Imagine a silent polluter crossing the oceans, responsible for nearly 3% of the world's carbon dioxide emissions—that's the often-overlooked impact of the global shipping industry.
Key Takeaways
- International shipping accounted for 2.89% of total global anthropogenic CO2 emissions in 2018, equivalent to 1,056 million tonnes
- Total GHG emissions from international shipping reached 1,056 Mt CO2e in 2018, including CO2, CH4, and N2O
- Shipping emissions constituted approximately 13% of total transportation sector GHG emissions globally in 2019
- Container ships emitted 222 million tonnes of CO2 in 2018, 21% of shipping total
- Bulk carriers accounted for 15% of shipping CO2 emissions in 2018, totaling 158 Mt CO2
- Tankers emitted 308 million tonnes of CO2 in 2018, representing 29% of total shipping emissions
- Heavy fuel oil (HFO) powered 70% of global shipping emissions in 2018
- Marine gas oil (MGO) contributed to 15% of shipping fuel use in 2018
- LNG-fueled ships emitted 25-30% less CO2 than HFO equivalents per tonne-mile
- Asia accounted for 60% of global shipping CO2 emissions in 2018
- European waters saw 10% of shipping emissions in 2018, totaling 105 Mt CO2
- Intra-Asia routes emitted 250 Mt CO2 in 2018, 24% of total shipping
- Global shipping CO2 emissions grew 10% from 2012 to 2018
- Emissions per tonne-mile fell 12% from 2012-2018 due to efficiency
- Post-IMO 2020, SOx emissions dropped 77% globally in 2020
International shipping contributes a significant share of global emissions despite improving efficiency.
By Fuel and Technology
- Heavy fuel oil (HFO) powered 70% of global shipping emissions in 2018
- Marine gas oil (MGO) contributed to 15% of shipping fuel use in 2018
- LNG-fueled ships emitted 25-30% less CO2 than HFO equivalents per tonne-mile
- Methanol as fuel reduces CO2 by up to 95% when green-produced
- Ammonia fuel could cut GHG emissions by 85-95% in shipping by 2050
- Biofuels in shipping reduced emissions by 76% lifecycle compared to fossil fuels
- Scrubbers on ships reduced SOx by 80-90% but increased CO2 by 2-3.5%
- Hybrid battery ships cut emissions by 20-30% on short routes
- Wind-assisted propulsion reduces fuel use by 5-20% on bulk carriers
- Air lubrication systems decrease drag, saving 4-8% fuel on large vessels
- VLSFO became 80% of bunker fuel post-2020, reducing SOx
- Hydrogen fuel cells in ships achieve 40% efficiency gain over diesel
- Carbon capture on ships can reduce CO2 by 80-90%
- Dual-fuel LNG ships numbered 500+ by 2023
- Methanol dual-fuel orders reached 100 ships by 2023
- ULSFO use 90% compliance post-2020
- Battery-electric ferries zero-emission on 20+ routes
- HFO sulfur content capped at 0.5% globally since 2020
- Propeller upgrades save 5% fuel on 30% fleet
- MGO emissions lower NOx by 20% vs HFO
- Solar panels on ships generate 1-5% power savings
- Warp drives (hull modifications) cut resistance 15%
- Diesel-electric propulsion 10% more efficient
- Flettner rotors save 8-12% fuel on retrofits
By Fuel and Technology Interpretation
The shipping industry is on a promising but comically convoluted path to decarbonization, swapping one dirty problem for another cleaner but imperfect one, as it juggles a bewildering array of partial solutions—from slashing sulfur with scrubbers that ironically boost CO2, to betting on future fuels like ammonia while retrofitting rotors to catch the wind—all while the stubborn specter of heavy fuel oil still looms over most of its emissions.
By Ship Type
- Container ships emitted 222 million tonnes of CO2 in 2018, 21% of shipping total
- Bulk carriers accounted for 15% of shipping CO2 emissions in 2018, totaling 158 Mt CO2
- Tankers emitted 308 million tonnes of CO2 in 2018, representing 29% of total shipping emissions
- LNG carriers contributed 14 Mt CO2 in 2018, about 1.3% of shipping emissions
- Passenger ships emitted 38 Mt CO2 in 2018, 3.6% of total shipping CO2
- General cargo vessels produced 47 Mt CO2 emissions in 2018, 4.5% share
- Ro-Ro cargo ships emitted 33 Mt CO2 in 2018, approximately 3.1% of shipping total
- Chemical tankers accounted for 5% of shipping CO2 at 53 Mt in 2018
- Offshore vessels emitted 17 Mt CO2 in 2018, 1.6% of total
- Fishing vessels contributed around 20 Mt CO2 annually in recent years
- Bulk carriers' CO2 intensity improved 1.5% annually 2012-2018
- Tanker emissions share stable at 29% despite fleet growth
- RoPax ferries emitted 0.025 gCO2/tonne-km in efficient operations
- Cruise ships' CO2 per passenger-day is 3x higher than air travel
- Oil tankers emitted 250 Mt CO2 in 2022, 25% share
- LNG carrier fleet grew 20% yearly, emissions up 15%
- Container fleet CO2 efficiency improved 25% since 2014
- Dry bulk carriers 500 Mt deadweight emit 120 Mt CO2/year
- Ferry emissions in EU 30 Mt CO2 annually
- Car carriers emitted 25 Mt CO2 in 2018, 2.4% share
- Reefers (reefer ships) 10 Mt CO2 annually
- Tugs and supply vessels 15 Mt CO2, high in ports
- Gas tankers 40 Mt CO2 in 2022, doubling since 2015
- Cruise fleet emissions 50 Mt CO2 pre-COVID
- Dredgers emit 5 Mt CO2 yearly globally
- VLCC tankers average 15 gCO2/tonne-mile
- Yachts and pleasure craft add 10 Mt CO2 unregulated
- Naval vessels emissions estimated 20 Mt CO2 globally
By Ship Type Interpretation
The shipping industry floats a sobering truth: while container ships, tankers, and bulk carriers haul the heaviest emissions burden—with tankers alone belching out a quarter of the fleet's CO2—even the most efficient RoPax ferry can't wash away the fact that our global supply chain is still steaming ahead on a sea of fossil fuels.
Global Totals
- International shipping accounted for 2.89% of total global anthropogenic CO2 emissions in 2018, equivalent to 1,056 million tonnes
- Total GHG emissions from international shipping reached 1,056 Mt CO2e in 2018, including CO2, CH4, and N2O
- Shipping emissions constituted approximately 13% of total transportation sector GHG emissions globally in 2019
- Global shipping CO2 emissions were estimated at 938 million tonnes in 2019, representing 2.5% of global energy-related CO2
- In 2021, maritime transport emitted about 1 billion tonnes of CO2, roughly 3% of global CO2 emissions
- Total annual SOx emissions from ships were 11.2 million tonnes in 2018 before IMO 2020 regulations
- NOx emissions from international shipping totaled 14.4 million tonnes in 2018
- Particulate matter (PM2.5) emissions from global shipping were 1.6 million tonnes in 2018
- Black carbon emissions from shipping reached 0.2 million tonnes annually in 2018
- Global shipping fuel consumption was 290 million tonnes of HFO in 2018, contributing to emissions
- Container ship speeds dropped 12% from 2004-2019, cutting emissions
- Total shipping CO2 hit 1,050 Mt in 2022, up from 2020 lows
- Global fleet average age 12 years, older ships 20% higher emissions
- Domestic shipping 10% of global emissions, often overlooked
Global Totals Interpretation
International shipping serves up a 3% slice of the world's CO2 pie—a billion-tonne appetizer of soot, sulfur, and black carbon—which tastes like progress when you consider slowing ships and new rules, but leaves a bitter aftertaste when you remember our global fleet is aging like a polluting cheese.
Regional and Route-Based
- Asia accounted for 60% of global shipping CO2 emissions in 2018
- European waters saw 10% of shipping emissions in 2018, totaling 105 Mt CO2
- Intra-Asia routes emitted 250 Mt CO2 in 2018, 24% of total shipping
- Trans-Pacific routes contributed 150 Mt CO2 annually
- North Atlantic routes accounted for 80 Mt CO2 emissions in 2018
- Middle East to Asia routes emitted 70 Mt CO2 in 2018
- Baltic Sea shipping NOx emissions were 0.2 Mt in 2019
- Mediterranean Sea contributed 5% of European shipping emissions
- West Africa routes saw high PM emissions due to older fleets
- Arctic shipping emissions projected to rise 4-fold by 2060
- East Asia ports handled 40% of global container traffic, high emissions
- Suez Canal traffic emitted 30 Mt CO2 annually pre-Ever Given
- Panama Canal shipping CO2 around 20 Mt per year
- Emissions in SECAs dropped 50% SOx after 2015 regulations
- Europe shipping CO2 150 Mt in 2021, 14% global
- Intra-regional Asia emissions 300 Mt CO2 yearly
- North America ports 15% global emissions concentration
- Indian Ocean routes 100 Mt CO2 from tanker traffic
- Africa shipping emissions 5% global, rising with trade
- Australia routes 40 Mt CO2 from bulk iron ore
- South America intra-trade emissions 20 Mt CO2
- Polar routes emissions doubled 2013-2019
- Middle East bunker hubs supply 30% global fuel, high emissions
- Transatlantic container emissions 50 Mt CO2 yearly
- Caribbean routes high cruise emissions 15 Mt CO2
- Black Sea shipping NOx 0.1 Mt yearly
Regional and Route-Based Interpretation
While the world's seas are theoretically connected, a brutally efficient map of shipping pollution reveals Asia as the undeniable, soot-stained heart of the matter, with its own internal trade pumping out a quarter of the global fleet's CO2, while Europe fumes over its own substantial contribution and the Arctic prepares for a sooty, four-fold expansion of its own.
Trends and Policies
- Global shipping CO2 emissions grew 10% from 2012 to 2018
- Emissions per tonne-mile fell 12% from 2012-2018 due to efficiency
- Post-IMO 2020, SOx emissions dropped 77% globally in 2020
- Shipping emissions declined 3.5% in 2020 due to COVID-19 slowdown
- Projected shipping emissions to rise 50-250% by 2050 without action
- EEDI reduced new ship emissions by 20% since 2013 implementation
- CII regulation targets 40% reduction by 2030 from 2008 levels
- FuelEU Maritime mandates 2% e-fuel uptake by 2025, rising to 80% by 2050
- IMO strategy aims for net-zero shipping by or around 2050
- Slow steaming saved 100 Mt CO2 annually since 2008 recession
- Global shipping emissions rebounded 5% in 2021 post-COVID
- Digital twins optimize routes, cutting fuel 10-15%
- IMO GHG strategy benchmarks 2008 as 1,120 Mt CO2 baseline
- EEXI retrofits target 10% CO2 reduction on 20,000+ ships
- Ship recycling reduced emissions via efficiency gains 15%
- Demand for shipping grew 3% yearly 2010-2019, driving emissions
- EU ETS covers 50% shipping emissions from 2024
- Just In Time arrival saves 5-10% fuel industry-wide
- Mass flowering events reduce fleet emissions 2% temporarily
- Green Corridor initiatives target 70% emission cuts by 2040
- Capacity growth outpaced efficiency 2:1 2015-2020
Trends and Policies Interpretation
While our ships have become leaner and cleaner in fits and starts, the stubborn growth in global trade means we're still sailing in circles unless we fully commit to the profound transformation demanded by our own ambitious targets.
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