Thursday, May 7, 2015

Global warming ‘pause’ — warmest 17 years on record, by far

Originally published in The Aquarian, Spring 2015.

The Warmest Year(s) on Record
2014 may not be the warmest year on record, statistically. But the past 17 years – the so-called pause in global warming – are without a doubt the warmest period. And it's all down to the carbon. 

The colour of warming: NASA's video builds to a sunburst heat climax during the “pause years” of 1998–2014.

It’s official. 2014 was the warmest year on record for the surface of our great big, blue marble. Well, nominally it was the warmest. Statistically, not so much. 

That's the gist of a debate that has broken out – mostly in the nerdy reaches of the blogosphere – about the latest bellwether signal that global warming has no intention of taking a hike – of stopping or “pausing” – unless we press pause ourselves.

Early this year, all five of the major climate research groups and agencies that keep tabs on the planet's temps on land and sea, as well as the World Meteorological Organization, concurred that the average temperature anomaly (the deviation, up or down, from a reference baseline period) for 2014 was higher than any they had ever recorded. Only one, the UK's Met Office, declared 2014 a dead heat with 2010.

In contrast, both of the research groups that analyze the satellite record reported that 2014 was warm, but not record warm. For one group, the anomaly was third highest; for the other, a tepid 6th.

What every report had in common was that the slight difference between the top three warmest years – or the top six for the outlier satellite group – was smaller than the margin of error of roughly 5 to 10 hundredths of a degree.

In the United States, for example, the National Oceanic and Atmospheric Administration's (NOAA's) global temperature anomaly for 2014 of +0.69 degrees C. (using the entire 20th century as their baseline) was just 4 hundredths of a degree higher than their previous record: a tie between 2010 and 2005. And those years had beaten the blowout record set in 1998 (thanks to the hottest El Niño ever recorded) by just 2 hundredths of a degree.

When the margin of error for measuring things with 95% accuracy is larger than the difference between those things, statistically they're considered to be no different – “tied.” So, statistically, no climate scientist could or would declare any of the last few warmest years to be the warmest. Still, 2014 was the best candidate. Such was the fine print in most every report, and even in some of the news stories.