I was looking at the latest temperature data for the lower troposphere, from UAH. That is, the latest version (v6.0 beta). Roy Spencer has provided an update at WUWT (archived here).
Did you know that the monthly global average for the lower troposphere has been lower than the average for the period from 1981 to 2010 on only 28 of the 128 months since January 2001? That is, in only 16% of the months this century, has the global monthly mean been less than the 30 year average to 2010. That's right. I'm not talking about an average from the twentieth century or the middle of last century. This is the average from 1981 to 2010. Recent times. And that's assuming he's got his tropospheric temperatures right this time around.
And it's only happened once in the three years since April 2012. And then only by 0.01°C - in May 2013.
Now I've got a chart for every taste in the following animation. WUWT-ers like the monthly version, probably because it hides the trend better. The animation shows the following - all using the new UAH v6.0 beta:
- Monthly from 1979
- Monthly from January 2001
- Monthly for the three years since April 2012
- Annual from 1979 to 2014 inclusive
- Decadal from 1980 - though we're not quite half way through the current decade.
The above are temperatures estimated for the average of the lower troposphere - up to about 8 km into the air. For comparison, here is what's been happening at the surface where most of us live, decade by decade.
|Data source: GISS NASA|
From the WUWT comments
dp is asking what "normal" means, and tosses in a strawman. Normal means precious little these days. When temperatures are rising more and more each decade, then it could be centuries before the earth settles into a new "normal".
May 6, 2015 at 11:33 pm
Not directed to Dr. Spencer but…
Define “normal”. Describe why it is considered normal. Defend why it can be the one “normal”. Discuss other possible normals. Explain why the one normal is more acceptable than any others. Explain why the accepted normal is applicable to evaluating time frames other than that used to produce the “normal” reference point. Explain how a “normal” can include a well-identified cooling period but not a well-identified warming period. Anybody?