Global warming may cause shortage of zinc in foods
https://www.theguardian.com/science/2018/aug/27/climate-change-will-make-hundreds-of-millions-more-people-nutrient-deficient
This appears to be a less-well publicised problem of the food industry already - that more intensve agrucultural methods may produce more food more quickly, but that such food has lower concentrations of trace elements. It is mentioned on pp.15-16 of the book, The Consuming Geographies of Food: Diet, food deserts and obesity. where a table shows declinign levels of magnesium, calcium and iron in a range of cheeses, also beef bacon and turkey, Some vitamin levels have also fallen.
http://fooddeserts.org/images/ConsGeogFood.pdf
If global warming also promotes a greater disease burden, as insect vectors proliferate and heatwaves and disease, and maybe climate conflicts, weaken people, this may predispose people to be yet more susceptible to many diseases.
http://fooddeserts.org/images/000Food.htm
Dr Hillary J. Shaw
Visiting Fellow - Centre for Urban Research on Austerity
Department of Politics and Public Policy
De Montfort University
LE1 9BH
www.fooddeserts.org