El Niño was not the cause of 2006 warming patterns in the U.S.

A new study by NOAA’s Earth System Research Lab finds:

Greenhouse gases likely accounted for more than half of the widespread warmth across the continental United States last year … [T]he probability of U.S. temperatures breaking a record in 2006 had increased 15-fold compared to pre-industrial times because of greenhouse gas increases in Earth’s atmosphere.

How did they come to this conclusion?

[T]he NOAA team analyzed 42 simulations of Earth’s climate from 18 climate models provided for the latest assessment by the Intergovernmental Panel on Climate Change … The results of the analysis showed that greenhouse gases produced warmth over the entire United States in the model projections, much like the warming pattern that was observed last year across the country.

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The warming pattern did not match that of El Niño, which the study found typically cools the country slightly:

For a final check, the scientists compared the observed 2006 pattern of abnormal surface temperatures to the projected effects of greenhouse-gas warming and El Niño temperature responses. The U.S. temperature pattern of widespread warming was completely inconsistent with the pattern expected from El Niño, but it closely matched the expected effects of greenhouse warming.

When even NOAA scientists attribute recent warming to greenhouse gases, you know it’s time to take action. Let’s see if the media give this important study the same attention they gave to the recent trivial revision in NASA’s U.S. land-based temperature data record.

This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.