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GHG Emissions on the High Seas

Countries must follow strict carbon emission regulations in their territorial seas or exclusive economic zones to meet their commitments under the Paris Agreement on climate change. However, because the agreement doesn't hold signatories directly accountable for reducing carbon emissions on the high seas, no policies have been proposed to tackle shipping's carbon footprint in these areas.

Source: NOAA Ocean Exploration.

The high seas cover more than two-thirds of the world's oceans. Shipping activities that rely on carbon-based fuels on the high seas could become a potential obstacle to global efforts toward reducing carbon emissions and achieving sustainability goals.

Source: Juan L Suarez de Vivero, Department of Human Geography, University of Seville.

High-seas shipping is responsible for almost one-third of all global shipping emissions, which exceeds the annual greenhouse gas emission outputs of many mid-sized European countries. Researchers estimate that emissions from these activities are increasing at about 7% per year, far above the global shipping emission growth rate of about 2%.

Source: Shouyang W. et. al., The Climate Impact of High Seas Shipping, Physical Sciences, Jan. 2022.

The researchers discovered that implementing specific carbon reduction policies in various high seas regions could decrease about 25 million tons of CO2 equivalent emissions during the primary intervention stage and about 54 million tons of CO2 equivalent emissions during the overall intervention stage.

Source: Sailors for the Sea.

The carbon mitigation policy, specifically designed for each high seas region, has proven to be the most effective, with an average of 46.84% emission reduction. This policy outperforms other policies in reducing emissions in a particular region.

Source: Third IMO GHG Study, 2014.

Identifying the key factors driving the emission patterns in different high seas regions and designing tailored carbon mitigation policies for each high seas region shall allow international high seas shipping to contribute to world trading and economic growth in a more environmentally-friendly manner.

However, there is still a need to identify the main emission drivers to implement them in each region on the high seas.

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