Global Anthropogenic Emissions Inventory for Hydrogen, Air Pollutants, and Greenhouse Gases: Historical Emissions (1990-2020) and Scenario Projections (2025-2050)

This file presents emissions estimated within the Greenhouse Gas – Air Pollution Interaction and Synergies (GAINS) framework. They show results from the hydrogen module in GAINS, which includes hydrogen (H2) as an indirect greenhouse gas and other emissions related to the hydrogen economy. 1. Emissions Hydrogen (H2) from incomplete combustion or leakages; Nitrogen oxides (NOx) from hydrogen combustion and hydrogen production; Ammonia (NH3) from hydrogen storage and handling; Methane (CH4) and carbon dioxide (CO2) from hydrogen production – production technology only, does not included feedstock lifecycle; Carbon monoxide (CO), fine particulate matter (PM2.5) and sulfur dioxide (SO2) from hydrogen production. Units in kilo tons (kt) of pollutant per five-year step (from 1990 to 2050) 2. Scenario definitions Emission Scenarios are defined as a combination of a) energy demand projections, b) control strategies and c) hydrogen production pathway. The table below indicate the existing combinations and their respective nomenclature. Energy Demand Projection Control Strategy Production Pathway Emissions Scenarios Baseline (BL) Current Legislation (CLE) Current Mix (CM) BL_CLE_CM Mitigation (MT) Current Legislation (CLE) No Fossil (NF) MT_CLE_NF Mitigation (MT) Maximum Feasible Reduction (MFR) No Fossil (NF) MT_MFR_NF Mitigation (MT) Current Legislation (CLE) Clean Production (CP) MT_CLE_CP Mitigation (MT) Maximum Feasible Reduction (MFR) Clean Production (CP) MT_MFR_CP Carbon Neutral (CN) Current Legislation (CLE) No Fossil (NF) CN_CLE_NF Carbon Neutral (CN) Maximum Feasible Reduction (MFR) No Fossil (NF) CN_MFR_NF Carbon Neutral (CN) Current Legislation (CLE) Clean Production (CP) CN_CLE_CP Carbon Neutral (CN) Maximum Feasible Reduction (MFR) Clean Production (CP) CN_MFR_CP Energy Demand Projections: indicate energy consumption predictions. Baseline (BL): This projection reflects the trajectory of current energy systems by following the IEA’s Stated Policies Scenario (STEPS). Mitigation (MT): Based on the IEA’s Announced Pledges Scenario (APS), this projection assumes that countries fulfill their stated climate commitments. Carbon Neutral (CN): Based on IEA’s Net Zero Emissions (NZE) Scenario, this projection foresees a global energy system that achieves net-zero CO₂ emissions by 2050. Control Strategies: represents set of strategies, policies and technologies that seeks to abate emissions. Current Legislation (CLE): This strategy reflects the anticipated emission outcomes based on the enforcement of existing and officially announced policies related to hydrogen production, distribution, leakage, and combustion. Maximum Feasible Reduction (MFR): This strategy illustrates the lowest possible emission levels by assuming widespread adoption of the most advanced technologies available for minimizing hydrogen leakage and controlling combustion-related emissions, without limitations from regulatory or financial barriers. Production Pathway: sensitivity analysis for different hydrogen production methods. Current Mix (CM): assumes the continuation of current hydrogen production mix (62% steam methane reforming, 21% coal, 16% oil, 1% electrolysis) No Fossil (NF): sensitivity analysis for hydrogen production mix composed of 50% biomass and 50% electrolysis Clean Production (CP): sensitivity analysis for hydrogen production mix composed of 50% steam methane reforming, with carbon capture and storage (CCS), and 50% electrolysis 3. Variables structure Activity: input for combustion, fuel cell or feedstock use Agricultural Waste Biofuels Blended Hydrogen (with Natural Gas) Coal Diesel Gasoline Natural Gas (Pure) Other Fossil Pure Hydrogen Waste Sectors: supply-chain area where emissions occur. Agriculture Distribution Networks (of hydrogen) Feedstock (industrial non-energy consumption) Industry (combustion or fuel cell) International Shipping Power Plants Production (of hydrogen) Residential (and commercial) Storage (of hydrogen) Transmission (of hydrogen) Transport (excluding international shipping and aviation) Waste