A project running almost 10,000 climate simulations on volunteers’ home computers has found that a global warming of 3 degrees Celsius by 2050 is ‘equally plausible’ as a rise of 1.4 degrees.
The study addresses some of the uncertainties that previous forecasts, using simpler models or only a few dozen simulations, may have over-looked.
Importantly, the forecast range is derived from using a complex Met Office model that accurately reproduces observed temperature changes over the last 50 years.
The results suggest that the world is very likely to cross the ‘2 degrees barrier’ at some point this century if emissions continue unabated.
It also suggests that those planning for the impacts of climate change need to consider the possibility of warming of up to 3 degrees (above the 1961-1990 average) by 2050, even on a mid-range emission scenario. This is a faster rate of warming than most other models predict.
The research was made possible because volunteers donated time to run the simulations on their home computers through climateprediction.net as part of the BBC Climate Change Experiment. A report of the research is published in Nature Geoscience.
“It’s only by running such a large number of simulations – with model versions deliberately chosen to display a range of behaviour – that you can get a handle on the uncertainty present in a complex system such as our climate,” said Dr Dan Rowlands of Oxford University’s Department of Physics, lead author of the paper. “Our work was only possible because thousands of people donated their home computer time to run these simulations.”
Dr Ben Booth, Senior Climate Scientist at the Met Office Hadley Centre, an author of the paper, said: “There have been substantial efforts within the international community to quantify and understand the consequence of climate uncertainties for future projections. Perhaps the most ambitious effort to date, this work illustrates how the citizen science movement is making an important contribution to this field.”
The model used in the project was supplied by the Met Office and the work was supported by the Natural Environment Research Council (NERC), the European Union FP6 WATCH and ENSEMBLES projects, the Oxford Martin School, the Smith School of Enterprise and the Environment, and Microsoft Research.
You can see this research covered here:
Official blog of the Met Office news team 
It’s currently 2012, 22 years after the end of the baseline period referred to in the article (1961-90). According to HADCRU, the world has thus far warmed by roughly 0.4C in that time, and has been flat since 2003 based on a 5 year mean. Over the entire temperature record since 1850, the earth has only warmed by roughly 0.8C. How the heck did any computer model come up with the ludicrous prediction that in 38 years time, we’ll have warmed by 3C? Answer: It’s been programmed by ideologically motivated climate quacks in order to generate more alarmist headlines. Climate quack global warming hypothesis can be summarised in 1 sentence. When observations fail to match predictions, make more alarming predictions.
Hi Judge Fudge, the HadCRUT record shows a warming trend of about 0.75C since 1900. You can see more about it in a recent press release here. When looking at global climate trends, it’s important to look at preiods of at least a few decades to draw conclusions.
http://m.npr.org/news/front/150005074