Climate scientists have made it easy for skeptics to poke holes in theories about global warming. Every model includes slightly different assumptions, conditions, calculations, or other parameters -- leading to differing results. Skeptics point at the differences to justify their conclusion that nothing is known with certainty.
A new advanced statistical analysis by researchers at Ohio State University bridges the differences between various climate change models in order to show the areas where a future two degree Celsius temperature change can be expected by 2070 with 97.5% probability.
As you can see in the image above, that zone covers almost all of the United States of America, excluding a narrow strip along the Pacific coast and a good size chunk around the Gulf of Mexico. The full statistical analysis shows that almost all of Canada will also be affected, excluding Canada's southern Pacific coast and the lower half of Newfoundland Island.
The areas outside of the 2 degree zones will also experience higher temperatures, as depicted by a second graphic, in which the color intensity corresponds to hotter zones.
Noel Cressie, professor of statistics and director of Ohio State’s Program in Spatial Statistics and Environmental Statistics, and former graduate student Emily Kang, now at the University of Cincinnati, present the statistical analysis in a paper published in the International Journal of Applied Earth Observation and Geoinformation.
Cressie pioneered the statistical techniques used in this analysis which combine spatial models with Bayesian hierarchical statistical analysis, a method that gives researchers tools to quantify the certainty of various outcomes. Cressie's observation on the value of his research:
We show that there are shared conclusions upon which scientists can agree with some certainty, and we are able to statistically quantify that certainty.
Although the current paper combines a small number of models, the techniques developed can be scaled up to bridge all of the major climate science models, extending those shared conclusions and certainties to the point where doubts can finally be dispelled and action to reduce global warming can proceed with haste and conviction.