Friday, January 15, 2016

U.S. Warming?

One of the most common false arguments made by deniers is a statement to the effect, "It was coldest in Umptysquatch, US State, this season than I can ever remember. This proves global warming isn't real." Fill in the town and state of your choice.

This is a false argument for a number of reasons. First, we're talking about global warming, not U.S. warming. The continental U.S. covers about 2% of the planet's surface. Picking a specific town is, obviously, much less. Deniers are engaging in a massive cherry-picking exercise when they do this.

But, the data rarely backs them up. When we look at the actual measured data and compare it to people's claims, it is not unusual at all to find the reality is very different. Here is the data for the continental U.S. for 2015 released by NOAA:


Month
Percent area of CONUS "very warm"
Percent area of CONUS "very cold"
January
25.90
0.00
February
29.87
31.42
March
46.50
2.22
April
8.17
0.00
May
16.10
2.01
June
39.77
1.10
July
13.13
5.04
August
23.39
0.00
September
61.21
0.00
October
38.86
0.00
November
46.13
0.22
December
51.17
0.00
 
For the purposes of this graphic, NOAA defines "very warm" as being in the top 10% of warm periods and "very cold" as being in the bottom 10%.

For the record, the average amount of CONUS that was 'very warm' was 33.3% per month. Fully one-third of CONUS was experiencing temperatures in the top 10% every month.The average for 'very cold' was 3.5%. This means the amount of CONUS experiencing 'very warm' conditions was nearly 10 times as much as the amount experiencing 'very cold.'

Some people will simply dismiss this as a consequence of the massive El Nino currently underway. This is a false argument for two reasons. First, where do they think the warmth being released by the oceans came from? El Ninos are not warming events, they are merely transferring heat trapped in the oceans into the atmosphere. But, that heat in the oceans had to come from somewhere. But, this argument also fails the data test. The current El Nino started in March. So, if we look at only the first three months we find the average for 'very warm' was 34% (less than for the entire year) and for 'very cold' it was over 11% (much greater than for the total year). If that argument contained any validity, we would see the percentages to be nearly equal.

So, the next time you hear someone claim global warming isn't real because they know someone who said they had the coldest season they can remember, you will know their claim is not valid.







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