The new study, published in the Nature journal, compared over 10 years of climate satellite data to predictions made by various climate models. The data includes the amount of sunlight reflected back into space, the amount of heat leaving earth, as well as the amount of energy entering and exiting the atmosphere. Scientists then compared data from climate models to determine which were the most accurate at predicting exactly how much warming would occur.
"We know enough about the climate system that it doesn't necessarily make sense to throw all the models in a pool and say, we're blind to which models might be good and which might be bad," said Patrick Brown, a postdoc at the Carnegie Institution and an author of the study.
All of the models predicted an average warming of 4.3 degrees Celsius — plus or minus 0.7 degrees Celsius — between 2081 and 2100, assuming that current atmospheric emission levels continue unabated.
However, the best and more accurate models suggest that there will be a warming of 4.8 degrees Celsius — plus or minus 0.4 degrees Celsius — during the same time period.
Some researchers claim that the study results are not definitive.
"The study is interesting and concerning, but the details need more investigation," asserted Ben Sanderson, a climate expert at the National Center for Atmospheric Research in Boulder, Colorado.