Climate change is shrinking some trees, killing others
Researchers warn that climate change is accelerating the death of trees, stunting their growth and making forests across the world younger and shorter. Forests now not only have less capacity to store carbon dioxide released by burning fossil fuels but they are also unable to host certain species that normally reside there.

Tropical droughts trigger biggest CO2 spike in 2,000 years

NASA's latest carbon dioxide-mapping satellite has detected a dramatic spike in the amount of the greenhouse gas in the atmosphere, measuring the largest annual increase Earth has seen in at least 2,000 years. The cause? Overheating of three major tropical forest regions across the globe.

Explosion of wildfires portends a new era -- the Pyrocene

Firefighters in the West are starting to see it every year: an earlier start to the fire season and millions of acres of forest and range burned or ablaze as the summer just begins to heat up.  At least 60 large blazes are currently devouring parts of the West, threatening to make 2017 a record-breaking wildfire year and adding to the 3.4 million acres already burned this year. Forest ecologists and climate scientists say this is the new normal—what the fire historian Stephen Pyne has called the "pyrocene" —and research has solidly linked it to human activity. A study last year found that human-caused climate change had nearly doubled the amount of forest burned in the West since 1984.

100 million California trees have died from long-term drought
California’s long-term drought has claimed another 36 million trees, the U.S. Forest Service said this week, announcing the results of a new aerial survey. Since 2010, more than 100 million trees have died across 7.7 million acres, the agency said.  The die-off intensified in 2016, after four years of drought,  with mortality increasing 100 percent. Millions of additional trees are weakened and expected to die in the coming months and years. Forest Service leaders emphasized that their ability to address safety issues linked with dead trees has been severely hampered by climate change and limited resources.

Wildfires surge as the temperature rises
Western firefighting veterans lamenting a “new normal” amid surging forest fires have received an explanation for the destructiveness they’ve been unable to quell. Rising temperatures are flatly to blame for recent fearsome fire seasons, leading scientists reported. The number of acres of forest burning yearly in large Western fires ballooned nine-fold from 1984 to 2015, with climate pollution and natural changes in the weather playing roughly equal roles in driving the deadly trend. The study showed that more than a century of fossil fuel burning, deforestation and farming has helped push the American West into an explosive new wildfire regime, and the findings suggest far worse could be ahead.

Boreal forests seen as victims, not mitigators, of warming
A new study suggests that boreal forests in the US may begin to wither as early as 2050.  While previous climate modeling studies counted on the boreal forests to save us from the climatic disaster, newer studies don't show any greening of forests. "Instead, we see browning. The positive influence that warmer temperatures are believed to have on boreal forests, we don't see that at all," one tree researcher said.

Drought cuts trees' CO2 storage capacity

A new study shows that forests devastated by drought may lose their ability to store carbon over a much longer period than previously thought, reducing their role as a buffer between humans’ carbon emissions and a changing climate. The study shows that the world’s forests take an average of between two and four years to return to their normal growth and carbon dioxide absorption rate following a severe drought — a finding that has significant climate implications.

Colorado stands to lose half its aspen, pine forests by 2060

The iconic pine and aspen forests of the Rocky Mountains are dying off at an alarming rate thanks to conditions exacerbated by climate change — drought, insect infestations and wildfires — a new report says. Colorado alone could lose 45% of its aspen stands over the next 45 years, says the report by the Union of Concerned Scientists and the Rocky Mountain Climate Organization. Pine bark beetles alone have killed 46 million acres of trees across the west, an area nearly the size of Colorado.

Rainforests prove long-term contributors to warming
Tropical rainforests are becoming less able to cope with rising global temperatures.  For each 1C rise in temperature, tropical regions now release about 2 billion extra tonnes of carbon-containing gases – such as carbon dioxide and methane – into the atmosphere, compared to the same amount of tropical warming in the 1960s and 1970s. Rising levels of man-made carbon dioxide could stimulate the growth of tropical vegetation by providing them with extra “carbon fertiliser” but scientists believe this beneficial effect is probably being outweighed by the detrimental impact on forest growth caused by the extra heat and drought resulting from higher CO2 concentrations.

Pine beetles threaten to decimate New Jersey's pine forests

An infestation of pine beetles has  killed tens of thousands of acres of pines in New Jersey , and it is marching northward. Scientists say it is a striking example of the way seemingly small climatic changes are disturbing the balance of nature. They see these changes as a warning of the costly impact that is likely to come with continued high emissions of greenhouse gases.

European forests becoming "carbon saturated"
Forests from Spain to Sweden are getting older, packed with trees less good at soaking up the emissions blamed for rising world temperatures, mounting sea levels and increasing numbers of heatwaves and floods, experts said. That means Europe should no longer assume its forests will be able to continue absorbing carbon emissions from factories, power plants and cars, at the same rate. Forests currently soak up about 10 per cent of Europe's emissions.

Wildfires on the rise in western U.S.

A warming trend has contributed to a sharp rise in the number and size of wildfires on forest lands in the U.S. West, where big burns are likely to become the norm, according to a report released by a climate research group. The average annual number of fires that cover more than 1,000 acres (405 hectares) has nearly quadrupled in Arizona and Idaho and doubled in California, Colorado and six other Western states since 1970, the study by Climate Central showed.  The report, which analyzed 42 years of records about fires on U.S. Forest Service lands in 11 Western states, linked rising spring and summer temperatures in the region to a fire season that begins earlier, ends later and sparks larger, more frequent blazes.

Trees Found to Absorb Less CO2 than IPCC Projected
Trees may not be the planetary saviors people have been counting on in a warming climate. A new study shows that while trees certainly help counteract rising temperatures, they are absorbing 3.4 percent less carbon than had been assumed in models used in the  Intergovernmental Panel on Climate Change reports. More CO2 in the atmosphere means more warming.

Alaska's Ancient Yellow Cedars Fall Victim to Warming

 U.S. Forest Service researchers have confirmed what has long been suspected about a valuable tree in Alaska's Panhandle: climate warming is killing off yellow cedar. The mighty trees can live more than 1,000 years, resisting bugs and rot and even defending themselves against injury, but their shallow roots are vulnerable to freezing if soil is not insulated by snow. And for more than a century, with less snow on the ground, frozen roots have killed yellow cedar on nearly a half-million acres in southeast Alaska, plus another 123,000 acres in adjacent British Columbia.

Epic Texas Drought Claims up to Half Billion Trees

The massive drought that has dried out Texas over the past year has killed as many as half a billion trees, according to new estimates from the Texas Forest Service. Between 100 million and 500 million trees were lost. That figure does not include trees killed in wildfires that have scorched an estimated 4 million acres in Texas since the beginning of 2011. A massive wildfire in Bastrop, east of Austin in September that destroyed 1,600 homes, is blamed for killing 1.5 million trees.

Warming Triggers a Huge Migration of Trees in Western US

A huge “migration” of trees has begun across much of the West due to global warming, insect attack, diseases and fire, and many tree species are projected to decline or die out in regions where they have been present for centuries, while others move in and replace them. In a new report, scientists outline the impact that a changing climate will have on which tree species can survive, and where. The study suggests that many species that were once able to survive and thrive are losing their competitive footholds, and opportunistic newcomers will eventually push them out.

Forests, Long Time Buffers Against Climate Change, are Now Becoming Its Casualties
Scientists have figured out — with the precise numbers deduced only recently — that forests have been absorbing more than a quarter of the carbon dioxide that people are putting into the air by burning fossil fuels and other activities. It is an amount so large that trees are effectively absorbing the emissions from all the world’s cars and trucks. Without that disposal service, the level of carbon dioxide in the atmosphere would be rising faster. Yet the forests have only been able to restrain the increase, not halt it. And  scientists are increasingly worried that as the warming accelerates, trees themselves could become climate-change victims on a massive scale.

Researchers Foresee Tenfold Increase in Large Wildfires
As Earth's climate warms up, Yellowstone National Park and the Grand Tetons are likely to experience large fires more frequently, according to a new study. Within just a few decades, big fires may become as much as 10 times more common than they have been in the last 10,000 years. An increase in fire frequency would reverberate through the environment in unpredictable ways -- affecting the kinds of plants that grow in the area, the kinds of animals that can find habitats there and the amount of carbon that vegetation might be expected to pull out of the atmosphere.

US Declares Iconic Tree an Imminent Casualty of Warming
An iconic species of the American West, the whitebark pine, is at risk of extinction from climate change and disease, the U.S. Fish and Wildlife Service said, but no immediate action is planned. The tall tree's range includes mountainous areas of California, Nevada, Wyoming, Oregon, Idaho, Montana and Washington state in the United States, and British Columbia and Alberta in Canada. One key threat is the mountain pine beetle whose  ability to reproduce and survive winters has improved as temperatures have risen over recent decades.

Forests Found to Absorb 10 percent of Carbon Emissions
The study released in Science details for the first time the volumes of CO2 absorbed from the atmosphere by tropical, temperate and boreal forests. The researchers found that forests soak up more than 10 percent of carbon dioxide from human activities such as burning coal, even after taking into account all of the global emissions from deforestation.

Insect Destruction of Forests Rises Threefold

Marauding insects have become a leading threat to the nation's forests over the past decade, a problem made worse by drought and a warming climate, a federal report says. Bark beetles, engraver beetles and gypsy moths are the primary culprits behind a threefold increase in forestland mortality caused by insect attacks between 2003 and 2007, according to a U.S. Forest Service report obtained by The Associated Press. The volume of forests in the lower 48 states killed by bugs totaled 37 million acres during the period, up from 12 million during the previous five years. Millions of additional acres have perished since.

Amazon Drought Generated As much CO2 as US

A widespread drought in the Amazon rain forest last year was worse than the "once-in-a-century" dry spell in 2005 and may have a bigger impact on global warming than the United States does in a year, British and Brazilian scientists said. More frequent severe droughts like those in 2005 and 2010 risk turning the world's largest rain forest from a sponge that absorbs carbon emissions into a source of the gases, accelerating global warming, the report found. Trees and other vegetation in the world's forests soak up heat-trapping carbon dioxide as they grow, helping cool the planet, but release it when they die and rot.

Excess CO2 Starves Plants of Nitrogen Nutrients

Some biologists had theorized earlier that rising greenhouse gas levels would encourage plant growth because of the increased amount of carbon dioxide in the atmosphere. But plant physiologists have shown that too much carbon dioxide actually can inhibit a plant's ability to assimilate nitrogen-based nutrients pulled from the soil that plants use to make enzymes and other essential proteins. Without those essential proteins, plant health — and food quality — may suffer.

CO2 Accelerates Tree Growth in eastern U.S.
Forests in the eastern United States appear to be growing faster in response to rising levels of carbon dioxide in the atmosphere, a new study has found. The study centered on trees in mixed hardwood stands on the western edge of the Chesapeake Bay in Maryland that are representative of much of the those on the Eastern Seaboard. All are growing two to four times as fast as normal, according to a study published in Tuesday’s issue of The Proceedings of the National Academy of Sciences. Scientists concluded that the change resulted largely from the increase in carbon dioxide, a major factor in climate change.

Warming Claims Vast Tract if Martha's Vineyard's Oak Trees

Two years ago a vast tract of Martha’s Vineyard forest died. The 500 acres of dead oak trees were the epicenter of an islandwide infestation of caterpillars that munched their way through millions of leaves for three consecutive springs ending in 2007. Then a severe summer drought hit the island, finishing off tens of thousands of the weakened trees. Now scientists are calling it a possible climate change lesson.

Amazon Rainforest Imperiled by Moderate Warming

The Amazon rainforest, one of the planet's most precious and besieged natural resources, is even more fragile than realized. If the planet warms even a moderate amount, a new study predicts that as much as 40 percent of it could be condemned to vanish by the end of the century.

Forests Seen as Potential CO2 Source
The world's forests are at risk of becoming a source of planet-warming emissions instead of soaking them up like a sponge unless greenhouse gases are controlled, scientists said.

Drought Turns Amazon Rainforest Into Net CO2 Emitter

Researchers monitoring the long-term health of the Amazon tropical rainforest have made a startling discovery. A severe drought in 2005 not only restricted the rainforest's ability to absorb carbon dioxide from the atmosphere but also, in some cases, killed off so many trees that it made areas net CO2 emitters.

US "Old Growth" Tree Deaths Doubled Over Past 30 Years

The death rates of trees in western U.S. forests have doubled over the past two to three decades, driven in large part by warmer temperatures and water scarcity linked to climate change, a new study spearheaded by the U.S. Geological Survey has found.

Canadian Forests Found to be Sources of CO2
In an alarming yet little-noticed series of recent studies, scientists have concluded that Canada's precious forests, stressed from damage caused by global warming, insect infestations and persistent fires, have crossed an ominous line and are now pumping out more climate-changing carbon dioxide than they are sequestering.

Pine Beetles Devastate Western Pine Forests

From New Mexico to British Columbia, the region's signature pine forests are succumbing to a huge infestation of mountain pine beetles that are turning a blanket of green forest into a blanket of rust red. Montana has lost a million acres of trees to the beetles, and in northern Colorado and southern Wyoming the situation is worse.

Old Growth Forests Help Absorb CO2

Old-growth forests remove carbon dioxide (CO2) from the atmosphere, helping to curb the greenhouse gases that drive global warming, according to a study to be published Thursday. Many environmental policies are based on the assumption that only younger forests, mainly in the tropics, absorb significantly more CO2 than they release. As a result, primary forests in temperate and subarctic regions of the northern hemisphere do not figure in climate change negotiations seeking ways to reward countries that protect carbon-absorbing woodlands within their borders.


Heat Destroyed Thousands of Mountainside Trees in California

Warmer temperatures and longer dry spells have killed thousands of trees and shrubs in a Southern California mountain range, pushing the plants' habitat an average of 213 feet up the mountain over the past 30 years, a UC Irvine study has determined. Almost all of the studied plants crept up the mountain a similar distance, countering the belief that slower-growing trees would move slower than faster-growing grasses and wildflowers.

Old Forests Store Three Times more CO2 Than New Plantations
Untouched natural forests store three times more carbon dioxide than previously estimated and 60 percent more than plantation forests, said a new Australian study of "green carbon" and its role in climate change.

Beetles Turn Western Forests Into CO2 Sources

A beetle about the length of a well-trimmed fingernail may be challenging scientists' projections for global warming. An infestation of mountain pine beetles is turning more than 144,000 square miles of woods in British Columbia from a slight carbon absorber -- or sink -- to a net CO2 emitter. Canadian scientists unveiled projections Wednesday that between 2000 and 2020, the forest will have lost 270 million tons of carbon into the atmosphere.

Scientists Startled By Speed of Change in New England Forests

Scientists have long thought it would take generations if not centuries for tree populations to shift in response to a warming world. But scientists' work on suggests that climate change might affect New England forests far sooner than scientists thought.

Boreal Forests Turning From CO2 Sinks to Sources

Researchers have found that wildfires  fuelled by climate change  may be turning boreal forests into sources of carbon dioxide. The boreal forests in northern Canada, Alaska, Siberia, China, Scandinavia and elsewhere were believed by scientists to as a carbon sink. But new research from the University of Wisconsin-Madison has found that the forests may be emitting more carbon than they are absorbing.

Experts Tie Western US Mega-Wildfires to Warming
Every year you can count on forest fires in the West like hurricanes in the East, but recently there has been an enormous change in Western fires. We've never seen anything like them in recorded history. It appears we're living in a new age of mega-fires -- forest infernos ten times bigger than the fires we're used to seeing -- which experts attribute to global warming.

Is the "Missing Carbon" hiding in Tropical Forests?
Scientists now say they have located the missing carbon in tropical forests that are removing much higher quantities of carbon dioxide from the atmosphere than realized. Tropical forests could be absorbing as much as one billion tonnes more carbon than previously realized.

Beetle Infestation Threatens Swedish Forestry Industry

For many years, forestry has been an immensely profitable business in southern Sweden. But now some see nature, in the shape of the five-millimeter, or 1/5-inch, hairy bark beetle, as striking back - induced by climate change.

Trees A Mixed Blessing in Climate Fight

Planting trees to offset carbon emissions could contribute to global warming if they are planted outside the tropics, scientists believe. While most forests do not have any overall effect on global temperature, by the end of the century forests in the mid and high latitudes could make their parts of the world more than 3C warmer than would have occurred if the trees did not exist.

Planting Trees Won't Help -- Caldeira

While preserving and restoring forests is unquestionably good for the natural environment, new scientific studies are concluding that preservation and restoration of forests outside the tropics will do little or nothing to help slow climate change. And some projects intended to slow the heating of the planet may be accelerating it instead.

Trees Offer Little Help Except In Tropics

Planting forests to combat global warming may be a waste of time, especially if those trees are at high latitudes. Scientists say the benefits that come from trees reducing atmospheric carbon dioxide can be outweighed by their capacity to trap heat near the ground.

Drought-driven Fires Take Major Toll on Amazon Rainforest

Fire-promoting droughts have become increasingly common in the Amazon,  taking a terrible toll on the rain forest -- and eventually on the climate of the rest of the world.

Amazon Rainforest Faces Desertification

The vast Amazon rainforest is on the brink of being turned into desert, with catastrophic consequences for the world's climate, alarming research suggests. And the process, which would be irreversible, could begin as early as next year.

Warming Tied to Rise in US Wildfires

A new study led by scientists at Scripps Institution of Oceanography at the University of California, San Diego, implicates rising seasonal

temperatures and the earlier arrival of spring conditions in connection with a dramatic increase of large wildfires in the western United States.

Warming Climate Drives Beetle Infestation of Canada Forests

Millions of acres of Canada's lush green forests are turning red in spasms of death. A voracious beetle, whose population has exploded with the warming climate, is killing more trees than wildfires or logging. The mountain pine beetle has infested an area three times the size of Maryland, devastating swaths of lodgepole pines and reshaping the future of the forest and the communities in it.


Amazon Basin Suffers "Calamity" From Record Drought

The Amazon River basin, the world's largest rain forest, is grappling with a devastating drought that in some areas is the worst since record keeping began a century ago. It has evaporated whole lagoons and kindled forest fires, killed off fish and crops, stranded boats and the villagers who travel by them, brought disease and wreaked economic havoc.

Canadian Forests In Jeopardy from Changing Climate

Canadian forests are at risk from rising temperatures, according to a government agency, which warns that an increased intensity of fires and insect outbreaks could  ravage the forests, affecting the forestry industry and the communities that are based in the forest.

Siberian Forests Dying from Warming-Driven Fires

Russia's pristine forests are the lungs of Europe. But vast swathes are being destroyed by global warming and loggers' greed - and ill-equipped firefighters are powerless to act.

Western Wildfires Linked to Global Warming

The raging Western wildfires of recent years have often been blamed on management practices that promoted dense, overpacked forests. But a new study indicates global warming may be the main culprit.
The linkage suggests that as the climate warms, damaging wildfires will continue to strike the West. "If we are just at the beginning of dramatic warming & we can simply expect larger, more severe fires," said Grant A. Meyer, a co-author of the study, published in today's journal Nature.

Bark Beetles Decimating Drought-Stricken Forests in Western U.S.

Unusually warm temperatures have extended the life and range of bark beetles over the last several years. Trees have been weakened by several years of severe drought. All of it has led to an explosion of insect-killed trees in conifer forests. Some experts worry that the widespread damage may be part of a vast ecological shift in response to warming temperatures. "As the climate is changing, these ecosystems are rearranging themselves," said Dr. Craig Allen, a research ecologist with the United States Geological Survey in New Mexico. "Massive forest die-back is one way these systems will reassemble."

CO2 Changes Rainforest Composition

Carbon dioxide (CO2) disgorged by fossil fuels is silently causing a dramatic change in the composition of tree species in the Amazonian forest, the world's most precious wildlife haven, a study says. The CO2 is causing some tree species to grow faster and dominate in the forest and this in turn is forcing other species into decline, a long-term change which is bad news for biodiversity and the fight against global warming.

Amazon Rainforests "No Solution"

Planting trees in the Amazon to curb global warming is unlikely to work. Brazilian and US scientists have found the rainforest emits more of the greenhouse gas carbon dioxide than it absorbs when conditions are very wet. Their report, published in the journal Science, comes just three days before the latest United Nations negotiations on climate change take place in Milan. The researchers say previous studies have almost certainly over-estimated how much CO2 the Amazon can take in.

Scientists Study Sink, Source Roles of Amazon Rain Forests

The long-standing debate about the Amazon's role in global climate change is intensifying. The Amazon is the largest tropical forest in the world -- bigger than all of Europe, with Brazil's section alone more than half the size of the continental United States. And it has always been assumed to be essential to inhibiting global warming by drawing in carbon dioxide during photosynthesis.  But it has never been established whether the rain forest here is in fact functioning as a giant sink that "sequesters," or traps and absorbs, carbon.

Ozone Cuts Trees' Ability to Absorb CO2

A new experiment has shown that fairly common concentrations of low-level ozone, the eye-stinging ingredient in smog, can sharply impede the ability of trees to absorb heat-trapping carbon dioxide.

Study Casts Doubt on Trees as CO2 Sink

Mature trees might not offset global warming by mopping up excess carbon dioxide, suggests a forest study in Switzerland. They may already have all the carbon dioxide that they need. If the phenomenon is widespread, it could be a setback to those hoping that existing and newly planted forests will buffer mounting CO2 levels.

Researchers: Trees No Solution to Climate Change

It was a comforting dream while it lasted: Carbon dioxide spewed into the air from tailpipes and smokestacks would speed up the growth of forests. The forests in turn would store the carbon in wood and soil, staving off climate change. But the latest research has delivered an unpleasant wake-up call.

Tree Farming Emits More CO2 Than Is Absorbed
Planting trees to soak up carbon dioxide actually releases a surge of CO2. The Kyoto Protocol says countries can help meet their targets for cutting ghg emissions over the next decade by planting forests to soak up carbon dioxide. But the soil in these But the soil in these "Kyoto forests" will actually release more carbon than the growing trees absorb in the first 10 years.

Indonesian Wildfires Jumped CO2 Levels

New research has shown that the forest fires which ravaged South East Asia five years ago caused a massive increase in levels of the greenhouse gases which cause global warming. Scientists from Indonesia and Europe believe that 2.6 million tons of carbon entered the atmosphere after the fires in Indonesia - contributing to the biggest annual increase in carbon emissions since records began. The world generates annually about 7 billion tons of carbon emissions.

East Coast Trees Imperiled by Heat, Drought

While forest fires in the West have captured the nation's attention, a similar but less visible disaster has been wreaking havoc with East Coast trees: an arboreal broil caused by this summer's record-breaking drought and high temperatures. From Georgia to New Jersey, extreme water shortages and heat waves have placed even drought-resistant trees under severe stress, causing early leaf loss, increased susceptibility to disease and premature death.

Tropical Forests May Soon Turn from Sinks to Sources

Human activities are changing the global climate, and these changes are having far reaching effects on tropical forests. University of Missouri scientist Deborah Clark re-evaluated the evidence and told the symposium that tropical forests may not be carbon sinks that can be used to absorb carbon dioxide generated by the burning of fossil fuels. Instead, tropical forest may end up contributing even more carbon dioxide (CO2) to the atmosphere as temperature rises, she said.

Warming Accelerates Reproduction of Alaskan Bark Beetles

Nearly four million acres of white spruce trees, dead or dying from an infestation of beetles in Alaska's Kenai Peninsula, the largest kill by insects of any forest in North America. A succession of warm years in Alaska has allowed spruce bark beetles to reproduce at twice their normal rate.

Drought, Infestation Threaten Eastern Hemlocks

After a mild winter, the sandgrain-sized Asian woolly adelgid, usually killed by the cold, is thriving and expected to burst into dozens more Massachusetts communities, some as soon as this summer. And hemlocks, weakened by one of the worst droughts on record, are not expected to withstand the infestation for long.

Two Studies Question Value of Sinks

Two new studies are challenging the idea that planting forests could be a cheap way to absorb emissions of carbon dioxide, the main heat- trapping gas released by human activities.In one, tracts of pine trees exposed to elevated levels of the gas initially absorbed large amounts and had a short growth spurt, but then reverted to typical growth rates. A separate study of the soil around the exposed trees found that decomposition released much of the carbon that had been absorbed.

US Forests Do Not Offset Emissions

New research has found that the massive amounts of atmospheric carbon dioxide generated by fossil fuel use in the U.S. are not offset by the storage of carbon in growing forests and other vegetation, as some earlier studies had suggested. The new study, has important implications for the role of the U.S. in combating the greenhouse effect and global warming.

Warming threatens massive forest loss
At least one third of the world's forests are expected to be seriously affected by global warming, accelerating the disappearance of both the forests themselves and the wildlife that depends on them. Particularly at risk are boreal areas in Alaska, Canada and Russia, where up to 40 percent of the forests could be lost altogether.

Rising CO2 Threatens to Reverse Plant Evolution
By increasing atmospheric [CO2] concentrations, humans may be changing the Earth's atmosphere to conditions not favorable to a 'C4 world,' the world in which we originally evolved. The CO2 buildup may reverse the evolution of vegetation on which our well-being is based.

Alaska's Sick Forests
Insect-ravaged forests are indicating the stress of warming in Alaska.

Warming Decimates Alaskan Forests
White spruce trees in the Anchorage and south-central Alaska regions have experienced strongly accelerated growth that is directly correlated with the warmer and moister conditions. However, one of the largest outbreaks of insect-caused (spruce bark beetle) tree mortality in the history of North America has left most trees dead over about 3-million acres of forest land.

Forest Growth Stunted by Increased Heat, CO2
Contrary to expectations, researchers discover that more warming and enhanced CO2 leads to an initial growth spurt in forests -- followed by flattening growth rates.

Researchers see rapid forest loss to warming
Japanese researchers project 40 percent forest loss by 2010.