While November 2010 saw fairly average temperatures in the continental United States, for Earth planetwide temperature readings were not so temperate. Last week NASA’s Goddard Institute for Space Studies released its latest data on average global temperature — a dataset stretching back in time to January 1880 and forward through last month, with two publicly released datasets, one incorporating temperature readings made over land only and the other reporting on temperature over both land and sea. In both datasets, November 2010 ranks as the hottest November on record.
The record-setting heat of November 2010 is a piece of weather information about just one month; in order to talk about climate change you have to show a pattern over time. So let’s put the warmth of November 2010 in climate context.
Let’s start in the shorter term. What’s the weather been like this year compared to the 131-year GISS temperature record?
November 2010 was the hottest on record, period.
October 2010 was the 2nd hottest October on record over land, and the 3rd hottest on record over both land and sea.
September 2010 was the 3rd hottest September on record over land, and the 4th hottest on record over both land and sea.
August 2010 was tied for the 4th hottest August on record over land, and the 6th hottest on record over both land and sea.
July 2010 was the 4th hottest July on record over land, and the 5th hottest on record over both land and sea.
June 2010 was the hottest June on record over land, and the 3rd hottest on record over both land and sea.
May 2010 was the 2nd hottest May on record over land, and the hottest on record over both land and sea.
April 2010 was the hottest April on record, period.
March 2010 was the hottest March on record over land, and the 2nd hottest on record over both land and sea.
February 2010 was the 2nd hottest February on record over land, and also the 2nd hottest on record over both land and sea.
January 2010 was the 2nd hottest January on record over land, and the 2nd hottest on record over both land and sea.
In other words, it’s not just the month of November; it’s been unusually hot every single month of this year.
But maybe, some skeptics may be saying to themselves right now, maybe it’s just a fluke and not part of a pattern over time. Maybe some of the other really hot Novembers have happened far back in the past, in the late 1800s or the early 1900s. Skepticism is a healthy reflex and it’s possible for that to be true; let’s check the data to see what’s really going on.
The following are the 10 hottest Novembers over land and sea around the globe in the Goddard Institute data:
Hottest on record: 2010
2nd hottest on record: 2009
3rd hottest on record: 2004
4th hottest on record: 2001
5th hottest on record: 2006
6th hottest on record: 2005
7th hottest on record: 2008
8th hottest on record: 1997
9th hottest on record: 2002
10th hottest on record: 2003
And the following are the ten coldest Novembers on record in the Goddard Institute’s global data:
Coldest on record: 1890
2nd coldest on record: 1919
3rd coldest on record: 1892
4th coldest on record: 1907
5th coldest on record: 1910
6th coldest on record: 1902
7th coldest on record: 1908
8th coldest on record: 1881
9th coldest on record: 1891
10th coldest on record: 1898
That’s not a random distribution of temperature. The coldest years are the earliest, the hottest years are the latest.
Just in case you’re still skeptical about the climate trend of global warming and think maybe the pattern disappears when looking at all years between 1880 and 2010, here’s the complete Goddard Institute temperature rankings (1 = coldest year, 131 = hottest year):
I’ve plotted and posted the linear trend along with the chart. The R-squared term for the November temperature data indicates not all of the temperature variation can be explained by the simple progression of the years. That’s OK: no reputable climate scientist who reports on global warming has indicated that there isn’t any short-term variability in temperature from one year to the next. But most of the variation in temperature — 62.4% of it — can be explained by the progression of the years. That’s climate change. That’s global warming.