Monday, July 9, 2012

Last 12 Months Hottest Year in US Records

NOAA reports that the last 12 months was the hottest year in the US on their instrumental record going back to 1895:
The last year in the continental US has been the country's hottest since modern record-keeping began in 1895, say government scientists.
The National Oceanic and Atmospheric Administration (NOAA) also said the US had broken its record for the hottest six months in a calendar year.
This is obviously bad news, but the silver lining is that maybe it will help put one of the most irritating climate denial talking points into its well deserved grave.  The claim that "global warming stopped in 1998" (or sometimes 2005) has been one of their go-to favourites for several years now.  I realize that talking point is talking about global average temperatures, and NOAA is just talking about the US, but the political impetus behind that talking point in North America evaporates in the face of persistent historically hot temperatures.  Of course, I've frequently seen denialists cynically confuse US local measurements with global measurements in order to falsely create an impression of falling average temperatures, so I won't shed any tears if anyone reads articles like the above and confuses this for a global measurement.  1998 was exceptionally warm because of a giant El Niño cycle, and of course any measurement of global temperature that uses multi year averages will still find the temperature increasing.  Here's NASA:

Has Global Warming Slowed in the Past Decade?

Figure 7 helps us examine the issue of whether global warming has "stopped" in the past decade or at least slowed down from the rate of the prior two decades. Global temperature in 2011 was lower than in 1998. However, global temperature has a strong interannual variability tied to the Southern Oscillation (El Niño-La Niña cycle), as is apparent in Fig. 7.
Line plots of surface temperature anomaly and of Niño phase
Figure 7. Global monthly and 12-month running mean surface temperature anomalies relative to 1951-1980 base period, and 12-month running mean of the Niño 3.4 index.

And those multi-year averages graphed (right graph, blue line is best, click to enlarge):

Line plots of global temperature anomaly 1880-2011 
I suspect a lot of people really wish global warming would just "go away" on its own somehow, and when wingnuts confidently assert (with links to climate denial sites with science-y names) that climate change has "stopped" they're only too happy to believe this.  It's a pretty natural reaction to wish away bad news and believe those who tell you what you want to hear.  But it really falls flat in the face of weather like this.  And that NOAA report has other worrisome news:
According to the U.S. Drought Monitor, as of July 3, 56.0 percent of the contiguous U.S. experienced drought conditions, marking the largest percentage of the nation experiencing drought conditions in the 12-year record of the U.S. Drought Monitor. Drought conditions improved across Florida, due to the rains from Tropical Storm Debby. Drought conditions worsened across much of the West, Central Plains, and the Ohio Valley, causing significant impacts on agriculture in those regions. 
I saw some denialists today taking comfort that this recent heat wave hasn't been as severe as some of the ones in the 1930s.  Of course, those heat waves were caused by the Dust Bowl, which was itself caused by human agricultural practices, so ironically they're citing a human caused climate event as proof against the notion that we're warming the planet today.  But if droughts become the norm, another Dust Bowl could be on the way too.  We really are replaying the Great Depression in slow motion.


  1. wishing away bad news? in north carolina they're outlawing them!

    1. More and more I really understand why medieval messengers were terrified to deliver bad news to any noble. Once you enter a conservative feudal mindset, the person delivering the bad news is somehow responsible for it too and deserves it.