A team of researchers from Bern University claims global warming will continue until the end of this century.This content was published on April 17, 2002 - 21:10
Using a series of computer simulations, they have concluded that after the warmest hundred years on record, temperatures will keep on rising - at least until 2100.
Last year, the United Nations Intergovernmental Panel on Climate Change (IPCC) published its third assessment report. The report not only stated that global warming was a reality, but that the average temperature around the world would rise between 1.4 and 5.8 degrees centigrade this century.
The announcement generated a great deal of controversy, with some policymakers downplaying global warming. But the findings of the Swiss scientists support the IPCC's assessment.
The researchers built on their experience of using ice samples to measure earlier climate changes. The computer model they developed proved so consistent in logging past weather patterns that they applied it to predicting future trends.
The Bern team was also able to go one step further than the IPCC report and issue precise temperature predictions.
"We have made calculations that show that by the year 2020, we will have an increase in temperatures between 0.5 and 1.1 degrees centigrade," says Thomas Stocker, a professor of climate and environmental physics at Bern University. "Temperatures will probably increase even more at higher latitudes."
However, the computer simulations used by the Bern researchers are not perfect. They reflect only a global situation and need refining before local predictions can be made.
"On the regional level, the implications are still difficult to project," Stocker told swissinfo. "That is because the uncertainties associated with small regional changes are very large."
Urgent action needed
The research team says the overall prediction of an increase in temperatures highlights the need to act urgently in dealing with, and slowing down, global warming. But what will actually happen is down to human behaviour in the coming years.
"It depends on the amount of fossil fuels global society will consume in this century," says Stocker. "There is a choice here."
"If the society of the second half of the 21st century has a very sustainable approach, if it uses much less energy, we will experience warming at the lower end of the range. But if the business-as-usual scenario prevails, the result will be at the high end of our predictions."
According to Stocker, action should be taken now to reduce greenhouse gas emissions and slow global warming, for example, by consuming less. But there are other ways too.
"If we look at the way carbon dioxide is distributed globally, we see about a third is due to land-use changes, mainly because of deforestation. The cleared land absorbs less carbon dioxide than forests do, so there is an incentive to stop logging."
The results of the Swiss researchers' work can be seen in this week's edition of the scientific journal, "Nature".
by Scott Capper