Mira Oberman Yahoo News 15 Feb 09;
CHICAGO (AFP) – It seems the dire warnings about future devastation sparked by global warming have not been dire enough, top climate scientists warned Saturday.
It has been just over a year since the Nobel-winning Intergovernmental Panel on Climate Change (IPCC) published a landmark report warning of rising sea levels, expanding deserts, more intense storms and the extinction of up to 30 percent of plant and animal species.
But recent climate studies suggest that report significantly underestimates the potential severity of global warming over the next 100 years, a senior member of the panel warned.
"We are basically looking now at a future climate that is beyond anything that we've considered seriously in climate policy," said Chris Field, who was a coordinating lead author of the report.
"Without effective action, climate change is going to be larger and more difficult to deal with than we thought."
Fresh data has shown that greenhouse gas emissions have grown by an average of 3.5 percent a year from 2000 to 2007, Field told reporters at a meeting of the American Association for the Advancement of Science.
That's "far more rapid than we expected" and more than three times the 0.9 growth rate in the 1990's, he said.
While increased economic activity could have contributed to the growth in emissions, Field said it appears as though the bulk of the growth is "because developing countries like China and India saw a huge upsurge in electric power generation, almost all of it based on coal."
Further complicating the problem is that higher temperatures could thaw the Arctic tundra and ignite tropical forests, potentially releasing billions of tons of carbon dioxide that has been stored for thousands of years.
That could raise temperatures even more and create "a vicious cycle that could spiral out of control by the end of the century."
"We don't want to cross a critical threshold where this massive release of carbon starts to run on autopilot," said Field, a professor of biology and of environmental Earth system science at Stanford University.
The amount of carbon that could be released is staggering.
Since the beginning of the Industrial Revolution an estimated 350 billion tonnes of carbon dioxide (CO2) have been released through the burning of fossil fuels.
The new estimate of the amount of carbon stored in the Arctic's permafrost soils is around 1,000 billion tonnes. And the Arctic is warming faster than any other part of the globe.
Several recent climate models have estimated that the loss of tropical rainforests to wildfires, deforestation and other causes could increase the concentration of carbon dioxide in the atmosphere from 10 to 100 parts per million by the end of the century.
The current level is about 380 parts per million.
"Tropical forests are essentially inflammable," Field said. "You couldn't get a fire to burn there if you tried. But if they dry out just a little bit, the result can be very large and destructive wildfires."
Recent studies have also shown that global warming is reducing the ocean's ability to absorb carbon by altering wind patterns in the Southern Ocean. Faster winds blow surface out of the way, causing water with higher concentrations of carbon dioxide to rise to the surface.
Sea levels are also rising faster than previously estimated as ocean temperatures warm and melting ice in mountain glaciers and at the poles flows into the ocean, warned Anny Cazenave, of France's Centre National d'Etudes Spatiales.
Fresh analysis using satellite imaging has shown that in the past 16 years, average sea levels have risen at a rate that is twice as fast as the last century: more than three millimeters a year.
Some regions have seen levels rise as much as one centimeter a year, Cazenave told reporters.
The expanding use of biofuels could also contribute to global warming because farmers are cutting down and burning down tropical forests to plant crops, said Holly Gibbs of Stanford University.
"If we run our cars on biofuels produced in the tropics, chances will be good that we are effectively burning rainforests in our gas tanks," she warned.
Global warming seen worse than predicted
Julie Steenhuysen Reuters 15 Feb 09;
CHICAGO (Reuters) - The climate is heating up far faster than scientists had predicted, spurred by sharp increases in greenhouse gas emissions from developing countries like China and India, a top climate scientist said on Saturday.
"The consequence of that is we are basically looking now at a future climate that is beyond anything that we've considered seriously," Chris Field, a member of the Intergovernmental Panel on Climate Change, or IPCC, told the American Association for the Advancement of Science meeting in Chicago.
Field said "the actual trajectory of climate change is more serious" than any of the climate predictions in the IPCC's fourth assessment report called "Climate Change 2007."
He said recent climate studies suggested the continued warming of the planet from greenhouse gas emissions could touch off large, destructive wildfires in tropical rain forests and melt permafrost in the Arctic tundra, releasing billions of tons of greenhouse gasses that could raise global temperatures even more.
"There is a real risk that human-caused climate change will accelerate the release of carbon dioxide from forest and tundra ecosystems, which have been storing a lot of carbon for thousands of years," Field, of Stanford University and the Carnegie Institution for Science, said in a statement.
He pointed to recent studies showing the fourth assessment report underestimated the potential severity of global warming over the next 100 years.
"We now have data showing that from 2000 to 2007, greenhouse gas emissions increased far more rapidly than we expected, primarily because developing countries, like China and India, saw a huge surge in electric power generation, almost all of it based on coal," Field said.
He said that trend was likely to continue if more countries turned to coal and other carbon-intensive fuels to meet their energy needs. If so, he said the impact of climate change would be "more serious and diverse" than the IPCC's most recent predictions.
(Editing by Peter Cooney)
Climate warming gases rising faster than expected
Randolph E. Schmid, Associated Press Yahoo News 14 Feb 09;
CHICAGO – Despite widespread concern over global warming, humans are adding carbon to the atmosphere even faster than in the 1990s, researchers warned Saturday.
Carbon dioxide and other gases added to the air by industrial and other activities have been blamed for rising temperatures, increasing worries about possible major changes in weather and climate.
Carbon emissions have been growing at 3.5 percent per year since 2000, up sharply from the 0.9 percent per year in the 1990s, Christopher Field of the Carnegie Institution for Science told the annual meeting of the American Association for the Advancement of Science.
"It is now outside the entire envelope of possibilities" considered in the 2007 report of the International Panel on Climate Change, he said. The IPCC and former vice president Al Gore received the Nobel Prize for drawing attention to the dangers of climate change.
The largest factor in this increase is the widespread adoption of coal as an energy source, Field said, "and without aggressive attention societies will continue to focus on the energy sources that are cheapest, and that means coal."
Past projections for declines in the emissions of greenhouse gases were too optimistic, he added. No part of the world had a decline in emissions from 2000 to 2008.
Anny Cazenave of France's National Center for Space Studies told the meeting that improved satellite measurements show that sea levels are rising faster than had been expected.
Rising oceans can pose a threat to low level areas such as South Florida, New York and other coastal areas as the ocean warms and expands and as water is added from melting ice sheets.
And the rise is uneven, with the fastest rising areas at about 1 centimeter — 0.39 inch — per year in parts of the North Atlantic, western Pacific and the Southern Ocean surrounding Antarctica, she said.
Also, highly promoted efforts to curb carbon emissions through the use of biofuels may even backfire, other researchers said.
Demand for biologically based fuels has led to the growing of more corn in the United States, but that means fields were switched from soybeans to corn, explained Michael Coe of the Woods Hole Research Center.
But there was no decline in the demand for soy, he said, meaning other countries, such as Brazil, increased their soy crops to make up for the deficit.
In turn, Brazil created more soy fields by destroying tropical forests, which tend to soak up carbon dioxide. Instead the forests were burned, releasing the gasses into the air.
The increased emissions from Brazil swamp any declines recorded by the United States, he said.
Holly Gibbs of Stanford University said that if crops like sugar and oil palm are planted after tropical forests are burned, the extra carbon released may be balanced by lower emissions from biofuel in 40 to 120 years, but for crops such as corn and cassava it can take hundreds of years to break equal.
"If we run our cars on biofuels produced in the tropics, chances will be good that we are effectively burning rainforests in our gas tanks," she said.
However, there could be benefits from planting crops for biofuels on degraded land, such as fields that are not offering low productivity due to salinity, soil erosion or nutrient leaching.
"In a sense that would be restoring land to a higher potential," she said. But there would be costs in fertilizer and improved farming practices.
In some cases simply allowing the degraded land to return to forest might be the best answer, she said.
