SEANA -Shipping Emissions in the Arctic and North Atlantic atmosphere

Shipping is the largest means of moving freight globally. Ships consume dirty fuels, making them one of the most important sources of anthropogenic aerosol in the marine atmosphere. Aerosols from shipping can affect the climate directly through absorption and scattering of radiation, with an overall cooling effect to the atmosphere. They can also indirectly influence the climate by changing cloud properties, e.g., albedo and lifetime, which further cools the atmosphere.

Two key challenges for assessing future climate impact of shipping emission are (i) knowing the status of the present-day aerosol system - as a baseline from which any climate predictions are made and (ii) quantifying the amount of pollutants emitted.

Currently little consensus exists on the impact of shipping emissions in the Arctic and North Atlantic Atmosphere (ANAA) primarily due to a lack of observations and insufficient model skills. Recent modelling work suggests that the Arctic aerosol baseline should account for a disparate range of natural sources. Few models are sufficiently comprehensive, and while some models can reproduce aerosol in some Arctic regions, there is evidence that models can produce similar results via different sources and processes. An inability to reflect the aerosol baseline processes can have significant impact on the reliability of future climate projections.

Shipping is also undergoing significant changes. In January 2020, a new International Maritime Organisation (IMO) regulation comes into force, which reduces, by more than 80%, the sulphur content in maritime fuel oils. Superimposed on that, recent climate induced changes in Arctic sea ice are opening up new seaways enabling shorter sea passages between key markets. Significant growth in shipping via the North West Passage (NWP) is anticipated in the coming years. Thus, there is a short window of opportunity to define current atmospheric conditions, against which the impact of these changes must be determined.

SEANA will take advantage of the above-mentioned opportunity to make multiple atmospheric measurements over multiple platforms to understand the present-day baselines - sources of aerosol particles including the contribution from shipping - and to determine the response of ANAA aerosol to new fuel standards after 2020. Extended measurements will be conducted at two stations adjacent to the NWP enabling the source of particles to be apportioned using receptor modelling approaches. In addition, SEANA will participate in a Korean cruise to the west side of the NWP, and a NERC cruise to the east, to measure both natural and anthropogenic particles and aerosol processes in two contrasting Arctic environments.

These new observations will be integrated with recent / ongoing measurements at partner ANAA stations to generate a benchmark dataset on aerosol baseline in ANAA to constrain processes in the UK's leading global aerosol model, ensuring that the model is reproducing the baseline aerosol in the ANAA faithfully. We will then test the models' response to significant reductions in shipping sulphur emissions using observations taken during the transition to low-sulphur fuels in 2020. The revised model, which can reproduce current "baselines" and accurately predict the response of emission changes in the ANAA, will then be used to predict the future impact of shipping on air quality, clouds and radiative forcing under multiple sea-ice and shipping scenarios.

SEANA will deliver a major enhancement of UK's national capacity in capturing baseline ANAA aerosol and responses to emission regulations, results of which will inform shipping policy at high-latitudes.

The principal beneficiaries include government agencies including UK Met Office, Faroe Islands and Greenland Environment Agency; Arctic Council; Intergovernmental Panel on Climate Change (IPCC); and International Maritime Organisation (IMO) and the shipping industry.

Government agencies: Across the Arctic regions, observations are extremely sparse, either continuous or on a focussed-intensive basis. The lack of observations severely hinders progress towards understanding/managing the regional environment. For example, the recent (2017) Scientific Report from DCE - Danish Centre for Environment and Energy demonstrates the need for information on the impact of shipping in Greenland. SEANA will provide new data and model tools to improve the assessment on the impact of shipping on the Greenland environment. The Faroese Environment Agency operate long-term monitoring activities to capture information on air pollutants, including those from shipping activities in the region. Their activities will be considerably enhanced by the more detailed observations on the Faroe Islands as part of SEANA, enabling them to better understand the sources of air pollution. This will support the development of potential air pollution mitigation strategies, including the control of shipping emissions. Improvements to numerical models, underpinned by robust measurements, will provide more confidence that future projections of air quality/climate are reliable - currently this is not the case.

Arctic Council: The Arctic Council is a high-level intergovernmental forum which addresses issues faced by the Arctic governments and people living in the Arctic region. SEANA results will provide benchmark data on aerosol baselines and predictions of future shipping impact that can support policy-making in slowing down Arctic climate change.

IPCC: IPCC would benefit from an improved global climate model with a better understanding of the aerosol and climate in the high latitudes, which is highly uncertain in models.

International Maritime Organisation and the Shipping industry: Shipping industry and IMO will need evidence of the impact of their sulphur-reduction policy on air quality and its benefits to human health, as well as on the climate. SEANA will also provide fundamental information and modelling tool that can be used by IMO in the future to assess impacts of shipping for years to come and to develop future policies.


Wider Beneficiaries include the general public and the indigenous people living in the Arctic.

General public: It is expected that the IMO's new regulation on shipping fuel limit will deliver a cleaner air and health improvement globally, in particular in the coastal regions. The general public will be interested in knowing whether it actually delivers what it was predicted by the IMO. Furthermore, there is a considerable interest/awareness within the wider general public over the status of the Arctic region, in particular in light of changing sea ice. Future changes to the Arctic climate system is a sensitive issue that has direct impact on daily life, as demonstrated by the occasional Arctic snow blasts of the UK, causing major disruption to transport. We expect SEANA result will excite the next generation of scientists and likely capture the imagination of a plethora of young people.

Indigenous people living in the Arctic: They will benefit from an improved understanding and prediction of climate change in the Arctic, which has direct impact on their life in the future. They will also benefit from an improved understanding of the likely impact of future shipping on local air quality, which directly affects their health. SEANA's outcomes will support future policy actions to control future climate change and air pollution in the Arctic, which will directly improve their welfare.