SINGAPORE — Researchers from around the world meet in Denmark this week to discuss the latest scientific findings on climate change, following recent warnings that the severity of global warming this century will be much worse than previously expected and that changes to the climate will be difficult if not impossible to reverse for centuries to come.
The three-day international research congress at the University of Copenhagen is sponsored by a consortium of 11 research universities in Europe, the United States, Asia and Australia, including the University of Tokyo. It is part of the leadup to a conference of world leaders in Copenhagen in December to try to agree on a global treaty or framework to replace the Kyoto Protocol to combat global warming.
That protocol, which expires in 2012, has had limited impact partly because it only binds about three dozen developed economies to cut carbon dioxide and other greenhouse-gas emissions blamed by many scientists for causing an increase in temperature, more extreme weather, the spread of disease and rises in sea levels. The two biggest emitters, China and the U.S., are not in this group. Nor are emerging economies such as India, Indonesia and Brazil, whose recent growth and development have made them important emitters.
One of the questions the research congress in Copenhagen will consider is whether the scientific evidence on the pace, scope and consequences of climate change presented to governments less than two years ago is already significantly out of date, and whether there should be more frequent scientific reports to policymakers.
The present process is cumbersome and lags well behind advances in research. The Intergovernmental Panel on Climate Change (IPCC), established by the United Nations in 1988, brings together hundreds of experts from around the world to assess the science and policy implications of global warming. Their task is to combine all available evidence.
Since 1990, the IPCC has published four comprehensive assessment reports on human-induced climate change. The next is not due until 2014. The most recent, in November 2007, concluded that Earth’s temperature is likely to rise by 1.1 to 6.4 degrees Celsius by 2100, depending on how much greenhouse gas is released into the atmosphere in coming decades.
One of the lead authors of that report said last month it had probably seriously underestimated the consequences of climate change. Professor Chris Field, a Stanford University climate scientist, said “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 upsurge in electric- power generation, almost all of it based on coal.”
Coal and other fossil fuels are major contributors to releases of carbon dioxide, the main greenhouse gas. Field, who co-chairs the IPCC working group charged with assessing the impacts of climate change, said he is particularly concerned about new evidence that tropical forests would dry out and catch fire, and that permafrost in the Arctic, which is warming faster than anywhere else, would thaw, releasing enormous amounts of CO2 and methane, an even more potent global warming gas, into the atmosphere.
Meanwhile, other recent studies forecast that, by 2100, sea levels will rise substantially higher than the IPCC projected and that the capacity of oceans to soak up excess CO2 is declining. The oceans, forests and other vegetation as well as soil absorb about half of all man-made CO2 emissions. The rest stays in the atmosphere.
In January, a team of U.S. and European scientists headed by another IPCC lead author published a study demonstrating how changes in surface temperature, rainfall and sea levels would be largely irreversible for more than 1,000 years after CO2 emissions are completely stopped.
“Our study convinced us that current choices regarding carbon dioxide will have legacies that will irreversibly change the planet,” said team leader Susan Solomon, a senior scientist in the U.S. National Oceanic and Atmospheric Administration.
NOAA next month is due to release its annual update for 2008 on global greenhouse-gas emissions. It is expected to show that, despite the recession and slowdown in industrial output, CO2 levels in the atmosphere, already at their highest in over 800,000 years, increased slightly in 2008.
Still, some experts say the recession will temporarily cut emissions by as much as one-third over the next couple of years and that this will provide an opportunity for policymakers to act before the situation gets worse.
Not all the recent research reaches dire conclusions about climate change. One study suggests that tropical forests in the Amazon basin may be less vulnerable to temperature rises than previously believed. Another concludes that the melting of the Greenland ice sheet, which accelerated in the early part of this decade, has slowed again.
Vicky Pope, Ph.D., head of climate change advice at the Hadley Center in Britain’s Meteorological Office, says there will always be natural variations in climatic trends, but that the implications of climate change will be severe if greenhouse-gas emissions are not cut “drastically” over coming decades.
The message from scientists to political leaders trying to cushion recession and spark a recovery is this: You may try to run from the costs of the climate change challenge, but ultimately there is nowhere to hide.
Michael Richardson is a visiting senior research fellow at the Institute of Southeast Asian Studies, Singapore.