1990 climate change predictions turn out to be accurate

Posted by Emma Woollacott

In a blow to those people who believe that global warming predictions are just a lot of hot air, an international team has established that predictions made 20 years ago are turning out pretty accurate.

The report compares predictions from the first Intergovernmental Panel on Climate Change (IPCC) Assessment Report, published in 1990, with real-world global climate change data gathered since.

It's the first time that IPCC estimates have been compared with real world changes, and should give more credence to the organization's increasingly alarming predictions. Its next set of forecasts - based on much more refined computer models than those of 1990 - are due next year.

"It is important for scientists to go back and see how early climate change predictions are going," says Professor David Frame, Director of the New Zealand Climate Change Research Institute at Victoria University.

"What we've found is that these early predictions seem pretty good, and this is likely due to the climate responding to concentrations of greenhouse gases in the earth's atmosphere at a rate broadly in line with what scientists in 1990 expected."

The IPCC report predicted a rise of 0.7˚C to 1.5˚C by 2030, and of 0.35˚C to 0.75˚C by 2010. And, in fact, observations show that the actual global mean surface temperature has increased by between 0.35 and 0.39˚C - a figure that's in reasonable agreement with the 1990 predictions, says the team.

"It seems highly unlikely that recent changes can be accounted for by natural variability alone, even if the current generation of models significantly underestimated natural variations," say the authors.

The paper's here.