Global warming calculations have been too optimistic and global sea levels are likely to rise a full meter this century, senior German scientists have warned. They say UN-backed data on climate change is out of date.
“We should prepare for a rise of sea levels of one meter this century,” said Joachim Schellnhuber, head of the Potsdam Institute for Climate Impact Research (PIK), which advises the German government on environmental policy.
The melting rates of glaciers in the Himalayas and the Greenland ice-sheet have doubled or even tripled in recent years, due partly to increased greenhouse gas emissions by Chinese power stations, he said.
His findings used data which was unavailable to the Intergovernmental Panel on Climate Change (IPCC) when it compiled its most recent global warming report.
In February 2007, in the first volume of a landmark report, the Nobel Prize-winning IPCC predicted the oceans would rise by between 18 and 59 centimeters by 2100.
Further causes for concern include a drop in the amount of dirt particles in the air that protect from sunlight. Schellnhuber warned that cleaning air in Beijing and in other large cities suffering from pollution problems by limiting car and power-plant emissions may raise global temperatures instead of lowering them.
Aerosols, or particles suspended in air, have a cooling effect on the earth, countering global warming linked to carbon dioxide, said Schellnhuber, explaining that a drop in aerosols in the atmosphere could cause a rapid rise in temperatures.
Airborne pollutants act as an umbrella worldwide while CO2 provides insulation, trapping heat attempting to escape into the atmosphere. A rise in temperature because of declines in aerosols in the atmosphere can be offset by slashing CO2 emissions, he said.
By not reducing carbon output, humanity “is closing the last door we have through which we can possibly influence the global climate,” Schellnhuber warned.
Urgent need for action
The scientist stressed that there is what he called a 50-50 chance of limiting the global temperature rise to 2 degrees Celsius (3.6 degrees Fahrenheit) before 2100, which would avert the worst damage of climate change — so long as plans fleshed out by the G8 countries to reduce emissions are realized.
The United Nations-sponsored climate-change talks this December in Poznan, Poland, and next year in Copenhagen must reach an agreement to limit CO2, he added.
“There is really no time to spare,” Schellnhuber said in an interview with Bloomberg. “Technology will play a decisive role in limiting carbon but we have to move to a carbon-free world by the end of the century.”
“We can spend relatively little money now or vast sums in decades to come,” he was quoted as saying in Zeit Online. “We are wealthy enough to afford climate protection — and we are too badly-off to ignore it.”
DW staff
