Energy & Transition
Ammonia
A nitrogen-hydrogen compound essential to fertiliser production — currently made mainly from fossil fuels with significant emissions — and a candidate low-emission fuel and hydrogen carrier.
Definition
A compound of nitrogen and hydrogen (NH₃) produced industrially by combining nitrogen with hydrogen, mostly derived from natural gas or coal. About 70% of output feeds fertiliser production; the remainder serves chemicals and industrial uses. Conventional production is highly energy- and emissions-intensive, averaging around 41 GJ of energy per tonne.
References
Energy intensity (41 GJ/t vs 28–36 BAT); use-phase >70% of fertiliser life-cycle emissions; near-zero routes (electrolysis, CCS, pyrolysis) and announced capacity; scenario emission cuts.
Overview
What it means
Ammonia matters to sustainability on three fronts.
Production emits roughly 2% of global CO₂ from energy and industrial processes (IEA roadmap analysis); fertiliser use generates further nitrous oxide emissions — with use-phase emissions estimated at upwards of 70% of life-cycle GHG emissions of nitrogen fertilisers; and, because NH₃ carries hydrogen without carbon, near-zero-emission ammonia (from electrolysis, or fossil routes with CCS) is being developed as a fuel for shipping and power and as a hydrogen carrier.
How it is used
The IEA's Ammonia Technology Roadmap tracks deployment of near-zero-emission production (about 8 Mt of announced capacity by 2030, ~3% of 2020 capacity) and efficiency gains. Agricultural ammonia emissions (the air pollutant NH₃, a precursor of fine particulate matter) are regulated separately under air-quality regimes such as the UNECE Gothenburg Protocol.
Why it matters
Ammonia sits at the junction of food security and decarbonisation: the world needs its fertilisers, but must cut production and use-phase emissions while scaling cleaner routes. Its dual identity — pollutant precursor and prospective clean fuel — makes it a recurring subject in climate and air-quality policy.
Definitions and controversy
"Ammonia emissions" in air-pollution contexts refers to gaseous NH₃ released mainly from livestock and fertilised fields, distinct from the CO₂ emissions of ammonia manufacture.
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