Here's David Lobell at the Chicago Council on Global Affairs:
For all of the talk about the need to adapt to climate
change, we still know fairly little about two basic questions: what works best,
and how much can adaptation deliver? ....
Why don’t we know more? It would be easy to blame our
ignorance on complacency. There is a tendency to marvel at the progress made in
agriculture in the past 50 years, and assume it can handle anything....
It is also tempting to blame ignorance on inexperience.
After all, many people continue to view climate change as something to deal
with in the future. But the evidence is clear that climate has already been
changing over the past 30 years in most agricultural areas, and farmers are
doubtlessly trying to adapt. Up until now, the United States was an exception
to that trend. But the 2012 drought has changed that, and projections indicate
that years like this will be increasingly common in the coming decades.
.... why was US agriculture not better prepared for the
2012 drought? And did anything work well that can be scaled up?
A lot has changed in US agriculture since the 1988 drought,
and many of the changes were textbook examples of what should help to reduce
impacts of hot summers. Farmers now sow corn and soybeans more than a week
earlier on average, and use longer maturing varieties than in 1988. Advances in
cold tolerance along with spring warming trends allowed corn to expand in
northern states where temperatures are cooler.... Carbon dioxide levels, which improve crop water use efficiency, have
increased by more than 10% since 1988. And farmers have begun to grow drought
tolerant seeds that were unavailable in 1988.
Yet when the 2012 drought arrived, with fairly similar
characteristics to 1988, impacts on crop yields were roughly the same. Corn
yields are expected to be about 25% below trend, close to the 28% drop in 1988.
What can we learn from this experience? It is too early to
say anything definitive, but two explanations seem plausible.....
[see link for the rest]
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