Crop yield change indications under global warming

[Dill]

(05-14-2017, 02:47 PM)bfine32 Wrote: Wish this had a link; as I would be curious as to how they compile their data. *For instance, wouldn't a small climate change simply change to type of crop you can grow?


*Disclaimer: not argueing the validity of Climate Change one way or the other. Nor am I "ignoring" science. Just would be curious how they got the data for future yields.

1. Depends on where you are growing crops. E.g., in lower temperate zones like Texas, farmers always have wide range of crop options--unless affected by drought.  In places like the Persian Gulf and Syria, a few degrees rise in temperature largely extinguishes any possibility of traditional farming. There may be other solutions (hydroponics) but they are yet to be developed. Food activists have been working on this problem for decades--

2. The first graph/map on crop yields may be somewhat distortive. E.g. you see a huge region going orange or green, when if fact in terms of volume, there may be little going on there. E.g. look at Russia, the Republic of Sakha is a huge orange spot the size of Argentina, but has less than one million people. 40% is in the Arctic circle. A strip of southern land has a short summer for growing grain.  I am guessing it's total crop yield compares to the state of Main. But because the map goes by administrative region, it covers an area larger than Europe. The second map of cropland gives a much better sense of where food is actually produced in significant volume. When you read the latter with the former, you get a rather different picture of how much agriculture is being affected and to what degree.

3. I don't know how they got the future projections. Maybe they were measuring the rate of climate change against the potential for crop variability. In some places, perhaps Libya, they may be already at the upper temperature range for crops like maize, so a few extra degrees eliminates that food source. And since the temperature is already high enough to close out other food crops, they go red.