Warming will not help crop yields

corn fieldby fishhawk

A Warming Climate Could Wither Crop Yields
[Via AAAS News – RSS Feed]

A Warming Climate Could Cause Dramatic Reduction in U.S. Crop Yields, Expert Says

U.S. crop yields could fall by up to 20% between 2020 and 2049, and by up to 80% by the century’s end, a leading agricultural economist said at a Capitol Hill briefing co-sponsored by AAAS.

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There is a slim possibility that higher carbon dioxide levels might increase individual plant production – the data are not strong. But this is swamped out by the large disruptive effects of drought and changing weather patterns. The extremely fertile Midwest could see large drops in crop yields simply because of altered weather.

The researchers used data from 100 years back demonstrating that the number of hot days inversely correlated to crop yields. Too hot and the yields of a variety of staples decreases. These data are well known but have not been previously incorporated into climate models to look at crop yields.

When they included this data with the ‘business as usual’ climate models – that is, we do nothing to alter our carbon dioxide levels – crop yields in the US dropped by 20% by mid-century, and even more in the half-century after that.

We can argue about the merits of climate models but they certainly provide us with a place to start. What would happen to the US and the world if our crop yields, which help feed the world, dropped by 20%? During a time when the world’s population increases by 50%?

It seems to me that this could be devastating. The data certainly suggest it can happen. What is the probability and how high does it have to be before we take action?

I mean, would anyone accept a 10% failure rate for a nuclear power plant? Nope. Yet many seem to be willing to accept a possibility of crop failure that could be much higher than that.

2 thoughts on “Warming will not help crop yields

    1. I’ve seen climate models providing insights into rainfall and drought. I believe what he is including here are the data having to do with the number of days with high temperatures on crop yield. Very often, less rain means hotter days so I would imagine there is some coupling here.

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