Warmest Consective 12 Months on US Record

Well, at long last I venture another blog post.  We'll see if I can keep this going...

I think most people noticed the warm winter and spring.  Now we have official statistics:  via Climate Progress and WunderBlog, we've just experience the warmest 12 consecutive months on record in the United States, and by far the warmest January through April temperature anomaly on record. 

This kind of warming in Spring will probably turn out to be good for agriculture.  It lengthens the growing season, allowing farmers to plant earlier.

The bad side of warming comes in summer months.  Interestingly, we *still* haven't had especially warm weather during the critical summer months in the key crop-growing regions.  The last two summers were warm, but just a little warmer than average, according to our own extreme-heat degree-day calculations.  Here are some figures my colleague Wolfram Schlenker recently put together for degree days above 29C, our measure of extreme heat, in corn-growing areas between March and August.  Both 2010 and 2011 were above average, but not by much.  And based on the evidence we have, the 1930s were a lot hotter than 1988.

My take on this is that we've been lucky.  Tack this winter/spring weather anomaly onto historical mid-summer temperatures and agricultural production will take a huge hit.  Farmers won't do badly at all, since they're mostly insured anyway and commodity prices will soar.  But high prices would exacerbate the global food crisis. 

Maybe, if we're really lucky, warming will continue in manner that affects Winter and Spring more than Summer.  But I don't think we can count on that, and I don't think it's what climate models are generally predicting. 

It might also be true that crops are becoming more tolerant to extreme heat.  Last summer was unusually wet in the corn belt just before the heat wave struck, which may be why yields weren't hit as badly as we might have expected.  Even so, yields were only slightly better than our model predicted.  Here's a plot of those predictions that Wolfram put together.


  1. The Keystone GarterMay 13, 2012 at 8:05 PM

    I worked or walked in the Cdn prairies this winter: didn't notice it.
    Figured out how to find the optimal amount of food to store, grains for instance, to mitigate some AGW famines. Also, some oats might be better than more storable (less perishable oil in wheat) wheat as oats don't need to be cooked, which would be useful in a pandemic season if utilities fail. And manpower-intensive coal will fail.
    You store as much food as you need to feed people during massive crop failures (coastal flooding too later), until more farms are brought online. Marginal lands and forests can be farmed at massive cost. Grain-fed meat can be slaughtered and canned while feed farms converted to human consumption. Farming forests will require more fertilizer and maybe some GMO crops (that can't be researched in time but can be in reserve, for instance high protein crops). ALso irrigation projects. So if mid latitude Canada and Northern Russia take four years to come online, and S.Europe is sent to severe Great Depression by a lack of industrial water, and crops fail, and if the new grain yields equal what is lost, that is maybe a 1/2 year of oats and 3.5 yrs of wheat to have stored, at least until we run out of new land. Though if existing tar and coal turn Africa and Asia into a giant failed state, it might not matter.


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