Future Impacts

The map projections above show crop yields falling an average of 30% or more across the American Midwest, Southeast Asia, southern China, Australia, Brazil, Argentina, Pakistan, Korea, and Mongolia. Crop yield declines are similar across most of India, the Ukraine, the Middle East, north Africa, and southern Africa, as well as much of the rest of South America. That includes almost 50% in Iowa and Illinois, and more than 50% in Pakistan and northwest India.

Crop yields rise (with +3°C) across Scandinavia; most of Canada; most of Russia, eastern Europe and central Asia; and in north and west China. They rise too in Chile, New Zealand, Kenya, the northern US Rockies, and a few other places.

The IPCC in March 2014 summarrized many such studies below. The key shows % of total number of studies examined.

The bars above show % of the 56 or more studies considered that found various % yield changes (color key at right). The black horizontal bars show the line between yields higher than now and lower ones. Farther into the future, more and more studies project lower yields, especially much lower yields (18% project 50-100% losses after 2090). Assumptions about adaptation, CO2 fertilization, region, and other matters varied from study to study.

The graph below summarizes key parts of the IPCC’s review.

Below is another graph from the March 2014 IPCC Food Impacts summary.
Impacts are worst for wheat and temperate regions. Negative projected soybean impacts were rare.

The two graphs below extrapolate from Hatfield's summary of obersavtions, a bit above.

Note the steep decline in rice production around a tropical city. This is broadly representative of the tropics and subtropics. Yields decline (much) less steeply in currently temperate areas. Soybeans are least vulnerable to heat.
The soybean projections are consistent between the US and IPCC, but the IPCC sees tropics faring better.

This assumes no constraints from nitrogen or water, etc.

Without allowance for increased insect activity and weeds, etc., yields rise 10% for wheat in North Dakota, 18% for soybeans in Kansas, and 5% for rice in Arkansas, but fall 3% for corn in Iowa. The tropics are hit much harder; rice yields fall about 20% in India.

The 2nd graph uses a warming projection more in line with some recent paleoclimate studies. For example, the last time CO2 levels were this high (380-425 ppm (3 and 15 million years ago), which is roughly the square root of 2 (declining marginal return to more CO2) times 1750 CO2 levels of 280 ppm), temperatures were 2-6°C higher (Tripati, Pagani, Csank, etc.)

This implies 4-12°C warming with CO2 twice 1750 levels. The “equilibrium" climate sensitivities implied are much higher than “transient” (geologically short-term) climate sensitivities derived from many studies by the IPCC. Debate rages from 1° to 5°C for “transient” climate sensitivity for doubled CO2.

Again, this assumes no nitrogen or water constraints.

Without allowance for increased insect activity and weeds, etc., yields fall 7% for wheat in North Dakota, 15% for corn in Iowa, and 13% for rice in Arkansas, but rise 11% for soybeans in Kansas.
The tropics are hit even harder; rice yields fall about 47% in India. Moves to winter wheat in north India no longer work, as even winters are too hot.

A table with a simplistic projection of crop yields around various cities amid the world's major growing regions, for combinations of higher temperatures and double pre-industrial CO2.

In general, corn, rice, and wheat are adversely impacted, but not soybeans. Winter wheat is chosen in Pakistant and India.

2020-2025 Articles

Global Agriculture’s Greenhouse Gas Emissions Set to Rise 6% by 2034 - 0725.rtf‘Climateflation’ Could Push Up UK Food Prices More than 1:3 by 2050 - 0725.rtfSoaring Temperatures Threaten Crops, So Scientists Look to Alter the Plants 0625.rtfProduction of Main Crops in the US Could Plummet 50% by 2100 - 0625.rtfStaple Crops Yields Can Fall Substantially in Warmer World, Even with Adaptation 0625.rtfA Gene Could Be Key to Growing Rice, and Feeding Billions, in a Hotter World 0525.rtfHalf the World’s People Depend on Rice. Climate Change Will Make it Toxic. 0425.rtfGlacier Meltdown Risks Food and Water Supply of 2 Billion People - UN 0325.rtfClimate Disruption May Cut Global GDP and Crop Area 50% by 2070 - 0225.rtfGlobal Food Production at Increased Risk from Excess Salt in Soil - UN 1224.rtfWorsened by Rising Temperatures, Water Challenges Threaten World’s Crops 1024.rtfPoorest Areas Have Zero Harvests Left – UN Chief 0624.rtfWill a Shrinking Colorado River Shrivel the Produce Aisle? 0124.rtfCorn Harvests in the Yukon? Will Climate Change Turn Wilderness into Farms? 1023.rtfWild Rice Survival Threatened by Warming, More Rain in Northern Minnesota 0823.rtfAs Simultaneous Crop Failures Threaten Food System Collapse, Plutocrats vs Us 0723.rtf - The year is approaching when simultaneous crop failures will happen in Europe, North American and China and/or India. The very rich will eat well, while the poor and middle suffer, as it has been for centuries.Click for more

The IPCC’s Latest Climate Report Is a Final Alarm for Food Systems, Too 0323.rtfGlobal Seaweed Industry Could Reduce Land for Farming by 1.1 Million Km2 - 0123.rtfMarine Heat Waves Could Wipe Out Fish Stocks 1022.rtfFalling Crop Yields with Warming Could See Rapid Decline in Bioenergy Potential 0922.rtfMideast Nations Wake Up to Damage from Climate Change 0722.rtf - crop losses up to 30% by 2025 and GDP losses of 6-14% by 2050Pollen and Heat - a Looming Challenge for Global Agriculture 0622.rtf - More heat can incapacitate pollen from doing its job.Climate Change Likely to Slow Plant Growth in Northern Hemisphere 0622.rtfFood Shocks Will Also Destabilize the ESG World 0522.rtfSalt Scourge - The Dual Threat of Warming and Rising Salinity 0522.rtfClimate Change Could Significantly Impact Commercial Fishing 0422.rtfOur Food System Isn't Ready for the Climate Crisis 0422.rtf - We have selected the “best” variety out of many and monocropped it. New pests and weeds, drought,etc. can wipe our entire consumption of bananas, wheat, corn, avocados, coffee and more. We must cherish the diversity of original varieties, so we can restart the crops when our favorite varieties are wiped out, by climate change or otherwise.Complex Models Now Project Alarming Impact of Climate Change on Global Food Production 0322.rtfFarmers’ Report - Climate Crisis Puts Australia’s Food Supply at Increasing Risk 0322.rtfWhat to Expect from the World’s 6th Mass Extinction 0122.rtf - Emphasis is on loss of pollinators pollinated crops account for maybe 1/4 of the crops in a healthy diet, especially fruit, veggies and nuts. Also, loss of soil quality if critical microorganisms die off. Water shortages (and flooding) will compound the problems.Warmer Winters Can Wreak as Much Havoc as Hotter Summers 1221.rtfAmid Drought, Conflict, and Rocketing Prices, a Global Food Crisis Looms 1221.rtfWarming Temperatures Threaten Greece's Prized Olive Oil 1221.rtfClimate Change Agricultural Impacts to Heighten Inequality 1221.rtfWorld Faces Growing Risk of Food Shortages due to Climate Change 0921.rtfGrain Production Depends on Ending Deforestation 0821.rtf - in BrazilHungry for Solutions 0621.rtf - Concentrations of protein, iron, and zinc are 3% to 17% lower when crops are grown in environments where CO2 concentrations are 550 parts per million (ppm)—the projected level by 2050 if emissions continue at current rates—compared with crops grown under current atmospheric conditions of CO2 concentrations near 400 ppm.Russia’s Far North Could Be Arable in 20-30 Years as Permafrost Melts? 0521.rtf - But soils may be too poor for warming to do much good.Tea-Growing Areas to Be Badly Hit if Global Heating Intensifies 0521.rtfFocus on Food Helps Solve Climate Change 0220.rtfWill Rising Temperatures Make Rice Too Toxic? 1220.rtfWill Rising Temperatures Make Superweeds Even Stronger? 1220.rtfClimate Change Could Make Swathes of Farmland Largely Useless in U.S. South 1020.rtfClimate Change Will Continue to Widen Gaps in Food Security 1020.rtfRising Temperatures Put Heat on Nebraska's $7 Billion Corn Industry 0920.rtfUnless We Change Course, the US Agricultural System Could Collapse 0820.rtf - Water vanishes with the Sierra snowpack in America’s sald bowl. Soil vanishes with heavier rainstorms in America’s breadbasket. Fertilizer problems too.India’s Food Bowl Heads toward Desertification 0820.rtfClimate Change Forces Farmers to Choose Low Yields or Unstable Returns 0720.rtfClimate Change May Double the Risk of Breadbasket Failures 0520.rtfA 2nd US Dust Bowl Would Hit World Food Stocks 0320.rtfU.S. Food Trade Increasingly Leans on Unsustainable Groundwater 0120.rtfWest’s ‘Dust Bowl’ Future Now ‘Locked In’, as World Risks Imminent Food Crisis 1219.rtfClimate Change Could Cut Fruit Production by Almost 1:3 - 1219.rtf

Climate Change Agricultural Impacts to Heighten Inequality 1221.rtf - Production to fall for maize but rise for wheat.

Climate Change May Double the Risk of Breadbasket Failures 0520.rtf

Climate Change Could Cut Fruit Production by Almost 1:3 - 1219.rtf

Projected changes in yields of several crops worldwide as a function of global warming (relative to pre-industrial temperatures) in the absence of adaptation. Best estimates and likely uncertainty ranges are shown.

2 graphs drawn from Obama Science Advisor John Holdren's slides

Local ∆ (+°C) for Low Latitudes
Mid-High Latitudes

from Climate Stabilization Targets by US National Academy of Sciences, late 2011 (on Overviews web page)

2016-2019 Articles

Will Rice Survive Climate Change? 1219.rtfCanadians Will Pay More for Food Next Year, Thanks to Climate Change 1219.rtfThirsty Future Ahead as Climate Change Explodes Plant Growth 1119.rtfClimate Change Could Leave Southern Britain ‘Unable’ to Support Crops 1019.rtfHealthy Diet Means a Healthy Planet, Study Shows 1019.rtfAl Gore Warns of Looming Food Crisis Caused by Climate Change 1019.rtf - subsidies to what we don’t want, and yields fall with rising temperaturesHow More Organic Farming Could Worsen Global Warming 1019.rtf - Organic farm yields are lower; to replace them, import food from high emitters. Billions Face Food, Water Shortages over Next 30 Years, as Nature Fails 1019.rtfClimate Change Threatens World Fisheries, Food for Billions of People 0919.rtf$1 Million a Minute Farm Subsidies Are Destroying the World 0919.rtf - Much of the total instead promotes high-emission cattle production, forest destruction, and pollution from the overuse of fertilizer. “Continuing on current trends means sleepwalking into a scenario wherein climate change increasingly threatens human life, biodiversity and natural resources are depleted, people increasingly suffer life-threatening, diet-induced diseases."Climate Change Is Likely to Devastate the Global Food Supply, but There's Hope 0819.rtf - Extreme heat, drought and flooding are the major culprits that will cut food production. But altrernative food production processes will rise: robotics, alternative meats, vertical farms, fertilizer management and ancient plants.Climate Change Is Sapping Nutrients from Our Food, so Global Crisis Possible 0819.rtfClimate Change Threatens the World’s Food Supply, UN Warns 0819.rtfCO2-Driven Nutrient Loss in Rice Could Lead to Vast Vitamin B Deficiencies 0719.rtf - lose 17-30% of vitamin B by 2050As Climate Changes, Taxpayers Will Shoulder Larger U.S. Payouts to Farmers 0719.rtfIt’s Not if We're Approaching Agricultural Disaster; It's How Often They'll Happen 0519.rtfClimate Change Is Already Hurting Fruit Breeders. Consumers Are Next. 0319.rtfMore Nitrogen May Help Offset Warming Effect of Climate Change on Wheat 0319.rtfGlobal Warming Could Decimate Fish Supplies and Fuel Migration 0219.rtfFuture of Food under ‘Severe Threat' as Species Diversity Disappears - U.N. 0219.rtfVanishing Nutrients 1218.rtf - Rising CO2 means lower nutrient density in food and nutrient deficiencies.Rising Heat from Climate Change Threatens U.S. Crop Yields 1118.rtf5 Major Crops in the Crosshairs of Climate Change 1018.rtf - wheat, peaches, coffee, corn, almondsAs India’s Ganges Runs Out of Water, a Potential Food Shortage Looms 0918.rtfCrop Losses to Pests Will Soar as Climate Warms 0818.rtf - For example, Russia’s losses will rise from 10% to 16% with 2°C warming.Rising CO2 Will Leave Crops—and Millions of Humans—Less Healthy 0818.rtf - protein, iron & zinc deficienciesExtreme Weather Could Force Food Prices Up 5% in UK 0818.rtfBiofuels, Planting Forests to Cut Emissions Could Cause More Hunger than Climate Change 0718.rtfWineries Hedge against Climate Change, Move to Cool Climates 0618.rtfClimate Change Strips Nutrients from Food Crops 0618.rtf - take #1 on 2 studiesClimate Change Could Cause Major Crop Failures in World’s Top Corn Regions 0618.rtf - take #2If Global Warming Continues at Same Rate, It May Be Leave No Vegetables to Eat 0618.rtf - take #3How More CO2 Can Make Food Less Nutritious 0518.rtfWhy More CO2 May Not Lead to More-Productive Crops 0518.rtfScientists Examine Threats to Food Security if We Meet Paris Climate Targets 0418.rtfMaple Sugar Season Faces Mounting Climate Change Pressure 0318.rtfWill Chocolate Be among the Foods That Go Extinct due to Climate Change? 0118.rtfMass Starvation Is Humanity’s Fate if We Keep Flogging the Land to Death 1217.rtfIn Peru’s Deserts, Melting Glaciers Are a Godsend (Until They’re Gone) 1117.rtfManage Climate Risks or Face Much More Hunger by 2050 – U.N. 1117.rtfGlobal Climate Change Raising Risk of Crop Yield Losses in Tropical Andes 1117.rtf6th Mass Wildlife Extinction Also Threatens Global Food Supplies 0917.rtfGlobal Warming Reduces Protein in Key Crops 0817.rtfHow the Climate Crisis Could Become a Food Crisis Overnight 0717.rtfMaize, Rice, Wheat - Alarm at Rising Climate Risk to Vital Crops 0717.rtfMajor Greenland Melting Could Devastate Crops in Africa 0617.rtfClimate Change Could Slash Staple Crops 0517.rtfAs Global Groundwater Disappears, Rice, Wheat, Other Crops May Start to Vanish 0417.rtfEurope's Meat and Dairy Farms Vulnerable, as Climate Change Worsens Water 0417.rtfDrylands Will Suffer if World Reaches 2°C 0417.rtfClimate Change May Hurt US Agricultural Productivity 0317.rtfClimate Change Is Transforming the World's Food Supply 0217.rtfClimate Change Will Hurt Crops More than It Helps Them, Study Suggests 0117.rtf - take 1 on studyClimate Change May Reduce Some US Grain Harvests by Half 0117.rtf - take 2 on studyGlobal Farming Must Transform to Fight Climate Change, Protect Food Security 1016.rtfClimate Change Outpaces Niche Change Rate in Grasses, Threatens Food Supply 0916.rtfWheat, One of the World’s Key Drops, Is Threatened by Climate Change 0916.rtfClimate Change Threatens Japan’s Agriculture 0816.rtf - Growing zones move north. Heat & drought in current zones.New Crop Varieties ‘Can't Keep Up with Global Warming' 0616.rtfCoffee Bean Shortage Predicted due to Climate Change 0516.rtfFood System Shock - Climate Change's Greatest Threat to Civilization 0416.rtfAgriculture on the Brink 0416.rtfClimate Change Will Make Us Sicker and Make Our Food Less Nutritious 0416.rtfFood Scarcity due to Climate Change Could Cause 500,000 Deaths by 2050 - 0316.rtfFarm Report - Montana to Lose Millions to Climate Change 0216.rtfClimate Change Raises a Troubling Question - Who Gets to Eat? 0116.rtfWorld 'Faces Food Shortages and Mass Migration' Caused by Global Warming 1215.rtfThe USDA Puts Food and Climate Change Center Stage In Paris 1215.rtfAustralian Researchers Working on G20 Plan to Increase Global Crop Yields 1115.rtfRising Temperatures Kick-Start Subarctic Farming In Alaska 1115.rtfNational Chocolate Day - Could Climate Change Hurt Supplies? 1015.rtfIndia's Tea Estates Face Climate-Change Threat 1015.rtf

West’s ‘Dust Bowl’ Future Now ‘Locked In’, as World Risks Imminent Food Crisis 1219.rtf

2015 Articles and earlier

Millions Face Hunger due to Climate Change, ‘Super El Niño'- Oxfam 0915.rtfKale or Steak? Change in Diet Is Key to U.N. Plan to End Hunger by 2030 - 0915.rtfFood Production Shocks Will Happen More Often, due to Extreme Weather 0815.rtf - take 1 on studyGlobal Warming Increases ‘Food Shocks' Threat 0815.rtf - take 2 on studyClimate Change Threatens Food Production in Nigeria 0815.rtfScientists Predict Climate Change Will Increase Child Malnutrition 0715.rtfMillions More to Suffer Nutrient Deficiency by 2050, due to CO2 Emissions 0715.rtfHow Will We Feed a World of 9 Billion People? 0715.rtfSociety Will Collapse by 2040, Due to Catastrophic Food Shortages - GSI 0615.rtfHow Climate Change Could Alter the Food on Your Plate 0619.rtfGlobal Warming May Not Be So Great for Plant Life, after All 0615.rtf - gain range near poles, but lose far more in tropicsSaving Coffee from Extinction 0515.rtfEl Niño Could ‘Disrupt Food Markets' 0515.rtfTroubling New Research Suggests Global Warming Will Cut Wheat Yields 0515.rtfCoffee Production Slipping in Tanzania as Temperatures Rise 0415.rtfDairy Straits 0415.rtfVanishing Fruits, Veggies - Could Climate Change What We Eat? 0415.rtfOver-Consumption, Climate Change Threaten Food, Water Supplies - FAO 0415.rtfClimate Change Could Make Your Food Taste Worse 0315.rtfFeeding a Warmer, Riskier World 0315.rtfWhy Fresh Water Shortages Will Cause the Next Great Global Crisis 0315.rtfYields of Key Cassava Crop Not Keeping Pace with Africa Population Growth 0315.rtfCould Climate Change Take Oysters Off the Menu? 0215.rtfClimate Change Hampering World Food Production 0215.rtfClimate Change Could Bring More Disease, Crop Damage, Fires to Colorado 0215.rtfMidwest Climate Future- Missouri Becomes Like Arizona and Chicago Like Texas 0115.rtf - take 1 on the above studyClimate Change Could Hammer Iowa Agriculture, Manufacturing 0115.rtf - take 2 on study, Iowa-specificFood Diversity under Siege from Global Warming, U.N. Says 0115.rtfClimate Change Threatens Staple Potato Crop in High Andes 0115.rtfTropical Deforestation Could Disrupt Rainfall Globally 1214.rtf - take 1 on studyTropical Deforestation Threatens Global Food Production 1214.rtf - take 2 on studyClimate Change Creates New Geography of Food 1214.rtfAfrican Soil Crisis Threatens Food Security 1214.rtf - primarily soil lossHigh-Tech Farming Poised to Change the Way the World Eats 1114.rtfGlobal Warming Could Undercut Efforts to Eradicate Poverty 1114.rtf - For the 320-page PDF of the World Bank study, see Costs, War+ page, as well as the Overviews page. Among the report's many findings, among several regions, is that 2°C warming could cut Brazil’s soybean crop 30-70% and its wheat crop 50%.
See another summary of the World Bank report on the Cost, War+ page, as "UN: Climate Change Costs to Poor Underestimated”.Climate Change a 'Threat Multiplier’ for Farming-Dependent Nations 1014.rtfWarmer Days a Catastrophe in the Making for Kenya’s Pastoralists 1014.rtfFood Security Faces Growing Pest Advance 0814.rtfHow to Stop Climate Change Making Food Less Nutritious? 0714.rtfInside the Looming Food Crisis 0514.rtfEl Niño's Threat to Major Food Crop Yields 0514.rtfClimate Change Will 'Lead to Battles for Food', Says World Bank Chief 0414.rtfWorld Unprepared for Climate Damage to Food Security – Oxfam 0314.rtfCan We Prevent a Food Breakdown? 0314.rtfIs Japan Playing Hunger Games with Climate Change? 0314.rtfIs Japan Playing Hunger Games with Climate Change? 0314.docCrop Yield Impacts for +3°C by 2050.jpgCan the World Feed China? - L Brown 0214.rtfDrought Could Drain More Than Brazil's Coffee Crop 0214.rtfClimate Downgrade- Food Production Hit 1112.rtfWarming Projected to Cut Food Production 2% per Decade 1113.rtfCosts of Damages from & Adaptation to Climate Change in East Asia - Asian Develop Bank 2013.pdf - 216 ppPeak Water and Food Scarcity 0114.rtfClimate Forecasts Shown to Warn of Crop Failures 0713.rtfAs Michigan Warms, Cotton Instead of Cherry and Grapes? 0713.rtfCattle Weight Loss Means Slimmer Profits in a Warmer World 0713.rtfGlobal Food Production Trajectory Won’t Meet 2050 Needs 0613.rtfHow a Warming World Threatens Our Food Supplies 0413.rtfClimate Change Will Harm Mekong Basin Harvests 0313.rtfWarming May Hurt Michigan Farms 0213.rtfClimate Change Could Devastate US Agriculture 0213.rtfClimate Change and Agriculture in Australia 0213.rtfFuture Heat Waves Will Cut Crop Yields a Bunch 0113.rtfPinpoint Climate Studies Flag Trouble for Mexican Farmers 1212.rtfClimate Change Means More Malnourished Children 1212.rtfYour Thanksgiving on Climate Change 1112.rtfBananas Could Replace Potatoes in Warming World 1012.rtfWarming Earth Struggles to Feed Itself 0611.rtfHeat to Hurt Rice More than CO2 Helps 1012.rtfWorld in Serious Trouble on Food Front 0712.rtfAnnan Links Climate Change to Less Food 1111.rtfClimate to Wreak Havoc on Food Supply 0611.rtfFAO Warns of Long Term Impacts on Food 0411.rtfFuture of Food Riots 0111.rtfStern - Warming Destroys Agriculture 0309.rtfMajor Crop Failures Coming Up 0109.rtfUN Chief Links Warming to Food Crisis 0708.rtfClimate Change Threatens Rice 0408.rtfIPCC on CO2 & Agriculture 1207.rtfWarming to Starve 400 Million 0406.rtfFuture Food Insecurity with Unprecedented Heat 0109.pdfWater & Ag Rosenzweig 1004.pdfGlobal Food Parry et al 0104.pdf

Heat in the Heartland - Climate Change and Economic Risk in the Midwest - Risky Business / Grayson 0115.pdf of Farming chapter. Full study is on the Overviews and Heat pages.

Agriculture will be harmed in a major way. Crop losses of 40-64% by 2100 are likely for corn in the Corn Belt and 8-38% by 2100 for soybeans in the same states (IA, IL, IN, OH, MO). The Corn Belt will have moved into Canada, North Dakota, and NW Minnesota. See maps and table below. In most of Missouri and Illinois, plus about half of Iowa and Indiana, crops losses are 25-50%, and worse in a few places. Wheat is much less affected, as it is often grown in the colder months and harvested by June.