The crop value is resulting from suitability S. Both harvest index and quality determine S. Climate variations can modify biotic and abiotic limitations but the frequency of failures in S is an experimental evidence that should be statistical. Often crop type and management were the critical variable.

Dear Joseph,

Food is a key driver of climate change. The way we produce our food and the steps traversed before arriving on our table are responsible for nearly half of all emissions of greenhouse gas (GHG) emissions of human origin. Chemical fertilizers, heavy equipment and other agricultural technologies dependent on oil largely contribute. But the impact of the food industry as a whole is even more important: it destroys forests and savannahs to produce animal feed, it generates hazardous waste for the climate through excess packaging, processing, refrigerating and transporting food over long distances, leaving still millions of hungry in the process.

Most studies consider that the share of agricultural emissions is to say emissions on the ground, is between 11 and 15% of total emissions. What is not often said, however, is that most of these emissions come from the practices of industrial agriculture, based on the use of chemical fertilizers (nitrogen) and heavy equipment marching on oil, and focused factory farms that release huge amounts of methane.

Moreover, the figures for agriculture's contribution often fail to take into account the role of the latter in the land use change and deforestation, are responsible for almost a fifth of all greenhouse gas emissions. Everywhere agriculture invades savannas, wetlands, cerrados (savannah woodlands) and forests, and so plowing vast amounts of land. The expansion of the agricultural frontier is the main factor of deforestation; it represents 70 to 90% of deforestation in the world. In other words, between 15 and 18% of total GHG emissions are caused by the land use change and deforestation caused by agriculture. Again, the global food system and the model of industrial agriculture are the main culprits. The primary cause of this deforestation is the expansion of industrial plantations of agricultural commodities such as soybeans, sugar cane, palm oil, maize and rapeseed. Since 1990, the area planted with these five agricultural products increased by 38%, while the area planted to staple foods like rice and wheat declined. Emissions from agriculture are only part of the contribution of the whole food system to climate change. What happens between the time food leaves the farm to when it arrives on our table is equally important.

The relationship between climate change and agriculture is two-way: agriculture contributes in many ways to climate change, and climate change in general adversely affect agriculture.

With my best regards

Prof. Bachir ACHOUR

If I explain simply due to climate change, most of the agricultural products have to experience negative impacts even though in some instances increase in yield.  Therefore most of the food cultivations are vulnerable to climate change and will have an impact on food safety in future.

Dear Dr. Joseph, climate change may affect food safety in various ways.Like heavy metal contents in plant products may change with their availability in soils, residues of pesticides in plant products may change with changes in pest pressure, mycotoxins may form on plant products in the field or in storage, marine biotoxins may accumulate in seafood following production of phycotoxins by harmful algal blooms, pathogenic bacteria in foods may increase by extreme weather conditions such as flooding and heat waves, polycyclic aromatic hydrocarbons may adulterate foods following changes in their transport and deposition into the environment, etc. You may go through some review articles like: Tirado et al. (2010) Food Research Journal, vol. 43, issue 7, pages 1745-65 for more details.  

I think another factor that has not been discussed yet is an indirect impact.  Crop failures/yield reductions will lead to crop price rises.  This will make affected crops more attractive targets for adulteration.  We have already observed these practices e.g. with spices being adulterated with nut derivatives leading to food safety issues. 

Please see my paper entitle" The Effects of Droughts on Food Safety" which was presented in THE U.S.-IRAN SYMPOSIUM ON CLIMATE CHANGE: IMPACTS AND MITIGATION.

If you want proceeding of the symposium, please do not hesitate to contact me 

Thank you all for the invaluable contribution. My question has been conclusively answered and the answers have been highly constructive.