Climate Change Is Affecting Crop Yields And Reducing Global Food Supplies

Climate Change Is Affecting Crop Yields And Reducing Global Food Supplies Farm land near Holly Bluff, Miss., covered with backwater flooding, May 23, 2019. AP Photo/Rogelio V. Solis

Farmers are used to dealing with weather, but climate change is making it harder by altering temperature and rainfall patterns, as in this year’s unusually cool and wet spring in the central U.S. In a recently published study, I worked with other scientists to see whether climate change was measurably affecting crop productivity and global food security.

To analyze these questions, a team of researchers led by the University of Minnesota’s Institute on the Environment spent four years collecting information on crop productivity from around the world. We focused on the top 10 global crops that provide the bulk of consumable food calories: Maize (corn), rice, wheat, soybeans, oil palm, sugarcane, barley, rapeseed (canola), cassava and sorghum. Roughly 83 percent of consumable food calories come from just these 10 sources. Other than cassava and oil palm, all are important U.S. crops.

We found that climate change has affected yields in many places. Not all of the changes are negative: Some crop yields have increased in some locations. Overall, however, climate change is reducing global production of staples such as rice and wheat. And when we translated crop yields into consumable calories – the actual food on people’s plates – we found that climate change is already shrinking food supplies, particularly in food-insecure developing countries.

Feeding a growing world population in a changing climate will require a global-scale transformation of agriculture.

Adding up local trends

The first thing we needed to understand was how temperature and precipitation influenced crop productivity in many locations. To do this, we analyzed data from up to 20,000 counties and districts around the world to see how crop yields varied in each place with changes in precipitation and temperature.

Once we had constructed an empirical model connecting crop yield to weather variations at each location, we could use it to assess how much yields had changed from what we would have expected to see if average weather patterns had not changed. The difference between what we would have predicted, based on the counterfactual weather, and what actually occurred reflects the influence of climate change.

Our analysis showed that climate change has already affected crop yields around the world. There were variations between locations and among crops, but when all of these different results were totaled, we found yields of some important global staples were already declining. For example, we estimated that climate change was reducing global rice yields by 0.3% and wheat yields by 0.9% on average each year.

In contrast, some more drought-tolerant crops have benefited from climate change. Yields of sorghum, which many people in the developing world use as a food grain, have increased by 0.7% in sub-Saharan Africa and 0.9% yearly in western, southern and southeastern Asia due to climate shifts since the 1970s.

Climate Change Is Affecting Crop Yields And Reducing Global Food Supplies Climate change is boosting maize (corn) yields in parts of the U.S., Latin America and Asia, but sharply reducing them elsewhere. Ray et al., 2019, CC BY

A mixed US picture

In the United States corn and soybeans are important cash crops, with a combined value of more than US$90 billion in 2017. We found that climate change is causing a small net increase in yields of these crops – on average, about 0.1% and 3.7% respectively each year.

But these numbers reflect both gains and losses. In some Corn Belt states, such as Indiana and Illinois, climate change is shaving up to 8% off of annual corn yields. At the same time, it has boosted annual yields in Iowa and Minnesota by approximately 2.8%. All four of these states now have slightly warmer and wetter corn growing seasons, but Indiana and Illinois have seen larger increases in warming and smaller increases in moisture compared to Iowa and Minnesota.

Our maps track these changes down to the county level. In eastern Iowa, Illinois and Indiana, climate change has been reducing corn yields even as it boosts them to the northwest in Minnesota and North Dakota. We see similar patterns for soybean farming: Reductions are moving up from the south and east parts of the country, where slightly more warming has occurred than in states farther north. Climate change is also reducing overall yields of other important crops, such as wheat and barley.

Climate Change Is Affecting Crop Yields And Reducing Global Food Supplies Climate change is reducing U.S. soybean yields in southern and eastern states (red areas) and expanding them to the north and west (green areas). Deepak Ray, CC BY-ND

From harvests to meals

While these impacts on crop yields are notable in themselves, we had to go a step farther to understand how they could affect global food security. Humans eat food, not crop yields, so we needed to determine how climate change was affecting supplies of consumable food calories. In its most recent assessment report, the Intergovernmental Panel on Climate Change recognized that this question had not yet been answered and was critical to building a strong case for climate change action.

Our study showed that climate change is reducing consumable food calories by around 1% yearly for the top 10 global crops. This may sound small, but it represents some 35 trillion calories each year. That’s enough to provide more than 50 million people with a daily diet of over 1,800 calories – the level that the U.N. Food and Agriculture Organization identifies as essential to avoid food deprivation or undernourishment.

What’s more, we found that decreases in consumable food calories are already occurring in roughly half of the world’s food insecure countries, which have high rates of undernourishment, child stunting and wasting, and mortality among children under age 5 due to lack of sufficient food. For example, in India annual food calories have declined by 0.8% annually and in Nepal they have fallen by 2.2% annually.

Reductions are also occurring in southern African countries, including Malawi, Mozambique and Zimbabwe. We even found losses in some rich industrialized nations, such as Australia, France and Germany.

Rich countries can work their way out of food calorie shortages by importing food. But poorer countries may need help. Short-term strategies could include using our findings to breed or increase cultivation of crops that are resilient to or even benefit from climate change. Farming techniques and agriculture policies can also help small-scale farmers increase crop yields.

The fact that world hunger has started to rise after a decadelong decline is alarming. In the long run, wealthy and developing countries alike will have to find ways to produce food in a changing climate. I hope this will lead to a rethinking of the entire food system, from diets to food waste, and to more sustainable techniques for feeding the world.The Conversation

About The Author

Deepak Ray, Senior scientist, University of Minnesota

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Related Books

Life After Carbon: The Next Global Transformation of Cities

by Peter Plastrik , John Cleveland
1610918495The future of our cities is not what it used to be. The modern-city model that took hold globally in the twentieth century has outlived its usefulness. It cannot solve the problems it helped to create—especially global warming. Fortunately, a new model for urban development is emerging in cities to aggressively tackle the realities of climate change. It transforms the way cities design and use physical space, generate economic wealth, consume and dispose of resources, exploit and sustain the natural ecosystems, and prepare for the future. Available On Amazon

The Sixth Extinction: An Unnatural History

by Elizabeth Kolbert
1250062187Over the last half-billion years, there have been Five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted. Scientists around the world are currently monitoring the sixth extinction, predicted to be the most devastating extinction event since the asteroid impact that wiped out the dinosaurs. This time around, the cataclysm is us. In prose that is at once frank, entertaining, and deeply informed, New Yorker writer Elizabeth Kolbert tells us why and how human beings have altered life on the planet in a way no species has before. Interweaving research in half a dozen disciplines, descriptions of the fascinating species that have already been lost, and the history of extinction as a concept, Kolbert provides a moving and comprehensive account of the disappearances occurring before our very eyes. She shows that the sixth extinction is likely to be mankind's most lasting legacy, compelling us to rethink the fundamental question of what it means to be human. Available On Amazon

Climate Wars: The Fight for Survival as the World Overheats

by Gwynne Dyer
1851687181Waves of climate refugees. Dozens of failed states. All-out war. From one of the world’s great geopolitical analysts comes a terrifying glimpse of the strategic realities of the near future, when climate change drives the world’s powers towards the cut-throat politics of survival. Prescient and unflinching, Climate Wars will be one of the most important books of the coming years. Read it and find out what we’re heading for. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

 
enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration

LATEST VIDEOS

The Great Climate Migration Has Begun
The Great Climate Migration Has Begun
by Super User
The climate crisis is forcing thousands around the world to flee as their homes become increasingly uninhabitable.
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
by Alan N Williams, et al
The latest report from the Intergovernmental Panel on Climate Change (IPCC) states that without a substantial decrease…
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
by Toby Tyrrell
It took evolution 3 or 4 billion years to produce Homo sapiens. If the climate had completely failed just once in that…
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
by Brice Rea
The end of the last ice age, around 12,000 years ago, was characterised by a final cold phase called the Younger Dryas.…
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
by Frank Wesselingh and Matteo Lattuada
Imagine you are on the coast, looking out to sea. In front of you lies 100 metres of barren sand that looks like a…
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
by Richard Ernst
We can learn a lot about climate change from Venus, our sister planet. Venus currently has a surface temperature of…
Five Climate Disbeliefs: A Crash Course In Climate Misinformation
The Five Climate Disbeliefs: A Crash Course In Climate Misinformation
by John Cook
This video is a crash course in climate misinformation, summarizing the key arguments used to cast doubt on the reality…
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
by Julie Brigham-Grette and Steve Petsch
Every year, sea ice cover in the Arctic Ocean shrinks to a low point in mid-September. This year it measures just 1.44…

LATEST ARTICLES

green energy2 3
Four Green Hydrogen Opportunities for the Midwest
by Christian Tae
To avert a climate crisis, the Midwest, like the rest of the country, will need to fully decarbonize its economy by…
ug83qrfw
Major Barrier to Demand Response Needs to End
by John Moore, On Earth
If federal regulators do the right thing, electricity customers across the Midwest may soon be able to earn money while…
trees to plant for climate2
Plant These Trees To Improve City Life
by Mike Williams-Rice
A new study establishes live oaks and American sycamores as champions among 17 “super trees” that will help make cities…
north sea sea bed
Why We Must Understand Seabed Geology To Harness The Winds
by Natasha Barlow, Associate Professor of Quaternary Environmental Change, University of Leeds
For any country blessed with easy access to the shallow and windy North Sea, offshore wind will be key to meeting net…
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
by Bart Johnson, Professor of Landscape Architecture, University of Oregon
A wildfire burning in hot, dry mountain forest swept through the Gold Rush town of Greenville, California, on Aug. 4,…
China Can Meet Energy and Climate Goals Capping Coal Power
China Can Meet Energy and Climate Goals Capping Coal Power
by Alvin Lin
At the Leader’s Climate Summit in April, Xi Jinping pledged that China will “strictly control coal-fired power…
Blue water surrounded by dead white grass
Map tracks 30 years of extreme snowmelt across US
by Mikayla Mace-Arizona
A new map of extreme snowmelt events over the last 30 years clarifies the processes that drive rapid melting.
A plane drops red fire retardant on to a forest fire as firefighters parked along a road look up into the orange sky
Model predicts 10-year burst of wildfire, then gradual decline
by Hannah Hickey-U. Washington
A look at the long-term future of wildfires predicts an initial roughly decade-long burst of wildfire activity,…

 Get The Latest By Email

Weekly Magazine Daily Inspiration

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.