Climate change can affect food production through the effect of raised temperature, changes in precipitation, extreme weather events, sea level rise and loss or degradation of agricultural land. The vulnerability to the effects of climate change will vary in different regions, among different populations and will vary by gender.
Climate change will have its impact on pasture, crops and livestock production; will lower the nutritional value of certain crops; will affect fisheries and aquaculture and will affect food manufacture, logistics and trade.
Climate change affects the 4 dimensions of food security: availability, stability access and utilization; the effect on availability will cause an increase of food prices. Human health and nutrition are affected by climate change through the effect on absorption and utilization. Food borne diseases, which are affected by climate change, increase the nutritional need while simultaneously reducing absorption. Food can be contaminated with micro-organisms, animal disease pathogens, fungal toxins, toxic products of harmful algae, chemicals, pesticides and veterinary drugs.
Environmental factors can affect abundance of pathogens, their survival and/or their virulence. Morbidity and mortality from diarrhoeal diseases will increase due to contamination of food and water. Through the effects of climate change, the spatial and temporal distribution of disease vectors and animal reservoirs will expand and, consequently, the distribution of vector borne and zoonotic diseases will expand. Climate change will impact emergence and re-emergence of infectious diseases. It will also encourage infection of crops with toxigenic fungi and the production of mycotoxins, famous among which is aflatoxin which will reach man through ingestion of infected crops. Through its effect on marine environment climate change will enhance the formation of harmful algal blooms and the formation of algal toxins with consequent occurrence of sea-food borne intoxications. Due to the increased use of chemicals, pesticides and veterinary drugs to deal with plant pests and animal diseases, residues of these substances can be present in food in toxic amounts.Attempts for climate change mitigation, and the use of bio-fuels as substitutes for fossil fuels will affect food production and can result in an increase in prices of food crops.