.
The Intergovernmental Panel on Climate Change (IPCC) is the United Nations body for assessing the science related to climate change.

Observed climate change is already affecting food security through increasing temperatures, changing precipitation patterns, and greater frequency of some extreme events (high confidence). Studies that separate out climate change from other factors affecting crop yields have shown that yields of some crops (e.g., maize and wheat) in many lower-latitude regions have been affected negatively by observed climate changes, while in many higher-latitude regions, yields of some crops (e.g., maize, wheat, and sugar beets) have been affected positively over recent decades. Warming compounded by drying has caused large negative effects on yields in parts of the Mediterranean. Based on indigenous and local knowledge (ILK), climate change is affecting food security in drylands, particularly those in Africa, and high mountain regions of Asia and South America.
…
Greenhouse gas emissions from food systems
This chapter assesses the contributions of the entire food system to greenhouse gas (GHG) emissions. Food systems emissions include CO2 and non-CO2 gases, specifically those generated from: (i) crop and livestock activities within the farm gate (Table 5.4, category ‘Agriculture’); (ii) land use and land-use change dynamics associated with agriculture (Table 5.4, category ‘Land Use’); and (iii) food processing, retail and consumption patterns, including upstream and downstream processes such as manufacture of chemical fertilisers and fuel (Table 5.4, category ‘Beyond Farm Gate’). The first two categories comprise emissions reported by countries in the AFOLU (agriculture, forestry, and other land use) sectors of national GHG inventories; the latter comprises emissions reported in other sectors of the inventory, as appropriate. For instance, industrial processes, energy use, and food loss and waste.
…
Migration
There has been a surge in international migration in recent years, with around five million people migrating permanently in 2016 (OECD 20171366). Though the initial driver of migration may differ across populations, countries and contexts, migrants tend to seek the same fundamental objective: to provide security and adequate living conditions for their families and themselves. Food insecurity is a critical ‘push’ factor driving international migration, along with conflict, income inequality, and population growth. The act of migration itself causes food insecurity, given the lack of income opportunities and adverse conditions compounded by conflict situations.
…

Read complete report: =>

…
As climates around the world grow harsher and increasingly unpredictable, concerns are increasing over our world’s food security. Already, yields of staple crops like maize and wheat are dropping in low-latitude tropical regions and in dry and drying regions such as African drylands and parts of the Mediterranean.
=> Fluke Discovery of Ancient Farming Technique Could Stabilize Crop Yields