Dried up lake in San Angelo, Texas, June 2011. f150online.com

By David Mark
26 March 2012 A new study suggests climate scientists may have underestimated the effect of greenhouse gases, with global temperatures now predicted to rise by between 1.4 and 3 degrees Celsius by 2050. The study was published in the journal Nature Geoscience by a team of international scientists who ran 10,000 computer simulations of climate models in an attempt to explore the range of global warming predictions made by climate scientists. The researchers found that while their results matched the predictions made by the Intergovernmental Panel on Climate Change (IPCC) at the lower end, they were higher than earlier predictions at the higher end. One of the certainties about predicting climate change is uncertainty, which is why climate change professor David Frame and 26 of his colleagues from around the world have tried to narrow things down. “We set out to look at how a large range of climate models could try to span a range of uncertainties to try to get a better handle on the sort of range of plausible climates we might see in the next half century and beyond,” said Professor Frame, who works at the Victoria University of Wellington. […] “If people keep emitting fossil fuels in the way we expect, with no price on carbon or no future policy initiatives, we expect a range of 1.4 to 3 degrees by 2050,” he said. Those numbers are based on average temperatures between 1960 and 1990. At the bottom end it is similar to the last prediction made by the IPCC, but it exceeds that group’s prediction at the higher end. “What we’ve kind of got is just a broader sweep of that uncertainty range,” Professor Frame said. […] The journal has also published a paper which states that extreme weather events over the past decade have increased and were “very likely” caused by man-made global warming.

Impact of climate change may be underestimated