Hydrogen: Emissions

The 920 Mt CO2 problem clean hydrogen must solve

What this tab covers The greenhouse-gas footprint per tonne, split by lifecycle phase (feedstock, production, movement, use, end of life), the global total, other environmental impacts, levers and low-carbon routes, India's position, and where the investment opportunity lies. Emission intensity 12.0 t CO2e per t H2 range about 0.5-26 · cradle-to-gate world average; gas SMR about 10-12 including upstream, coal 22-26, electrolysis on renewables under 1 Global emissions per year 920 Mt CO2 per year 2022 · direct CO2 from hydrogen production as reported by IEA; upstream methane adds more

Per t of hydrogen, cradle-to-gate. Intensity: IEA Global Hydrogen Review series (indicative). Global total: IEA Global Hydrogen Review 2023 (indicative).

Share of footprint by lifecycle phase

Feedstock 15% Production / process 83% Movement 2%

Footprint by lifecycle phase

Phase	Intensity	Share	Main sources of emissions	Notes	Source
Feedstock	about 1.5-2 t CO2e per t H2	15%	methane leaks and energy in gas supply; coal mine methane	highly variable by gas basin	indicative
Production / process	about 9-10 t CO2 per t H2 (SMR); 20+ (coal)	83%	carbon in the feedstock released as CO2, plus reformer fuel	about half is a pure CO2 stream; some is used to make urea	IEA (indicative)
Movement	about 0.1-0.3 t CO2e per t H2	2%	compression, pipeline, trucking	most hydrogen is used on site	indicative
Use	zero CO2 at point of use	–	burned or reacted to water	leaked hydrogen has an indirect warming potential of about 11 over 100 years (Sand et al. 2023, indicative)	indicative
End of life	not applicable	–	consumed in products	not applicable	not applicable

Other environmental impacts

Water use of 9 t per t H2 or more for electrolysis matters in dry regions. Coal gasification produces slag and sulphur. Leaks raise methane lifetime in the air.

Levers to cut emissions

Carbon capture on SMR or ATR (blue), cutting process CO2 by 60-95% at about $0.5-1/kg extra (indicative)
Electrolysis on renewable power, under 2 kg CO2e/kg H2 under India's standard
Replace grey hydrogen in existing refineries and ammonia plants first: IEA expects >2 Mt a year of such use by 2030 from committed projects
Cut upstream methane leaks from gas supply
Use Chinese electrolysers at $600-1,200/kW to lower capex (IEA 2024)

India

India's roughly 6 Mt of grey hydrogen emits about 60-70 Mt CO2 a year (indicative, basis: about 10-12 t CO2 per t H2). The Mission targets 5 Mt a year of green hydrogen by 2030 and has awarded refinery and green ammonia tenders.

Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.

Low-carbon routes

Route	Intensity	Cost premium	Status	Source
Green hydrogen (renewable electrolysis)	under 1-2 t CO2e per t H2	about $2.4/kg over grey in India (2025)	2 GW installed worldwide (2024); IOCL Panipat 10 kt a year; NEOM about 2.2 GW	IEA GHR 2025; JMK Research (2025)
Blue hydrogen (ATR with CCS)	about 1-4 t CO2e per t H2 depending on capture rate and methane leakage (indicative)	about $0.5-1/kg (indicative)	CF/JERA/Mitsui Blue Point (Louisiana) for ammonia; civil construction from 2026	CF Industries 2025 results; indicative

For a climate investor The first real market for green hydrogen is replacing grey hydrogen inside existing refineries and fertiliser plants, where the offtaker and the pipe already exist. India's tenders show $4.4-4.6/kg is achievable with cheap solar and wind; parity with grey needs about $2/kg, which depends on electrolyser cost, high power capacity factors and low-cost capital. Builders include L&T Green, ACME, Ocior Energy, NTPC Green, AM Green and Reliance in India, and Air Products and ACWA Power at NEOM.