Posted on 15 October 2025 by dana1981

This is a re-post from Yale Climate Connections

A draft report commissioned by the Trump administration’s Department of Energy, or DOE, misleadingly claims that increasing levels of carbon dioxide could be beneficial for agriculture. In fact, mainstream climate experts have found that rising CO2 levels, by causing climate change, are harmful to agriculture overall – and likely to cause food prices to increase.

The Trump administration’s claim arose from a draft “critical review” report commissioned by DOE and written by fringe experts. The DOE subsequently disbanded that group when faced with a lawsuit alleging that it violated a law requiring that such federal advisory committees must be transparent and unbiased.

The Environmental Protection Agency cited the DOE report in a proposal to reverse its Obama-era determination that carbon pollution poses a threat to public health and welfare. The agency argued that higher carbon dioxide levels in the atmosphere will increase the amount of food that farmers produce, implying that carbon pollution is a good thing.

“Recent data and analysis show that even marginal increases in CO2 concentrations have substantial beneficial impacts on plant growth and agricultural productivity, and that this benefit has been significantly greater than previously believed,” the agency wrote.

Mainstream climate experts say that’s incorrect.

In response to the DOE report, a group of 85 climate experts and the National Academies of Sciences, Engineering, and Medicine each published comprehensive reviews of the scientific literature and arrived at the opposite conclusion. These expert reports found that rather than boosting agricultural productivity, the body of scientific evidence indicates that increased extreme weather resulting from climate change will instead reduce crop yields, making food more expensive. 

Weather disasters are very, very bad for crops

The notion that crops will benefit from climate pollution is based on the fact that plants absorb carbon dioxide during photosynthesis. Scientists have known for decades that in a controlled environment like a glass greenhouse, higher CO2 levels in the air will cause plants to grow bigger.

But Earth’s atmosphere isn’t a controlled environment. Increased carbon dioxide concentrations in the atmosphere trap extra heat like a blanket, causing more frequent extreme weather like heat waves, droughts, and floods. These events stress plants and hamper their growth and productivity.

Innovations in agricultural practices like the use of fertilizers, pesticides, new seed varieties, and irrigation have boosted crop yields over the past century. But increasingly extreme weather could slow those gains.

To study these complex variables, scientists have conducted what are known as free-air CO2 enrichment, or FACE, experiments. These studies use pipes or vents to release carbon dioxide into large open plots of crops.

A 2020 analysis of 30 years of FACE experiments found that higher carbon dioxide concentrations increased crop yields as expected when “under non-stress conditions.” But when stressed by factors like changing temperatures or precipitation, as climate experts said recently, “the yield increases were suppressed and in some cases erased.”

Climate damages overwhelm farmers’ efforts to adapt

Farmers may be able to adapt to some climate impacts, for example, by adjusting plant varieties, fertilizers, and crop cultivation windows. But those changes won’t be sufficient to fully overcome damage from climate change, according to a study published in June 2025.

The study’s authors estimated that each additional 1°C of global warming in 2100 will reduce crop yields by the equivalent of 4.4% of each person on Earth’s recommended daily calorie intake. Most staple crops, including wheat, corn, and soybeans, will see significant yield declines.

And farmers are already experiencing the impacts of climate change. Another 2025 study found that thanks to more efficient farming practices, the amount of global land devoted to agriculture could have decreased 2% over the past 30 years – while growing the same amount of food. Instead, global croplands expanded by nearly 4% during that time because climate change slowed the growth in agricultural productivity.

The paper estimated that those climate impacts caused over 200 million acres of land to be converted to cropland – twice the area of California. And converting existing ecosystems like forests to agricultural land reduced the amount of carbon absorbed by plant life on Earth. The study estimated that this land conversion added 22 billion tons of carbon dioxide to the atmosphere. That’s the equivalent of about six months of humanity’s carbon dioxide emissions.

It’s a vicious cycle – climate change reduces agricultural yields, which forces farmers to convert more forests to cropland, which adds more carbon to the atmosphere and worsens climate change.

Climate change could make food more expensive

As the law of supply and demand tells us, if crop yields are suppressed while people still need to eat the same amount of food, prices will rise. A 2024 study estimated that “annual food inflation of 1-3 percentage points per year could result from temperatures projected for 2035.”

Another problem is that climate change is worsening many different types of extreme weather, which can sometimes strike the same place at the same time. Scientists call these events compound extremes.

And a 2021 paper found that over the prior three decades, temperature-related crop losses resulted in $27 billion in crop insurance claims due to reduced yields in part as a result of these kinds of severely suppressed crop yield seasons.

The verdict: carbon damages overwhelm benefits for crops

As this body of scientific research illustrates, although plants directly benefit from higher carbon dioxide levels, the damages from extreme weather are already becoming bigger than those benefits.

Farmers have so far been able to overcome those climate damages by devoting more land to agriculture and implementing innovative practices. But there are limits to land and water availability, and detrimental effects on the environment and health from applying too many pesticides and fertilizers.

Meanwhile, climate damages will only worsen as long as temperatures continue to rise. As the report written by 85 climate scientists concluded, “in the major agricultural growing regions of the U.S. (and in most parts of the world), CO2-induced climate change will lead to yield declines.” That will lead to higher food prices until humanity stops the rise in global temperatures by reaching net-zero carbon pollution.