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Atmospheric Composition and Radiative forcing changes due to UN International Ship Emissions regulations (ACRUISE)

Ships on the horizon with sunlight showing through clouds

Completed project

Project start: January 2019  |  Project end: January 2022
Principal Investigator: Dr Ming-Xi Yang
Other participants from PML: Dr Frances Hopkins, Dr Tim Smyth, Dr Tom Bell

Ship emissions are significant sources of polluting aerosols in coastal regions, causing hundreds of thousands of premature deaths per year globally. To address this, in 2015 the International Maritime Organization (IMO) ordered a reduction in the maximum ship sulphur emissions in coastal Sulphur Emission Control Areas (SECAs) of Europe and North America. From January 2020 this will be expanded to international waters, to reduce sulphur emissions from 3.5% to 0.5% of fuel mass.

This reduction in sulphur emissions from shipping is predicted to almost halve the number of premature deaths globally from sulphate aerosols but less sulphate in the atmosphere is also expected to reduce cloud brightness, reflecting less incoming solar radiation, which may ultimately lead to an increase in global average temperature.

ACRUISE will use a multidisciplinary approach to quantify the impact on atmospheric chemistry and climate due to the introduction of the IMO’s regulation of sulphur emissions from shipping in international waters in January 2020. This approach will combine in situ observations (aircraft and surface stations), satellite analysis and modelling across a large range of scales (from cloud, to regional to global) to quantify the chemical and climatic impact of the 2020 sulphur emission regulation.

ACRUISE is endorsed by the Surface Ocean Lower Atmosphere Study (SOLAS).