Wheat Yields in USA and China Threatened by Heat Waves Breaking EnzymesVideo: Wheat Yields in USA and China Threatened by Heat Waves Breaking Enzymes
A new peer reviewed study looks at the generally unrecognized risk of heat waves surpassing the threshold for enzyme damage in wheat.
Most studies that look at crop failure in the main food growing regions (breadbaskets of the planet) look at temperatures and droughts in the historical records to assess present day risk. Since the climate system has changed, these historical based risk analysis studies underestimate the present-day risks.
What this new research study does is generate an ensemble of plausible scenarios for the present climate in terms of temperatures and precipitation, and looks at how many of these plausible scenarios exceed the enzyme-breaking temperature of 32.8 C for wheat, and exceed the high stress yield reducing temperature of 27.8 C for wheat. Also, the study considers the possibility of a compounded failure with heat waves in both regions simultaneously, this greatly reducing global wheat supply and causing severe shortages.
Results show that the likelihood (risk) of wheat crop failure with a one-in-hundred likelihood in 1981 has in today’s climate become increased by 16x in the USA winter wheat crop (to one-in-six) and by 6x in northeast China (to one-in-sixteen).
The risks determined in this new paper are much greater than that obtained in previous work that determines risk by analyzing historical climate patterns.
Clearly, since the climate system is rapidly changing, we cannot assume stationarity and calculate risk probabilities like we did traditionally before.
We are essentially on a new planet, with a new climate regime, and have to understand that everything is different now.