading to drier summers and
increased drought.

Two areas of the boreal forest are especially prone to an increase in
drought: the region around east of Lake Baikal in Siberia, and the western
Canadian provinces of Alberta, Saskatchewan and Manitoba. Most GCMs project
significant drought in these areas. Much of the oroboreal forest in the Rocky
Mountains may also be replaced by scrubland or grassland.

Fire would rapidly accelerate the conversion of drought-stricken forest to
grassland. NASA scientists Colin Price and David Rind found that doubling carbon
dioxide levels would lead to a 26 percent increase in lightning strikes.[129]
Warmer weather would also add to atmospheric turbulence, increasing the
intensity and frequency of windstorms, turning ordinary forest fires into
roaring infernos.[130]

Based on an examination of the results of three different GCMs, Flannigan and
Van Wagner concluded that climate change would increase Canada's annual fire
severity rating by about 46 percent. However, this study may be an underestimate
because it did not consider changes in lightning frequency or in the length of
the forest fire season. In a follow-up study, Wotton and Flannigan concluded
that the Canadian fire season would increase by more than 20
percent.[132]

Insects and Competition

IN SOUTHERN AREAS OF the boreal forest where increased temperature does not
lead to decline into grassland, conifers will suffer from insect outbreaks and
increased competition from temperate broad-leaved species like maple and oak.
Spruce is especially sensitive to warm weather. A study of boreal forest around
Stockholm, Sweden, predicts the complete disappearance of spruce due to warm
winters.[133] A similar study of eastern North America shows a retreat of spruce
to the shores of Hudson Bay and part of northern Quebec.[134]

Conifers would be extremely vulnerable to insect outbreaks, and spruce
budworm and bark beetle outbreaks would be strongly encouraged by warmer
temperatures. Increased drought could change the effect of storms and insect
outbreaks. Instead of encouraging the growth of conifer seedlings by removing
the forest overstory, storms and insect outbreaks could create large amounts of
fuel for more frequent fires, transforming many spruce and fir stands into
grassland or stands dominated by pine or boreal broad-leaved trees. Higher
temperatures are also likely to decrease the reproductive success of many
conifers, making it less likely that conifer stands will be able to recover from
major disturbances.

A computer simulation of responses to climate change in the boreal forest of
interior Alaska also predicted a diverse response. Climate warming in poorly
drained north slopes would convert a cold black spruce forest into a warm mixed
deciduous and spruce forest. Warming of a well drained south slope would lead to
a dry aspen-dominated forest or even the formation of grassland.[135]

This patchwork response is consistent with federal researchers' projections
for the Canadian boreal forest. Their study concluded that much of the boreal
forest in Ontario and southern Quebec will decline into a patchwork of grassland
and temperate forested area, or transitional grassland.[136]

Climate change is likely to drive the southern boundary of the boreal forest
northwards much more rapidly than the migration rates of temperate trees, such
as maple and oak. As a result, much of the southern boreal forest may be reduced
to a degraded ecosystem of shrubs and scattered stands of aspen and
birch.[137]

INTERACTION WITH ACID RAIN and air pollutants may worsen forest decline and
lead to the development of grassland or degraded forest where climate models
alone might suggest the development of temperate forest. Surveys in Finland, for
example, reveal an acid-rain-linked decline in lichen over an area of more than
10 million hectares. [138]

Lichens play a crucial role in the moisture and thermal regimes of forest
soils. A lichen mat reduces moisture stress and allows trees to exist on soil
that would otherwise be too dry to support growth. Because lichens have high
reflectivity and low thermal conductivity, they also insulate the underlying
soil from heat. A 12 cm deep lichen mat can reduce the soil heat flux by almost
50 percent. [139] An important effect of the lichen decline may be to dry out
the soil and increase the frequency of drought.

Expansion Into Tundra

THE ARCTIC TUNDRA is particularly vulnerable to climate change. Vegetation
models based on the GFDL and UKMO GCMs predict the complete disappearance of the
existing tundra if atmospheric carbon dioxide levels double. Modeling based on
the OSU and GISS GCMs predicts the disappearance of 75 percent of the existing
tundra. Although melting polar ice is expected to allow the development of new
tundra closer to the pole, all models predict a drastic overall
reduction.[140]

The major reason for the shrinking of the tundra is the northward expansion
of the boreal forest. The tree-line where the forest meets the tundra is
strongly influenced by climate and has moved long distances in the past. Tree
growth within the existing forest-tundra transitional zone may occur quickly
because tree stands are already widely dispersed and can expand rapidly.
However, movement of the tree-line further north into the tundra is likely to
happen more slowly.

The fossil pollen record shows that past migration rates were far slower than
the changes predicted for the future climate. Spruce, for example, has responded
to past climate change by expanding its range by 80-500 metres per year. Fir has
moved about 20-300 metres per year, while pine has moved more rapidly, by about
1,500 metres per year.

On the other hand, climate-vegetation models suggest shifts in the boreal
forest of 500 kilometres or more in less than a century. This works out to 5,000
metres per year or more than 10 times the historic migration rates of most
boreal species. It may take the boreal forest several centuries to expand as far
north as some models predict the climate will allow.

"The carbon pulse could release as much as 225 billion tonnes -- or almost
one-third of all the carbon now in the Earth's
atmosphere."[141]

The Ozone Threat

THE NORTHWARD EXPANSION of the boreal forest is likely to be delayed by
exposure to ultraviolet radiation because of ozone depletion. While an ozone
hole has not yet developed over the northern hemisphere, increasing greenhouse
gases could in future further lower Arctic stratospheric temperatures enough for
this to happen. The boreal forest - and the one billion people that live to its
south - would be exposed to sharply increased levels of ultraviolet
radiation.[142]

Studies show that ultraviolet radiation negatively affects seedling growth.
For example, three-year-old loblolly pine seedlings exposed to ultraviolet
radiation grew 20 percent less than similar unexposed plants.[143] A similar
study on other seedlings found that UV-B reduced jack pine biomass by about 25
percent, and reduced white spruce and black spruce biomass by about 50
percent.[144]

Unfortunately, phasing out all ozone depleting substances will not be enough
to prevent a hole in the northern ozone layer. Enough ozone destroyers will
remain in the atmosphere to cause serious ozone depletion for at least a
century.[145]

The Carbon Pulse

Increased stress and disturbances are likely to destroy existing boreal
forest much more quickly than new boreal forest can expand onto tundra, or
temperate forest can expand into former boreal areas. Moreover, warmer
temperatures will have an immediate impact on the rate of soil decay, and the
subsequent increased rate of soil carbon release into the atmosphere.

As a result, many studies project a massive net release of carbon into the
atmosphere - a "carbon pulse". A recent study on the implications of a doubling
of carbon dioxide levels concluded that forest dieback, mostly in the boreal
forest, could release 70 to 130 billion tonnes of additional carbon into the
atmosphere.[146] Another study found that the carbon pulse could release as much
as 225 billion tonnes of carbon - or almost one third of all the carbon now in
the Earth's atmosphere.[147]

The accelerated rate of climate change caused by the carbon pulse could cause
further carbon release, and hence even more rapid climate change - a potentially
catastrophic positive feedback.

An unknown factor is the response of peatlands to climate change. Peatlands,
which cover a fifth of the boreal forest, store almost two-thirds of its carbon
- 419 billion tonnes out of a total 709 billion tonnes.[148] Peatlands are
currently a minor net carbon sink, absorbing about 45 million tonnes of carbon
each year. However, they are a significant source of methane, a greenhouse gas
that is 21 times more powerful than carbon dioxide.

Rising temperatures could dry out southern peatlands and reduce methane
emissions. However, warmer conditions could also melt tundra and permafrost in
the north and release huge quantities of methane into the atmosphere. Fire could
also speed up the release of large amounts of carbon from dried-out southern
peatlands. Clearly more research is necessary on the role of peatlands in the
carbon cycle.[149]

IT IS DIFFICULT to predict the detailed impacts of climate change on the
boreal forest. However, the oroboreal forest located high in the Rocky Mountains
is already being devastated by the warming climate in one particular area.

The severe drought that continued into 1992 in Nevada and California provided
a frightening glimpse of the ecological destruction that lies ahead if
human-enhanced climate change is not redressed. In addition to
drought-encouraged fires, the six long years of little or no rain had dried up
manmade reservoirs and natural trout streams and reduced streams to a trickle,
destroying more than 90 percent of wildfowl nesting areas, and killing deer,
wild horses and bears. Thousands of hectares of forest gradually weakened by the
years of drought, succumbed to insects and disease.

Chapter 6 -- Disarming the Carbon Bomb: Positive Solutions for
Stabilizing the Climate and Saving the Forest

GREENPEACE BELIEVES that the only effective and direct way to stabilize the
climate is by sharply reducing anthropogenic greenhouse gas emissions from
fossil fuel use and deforestation. Catastrophic climate change and a severe
decline in the boreal forest can only be prevented by stopping the build-up of
greenhouse gases in the atmosphere. This will require three major policy
initiatives.

1. PHASE OUT FOSSIL FUELS

THE IPCC ESTIMATES that current fossil fuel and energy use trends will result
in a doubling of 1990 greenhouse gas emissions by about 2030, and a quadrupling
by the year 2100. The IPCC concluded that the only way to prevent a rapid
build-up of greenhouse gases is to cut emissions by 6080 percent from 1990
levels, which amounts to a 95 percent cut from projected emissions in the year
2100.[150] The only way to achieve such radical cuts in greenhouse gas emissions
is to phase out fossil fuels. The fossil fuel industry often claims that a
large-scale change in the global energy system is impossible.

A recent detailed study released by Greenpeace International shows that
phasing out fossil fuels is entirely practical and proves the fossil fuel
industry wrong. The study examined renewable "clean energy" sources such as wind
turbines, solar photovoltaic panels, biomass energy crops, geothermal power, and
small-scale hydro-electricity alternatives. It concluded that enough renewable
clean energy is available to replace current fossil fuels and nuclear power,
even under UN and World Bank forecasts in which the world population doubles and
the global economy expands 14 times its present size. The fossil fuel phase-out
would be easier to achieve if such upward population and economic trends are
stabilized at ecologically sustainable levels.

The Greenpeace study assumes that clean energy technologies would only be
adopted when cost-effective. Energy bills are not expected to rise higher than
they are now. Using conservative assumptions, fossil fuel use can be cut in half
by 2030 and eliminated by 2100.[151]

Phasing out fossil fuels will not be easy. It will take major changes in
public and private sector policy. But there is no credible alternative if the
world is to avoid irreversible climate change.[152]

Phasing out fossil fuels will also eliminate acid rain, smog, and other forms
of air pollution that are causing forest decline.

1. Cut Subsidies for Dirty Energy

About 80 percent of OECD government spending on energy research and
development goes on non-renewable and highly polluting fossil fuels and nuclear
power. This money should be used to research the efficient use of renewable
energy.

Billions of dollars of taxpayer money is spent on giving tax breaks and
subsidies to fossil fuel exploration and marketing. Still more billions are
spent on unnecessary road construction. These taxpayer funded subsidies should
be cut or transferred into spending on mass public transit.

2. Ban Inefficient Products

Masses of energy are currently wasted through the inefficient use of gas
guzzling cars, heat losing building, unnecessary and energy inefficient
appliance, and out-dated industrial processes. Instead of this power madness
tough standards are necessary to outlaw poorly designed products, and training
programmes to ensure industry moves to producing and using efficient technology
as soon as possible.

3. Energy Sector Reforms

Most of today's electricity and gas companies make their profits by selling
as much energy as possible. This inevitably leads to the inefficient use of
energy produced as cheaply as possible - with prices that do not take into
account the environmental damage and costs of fossil fuels and nuclear power.
Energy sector reforms are necessary to:

* include the environmental and social costs of energy in prices;

* invest in reducing energy consumption rather than building new power
stations or pipelines;

* purchase more power from small-scale sources rather than destructive energy
mega-projects.

These reforms will allow companies to phase in the more efficient use of more
expensive renewable energy. As a result, overall energy bills will not change.
These reforms are still compatible with profits for shareholders. A number of US
utilities are already operating using similar principles, sometimes called
Integrated Resource Planning.

4. Better Urban Planning

Urban sprawl must be stopped. The trend should be towards smaller cities with
a higher population density. Cars should be excluded from most or all of each
city, and replaced with a fast, efficient mass transit system. Cities should be
connected by a rapid rail system.

2. SAVE THE FORESTS - STOP DEFORESTATION

AT THE CURRENT RATE of deforestation, most of the world's natural forests
will be gone in a few decades. This would result in the elimination of much of
the Earth's ability to regulate the climate by absorbing carbon dioxide. It
would also result in a massive additional release in carbon.

Clear-cut logging should be halted in temperate and boreal forests. Logging
should proceed only on ecologically-defined principles which preserve the forest
ecosystems. Clear-cuts followed by planting monoculture tree farms do not
preserve the forest or biodiversity.

Much of the logging in temperate and boreal forests is to produce pulp for
unnecessary paper and packaging. Sharp reductions in packaging, combined with
the extensive use of recycled paper, should eliminate the need for most of the
pulp now being produced. Changing to more labour-intensive selective logging
practices and switching to the production of more value-added forest products
such as furniture should result in the disturbance of far less forest with no
loss of employment in the forest industry.

At present, tropical deforestation is being driven by inappropriate aid and
economic development programmes that fail to offer poor people living in
developing countries a decent standard of living. Aid and development programs
must be changed so that they no longer contribute to tropical deforestation.

Some 200 million indigenous people live in the world's forests. They are
often in the front line of defence against deforestation. Upholding the rights
of these people to their lands and livelihoods is the key to stopping
deforestation.

Carefully designed labour-intensive reforestation programmes should be
introduced by all sectors to restore natural forest ecology. Monoculture tree
plantations are not reforestation.

3. BAN HALOCARBONS

HALOCARBONS SUCH AS CFCs and HCFCs are greenhouse gases that also destroy the
ozone layer. They should be banned immediately. HFCs are not acceptable
replacements for CFCs because they are potent greenhouse gases. Acceptable
replacements are already available for virtually all uses for halocarbons. There
is no excuse for not using these replacements immediately.

Endnotes

1 Cited in Harrison E. Salisbury, The Great Black Dragon Fire: A Chinese
Inferno, Little, Brown and Company, 1989.

2 Intergovernmental Panel on Climate Change, Report to IPCC from Working
Group 1: Policymakers' Summary of the Scientific Assessment of Climate Change,
June 1990, p. XIV.

3 Charles D. Keeling, et al., A three-dimensional model of atmospheric CO,)
transport based on observed winds: Analysis of observed data, in David H.
Peterson (ed.), Aspects of Climate Variability in the Pacific and the Western
Americas, Geophysical Monograph 55, American Geophysical Union, 1989.

4 Peter M. Vitosek, Global Environmental Change: An Introduction, Annual
Review of Ecological Systematics, 23:1149 1992.

5 IPCC 1990, op.cit., p. xv.

6 Greenpeace International, The Climate Time Bomb, Greenpeace International,
June 1994.

7 IPCC 1990, op.cit. and Intergovernmental Panel on Climate Change, Climate
Change 1992: The Supplementary Report to The IPCC Scientific Assessment,
Cambridge University Press, 1992.

8 IPCC 1990, op.cit., p. 300.

9 Jeremy Leggett, Global Warming .. the Worst Case, Bulletin of Atomic
Scientists, 85: 28-32, 1992.

10 Allen M. Solomon and Wolfgang Cramer, Biospheric implications of global
environmental change, in Allen M. Solomon and Herman H. Shugart (eds.),
Vegetation Dynamics and Global Change, Chapman and Hall, New York, 1993, p.
41.

11 IPCC 1992, op.cit., p. 31.

12 W.M. Post, Uncertainties in the Terrestrial Carbon Cycle in Allen M.
Solomon and Herman H. Shugart, Vegetation Dynamics and Global Change, Chapman
and Hall, New York, 1993.

13 IPCC 1990, op.cit., p. 10.

14 Mark E. Harmon, et al., Effects on carbon storage of conversion of
old-growth forests to young forests, Science, 247:699-702, 1990.

15 Charles F. Cooper, Carbon storage in managed forests, Canadian Journal of
Forest Research, 13:155-166, 1983.

16 Gordan B. Bonan and Herman H. Shugart, Environmental factors and
ecological processes in boreal forests, Annual Review of Ecological Systematics,
20:1-28, 1989.

17 For information on the boreal forest in Japan, see A. Miyawaki and R.
Tuxen (eds.), Vegetation Science and Environmental Protection, Maruzen Co. Ltd.,
Tokyo, 1977.

18 FAO, Forest Resources 1980, FAO, 1985.

19 Ibid. For the purpose of this calculation, boreal forest was considered to
be roughly equivalent to coniferous forest in northern countries.

20 IPCC 1990, op.cit., p. 300.

21 Ibid.

22 T. Webb and P.J. Bartlein, Global changes during the last 3 million years:
Climatic controls and biotic responses, Annual Review of Ecological Systematics
23:141-173, 1992.

23 M.J. Apps, et al., The changing role of circumpolar boreal forests and
tundra in the global carbon cycle, Water, Air and Soil Pollution, (in press),
1993.

24 E.E. Wheaton, et al., An exploration and assessment of the implications of
climatic change for the boreal forest and forestry economics of the Prairie
Provinces and Northwest Territories: Phase One. SRC Technical Report No. 21 1,
Environment Canada, Atmospheric Environment Service, 1987.

25 S. Tyhknen, A circumpolar system of climatic-phytogeographical regions,
Acta Bot. Fenn., 127:1-50, 1984.

26 P.V. Wells and J.D. Stewart, Cordilleran-boreal taiga and fauna on the
central Great Plains of North America, 14,00018,000 years ago, American Midland
Naturalist, 118(l): 94106, 1987.

27 For maps of these changes, see J.C. Ritchie and G.M. MacDonald, Patterns
of post-glacial spread of white spruce, Journal of Biogeography 13:527-540,
1986

28 The close correlation between temperature and atmospheric greenhouse gas
levels can be seen in the famous Vostok ice core. See IPCC 1990, p. I I and p.
18.

29 J.S. Rowe and G.W. Scotter, Fire in the boreal forest, Quaternary
Research, 3:444-464, 1973; and Leslie A. Viereck, Wildfire in the taiga of
Alaska, Quaternary Research, 3:465495, 1973.

30 Shigeru Uemura, Satoshi Tsuda and Sakae Hasegawa, Effects of fire on the
vegetation of Siberian taiga predominated by Larix dahurica, Canadian Journal of
Forest Research, 20:547-553, 1990.

31 0. Zackrisson, Influence of fires on the North Swedish boreal forest,
Oikos, 29:22-32, 1977.

32 M.D. Flannigan and C.E. Van Wagner, Climate change and wildfire in Canada,
Canadian Journal of Forest Research, 21(l):66-72, 1991.

33 Ross W. Wein, Effects of fire in the boreal forest, Boreal Forest
Conference Proceedings, Athabasca University, 1992.

34 Serge Payette and R. Gagnon, Late Holocene deforestation and tree
regeneration in the forest-tundra of Quebec, Nature, 313:570-572, 1985.

35 Rowe and Scotter 1973, op.cit., p. 460.

36 JR. Blais, The ecology of the eastern spruce budworm: a review and
discussion, in Recent advances in spruce budworms research: proceedings of the
CANUSA spruce budworms research symposium, Bangor, Maine, September 16209
1984.

37 R.B.B. Dickison, Eastern spruce budworm larval development and behavior,
adult dispersal, and efficacy of control methods, in Climate Applications in
Forest Management and Forest Production: Proceedings of Forest Climate 86,
Environment Canada, 1988, pp. 165-170.

38 Jacques Rignihre, An oviposition model for the spruce budworm,
Choristoneura fumiferana (Lepidoptera: Tortricidae), Canadian Entomologist
115:1371-1382, 1983.

39 W.J.A. Volney and H.F. Cerezke, The phenology of white spruce and the
spruce budworm in northern Alberta, Canadian Journal of Forest Research,
22(2):198-205, 1992.

40 Erkki Annila, Influence of temperature upon the development and voltinism
of Ips typographus L. (Coleoptera, Scolytidae), Ann. Zool. Fennici, 6:161-208,
1969.

41 Ibid., p. 203.

42 Ibid.

43 Clark L. Lovelady, et.al., Relation of lightning to herbivory by the
southern pine bark beetle guild (Coleoptera: Scolytidae), Environmental
Entomology 20(5):1279-1284, 1991.

44 Erik Christiansen and Alf Bakke, The spruce bark beetle of Eurasia, in
A.A. Berryman (ed.), Dynamics of Forest Insect Populations, Plenum Press, New
York, 1988.

45 K. Furuta, A comparison of endemic and epidemic populations of the spruce
beetle (Ips typographus japonicus Niijima) in Hokkaido Journal of Applied
Ecology, 107:289-295, 1989.

46 Kenneth F. Raffa, The Mountain Pine Beetle in Western North America, in
A.A. Berryman (ed.), Dynamics of Forest Insect Populations, Plenum Press, New
York, 1988.

47 J.T. Overpeck, D. Rind and R. Goldberg, Climate-induced changes in forest
disturbance and vegetation, Nature 343:5 1 53, 1990; Colin Price and David Rind,
Lightning activity in a greenhouse world, in American Forestry Association,
Proceedings of the 11th Conference of Fire and Forest Meteorology, April 16-19,
1991, Missoula, Montana. 48 Furuta 1989 op.cit.

49 Alexander Robertson, Some effects of wind on northern forests in a
changing climate, Commonwealth Forestry Review, 70(1/2):47-55, 1991.

50 James B. Harrington and Michael J. Newark, The interaction of a tornado
with rough terrain, Weather, 41:310-318.

51 David Etkin, Tornado climatology, Climatic Perspectives, Atmospheric
Environment Service, Environment Canada, October 1993, pp. 10-13; Edward
Ferguson and Frederick Ostby, Tornadoes of 1990: An Al] Time Record Year,
National Severe Storms Forecast Center, USA, Weatherwise, 44(2):19-28, April
1991.

52 Price and Rind 1991, op.cit..

53 Brian J. Stocks, The extent and impact of forest fires in northern
circumpolar countries, in Joel S. Levine, ed., Global Biomass Burning:
Atmospheric, Climatic and Biospheric Implications, The MIT Press, Cambridge,
Massachusetts, 1991, pp. 197-202.

54 R.J. Day and R.G. Butson, Seedling-water relationships after outplanting,
in Climate Applications in Forest Management and Forest Production: Proceedings
of Forest Climate 86, Environment Canada, 1989, pp. 55-62.

55 M.G.R. Cannell and R.I. Smith, Thermal time, chill days and prediction of
budburst in Picea sitchensis, Journal of Applied Ecology, 20:951-963, 1983, and
M.G.R. Cannell and R.I. Smith, Climatic warming, spring budburst and frost
damage on trees, Journal of Applied Ecology, 23:177-191, 1986.

56 Stephen D. Ross, Temperature influences on reproductive processes in
conifers, in Climate Applications in Forest Management and Forest Production:
Proceedings of Forest Climate 86, Environment Canada, 1988, pp. 40-43.

57 R. Alan Black, Reproductive biology of Picea Mariana (Mill.) Bsp. at
treeline, Ph.D. Thesis, Department of Botany, University of Alberta, 1977; and
R. Alan Black and L.C. Bliss, op.cit., p. 349.

58 Robert E. Dickinson and Ralph J. Cicerone, Future global warming from
atmospheric trace gases, Nature, 319:109-115, 1986.

59 Climate News, World Meteorological Organization, 2, Jan 1993.

60 R.M. Koerner and D.A. Fisher, A record of Holocene summer climate from a
Canadian high-Arctic ice core, Nature, 343:630-631, 1990.

61 D.W. Schindler, et al. Effects of climatic warming on lakes of the central
boreal forest, Science, 250:967-970, 1990.

62 Stocks 1991, op.cit.

63 Allan N.D. Auclair and Thomas B. Carter, Forest wildfires as a recent
source of CO? at mid-high northern latitudes, Canadian Journal of Forest
Research, 23: 1528-1536, 1993 .

64 Olga N. Krankina, Forest fires in the former Soviet Union: Past, present
and future greenhouse gas contributions to the atmosphere, in: Ted S. Vinson and
Tatyana P. Kolchugina (eds.), Proceedings of the International Workshop on
Carbon Cycling in Boreal Forest and Sub-Arctic Ecosystems, U.S. Environmental
Protection Agency, Global Change Research Program, 1991.

65 Stocks, 1991, op.cit.

66 "Severe drop in tree growth rate found", Toronto Star, January 30,
1987.

67 Blais 1984, op.cit.

68 Etkin 1993, op.cit.

69 Schindler 1990, op.cit.

70 Most of the information in this section is taken from Harrison E.
Salisbury, The Great Black Dragon Fire: A Chinese Inferno, Little, Brown and
Company, 1989.

71 C.W. Philpot, The Wildfires in the Northern Rocky Mountains and Greater
Yellowstone Area - 1988, Transactions of the 55th North American Wildlife and
Natural Resources Conference, 1990, pp. 185-187.

72 Most of this information is from Gregory Vogt, Forests on Fire: The Fight
to Save Our Trees, K. Watts, New York, 1990.

73 Information from this section taken from Maureen Brosnahan, "After the
inferno: Northern Manitoba slowly comes back to life one year after the worst
forest fires on record", Canadian Geographic, December 90/January 91, pp. 69-75,
and the Winnipeg Free Press: "Fire emergency declared as 18,000 flee from
homes". July 24, 1989; Sifting the Ashes series, September 6, 7, 8, 12; ...
Unprecedented' weather cited in record forest fires", September 28, 1989.

74 "Fire in Mongolia burns 600,000 hectares of forests", Xinhua, May
26,1990.

75 "Forest fires rage in Trans-Baikal area", Tass, May 17, 1990; "Forest
fires continue raging in Buryat Republic", Tass, May 18, 1990.

76 "Oregon fire", AP, August 6, 1990.

77 "Department of National Defence Notice to the Media", August 24, 1990.

78 "Quebec forest fires send smoke to Maritimes", Reuter, June 27, 1991.

79 "Russian farmland hit by drought and forest fires", Reuter, July 2, 1991.
"Forest blaze in Soviet Far East defeats firefighters", Reuter, May 5, 1991.

80 "Forest fires in CIS rage during worst drought in 100 years", IPS, August
25, 1992; "Huge blast at Russian Pacific Ammunition Depot", Reuter, March 24,
1992; "Soviet-fires", AP, August 14, 1992.

81 "Fires Continue Rampage Through Drought-Stricken California", Reuter,
August 23, 1992.

82 "Air force generators exposed by wildfire", Anchorage Daily News,
September 27, 1992.

83 Lloyd's List, 20 August 1993.

84 Lloyd's List, 20 November 1993.

85 Keeling 1989, op.cit., p. 187.

86 R.A. Houghton, Effects of land-use change, surface temperature, and C02
concentration on terrestrial stores of carbon. Paper presented at the IPCC/WHRC
workshop, Biotic Feedbacks in the Global Climate System, Woods Hole, October
1992.

87 Keeling 1989, op.cit., p. 192.

88 Jorge L. Sarmiento, et al, A perturbation simulation of C02 uptake in an
ocean general circulation model, Journal of Geophysical Research,
97(C3):3621-3645, 1992.

89 The annual average figures are cited in J.L. Sarmiento and E.T. Sundquist,
Revised budget for the oceanic uptake of anthropogenic carbon dioxide, Nature
356:589-593, 16 April 1992

90 M.J. Apps, et al., The changing role of circumpolar boreal forests and
tundra in the global carbon cycle, Water, Air and Soil Pollution, 1993.

91 Keeling 1989, op.cit., p. 198.

92 Bert Bolin, Address to the Ninth Meeting of the Intergovernmental
Negotiating Committee for a Framework Convention on Climate Change, Geneva,
Switzerland, February 1994.

93 Allan Auclair and Julie Bedford, New perspectives on the terrestrial
carbon flux: Importance to the policy debate, ORD EPA Technical Briefing, U.S.
Environmental Protection Agency, April 28, 1993.

94 D. Eamus and P.G. Jarvis, The direct effects of increase in the global
atmospheric C02 concentration on natural and commercial temperate trees and
forests, Advances in Ecological Research, 19:1-55, 1989, p. 24.

95 S.D. Wullschleger, et al., On the potential for a C02 fertilization effect
on forest trees - an assessment of 58 controlled exposure studies and estimates
of the biotic growth factor, in Woodwell, G.M. (ed.), Biospheric Feedbacks in
the Global Climate System: Will the Warming Speed the Warming?, Oxford
University Press (in press).

96 Eamus and Jarvis 1989, op. cit., pp. 18-21.

97 Christian Komer and John A. Arnone 111, Responses to elevated carbon
dioxide in artificial tropical ecosystems, Science, 257:1672-1675, 1992.

98 Karen M. Clancy, Response of western spruce budworm (Lepidoptera:
Tortricidae) to increased nitrogen in artificial diets, Environmental Entomology
21(2)331-344, 1992; D.E.

Lincoln, et al., Response of an insect herbivore to host plants grown in
carbon dioxide enriched atmospheres, Oecologia, 69:556-560, 1986.

99 W.M. Havranek and V. Benecke, The influence of soil moisture on water
potential, transpiration and photosynthesis of conifer seedlings, Plant and
Soil, 49:91-103, 1978.

100 Eamus and Jarvis 1989, op. cit. p. 13.

101 Jerry M. Melillo, et al., Global climate change and terrestial net
primary production, Nature, 363:234-240, 1993.

102 Christian Komer, CO,) fertilization: The great uncertainty in future
vegetation development, in Vegetation Dynamics and Global Change, 1993, op.cit.,
pp. 53-70.

103 lbid, p. 63.

104 F. Wayne Bell, Critical Silvics of Conifer Crop Species and Selected
Competitive Vegetation in Northwestern Ontario, Forestry Canada, Ontario Region,
Great Lakes Forestry Centre, Northwestern Ontario Forest Technology Development
Unit, Technical Report 19, 199 1, p. 62.

105 Pekka E. Kauppi, Kari Mielikainen and Kullervo Kuusela, Biomass and the
carbon budget of European forests, 1971 to 1990, Science, 256:70-74, 1992.

106 Werner A. Kurz and Michael J. Apps, Contribution of northern forests to
the global C cycle: Canada as a case study, Water, Air and Soil Pollution,
1993.

107 Ibid.

108 Apps et al. 1993, op.cit.

109 Preliminary estimates from the United Nations Food and Agriculture
Organization, cited in Allen Hammond (ed.), The 1993 Information Please
Environmental Almanac, World Resources Institute, Houghton Mifflin Co., New
York, 1992. p. 326.

110 A.M. Gordon, et al., Seasonal patterns of soil respiration and C02
evolution following harvesting in the white spruce forests of interior Alaska,
Canadian Journal of Forest Research 17:304-319, 1987.

111 W.A. Kurz et al, The carbon budget of the Canadian forest sector: Phase
I, Forestry Canada, Information Report NOR-X-326,1992.

112 Roger D. Hungerford and Ronald E. Babbitt, Overstory removal and residue
treatments affect soil surface, air and soil temperature: implications for
seedling survival, United States Department of Agriculture, Forest Service,
Intermountain Research Station, Research Paper INT 377, 1987.

113 KW. Hearnden, et al., A Report on the Status of Forest Regeneration,
Ontario Independent Forest Audit Committee, October 1992.

114 Brian J. Stocks, Global warming and the forest fire business in Canada,
in Geoffrey Wall (ed.), Symposium on the Impacts of Climate Change and
Variability on the Great Plains, Department of Geography, University of
Waterloo, Occasional Paper No. 12, 199 1.

115 Herb Hammond, Seeing the Forest Among the Trees, Polestar, Vancouver,
1991, p. 16.

116 Ibid., p. 29.

117 Ibid., p. 114.

118 Ibid., p. 115.

119 Ibid., p. 116.

120 Apps et al. 1993, op.cit..

121 Ibid., p. 121

122 Thomas M. Smith, Rik Leemans and Herman H. Shugart, Sensitivity of
terrestrial carbon storage to C02 -induced climate change: Comparison of four
scenarios based on general circulation models, Climatic Change, 21:367-384,
1992.

123 T.M. Smith, J.F. Weishampel, H.H. Shugart and G.B. Bonan, The response of
terrestrial C storage to climate change: Modelling C dynamics at varying
temporal and spatial scales, Water, Air and Soil Pollution, 64:307-326, 1992, p.
315.

124 L.R. Holdridge, Determination of world plant formations from simple
climatic data, Science, 105:367-368, 1947.

125 Thomas M. Smith, Rik Leemans and Harman H. Shugart, Sensistivity of
terrestrial carbon storage to C02 -induced climate change: Comparison of four
scenarios based on general circulation models, Climatic Change, 21:367-384,
1992. Any transcription errors are the responsibility of Greenpeace.

126 Wolfgang P. Cramer and Rik Leemans, Assessing impacts of climate change
on vegetation using climate classification systems, in: Allen M. Solomon and
Herman H. Shugart (eds.), Vegetation Dynamics and Global Change, New York,
Chapman and Hall, 1993.

127 Allen M. Solomon and Wolfgang Cramer, Biospheric implications of global
environmental change, in: Solomon and Shugart, 1993, op cit..

128 Reprinted in James S. Clark, Ecosystem sensitivity to climate change and
complex responses, in Richard L. Wyman (ed.), Global Climate Change and Life on
Earth, New York, Chapman and Hall, 199 1.

129 Price and Rind 1991, op.cit.

130 Overpeck 1990, op.cit.

131 M.D. Flannigan and C.E. Van Wagner, Canadian Journal of Forest Research,
21(l): 66-72, 1991.

132 B.M. Wotton and M.D. Flannigan, Length of the fire season in a changing
climate, Forestry Chronicle, 69(2): 187-192, April 1993.

133 1. Colin Prentice, Martin T. Sykes and Wolfgang Cramer, A simulation
model for the transient effects of climate change on forest landscapes,
Ecological Modelling, 65:51-70, 1993.

134 J.T. Overpeck and P.J. Bartlein, Appendix D. Assessing the response of
vegetation to future climate change: ecological response surfaces and
paleoecological validation, in The Potential Effects of Global Climate Change on
the United States, EPA-230-05-89-054, U.S. Environmental Protection Agency,
Washington, D.C., 1989.

135 Gordan B. Bonan, Herman H. Shugart, and Dean L. Urban, The sensitivity of
some high-latitude boreal forests to climatic parameters, Climatic Change,
16:9-29, 1990.

136 B. Rizzo and E. Wiken, Assessing the sensitivity of Canada's ecosystems
to climatic change, Climatic Change, 21(l):37-56, 1992.

137 A.M. Solomon, The nature and distribution of past, present and future
boreal forests: lessons for a research and modelling agenda, in H.H. Shugart et
al., A Systems Analysis of the Global Boreal Forest, Cambridge, Cambridge
University Press, 1992, p. 305.

138 Kauppi et al. 1992, op.cit..

139 Bonan and Shugart 1989, op.cit., p. 13.

140 Smith et.al., 1992, op.cit..

141 H.H. Shugart, M. Ya Antonovsky, P.G. Jarvis and A.P. Sandford, CO,?,
Climate Change, and Forest Ecosystems, in B. Bolin, R.A. Waarrick, B.R. Doos,
and J. Jager (eds.), The Greenhouse Effect, Climatic Change and Ecosystems,
SCOPE 29, John Wiley, Chichester, 1986, p. 485, Table IO. 1.

142 John Austin, et al., Possibility of an Arctic ozone hole in a doubled-CO2
climate, Nature, 360:221-225, 1992.

143 Shawna L. Naidu, et al., The effects of ultraviolet-B radiation on
photosynthesis of different aged needles in fieldgrown loblolly pine, Tree
Physiology, 12:151-162, 1993.

144 John Hoddinott, Global Warming and the Forest Flora, in: Boreal Forest
Conference Proceedings, Athabasca University, 1992, pp. 172-178.

145 J.W. Waters, et.al., Stratospheric CIO and ozone from the Microwave Limb
Sounder on the Upper Atmosphere Research Satellite, Nature, 362:597-602,
1993.

146 George A. King and Ronald P. Neilson, The transient response of
vegetation to climate change: A potential source Of C02 to the atmosphere,
Water, Air and Soil Pollution, 64:365-383, 1992.

147 T.M. Smith and H.H. Shugart, The transient response of terrestrial carbon
storage to a perturbed climate, Nature, 361:523-526, 1993.

148 Apps cit. al. 1993, op.cit..

149 Eville Gorham, Northern peatlands: role in the carbon cycle and probable
responses to climatic warming, Ecological Applications 1(2):182-195, 1991.

150 IPCC 1990 op. cit.

151 Greenpeace International, Towards a Fossil Free Energy Future - The Next
Energy Transition: A Technical Analysis for Greenpeace International, Stockholm
Environment Institute - Boston Center, April 1993; The executive summary is
available as Fossil Fuels in a Changing Climate: How to Protect the World's
Climate by Ending the Use of Coal, Oil and Gas, 1993.

152 For more detailed information on renewable energy technologies, see
Thomas B. Johansson et al., Renewable Energy: Sources for Fuel and Electricity,
Island Press, Washington, D.C., 1993. See also, Greenpeace International, Power
To Change: Case Studies in Energy Efficiency and Renewable Energy,
1993.