Fossil Fuels and Crop Yields: Why Ammonia Still Underpins Global Food Security

Fossil fuels and crop yields are tightly linked through modern fertilizer, and fossil fuels and crop yields remain connected until scalable low‑carbon ammonia is competitive.

Synthetic nitrogen fertilizer is the quiet engine of modern agriculture. By supplying bioavailable nitrogen at scale, it has enabled the dramatic rise in cereal yields and helped spare land from conversion. Analyses from FAO and scholars such as Vaclav Smil note that roughly half of the world’s food supply relies on mineral nitrogen fertilizers. Globally, ammonia production feeds downstream products like urea, ammonium nitrate, and UAN that underpin staple crops. 

How the chemistry works. The Haber–Bosch process fixes atmospheric nitrogen (N₂) into ammonia (NH₃) under high temperature and pressure using a hydrogen source—today mostly derived from natural gas via steam‑methane reforming. Industry overviews from the IEA Ammonia Technology Roadmap explain that this route offers unmatched availability, affordability, and reliability at global scale, which is why it dominates current output. 

Why this matters for food and forests. Reliable nitrogen boosts yields so farmers can produce more on existing land, reducing pressure to clear forests or grasslands. Data collated by Our World in Data shows the strong association between fertilizer use and yield growth across regions since the Green Revolution. 

The climate and air‑quality challenge. Conventional ammonia emits substantial CO₂, mainly from hydrogen production. The IEA estimates place the sector among the largest industrial hydrogen consumers and a significant source of industrial emissions. Ammonia application can also generate nitrous oxide (N₂O), a potent greenhouse gas, which is why agronomic best practices are critical. Guidance such as the FAO’s 4R nutrient stewardship (right source, rate, time, place) raises efficiency and lowers losses. 

Transition pathways without risking food security. Low‑carbon options are advancing: • Blue ammonia pairs conventional synthesis with CO₂ capture and storage; • Green ammonia uses renewable electricity to make hydrogen via electrolysis; • efficiency upgrades—heat integration, better catalysts—cut energy per ton even in existing plants. However, today these routes remain cost‑sensitive to power and capital prices, so broad deployment must be sequenced carefully to avoid fertilizer price shocks that would ripple into food inflation. 

A pragmatic policy and market checklist:

1) protect fertilizer affordability for smallholders with targeted, transparent support while avoiding blanket subsidies that distort use;

2) expand pilots for low‑carbon ammonia where renewable or CCS resources are strongest;

3) fund agronomy programs that raise nitrogen‑use efficiency (enhanced‑efficiency fertilizers, precision application);

4) de‑risk new builds with long‑term offtake contracts and standards for hydrogen and ammonia certification; and

5) improve data and MRV so climate benefits are credible from plant to field. 

Until low‑carbon ammonia is competitive at scale, conventional production anchored by fossil energy remains integral to feeding billions. Managing this dependency responsibly—through efficiency, smarter agronomy, and phased deployment of cleaner hydrogen—can safeguard food security while bending the emissions curve. 

Fossil fuels and crop yields: managing today’s realities while scaling low‑carbon ammonia

Balance fertilizer affordability, land‑sparing yields, and stepwise decarbonization so food and climate goals advance together.