NASA's gloss on the Earth Obervatory site is measured:
The extreme weather events in Russia and Pakistan have fueled speculation about the role of climate. The GISS release stated, “The location of extreme events in any particular month depends on specific weather patterns, which are unpredictable except on short time scales. The weather patterns next summer will be different than this year. It could be a cooler than average summer in Moscow in 2011.” The GISS release went on to explain, however, that global warming does affect the probability and intensity of extreme events. Climate can drive precipitation because temperature affects the amount of water vapor that air can carry. Likewise, in areas experiencing drought, global warming can increase temperature extremes that exacerbate wildfires.Nothing about the peculiarity of the peculiar pattern, though. And that's the question.
10 comments:
I've come to the opinion that having NASA or NOAA or the media comment on the potential connection between these weather events and AGW is probably pointless, for two reasons.
One, denialists have shown themselves to be very adept at spinning these things in ways that hurt the overall cause of education on the issue.
Two, most people who would see or hear such announcements have heard of the issue and in time will come to opinions of their own as they experience these events themselves. Some won't ever, but such announcements wouldn't affect them anyway.
I know that those of us who are focused on the issue like to see the connection made publicly, but I just an skeptical that it really impacts the wider public or the political system.
Dean, frankly I don't care about such calculations.
People need to understand what is going on.
The picture of what is going on arguably has gotten dramatically worse as a result of this event. If the discussion isn't impacted by events like this the discussion is woefully out of touch with reality. That needs to be fixed, not worked around.
Can it be fixed by ignoring such calculations? Is it a fix or a workaround?
There has been much angst about messaging and communication by scientists. Is that a fix? I doubt it. The playing is not and will never be level.
Many people do not "gain understanding" of something by reading or listening. They must experience it. I suppose the process of science in part is getting past that. But most people aren't scientists, and I don't think they will get past it.
My point is that the fix for many will only come when their personal experience matches what we are trying to tell them.
MT: by any chance do you know offhand if there's an equivalent "precipitation" anomaly map for the same time period?
As you know, for many people, the precipitation issues actually come sooner than the direct temperature effects...
I could wish both for:
(a) Precipitation anomaly.
(b) Some visual display for variability, I'm not sure what that should be, but one could probably start with a weekly/monthly series from (a).
Speaking as an old farmboy, it's nice when rain comes regularly, it's not so nice when a year's average rain all arrives in a few months, and none the rest of the year. (I.e., California taken to an extreme.)
Even if you *know* to expect that, (as CA farmers do) but the rain months change unpredictably, farming is messed up, because farmers have to make planting decisions in advance of knowing.
Of course, some areas have good dam systems and resources, some don't.
I'd guess that a lot of Pakistani farmers are really in trouble, not just for the immediate flood damage, but the longer-term disruption, especially if variability actually increases.
Still looking. This is interesting:
The twentieth century was the wettest period in northern Pakistan over the past millennium
Kerstin S. Treydte1, Gerhard H. Schleser2, Gerhard Helle2, David C. Frank1, Matthias Winiger3, Gerald H. Haug4 & Jan Esper1
Nature 440, 1179-1182 (27 April 2006) | doi:10.1038/nature04743; Received 22 August 2005; Accepted 23 March 2006
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Looks like the Pakistan floods didn't really show up on that scale, or else the big rains were in August.
(All: Note that huge anomalies in very dry places don't mean much except that it rained in the desert once or it didn't; these are percentage anomalies which are useful in most places but very awkward in deserts.)
Is this a "composition by committee (and consensus)" problem? Or does NASA really not have a good science communicator who's motivated to communicate what most needs communicating?
I'd guess that "length of duration of blocking event" is a statistic that's being collected, and so someone who knows the past history can figure out how many years will be required to detect the likelihood of a change in -- well, what? the average length of blocking? the number of events? the size of the area affected geographically? the intensity, whatever that might mean?
And of course that's just meteorology; addressing the human or biological impact is a whole different exercise.
Likely the last thing any scientist who's published in this area wants to do is rush to blog about it, in advance of the data.
But until she, he, or they do publish, all the rest of us can do is opine, I suppose.
'angstica' says Word Verification ...
I've been slogging through reanalysis data looking at blocking over Eastern Europe, and it's a difficult analysis. At a gross level (# of days w/blocking from 30E to 60E), there are years with more blocking than now (1999) for June-July. However, 1999 wasn't as hot as this year. So what's the catch?
Well, maybe the problem is that I'm not looking at the right time frame. To paraphrase Namias, "A warm spring means a hot/dry summer". And there was a rather strong/persistent block in May over western Russia. Interesting...
So now the gameplan is to see if this sequence of May then June-July blocking has occurred before (Didn't in 1999). Also, how unusual was the May blocking?
For John Mashey, here's a link to the July 2010 precipitation anomalies (using satellite derived rainfall estimates): http://www.cpc.noaa.gov/products/CDB/Extratropics/fige3.gif It's part of CPC's Climate Diagnostic Bulletin available here: http://www.cpc.noaa.gov/products/CDB/index.shtml.
Rob Carver
Robert: thanks.
Intuitively, the precipitation issue seems a more difficult one to create compelling visualizations, but we need them to help mroe people grok "weird weather".
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