Jason Samenow sends word of a new article in WaPo that does some of the same sort ofsurface temperature analyses we see right here on WUWT. Seeing what a good job Matt Rogers did in his defense against claims of cherry picking, statistical significance woes, and Trenberthian masking, it made me wonder; “How long before he gets called into the chief editors office at WaPo and reassigned to be the correspondent covering Botswana?”

Global warming of the Earth’s surface has decelerated – Matt Rogers, Capital Weather Gang

The recently-released National Climate Assessment (NCA) from the U.S. government offers considerable cause for concern for climate calamity, but downplays the decelerating trend in global surface temperature in the 2000s, which I document here.

Many climate scientists are currently working to figure out what is causing the slowdown, because if it continues, it would call into question the legitimacy of many climate model projections (and inversely offer some good news for our planet).

An article in Nature earlier this year discusses some of the possible causes for what some have to referred to as the global warming “pause” or “hiatus”.  Explanations include the quietest solar cycle in over a hundred years, increases in Asian pollution, more effective oceanic heat absorption, and even volcanic activity. Indeed, a peer-reviewed paper published in February estimates that about 15 percent of the pause can be attributed to increased volcanism. But some have questioned whether the pause or deceleration is even occurring at all.

 Verifying the pause

You can see the pause (or deceleration in warming) yourself by simply grabbing the freely available data from NASA and NOAA. For the chart below, I took the annual global temperature difference from average (or anomaly) and calculated the change from the prior year. So the very first data point is the change from 2000 to 2001 and so on. One sign of data validation is that the trends are the same on both datasets.  Both of these government sources show a slight downward slope since 2000:

You can see some of the spikes associated with El Niño events (when heat was released into the atmosphere from warmer than normal ocean temperatures in the tropical Pacific) that occurred in 2004-05 and 2009-10. But the warm changes have generally been decreasing while cool changes have grown.