The world’s most cultivated crop by weight is maize (corn). In 2023, global maize production reached approximately 1.22 billion metric tons, surpassing wheat (808 million metric tons) and rice (526 million metric tons).

But dark clouds are on the horizon. By the end of the century, global warming could slash corn yields by 12% to 28%, even if farmers deploy every adaptation strategy in their arsenal. The findings were published in a study published on June 18, 2025, in Nature by researchers at the University of Illinois Urbana-Champaign. They analyzed the impact of global warming on six staple crops: corn, wheat, rice, soybeans, barley, and cassava.

Corn will suffer the most so the study finds. And that is a major issue, because corn isn’t just food; it’s animal feed, fuel, sweetener, starch, and a linchpin of industrial agriculture. A collapse in its supply could ripple across industries and nations, potentially influencing how billions live and eat.

I read the study for you and give you the most important elements below.

The Scale of the Crisis

The study I talk about in this article analyzed the impact of global warming on six staple crops: corn, wheat, rice, soybeans, barley, and cassava. Together they provide over two-thirds of the world’s calories. As I pointed out in the introduction, corn emerged as one of the most vulnerable, with projected yield declines of 12% under moderate emissions scenarios and up to 28% under high-emissions pathways by 2100.

Even when you include efforts by farmers to adapt to climate change – such as using better corn hybrids, improving irrigation systems, applying more fertilizers, or shifting planting schedules – the projected losses in corn yields are still very high, and rather alarming.

The findings are in sync with a 2021 Nature Food study by NASA. That study projected a 24% global maize yield drop by 2100 under high-emission scenarios (SSP5-8.5), with impacts noticeable as early as 2030. A meta-analysis from the same year found that every 1°C rise in global average temperature cuts maize yields by approximately 7.4%. At 3°C of warming – where the world is headed – the global food system could lose the caloric equivalent of breakfast for every person on Earth, with corn driving a significant portion of that deficit.

Key Stat: Every 1°C of warming reduces global per capita food supply by ~121 kilocalories per day, with maize as a leading contributor to the shortfall.

Why Corn Is So Vulnerable

Corn’s sensitivity to climate change stems from its biology and growing conditions:

  • Heat Stress: Corn is a C4 plant, highly susceptible to heat stress. Sustained temperatures above 36°C can kill its flowers and pollen, drastically reducing yields. Unlike wheat or rice, which benefit modestly from CO₂ fertilization, corn sees minimal yield gains from rising atmospheric CO₂ levels.
  • Rainfall Volatility: Shifts in rainfall patterns, including delayed monsoons or increased droughts and floods, hit corn harder than more resilient crops like cassava. Even small disruptions in water availability during critical growth stages can devastate harvests.
  • Soil and Regional Dependence: High-yield regions like the U.S. Midwest and Europe rely on stable climates. Any deviation, be it warmer summers or erratic rains, will disrupt the delicate balance that maximizes output.

Despite smarter techniques – switching to heat-tolerant hybrids, optimizing planting schedules, expanding irrigation, and increasing fertilizer use – these measures will offset only 12% of corn yield losses by 2100.

Especially the wealthy agricultural heartlands, like the U.S. Midwest and Europe, face a surprising vulnerability. They’re not better adapted to climate change than poorer countries. Their reliance on high-yield systems, optimized for stable climates, means even small disruptions cause outsized losses.

In contrast, some higher-latitude regions, like Canada and Northern Europe, may see temporary yield increases due to warmer growing seasons. However, these gains are too small to offset global declines, especially in major maize-producing regions like Brazil, China, and sub-Saharan Africa, where losses could reach 20–30% by century’s end.

The Ripple Effects

Corn yields have soared by ~196% since 1961, thanks to advances in seeds, fertilizers, and mechanization. But climate change has already slowed progress. Without anthropogenic warming, yields would have grown 4–5% faster over the past six decades. Globally, agricultural productivity (total factor productivity, or TFP) is ~21% lower than it would have been without climate change, with warmer regions like sub-Saharan Africa hit hardest.

A 28% yield drop for corn by 2100 could trigger several other effects, including devastating losses that would cause mass starvation. Here are the most immediate effects we can expect:

  • Food Price Volatility: Similar to the 2007–2008 global food crisis, corn shortages would spike prices for staples, processed foods, and livestock feed, hitting low-income households hardest.
  • Livestock Impacts: With corn feeding 70% of global poultry and significant portions of cattle and pork, feed shortages could force herd reductions, driving up meat and dairy prices.
  • Bioethanol and Industry: Corn is a key source of bioethanol, starch, and bioplastics. A supply crunch could increase reliance on fossil fuels and disrupt industrial supply chains.
  • Geopolitical Tensions: Countries dependent on corn imports, particularly in Africa and parts of Asia, could face heightened instability as exporters like the U.S. and Brazil grapple with reduced output.

Regional Hotspots

The crisis won’t hit evenly:

  • U.S. Midwest: The Corn Belt, responsible for ~35% of global maize, faces steep declines. While some states may see slight yield gains by 2036, others could lose up to 25%, with growth slowing under rising heat stress.
  • Europe: High-yield regions like France and Germany, reliant on stable climates, could see 15–20% losses by 2100.
  • Sub-Saharan Africa: Rain-fed maize systems, critical for food security, face up to 30% yield drops, exacerbating hunger risks.
  • Mexico: Rain-fed maize production could fall by 7% by 2055, from ~1,555 kg/ha to 1,440 kg/ha, hitting smallholder farmers hard.
  • Brazil and China: As major exporters, their 20–25% yield declines could disrupt global trade.

A Race Against Time

Despite the not so bright future, there are still a few things which could be done to mitigate the effects. But it’s better to act now.

  1. Continue to Slash Emissions: Staying within 1.5–2°C of warming is critical. Current trajectories point to 3°C or higher, where corn losses become catastrophic.
  2. Innovate Crops: Investment in heat- and drought-resistant maize varieties is essential. Genomic research and accelerated breeding programs already develop hybrids that withstand higher temperatures and water stress. The question is how far the genetics can be stretched of course.
  3. Support Farmers: Wealthy nations must subsidize adaptive technologies – irrigation systems, precision agriculture, and climate-smart practices – while ensuring poorer farmers have access through international aid and financing.
  4. Strengthen Supply Chains: Global coordination on food stocks, trade policies, and price stabilization can mitigate shortages and prevent crises like we saw in 2007–2008.
  5. Diversify Diets and Crops: Reducing reliance on corn by promoting alternative staples like cassava or millet could buffer food systems against maize declines.

The projections are not written in stone, in a best-case scenario, aggressive emissions cuts and rapid innovation could limit losses to single digits. In the worst case, unchecked warming could trigger devastating shortfalls, leading to widespread hunger and economic disruption.

I have a background in environmental science and journalism. For WINSS I write articles on climate change, circular economy, and green innovations. When I am not writing, I enjoy hiking in the Black Forest and experimenting with plant-based recipes.