- Shipping emits about 1.0–1.1 Gt CO₂/year (2018 estimate). MaritimeCyprus
- Shipping is ~2–3% of global CO₂ emissions. International Maritime Organization+1
- Transport sector emits roughly ~8 Gt CO₂/year (recent years). IEA
- Oil & gas operations (including rigs/platforms) cause ~5.1 Gt CO₂-eq/year. IEA Blob Storage
- About 80% of world trade by volume moves by sea. ics.org.uk
Short comparison: ships vs rigs/platforms vs all others
- Shipping CO₂ ≈ 1.0 Gt per year. That is from IMO estimates. MaritimeCyprus
- Offshore oil & gas operations (rigs/platforms) sit inside the larger 5.1 Gt oil-and-gas total. IEA Blob Storage
- So oil & gas operations (onshore+offshore) are ~5x larger than shipping, by CO₂-eq. IEA Blob Storage+1
- Transport total (~8 Gt) is bigger than shipping alone. Shipping is ~12% of transport CO₂. IEA+1
- Other sectors (power, industry, buildings) together dominate global emissions. Shipping and rigs are smaller slices. IEA Blob Storage+1
Pollutant types — short note
- Ships release CO₂, SOx, NOx, PM, and some methane (low). Sulphur was reduced by fuel rule. ICCT+1
- Rigs/platforms emit CO₂ from fuel and flaring. They leak methane. Methane is potent short-term. globalmethane.org+1
How much transport is done by ships (market share)
- Sea carries ~80% of global trade by volume. That includes bulk cargo, oil, containers. ics.org.uk+1
- By value, seaborne trade is lower but still dominant for bulk and container goods. ScienceDirect
Trends over the last ~25 years (high level)
- Shipping CO₂ rose in recent decades, but growth slowed in some years. IMO found 2012→2018 growth ≈ +9.6%. MaritimeCyprus
- Transport CO₂ overall grew to near 8 Gt in 2022, after pandemic dips. Aviation grew faster than shipping. IEA+1
- Oil & gas operations emissions have stayed large. IEA estimates ~5.1 Gt CO₂-eq in 2022. Improvements in methane control are changing trends regionally. IEA Blob Storage+1
- Over ~25 years, shipping trade volume rose strongly. Emissions rose, but carbon intensity per transport work improved somewhat. greenvoyage2050.imo.org+1
What the numbers mean, simply
- Ships move most goods globally, so shipping’s CO₂ per tonne-km is low. But absolute shipping emissions still matter. arXiv+1
- Oil & gas operations emit more total GHGs than shipping. This includes methane and CO₂ from production, flaring, and fugitive leaks. IEA Blob Storage+1
Key sources used
- IMO Fourth GHG Study / IMO pages. greenvoyage2050.imo.org+1
- IEA transport and energy reports. IEA+1
- IEA report on oil & gas operations (2023). IEA Blob Storage
- UNCTAD Review of Maritime Transport (trade shares). ics.org.uk
- ICCT and methane studies for pollutant details. ICCT+1