Climate change is the current greatest threat to agricultural sustainability, but it doesn’t act alone. It amplifies nearly every other pressure on farming, from soil erosion and water scarcity to pest expansion and pollinator loss. The FAO’s 2025 report on global land and water resources identifies human-induced land degradation, water scarcity, and climate change as the urgent, interconnected challenges undermining agricultural productivity worldwide. Understanding how these threats feed into one another explains why the outlook is more complex than any single headline can capture.
Climate Change as the Central Threat
Rising temperatures directly reduce crop yields by shortening the window plants have to develop grain and by stressing them during flowering, the critical period when seeds form. Projections for 2050 show irrigated wheat yields in developing countries declining by roughly 31%, while irrigated rice in those same regions could drop by about 17%. Maize losses are more modest but still significant. Developed countries face smaller but real declines in irrigated crops as well.
These numbers come with considerable uncertainty. Different climate models produce very different projections, and the degree to which higher carbon dioxide levels might boost plant growth (a so-called fertilization effect) remains debated. But the broad consensus points in one direction: yields will fall in the regions that can least afford it. Tropical and subtropical areas, home to much of the world’s population growth, face the steepest losses because temperatures there are already near the upper limits many crops can tolerate.
What makes climate change uniquely dangerous is that it doesn’t just reduce yields on its own. It worsens water scarcity, accelerates soil degradation, pushes pests into new territories, and disrupts pollination. It is less a single threat and more a threat multiplier that makes every other vulnerability harder to manage.
Soil Erosion and Land Degradation
An estimated 36 billion tons of soil erode globally each year, and that figure may actually be conservative compared to older estimates. Topsoil, the nutrient-rich upper layer where most root activity happens, takes centuries to form but can wash away in a single heavy rainstorm on exposed farmland. Intensive tillage, monoculture planting, and the removal of cover crops all leave soil vulnerable.
Climate change accelerates this process. More intense rainfall events strip soil faster, while prolonged droughts dry it out and make it susceptible to wind erosion. The result is a shrinking foundation for food production. Degraded soil holds less water, supports fewer beneficial microorganisms, and requires more synthetic fertilizer to produce the same yields, creating a cycle that’s expensive to reverse and devastating if ignored.
Water Scarcity and Fertilizer Waste
Agriculture consumes roughly 70% of the world’s freshwater withdrawals, and many major aquifers and river basins are being drawn down faster than they recharge. As temperatures rise, evaporation increases, snowpack shrinks, and rainfall patterns shift, leaving some of the world’s most productive farmland competing for less reliable water supplies.
The way farmers use fertilizer compounds the problem. Nearly two-thirds of the nitrogen applied to crops never reaches the plant. About 75 million tonnes of nitrogen run off annually into rivers, lakes, and coastal waters, fueling algal blooms, creating oxygen-depleted dead zones, and contaminating drinking water. This isn’t just an environmental issue. It represents an enormous waste of a costly input, one that farmers in poorer regions can barely afford in the first place.
Phosphorus, the other essential crop nutrient, presents a different kind of risk. Unlike nitrogen, which can be synthesized from air, phosphorus must be mined from finite rock deposits. Estimates suggest readily available phosphorus supplies will fall short of agricultural demand within 30 to 40 years. The supply chain is concentrated in just a few countries, making global agriculture vulnerable to price spikes and geopolitical disruption. Recent volatility in phosphorus prices has already hit farmers in developing countries hardest.
Pests Moving Into New Territory
Warming temperatures are redrawing the map of agricultural pests. Insects that were once confined to tropical or subtropical zones are establishing themselves in regions that used to be too cold for them. The diamondback moth, a destructive pest of cabbage-family crops, has been found on Norway’s Svalbard archipelago, 800 kilometers north of its previous range limit. The pink bollworm, a major cotton pest, is expanding from frost-free zones in southern Arizona into central California’s cotton belt. The olive fly is expected to push northward across Europe as winters become milder.
A study of 35 non-migratory European butterfly species found that 63% had shifted their ranges 35 to 240 kilometers northward during the 20th century. Butterflies aren’t crop pests, but they serve as a biological indicator: if they’re moving, so are the insects that eat harvests. Warmer winters also mean fewer hard freezes to kill overwintering pest populations, leading to larger infestations earlier in the growing season. For farmers, this translates to higher pesticide costs, more crop damage, and the need to manage species they’ve never encountered before.
Pollinator Decline and Food Diversity
About 17% of global crop production value depends on animal pollination, primarily from bees. But pollination-dependent crops represent an outsized 28% of global agricultural trade, meaning disruptions ripple far beyond the farms where they occur. If pollinator populations collapsed entirely, models project crop prices would rise by 30%, producing a global welfare loss of $729 billion, roughly 0.9% of global GDP.
The nutritional consequences would be severe as well. Global vitamin A availability could fall by 8%, with similar declines in other micronutrients concentrated in fruits, vegetables, and nuts that rely on pollinators. These aren’t calorie crops like wheat and rice (which are wind-pollinated), so the damage wouldn’t show up as famine. It would appear as worsening malnutrition and diet-related disease, particularly in communities that already lack dietary diversity. Habitat loss, pesticide exposure, disease, and climate disruption of flowering schedules all contribute to pollinator decline, making it another threat that climate change intensifies rather than causes alone.
Why Short-Term Supply Hides Long-Term Risk
Current global grain production looks reassuring on the surface. The USDA’s 2025/26 projections estimate total grain supplies (wheat, coarse grains, and rice) at nearly 3.75 billion metric tons, with consumption at about 2.96 billion tons and comfortable ending stocks of 790 million tons. Oilseed and cotton supplies show similar buffers.
These numbers reflect a food system that is, for now, keeping pace with demand. But they mask the eroding foundation underneath. Yields are being maintained through intensification: more irrigation, more fertilizer, more pesticides. Each of those inputs faces its own sustainability wall. Aquifers deplete. Nitrogen pollutes. Phosphorus runs out. Pests develop resistance. The gap between what we produce today and what the land can sustain over decades is widening, even as this year’s harvest looks adequate.
The core challenge is that agricultural sustainability isn’t threatened by a single dramatic crisis. It’s threatened by the simultaneous, gradual degradation of soil, water, nutrient cycles, beneficial insects, and climate stability. Climate change sits at the center because it accelerates all the others. Addressing it means not only reducing emissions but rebuilding the resilience of farming systems, from the soil up, before the compounding pressures become impossible to reverse.