Odds of record U.S. heat being a random event: 1 in 1.6 million

[swag]

http://www.washingtonpost.com/blogs/ezra-klein/wp/2012/07/10/odds-of-record-u-s-heat-being-a-freak-event-1-in-1-6-million/

Posted by Brad Plumer on July 10, 2012 at 11:38 am

As hundreds of local temperature records have been smashed from Atlanta to Colorado Springs, there’s been plenty of discussion about whether the molten weather can be “blamed” on global warming. Isn’t it possible this heat is just a random outburst? Or are we really seeing the effects of all that carbon dioxide humans have put into the atmosphere?

Perhaps a chart can help. The National Climactic Data Center has just released its “State of the Climate” report for June 2012. The last 12 months in the mainland United States were the warmest on record. What’s notable, however, is that every single one of the last 13 months were in the top third for their historical distribution (i.e., March 2012 was in the top third for warmest Marches, etc). “The odds of this occurring randomly,” notes NCDC, “is 1 in 1,594,323.”


Source: National Climactic Data Center

Meteorologist Jeff Masters phrases it more plainly: “Thus, we should only see one more 13-month period so warm between now and 124,652 AD—assuming the climate is staying the same as it did during the past 118 years. These are ridiculously long odds, and it is highly unlikely that the extremity of the heat during the past 13 months could have occurred without a warming climate.”

In other words, it’s very, very unlikely that this sweltering 13-month period could have happened had humans not loaded the atmosphere with carbon dioxide and heated the surface temperature of the planet by 0.8 °C (1.4 °F) above pre-industrial levels. If this is just a freak outburst by Mother Nature, then it’s a spectacularly improbable one.

. . . more

[Arkansas Granny]

1. I'll have to say that after a few years of record breaking summers and very mild winters,

I haven't heard much out of the "Where's your global warming now?" crowd. I think they are beginning to realize where it is.

[Enrique]

2. what's missing is discussion of global temperatures

I believe there is a similar patters at the global level, that is what counts in my opinion. Of course talk about the heat we're seeing as a picture of what global warming looks like, but as far as making the case that it's happening, the focus should be on the global temperatures. Otherwise it's too easy to refute, like when we had the freak cold winter a couple of years ago.

[orwell]

3. El Rushbo and Jimmy Inhoffe sayz...

...la la la I CAN'T HEAR YOU!

Drill baby Drill! Job Creators! Socialism! EnviroNazis!

Now back to your regularly scheduled RepuliConMedia Propaganda spiel already in progress...

[AverageJoe90]

4. Although I suspect the 1 in 1.6 million figure is probably far, far higher than stated....

...perhaps more accurately 1 in 300-400 or something similar, I also believe that it's very likely that this was at least indirectly worsened by human activity.

[FiveGoodMen]

6. As long as you're proposing different probability estimates

Tell us what you're basing them on.

[GreenMask]

5. Worldwide Chart?

Is there a chart regarding data for other regions across the world? I think that we're only seeing part of the story...I would suggest that the argument holds up if it's true worldwide...

[Zoeisright]

7. Here you go:

http://www.good.is/post/real-heat-maps-watch-as-the-world-burns/

[GreenMask]

8. Data not current or long-term enough

What we're dealing with needs a broader scope, and the right wing is trotting out a "colder Europe" argument currently.

[PETRUS]

9. Huh?

The statistical aberration described in the OP is significant without further correlation.

The right wing can yell all they want, things don't become true via repetition.

[GreenMask]

10. Not quite

It covers the US. That's it. A worldwide picture would be more meaningful, particularly over a longer term. Europe is having seasonally low temps, from what I understand. That means there's a bigger picture, and all the evidence is not being presented.

[PETRUS]

11. What you're asking for isn't pertinent.

The OP is offering a self contained proposition. The rest of the world could be on fire or covered in ice without affecting the probabilities they are discussing (except for making the situation in total even less likely). It's one piece of data in a larger picture, yes (and surely you know there is no shortage of data) but it has relevance all by itself.

[GreenMask]

12. How relevant?

How is it relevant all by itself, divorced from a larger context? If conditions in Europe are opposite, then certain claims become a problem.

[PETRUS]

13. ...

First of all, it's hardly "divorced from a larger context." But it's unusual regardless. If Europe's temps are normal, colder, or hotter, it's still odd. It's an anomaly in need of an explanation. All by itself, it might be puzzling, but we have lots of other data. A warming climate is an explanation that is also consistent with the other data.

[Kingofalldems]

14. Who cares what the RW thinks?

[Kingofalldems]

15. Sounds like you agree with them