Fighting climate change: How clean air can help feed millions.

Stricter climate targets are meant to stop the planet tipping into dangerous overheating. At the same time, researchers caution that these very measures can push food prices up and drive millions closer to hunger. New analyses now show that a frequently overlooked factor can claw back part of the damage: cleaner air can lift crop yields noticeably.

How climate protection can unintentionally increase hunger

Many pathways designed to keep global warming to 1.5°C lean heavily on bioenergy and large-scale afforestation. On paper that sounds sensible, but there is a catch: both require land-the same land that currently produces food.

Where forests are planted for afforestation schemes, or where energy crops for biofuels expand across vast fields, there is less room left for wheat, rice, or vegetables. That reduces the supply of food on global markets.

On top of this comes carbon pricing (CO₂ pricing). Anyone using coal, oil, or gas pays more. Agriculture feels that pressure in several places at once:

• Fertiliser becomes more expensive because its production is energy-intensive.
• Tractors, harvesting machinery, and irrigation systems cost more to run.
• Transporting and processing food adds more to the bill.

As production costs rise, they show up in shop prices: food becomes pricier, and low-income households can afford less. Especially in places where many people already live on the edge, calorie intake can then fall short.

Figures from global models: 56 million more people at risk

An international research team examined this tension using six global agricultural and economic models. The findings were published in Nature Food.

"Without countermeasures, climate protection strategies on a 1.5°C pathway could, by 2050, put around 56 million additional people at acute risk of hunger-an increase of about 17 percent compared with a scenario without strict climate policy."

The striking point is what happens in the reference case: under an assumption of moderate economic development, the number of people facing hunger would otherwise fall sharply-from about 720 million today to around 330 million by mid-century. Climate action that ignores food security would significantly slow that progress.

Toxic air: why ozone destroys harvests (and what it means for climate policy)

Against this bleak backdrop, there is a ray of hope that has less to do with money and more to do with atmospheric chemistry. Ground-level (tropospheric) ozone acts like an invisible toxin for plants.

This gas forms when precursor substances such as methane or nitrogen oxides react in sunlight. When ozone enters leaves, it damages cells, disrupts metabolic processes, and prevents plants from turning as much of their energy into growth and grain.

Staple crops are particularly sensitive, including:

• Wheat
• Rice
• Maize

The higher the ozone load, the more yields drop. Farmers cannot simply “fertilise it away” or offset it with extra irrigation, because the harm happens directly within the leaf tissue.

Lower emissions, less ozone, higher yields

In practical terms, climate protection tends to reduce methane emissions and cut nitrogen oxides from transport, industry, and agriculture. Those are precisely the ingredients that ultimately create crop-damaging ozone.

So when countries reduce greenhouse gases, they not only limit warming; over time they also lower ground-level ozone. Plants, in effect, “breathe easier”, invest more energy in growth and seed formation, and harvests improve.

"According to the new calculations, higher yields from lower ozone offset around 15 percent of the additional hunger risk created by strict climate policy-equivalent to about 8.4 million people who would be less severely at risk in 2050."

Earlier studies on climate policy and food security often left this air-quality effect out. That meant they tended to overestimate the rise in hunger. The new analysis is the first to incorporate, in a systematic way, how strongly cleaner air can stabilise harvests.

India and Sub-Saharan Africa benefit most

The gains are not evenly spread. Two regions stand out: India and Sub-Saharan Africa.

These areas already include many people who regularly do not get enough calories. And it is here that cutting ozone has the strongest effect.

• India: Better air quality cushions the negative food-security impact of climate policy by around 39 percent. The main reason is that wheat-one of the country’s key staple foods-responds very strongly to reduced ozone.
• Sub-Saharan Africa: The relief is much smaller, at about 8 percent. Here, crops such as maize and soya dominate, and they are less sensitive to falling ozone levels.

Despite these regional advantages, most models still show the same overall message: emissions reductions alone do not bring hunger risk down, and in many scenarios it rises. Cleaner air helps-but it only absorbs part of the shock.

What climate policy must change to fill plates rather than empty them

The researchers argue that food security needs to be built into climate plans from the outset-not bolted on afterwards. If policymakers focus only on tonnes of CO₂, they risk missing empty plates.

"At its core, this is about linking climate protection and food policy, rather than letting them work against each other."

Three levers for more food alongside strict climate targets

Several tools can help ensure ambitious climate goals and well-stocked plates remain compatible:

• Sustainably raise productivity
  More resilient crop varieties, precision fertilisation, improved irrigation, and digital technologies can help farmers produce higher yields per hectare without automatically expanding land use.

• Plan land use more intelligently
  Afforestation projects should prioritise degraded soils or land poorly suited to arable farming. At the same time, clear limits are needed for energy crops so they do not compete directly with food production.

• Cut food losses
  A substantial share of what is grown spoils between field and plate-because of missing refrigeration, poor storage, or waste in retail and households. Every tonne of waste avoided eases pressure on land and on consumers’ budgets.

Key terms explained-briefly

Several expressions come up repeatedly in this debate and can be easy to mix up:

• 1.5°C target: A political and scientific benchmark aiming to keep average global warming, relative to pre-industrial times, as close as possible to 1.5°C. Many climate scenarios are aligned with it.
• Bioenergy: Energy from renewable biological materials such as maize, oilseed rape, or wood. It can replace fossil fuels but uses agricultural land.
• Tropospheric ozone: Ozone near the ground that harms plants, people, and animals. It is different from the protective ozone in the stratosphere that filters the Sun’s UV radiation.
• Agro-economic model: A computational model representing global agriculture, trade, prices, and consumption to estimate the effects of policy choices.

Practical examples: how cleaner air reaches the farm

What looks abstract in global modelling has very tangible consequences on the ground. If, for instance, a country cuts methane emissions from oil and gas production or from poorly covered landfill sites, air quality often improves within a few years. Farmers may not notice it in the colour of the sky, but they do see it in steadier yields.

A farmer in northern India who worries each year about the wheat harvest benefits twice when the air becomes cleaner: less ozone reduces stress on the plants, and the burden from particulate pollution-which can interfere with photosynthesis-often falls as well. Even a few per cent extra yield per hectare can determine whether families still have money at the end of the month for schoolbooks or medicines.

In cities, tighter vehicle emissions limits can look like a purely environmental measure at first. On closer inspection, fewer nitrogen oxides from exhaust pipes also means less ozone formation in rural areas. Anyone who judges climate policy only at the petrol pump or by the price of heating oil underestimates its impact on fields hundreds of kilometres away.

Looking ahead: integrating climate, food, and health

The study suggests that climate protection is about more than preventing heatwaves, droughts, and floods. Every tonne of methane or nitrogen oxide that does not enter the air also protects harvests-and therefore livelihoods. At the same time, it warns against treating climate policy as a purely technical CO₂ ledger.

Anyone planning for the long term needs integrated strategies: lower emissions, targeted support for farmers in poorer countries, a different approach to food in richer states, and a clear-eyed debate about how much land forests, energy crops, and food production should each be allowed to claim.