It has not been a good year for global-warming skeptics

נשלח 4 ביוני 2016, 7:37 על ידי Sustainability Org   [ עודכן 4 ביוני 2016, 7:37 ]
Henry Blodget, May 21, 2016

From NASA and asset-manager Jeremy Grantham at GMO, an update on global temperature trends.

The global-warming skeptics had an encouraging run for a while. But the acceleration of warming over the past year is alarming.

Global temperaturesNASA, GMO

Here's Mr. Grantham:

Global warming accelerates: “so much for the pause”

Because 1998 was an outlier warm year due to a large El Niño effect in the Pacific, many subsequent years, including 2013, had lower global temperatures and led some to believe, or claim to believe, that global warming had ceased. But it turned out to be, after all, just another series...with a little steady signal often obscured by a very great deal of noise.

As it turned out, the below-trend 2013 was followed immediately by a modest new record in 2014. And then came the real test as a new powerful El Niño started to build up in 2015. Ten of the twelve months of 2015 set new all-time records, an unheard of event, and 2015 in total became a monster, not only the warmest year in recent millennia but by a record increment.

Yet, the early months of 2016, still under the influence of what had become one of the most powerful El Niño effects, showed temperature increases that were even more remarkable. This current El Niño has accelerated underlying warming caused by increasing CO2 – as all El Niños do – but this time the combined effect has been far ahead of scientific forecasts that in general remain dangerously conservative. January 2016 was the hottest January ever on the NASA series and by a new record amount. It was a full 0.22 degrees Celsius above the previous high for January. Then February became the new shocker, washing away that record by being 0.33 degrees Celsius above the previous February record. Most recently, March was once again the warmest ever March, although not quite by a record amount (see Exhibit 2).

The exhibit makes the scary point clear: global temperature is not just increasing, but accelerating. The average increase from 1900 to 1958 was about 0.007 degrees Celsius per year. From 1958 to 2015 it doubled to 0.015 degrees Celsius per year, and from February 1998 to February 2016 it rose by an average of 0.025 degrees Celsius per year! Time is truly running out.