Thanks for furnishing the lovely graph of global temperature anomalies in your WMO Statement on Status of the Global Climate in 2012. I’ve reproduced it here.
The caption for it reads:
Figure 4. January–December global land and ocean surface temperature anomalies (relative to 1961–1990) for the period 1950–2012; years that started with a moderate or strong La Niña already in place are shown in blue, years that started with a moderate or strong El Niño already in place are shown in red; other years are shown in grey.
If you’re not aware, persons see the following three periods in that graph.
Just thought you’d be interested. That’s what I see, and I suspect many other persons see the same three periods in the graph. And that means no matter what you’ve written in the rest of that report, what people will see and take away from your report is that global surface temperatures warmed for a couple of decades, starting around the mid-1970s. Then surface temperatures stopped warming a decade and a half ago.
The graph that you’ve provided as part of your press release is worse. The funky blue shading at the bottom of the 2012 bar will make persons wonder what you’re trying to show with it. One thing is for sure: it draws the eye down. Odd that you should do that when you’re struggling to show global warming.
A question: The WMO recommends that the base years used for anomalies be updated every 10 years. Many organizations, such as NOAA, comply with that recommendation. They now use 1981 to 2010 as the base years for anomalies for many of their datasets. Is there any reason you continue to use 1961-1990, other than to make the temperature anomaly map look warmer? Also, the non-linear color-coded scaling of the contour intervals is very awkward.
Last, earlier this year I prepared an illustrated essay that discusses global warming. It’s titled “The Manmade Global Warming Challenge”. The preview is here [4MB] and the full essay is here [42MB]. It’s easy to read and understand. I thought you might be interested in a copy.