Climate Change and the Price of Eggs

Climate change is often named as a cause of rising food prices, and eggs are no exception. The connection is real, but it runs through several separate channels that work at very different speeds: heat on the farm, weather in the grain belts, and the movement of wild birds that carry avian influenza. Looking at each in turn, with this year's numbers, gives a more honest picture than a single headline can.

Laying hens cope poorly with heat. They cannot sweat, and in hot, humid conditions they eat less and lay fewer, smaller eggs with thinner shells. In one controlled study, hens kept at 33°C and high humidity for four weeks ate about 30 percent less feed and laid about 11 percent fewer eggs than hens kept at a comfortable temperature. Extreme heat can also kill birds outright.

Korea's summer of 2026 tested this. By 7 August, the agriculture ministry counted close to one million livestock deaths from the heat, most of them poultry. Laying hens, however, accounted for about 59,000 of those deaths, around 0.08 percent of the national flock, far below the share lost among broilers. The ministry judged the effect on supply to be minimal and, at the same time, forecast egg prices to fall as restocking and imports added supply. In other words, the heat was a cost and a warning, but not what moved the egg price this year.

The larger climate exposure for most egg markets sits far from the farm, in the fields that grow corn and soybeans for feed. Droughts and heatwaves in major producing regions cut harvests and push up grain prices, and because feed is the biggest cost of producing an egg, those moves reach the shelf months later. In September 2026, the FAO's cereal price index was about 17 percent higher than a year earlier; weaker corn supply from the United States and Brazil was among the reasons cited, alongside war-related shipping disruption.

Countries that import most of their feed, such as South Korea and Japan, feel this channel most directly. It is also where climate effects mix with others, such as currency and conflict, which makes it hard to say how much of any single price rise is due to weather alone.

The most consequential channel may be the least certain. Highly pathogenic avian influenza is spread largely by wild waterfowl, and the timing and routes of their migrations are shifting as winters warm. Researchers have linked those shifts to wider and less predictable spread of the virus, including into regions and seasons that used to be quieter. The evidence is still developing, and attributing any individual outbreak to climate change is not possible.

What is clear is the stake. Bird flu is by far the biggest single driver of sudden egg-price spikes, as Korea's own culls of more than 11 million laying hens last winter showed. If a warming climate makes outbreaks more frequent or less seasonal, its effect on egg prices will come mostly through this channel rather than through heat on the farm.

Farms are adapting: better ventilation and cooling, heat-reflective roofing, adjusted stocking density and feeding schedules during heatwaves. Korea's government this summer supported heat-shielding coatings and anti-stress supplements and ran an emergency response office. These measures reduce losses, but they add electricity and capital costs that eventually become part of the price of an egg. Climate change can raise egg prices even in a year when no flock is lost, simply by making it more expensive to keep hens comfortable.

For now, the honest summary is that climate change is a slow, background pressure on egg prices, punctuated by occasional sharp effects through disease and harvests. In 2026 the visible price movements in Korea, Japan and the United States were driven mainly by bird flu and the recovery from it. The heat was felt, but in a supporting role. The case to watch over the coming years is whether outbreaks become more frequent, because that is where a warming climate could turn a background cost into the main event.