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.

Climate Change Likely to Slow Plant Growth in Northern Hemisphere 0622

Food Shocks Will Also Destabilize the ESG World 0522

Salt Scourge - The Dual Threat of Warming and Rising Salinity 0522

Climate Change Could Significantly Impact Commercial Fishing 0422

Our Food System Isn't Ready for the Climate Crisis 0422 - 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

Farmers’ Report - Climate Crisis Puts Australia’s Food Supply at Increasing Risk 0322

What to Expect from the World’s 6th Mass Extinction 0122 - 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.

Warming Temperatures Threaten Greece's Prized Olive Oil 1221

Warmer Winters Can Wreak as Much Havoc as Hotter Summers 1221

Amid Drought, Conflict, and Rocketing Prices, a Global Food Crisis Looms 1221

World Faces Growing Risk of Food Shortages due to Climate Change 0921

Grain Production Depends on Ending Deforestation 0821 in Brazil

Hungry for Solutions 0621 - 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.

Tea-Growing Areas to Be Badly Hit if Global Heating Intensifies 0521

Russia’s Far North Could Be Arable in 20-30 Years as Permafrost Melts? 0521 - But soils may be too poor for warmi ng to do much good.

Will Rising Temperatures Make Rice Too Toxic? 1220

Will Rising Temperatures Make Superweeds Even Stronger? 1220

Climate Change Could Make Swathes of Farmland Largely Useless in U.S. South 1020

Climate Change Will Continue to Widen Gaps in Food Security 1020

Rising Temperatures Put Heat on Nebraska's $7 Billion Corn Industry 0920

Unless We Change Course, the US Agricultural System Could Collapse 0820 - 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

Climate Change Forces Farmers to Choose Low Yields or Unstable Returns 0720

A 2nd US Dust Bowl Would Hit World Food Stocks 0320

U.S. Food Trade Increasingly Leans on Unsustainable Groundwater 0120

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

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

Canadians Will Pay More for Food Next Year, Thanks to Climate Change 1219

Indoor Farming May Not Be the Easy Answer to Feeding a Hot and Hungry Earth 1119

Ocean Could Provide over 6 Times More Food than It Does Today 1119

Thirsty Future Ahead as Climate Change Explodes Plant Growth 1119

Climate Change Could Leave Southern Britain ‘Unable’ to Support Crops 1019

Al Gore Warns of Looming Food Crisis Caused by Climate Change 1019 - subsidies to what we don’t want, and yields fall with rising temperatures

How More Organic Farming Could Worsen Global Warming 1019 - 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

Climate Change Threatens World Fisheries, Food for Billions of People 0919

$1 Million a Minute Farm Subsidies Are Destroying the World 0919 - 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 - 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

Climate Change Threatens the World’s Food Supply, UN Warns 0819

CO2-Driven Nutrient Loss in Rice Could Lead to Vast Vitamin B Deficiencies 0719 - lose 17-30% of vitamin B by 2050

As Climate Changes, Taxpayers Will Shoulder Larger U.S. Payouts to Farmers 0719

It’s Not if We're Approaching Agricultural Disaster; It's How Often They'll Happen 0519

More Nitrogen May Help Offset Warming Effect of Climate Change on Wheat 0319

Global Warming Could Decimate Fish Supplies and Fuel Migration 0219

Future of Food under ‘Severe Threat' as Species Diversity Disappears - U.N. 0219

Vanishing Nutrients 1218 - Rising CO2 means lower nutrient density in food and nutrient deficiencies.

Rising Heat from Climate Change Threatens U.S. Crop Yields 1118

5 Major Crops in the Crosshairs of Climate Change 1018 - wheat, peaches, coffee, corn, almonds

As India’s Ganges Runs Out of Water, a Potential Food Shortage Looms 0918

Crop Losses to Pests Will Soar as Climate Warms 0818  For example, Russia’s losses will rise from 10% to 16% with 2°C warming.

Extreme Weather Could Force Food Prices Up 5% in UK 0818

Rising CO2 Will Leave Crops—and Millions of Humans—Less Healthy 0818 - protein, iron & zinc deficiencies

Biofuels, Planting Forests to Cut Emissions Could Cause More Hunger than Climate Change 0718

Wineries Hedge against Climate Change, Move to Cool Climates 0618

Climate Change Strips Nutrients from Food Crops 0618 - take #1 on 2 studies

Climate Change Could Cause Major Crop Failures in World’s Top Corn Regions 0618 - take #2

If Global Warming Continues at Same Rate, It May Be Leave No Vegetables to Eat 0618 - take #3

How More CO2 Can Make Food Less Nutritious 0518

Why More CO2 May Not Lead to More-Productive Crops 0518

Scientists Examine Threats to Food Security if We Meet Paris Climate Targets 0418

Maple Sugar Season Faces Mounting Climate Change Pressure 0318

Will Chocolate Be among the Foods That Go Extinct due to Climate Change? 0118

Mass Starvation Is Humanity’s Fate if We Keep Flogging the Land to Death 1217

In Peru’s Deserts, Melting Glaciers Are a Godsend (Until They’re Gone) 1117

Manage Climate Risks or Face Much More Hunger by 2050 – U.N. 1117

Global Climate Change Raising Risk of Crop Yield Losses in Tropical Andes 1117

6th Mass Wildlife Extinction Also Threatens Global Food Supplies 0917

Global Warming Reduces Protein in Key Crops 0817

How the Climate Crisis Could Become a Food Crisis Overnight 0717

Maize, Rice, Wheat - Alarm at Rising Climate Risk to Vital Crops 0717

Major Greenland Melting Could Devastate Crops in Africa 0617

Climate Change Could Slash Staple Crops 0517

As Global Groundwater Disappears, Rice, Wheat, Other Crops May Start to Vanish 0417

Drylands Will Suffer if World Reaches 2°C 0417

Europe's Meat and Dairy Farms Vulnerable, as Climate Change Worsens Water 0417

Climate Change May Hurt US Agricultural Productivity 0317

Climate Change Is Transforming the World's Food Supply 0217

Climate Change May Reduce Some US Grain Harvests by Half 0117 - take 2 on study

Climate Change Will Hurt Crops More than It Helps Them, Study Suggests 0117 - take 1 on study

Global Farming Must Transform to Fight Climate Change, Protect Food Security 1016

Climate Change Outpaces Niche Change Rate in Grasses, Threatens Food Supply 0916

Wheat, One of the World’s Key Drops, Is Threatened by Climate Change 0916

Climate Change Threatens Japan’s Agriculture 0816 - Growing zones move north.  Heat & drought in current zones.

New Crop Varieties ‘Can't Keep Up with Global Warming' 0616

Coffee Bean Shortage Predicted due to Climate Change 0516

Food System Shock - Climate Change's Greatest Threat to Civilization 0416

Agriculture on the Brink 0416

Climate Change Will Make Us Sicker and Make Our Food Less Nutritious 0416

Food Scarcity due to Climate Change Could Cause 500,000 Deaths by 2050 - 0316

Farm Report - Montana to Lose Millions to Climate Change 0216

Climate Change Raises a Troubling Question - Who Gets to Eat? 0116

2015 Articles and earlier

World 'Faces Food Shortages and Mass Migration' Caused by Global Warming 1215

The USDA Puts Food and Climate Change Center Stage In Paris 1215

Rising Temperatures Kick-Start Subarctic Farming In Alaska 1115

National Chocolate Day - Could Climate Change Hurt Supplies? 1015

India's Tea Estates Face Climate-Change Threat 1015

Millions Face Hunger due to Climate Change, ‘Super El Niño'- Oxfam 0915

Kale or Steak?  Change in Diet Is Key to U.N. Plan to End Hunger by 2030 - 0915

Climate Change Threatens Food Production in Nigeria 0815

Food Production Shocks Will Happen More Often, due to Extreme Weather 0815 - take 1 on study

Global Warming Increases ‘Food Shocks' Threat 0815 - take 2 on study

Scientists Predict Climate Change Will Increase Child Malnutrition 0715

Millions More to Suffer Nutrient Deficiency by 2050, due to CO2 Emissions 0715

How Will We Feed a World of 9 Billion People? 0715

Society Will Collapse by 2040, due to Catastrophic Food Shortages - GSI 0615

How Climate Change Could Alter the Food on Your Plate 0619

Global Warming May Not Be So Great for Plant Life, after All 0615 - gain range near poles, but lose far more in tropics

Saving Coffee from Extinction 0515

El Niño Could ‘Disrupt Food Markets’ 0515

Troubling New Research Suggests Global Warming Will Cut Wheat Yields 0515

Coffee Production Slipping in Tanzania as Temperatures Rise 0415

Dairy Straits 0415

Vanishing Fruits, Veggies - Could Climate Change What We Eat? 0415

Over-Consumption, Climate Change Threaten Food, Water Supplies - FAO 0415

Climate Change Could Make Your Food Taste Worse 0315

Feeding a Warmer, Riskier World 0315

Why Fresh Water Shortages Will Cause the Next Great Global Crisis 0315

Yields of Key Cassava Crop Not Keeping Pace with Africa Population Growth 0315

Could Climate Change Take Oysters Off the Menu? 0215

Climate Change Hampering World Food Production 0215

Climate Change Could Bring More Disease, Crop Damage, Fires to Colorado 0215

Midwest Climate Future - Missouri Becomes Like Arizona and Chicago Like Texas 0115 -  take 1 on the above study

Climate Change Could Hammer Iowa Agriculture, Manufacturing 0115 - take 2 on study, Iowa-specific

Climate Change Threatens Staple Potato Crop in High Andes 0115

Food Diversity under Siege from Global Warming, U.N. Says 0115

Tropical Deforestation Could Disrupt Rainfall Globally 1214 - take 1 on study

Tropical Deforestation Threatens Global Food Production 1214 - take 2 on study

Climate Change Creates New Geography of Food 1214

African Soil Crisis Threatens Food Security 1214 - primarily soil loss

Global Warming Could Undercut Efforts to Eradicate Poverty 1114 - 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”.

High-Tech Farming Poised to Change the Way the World Eats 1114

Climate Change a 'Threat Multiplier’ for Farming-Dependent Nations 1014

Warmer Days a Catastrophe in the Making for Kenya’s Pastoralists 1014

Food Security Faces Growing Pest Advance 0814

How to Stop Climate Change Making Food Less Nutritious? 0714

Inside the Looming Food Crisis 0514

Climate Change Will 'Lead to Battles for Food', Says World Bank Chief 0414

World Unprepared for Climate Damage to Food Security – Oxfam 0314

Can We Prevent a Food Breakdown? 0314

Can the World Feed China? - L Brown 0214

Drought Could Drain More Than Brazil's Coffee Crop 0214

Peak Water and Food Scarcity 0114

Warming Projected to Cut Food Production 2% per Decade 1113

Costs of Damages from & Adaptation to Climate Change in East Asia - Asian Development Bank 2013 - PDF, 216 pages

As Michigan Warms, Cotton Instead of Cherry and Grapes? 0713

Cattle Weight Loss Means Slimmer Profits in a Warmer World 0713

Global Food Production Trajectory Won’t Meet 2050 Needs 0613

How a Warming World Threatens Our Food Supplies 0413

Climate Change Will Harm Mekong Basin Harvests 0313

Warming May Hurt Michigan Farms 0213

Climate Change Could Devastate US Agriculture 0213

Climate Change and Agriculture in Australia 0213

Future Heat Waves Will Cut Crop Yields a Bunch 0113  

Pinpoint Climate Studies Flag Trouble for Mexican Farmers 1212  

Climate Change Means More Malnourished Children 1212 

Your Thanksgiving on Climate Change 1112

Climate Downgrade - Food Production Hit 1112

Bananas Could Replace Potatoes in Warming World 1012  

Heat to Hurt Rice More than CO2 Helps 1012  

World in Serious Trouble on Food Front 0712  

Annan Links Climate Change to Less Food 1111  

Warming Earth Struggles to Feed Itself 0611 

Climate to Wreak Havoc on Food Supply 0611  

FAO Warns of Long Term Impacts on Food 0411 

Future of Food Riots 0111

Stern - Warming Destroys Agriculture 0309 

Major Crop Failures Coming Up 0109 

Future Food Insecurity with Unprecedented Heat 0109 - PDF

UN Chief Links Warming to Food Crisis 0708  

Climate Change Threatens Rice 0408  

IPCC on CO2 & Agriculture 1207 

Warming to Starve 400 Million 0406 

Water Resources for Agriculture in a Changing Climate - Rosenzweig 1004 - PDF 

Effects of Climate Change on Global Food Production - Parry et al 0104 - PDF

Heat in the Heartland - Agriculture Impacts 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.

Costs of Damages from & Adaptation to Climate Change in East Asia - Asian Development Bank 2013 - PDF, 216 pages

projections by Asian Development Bank, 2013.  PRC = China

Section Map: Food Impacts