IPCC 5th 2014 assessment Food chapter
IPCC 5th assessment 2014  Based on many studies covering a wide range of regions and crops, negative impacts of climate change
​on crop yields have been more common than positive impacts (high confidence) WG2 SPM.

Without (successful) adaptation, local (/global is the same for 1.0C)
​temperature increases in excess of about 1°C above pre-industrial
​is projected to have negative effects on yields for the major crops (wheat, rice  and maize) in both tropical and temperate regions 
(IPCC AR5 WG2  Ch7 Exec Summary p.3 

​​With or without adaptation, negative impacts on average yields become likely from the 2030s with median yield impacts of 0 to –2% per decade projected for the rest of the century, and after 2050 the risk of more severe impacts increases.
​IPCC AR5 WG2 Table 7-3.

September 2014 ​​Scientists on drought:  Scientists warn of 'megadroughts' 

​​Nature March 2014
Climate change will reduce crop yields sooner than we thought.

​Most are becoming aware that the world is being hit by severely damaging increased extreme weather events. In particular these since 2000 have affected the world's best food producing regions of the Northern Hemisphere (NH).

The evidence amounts to causation since the publication of Potsdam Climate institute 2013 paper amplification of planetary waves and recent Northern Hemisphere weather extremes '​​...  amplification of planetary waves and recent Northern Hemisphere weather extremes' on the NH climate dynamics at work. 

​​We are already committed due systemic inertias to a global warming above 2.5C and on our current world economy at mid century.

​​Increasing world drought (especially N. hemisphere) exacerbates the water water crisis makingglobal food prices to become volatile. This in turn is causing a committed global food crisis that is a global emergency (Center for Climate & Security Jan 2013)

Evidence suggests world drought has been increasing  driven by global temperature increase as expected. Since 2000 the record shows an extraordinary increases in Northern hemisphere heat and drought. Today  (Dec 2012) central US (great grain belt) in a three increasing year drought predicted to persist the April 2013.

In particular over the past decade, and 2012 especially, all the world's top food producing regions in the North hemisphere are being hit by drought. ​​

Climate Emergency Institute

August 2019 Quarter of Humanity Faces  Water Crises
23 Jan 2017 Most important assessment
Projected productivity changes and extreme events 1.1.1 Crops
In terms of global temperature and the yield response curves for crops such as wheat and maize,..
is that a 1 or 2 ºC warming to increase yields in temperate regions is no longer expected
8 Mar 2021. Food systems are responsible for a third of global anthropogenic GHG emissions UN, FAO, Nature Journal
8 April 2021,  Study calls for urgent climate change action to secure global food supply
Word doc of Multiple adverse impacts  in above review paper
IMPORTANT RESEARCH, 2020 Maximum warming and related to crops
1 November 2021, Climate impacts on global agriculture emerge earlier in new generation of climate and crop models
1 Feb 2022 Phasing out animal agriculture could stabilize greenhouse gas levels
​ for decades  

Extreme weather is increasing, and is most damaging to populations and crops.
March 2023, M. Heino Increased probability of hot and dry weather extremes during the growing season threatens global crop yields​
IPCC 2019 Land Report 
Top food producers:
​1. China  2. USA  3. Brazil
IPCC AR6 Fact sheet - Food and Water
Climate Change Impacts and Risks​

​​Climate change impacts are negatively affecting agriculture, forestry, fisheries and aquaculture, increasingly hindering efforts to meet 
human needs.
Human-induced global warming has slowed growth of agricultural productivity over the past 50 years

​​​Warming is negatively affecting crop and grassland quality and harvest stability
​Ocean acidification and warming have already affected farmed aquatic species. 

Climate-related extremes have affected the
productivity of all agricultural and fishery
sectors, with negative consequences for food
security and livelihoods (high confidence).

frequency of sudden food production losses has increased since at least mid-20th century on land and sea.​​​

Drought and flood risks and societal damages are projected to increase with every degree of global warming. Over
large areas of northern South America, the Mediterranean, western China and high latitudes in North America and Eurasia, extreme agricultural droughts are projected to be at least twice as likely at 1.5°C global warming, 150 to 200% more likely at 2°C warming


​Climate change has contributed to malnutrition in all its forms in 
many regions, including undernutrition, especially for
women, pregnant women, children, low-income households, Indigenous Peoples, minority groups and small-scale producers. Extreme climate events have been key drivers
in rising undernutrition of millions of people, primarily in Africa and Central America 

​Climate impacts on food systems are projected to increase 
undernutrition and diet-related mortality and risks globally. Reduced marine and freshwater fisheries catch potential is projected to increase malnutrition in East, West and Central Africa
The long standing increase in world food productivity has slowed due to climate change. Extreme weather events have reduced crop yields temporarily in all producing regions. ​African and lower latitude regions have suffered most food production decline. Yields will decline in all food producing regions as maximum daily temperatures, heat waves, drought, heavy rains and floods increase under global warming- affecting all food producing regions ​
List of climate change adverse effects on food security already impacting

Taken from IPCC 2014 5th Assessment

Climate-related extremes have affected the productivity of all 
agricultural and fishery sectors, with negative consequences for food security and livelihoods​
Climate change impacts are stressing agriculture, 
fisheries and aquaculture, increasingly hindering efforts tomeet human needs (high confidence)
Sudden production losses The frequency 
of sudden food production losses has increased since at least mid20th century on land and sea (​Food production growth slowed
​Human-induced warming has slowed growth of agricultural productivity in mid and low latitudes.
Loss of lands 
Climate change will make some current food production areas unsuitable​
​Extreme climate events will become more frequent and force some of 
the current food production areas beyond the safe climatic space for production (high confidence)​
Surface ozone Crop yields are 
compromised by surface ozone.
​(Comment Surface ozone, a GHG, is toxic to green plants as well as human health It is increased by surface warming) 
​Methane emissions 
have negatively impacted crop yields by increasing temperatures and surface ozone concentrations.
​Harvests Warming is 
negatively affecting crop and grassland quality and harvest stability
Cascading impacts The impacts of climate change on food provisioning have cascading
effects on key elements of food security, such as food prices, household income, food safety and nutrition of vulnerable groups​​​
Heat stress Climate change will increasingly expose outdoor workers and 
animals to heat stress, reducing labour capacity, animal health, meat and dairy production
Weeds Pests Changes in the rates of reproduction and distribution of weeds, insect pests, pathogens and disease vectors will increase biotic stress on crops, forests and livestock​
Adaptation ​Implemented adaptation in crop production will be insufficient to
offset the negative effects of climate change (high confidence).​
Malnutrition Impacts on food availability and nutritional quality will increase 
the number of people at risk of hunger, malnutrition and diet related mortality. Climate change impacts will increase the number of people at risk of hunger, in 2050 ranging from 8 million people under SSP1 to 80 million
people under SSP3 scenarios (RCP6.0) [current track], compared with no climate change ​
​Ocean warming has decreased sustainable yields of some wild fish populations 
​Ocean acidification and warming have already affected farmed aquatic species
IPCC 6th Asessment
Overall negative impacts

All extreme weather events adversely affect agricultural crops ​