Climate change impacts on agriculture and biotech crops

It seems like every time I present this paper, or discuss it with folks, someone says "well, what about biotechnology--won't they be able to engineer crops that do better in warmer climates?"

My answer is, I don't know. We can't predict the future.

But we do know they haven't been able to produce more heat tolerant plants in the past, and they have been growing corn and soybeans in climates that are warmer than optimal, and in some cases much warmer than optimal, for a very long time. So the incentive to breed or engineer more heat tolerant plants has been around for a long time.

Of course, that incentive could be much greater in the future.

Yes, Monsanto has been making great claims about new heat/drought tolerant corn. But I haven't seen any evidence yet. Zilch. It's not because I haven't been looking.

And then there are reports like this one:
Despite industry claims of higher yields from biotech corn and soybeans, much of the increase can be tied to other improvements in agriculture, according to a study released on Tuesday.

The Union of Concerned Scientists said its review found genetically engineered herbicide-tolerant soybeans and corn did not increase yields compared with conventional methods. Still, farmers embraced the technology partly because of lower energy costs and convenience associated with applying pesticides.

It also found another variety, BT corn, contributed to about 3.3 percent of the estimated 28 percent increase in corn yields since it was made available commercially in 1996. BT crops are resistant to certain insects.


This isn't the universal story. It is true that genetically modified seeds help farmers in poor countries boost yields. That's because these seeds make management easier--one doesn't need to be as good and well-educated a farmer to get high yields if armed with genetically-modified seeds.

But I imagine it might be more difficult to engineer greater heat tolerance.

Okay, our predicted impacts from IPCCs projected climate changes are really bad--up to 79% of yield for a couple of the biggest and most important food crops in the world. And economists are not supposed to say dramatic things. But if you read that paper carefully you will see these statistics are rock solid. Identification is clear, more-than-plausibly exogenous, and extremely robust. You just can't make these big negative numbers go away. Unless, of course, you screw up your data or pretend irrigation in the Eastern U.S. can mimic the monster subsidized water projects in the West (see here, here, and especially here and here).

I'm not a doomsayer or a Malthusian. A lot of other things can and surely will happen between now and when (and if) the climate warms 10+ degrees F. But there is cause for serious concern and to blithely say otherwise is an article of blind faith, not science.



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