Thesis Defense - Master of Science Nikolai Figenschau

Master of Science Nikolai Figenschau will Wedneday November 5st, 2025, at 12:15 hold his Thesis Defense for the PhD degree in Science. The title of the thesis is:

« Assessing the impact of recent and future ship traffic on regional air quality degradation along the Northeast Passage. From a sea ice hypothesis to resource-driven destinational shipping, and its impact on regional air quality  »

Abstract:

The Arctic is experiencing intensified maritime activity as a result of declining sea ice driven by climate change. This rise in shipping presents a growing concern for regional air quality, particularly due to emissions of nitrogen oxides (NOₓ) and sulphur dioxide (SO₂). However, there is limited research on the temporal, spatial, and sectoral dynamics of Arctic ship emissions and their environmental impacts.

This thesis provides the first monthly-resolution, decadal (2013–2023) analysis of ship-associated emissions along the Northeast Passage (NEP), with a focus on NOₓ and SO₂. Using ship traffic data, emission inventories, sea ice extent, and production statistics, the study identifies key emission drivers, projects emissions to 2030, and evaluates air quality impacts using chemical transport modelling (CTM) and satellite observations (TROPOMI).

The results show that sea ice was the dominant control on emissions before 2018. Since then, emissions have been increasingly driven by resource extraction, particularly in the oil and gas sectors. Large, fuel-intensive ships with icebreaking capabilities now operate year-round in areas like the Kara Sea and Gulf of Ob. Between 2013 and 2023, NOₓ emissions more than doubled, while SO₂ increased by 68%, dampened by the International Maritime Organization's sulphur cap. Both pollutants are projected to double again by 2030.

Spatially, ship-induced NO₂ and SO₂ concentrations have increased most in the Fennoscandian coast, Svalbard, the Kola–Ob Lane, and especially the Gulf of Ob, where contributions reached up to 90%. These changes pose growing risks of acidification and ecosystem stress.

Finally, the study demonstrates the utility of combining CTM simulations with satellite observations to assess shipping impacts and detect underreported emissions, particularly in the Russian Arctic. The findings underline the need for improved monitoring, updated inventories, and regulatory action to address the growing environmental footprint of Arctic shipping.

Evaluation Committee:

• 1st Opponent: Professor Emeritus Harilaos N. Psaraftis, Technical University of Denmark

• 2nd Opponent: Associate Professor Jean-Christophe Raut, Sorbonne University, France

• Internal member and leader of the committee: Associate Professor Tae Eun Kim, Department of Technology and Safety, UiT