Diligent Californian climate researchers have pieced together the solution to the mystery of why corn yields are rising, in defiance of climate model predictions of falling corn yields.
But we shouldn’t get too excited about this discovery – researchers are concerned that corn is the exception, that the newly discovered process of “adaption” which has been so successfully used by farmers to improve corn yields may not be applicable to other types of farm produce.
How US Corn Farmers Adapted to Climate Change
Changing weather and planting practices in recent decades have led to increased corn yields, but whether the findings will apply to other crops and regions remains unknown.
Friday, December 14, 2018 – 10:00
Gabriel Popkin, Contributor
(Inside Science) — Few of climate change’s varied dangers are more dire than its potential to make the world’s farms produce less food. While we live in boom times of agricultural abundance, marked by record crop yields and cheap food, climate change threatens to slash yields and cause worldwide food busts. According to the Intergovernmental Panel on Climate Change and the recently released U.S. National Climate Assessment, droughts, temperature extremes and plagues of insect pests will increasingly harm farming worldwide.
But some experts hope humanity will be able to weather the wiles of climate change through adaptation — that farmers will be able to overcome climate-related threats by adjusting how they grow crops.
A new study analyzing U.S. corn yields over the last few decades seems to support that notion. It looked at temperature trends in the Midwest, examined how farmers adjusted their planting practices to take advantage of them, and showed that U.S. farmers were able to grow more corn, not less.
“It gives me some hope that when we see climate trends that are not quite so benevolent, farmers will have some tools at their disposal,” said Nathan Mueller, an Earth scientist at the University of California, Irvine and co-author of the study.
Not everyone is as sanguine, however. Some experts point to the fact that among all crops, corn may be the exception, not the rule, that demonstrates how adaptation can work.
“The risk is that if people overstate the benefits of adaptation, it’s sort of like, OK, the environment can change and we can figure out how to deal with it,” said David Lobell, an environmental scientist at Stanford University. “I’ve seen that happen so many times, I’m cautious when I talk to reporters about overemphasizing the ingenuity of what people can do.”
The abstract of the study;
Peculiarly pleasant weather for US maize
Ethan E. Butler, Nathaniel D. Mueller, and Peter Huybers
PNAS November 20, 2018 115 (47) 11935-11940; published ahead of print November 5, 2018
Continuation of historical trends in crop yield are critical to meeting the demands of a growing and more affluent world population. Climate change may compromise our ability to meet these demands, but estimates vary widely, highlighting the importance of understanding historical interactions between yield and climate trends. The relationship between temperature and yield is nuanced, involving differential yield outcomes to warm (9−29°C) and hot (>29° C) temperatures and differing sensitivity across growth phases. Here, we use a crop model that resolves temperature responses according to magnitude and growth phase to show that US maize has benefited from weather shifts since 1981. Improvements are related to lengthening of the growing season and cooling of the hottest temperatures. Furthermore, current farmer cropping schedules are more beneficial in the climate of the last decade than they would have been in earlier decades, indicating statistically significant adaptation to a changing climate of 13 kg·ha−1· decade−1. All together, the better weather experienced by US maize accounts for 28% of the yield trends since 1981. Sustaining positive trends in yield depends on whether improvements in agricultural climate continue and the degree to which farmers adapt to future climates.
Read more: https://www.pnas.org/content/115/47/11935
I know you folk will be as heartened by this ray of hope as I am. If the principles of “adaption” which have so far saved corn yields can be applied to crops other than corn, just maybe we may avoid some of the disastrous future declines in crop yields, and future hardships predicted by climate models.
via Watts Up With That?
December 16, 2018 at 04:05AM