REPOST: I've been looking for a good figure showing Extreme temperatures have gone up. After searching without success, I made this, adapted from @DrJamesEHansen's 2012 PNAS paper. Data are from Berkeley earth.
[previous post had an error in the plot; corrected here]
[previous post had an error in the plot; corrected here]
The left plot shows the 1951-1980 June-July-August seasonal average for northern hemisphere land (30°N-60°N). The blue area is the coolest is 33% of temperatures, the white area or the middle 33%, and the red or the highest 33%.
The right plot shows the 2011-2020 temperatures. Over the decade, 88% of the seasonal averages would have been in the top third in the 1951-1980 period. Only 1.2% would have been in the coolest third. And 14% are warmer than ANY temperatures in the 1951-1980 period.
Labels "cool", "average", … are based on standard deviations at the grid points. Here is a plot showing the SDs. 3.6% of the temperatures are > 4 sigma, and 0.7% are > 5 sigma.
Yes, global warming is real!
Yes, global warming is real!
Here, by the way, is the result from a climate model (20 ensemble members of the MPI grand ensemble). The 2090-2099 numbers come from a RCP4.5 scenario.
It's estimate for 2011-2020 is quite similar to the observed temperatures, although the model actually shows slightly less warming.
In 2090-2099 (under the RCP4.5 scenario), almost 100% of summertime temperatures would have been in the warmest third of 1951-1980 temperatures. And about half of the summer temps were warmer than EVER occurred in 1951-1980 period.
Note that global average temperatures in 2090-2099 are only 2.1°C above pre-industrial in this model+scenario, yet this is enough to make our summertime temperatures nearly unrecognizable to those of us alive today.
Yes, 2°C is a HUGE amount of warming.
Yes, 2°C is a HUGE amount of warming.
Here is the plot in terms of standard deviations. In 2090-2099, temperatures that would have been 4-6 sigma events in the 1951-1980 period become common.
