Articles | Volume 13, issue 23
Atmos. Chem. Phys., 13, 12059–12071, 2013

Special issue: Arctic Summer Cloud Ocean Study (ASCOS) (ACP/AMT/OS inter-journal...

Atmos. Chem. Phys., 13, 12059–12071, 2013

Research article 12 Dec 2013

Research article | 12 Dec 2013

Climate and air quality trade-offs in altering ship fuel sulfur content

A. I. Partanen1, A. Laakso1, A. Schmidt2, H. Kokkola1, T. Kuokkanen3, J.-P. Pietikäinen4, V.-M. Kerminen5, K. E. J. Lehtinen1,6, L. Laakso4,7, and H. Korhonen1 A. I. Partanen et al.
  • 1Kuopio Unit, Finnish Meteorological Institute, Kuopio, Finland
  • 2School of Earth and Environment, University of Leeds, Leeds, UK
  • 3Department of Law, University of Eastern Finland, Joensuu Campus, Joensuu, Finland
  • 4Climate change, Finnish Meteorological Institute, Helsinki, Finland
  • 5Department of Physics, University of Helsinki, Helsinki, Finland
  • 6Department of Applied Physics, University of Eastern Finland, Kuopio campus, Kuopio, Finland
  • 7School of Physical and Chemical Sciences, North-West University, Potchefstroom Campus, Potchefstroom, South Africa

Abstract. Aerosol particles from shipping emissions both cool the climate and cause adverse health effects. The cooling effect is, however, declining because of shipping emission controls aiming to improve air quality. We used an aerosol-climate model ECHAM-HAMMOZ to test whether by altering ship fuel sulfur content, the present-day aerosol-induced cooling effect from shipping could be preserved, while at the same time reducing premature mortality rates related to shipping emissions. We compared the climate and health effects of a present-day shipping emission scenario (ship fuel sulfur content of 2.7%) with (1) a simulation with strict emission controls in the coastal waters (ship fuel sulfur content of 0.1%) and twofold the present-day fuel sulfur content (i.e. 5.4%) elsewhere; and (2) a scenario with global strict shipping emission controls (ship fuel sulfur content of 0.1% in coastal waters and 0.5% elsewhere) roughly corresponding to international agreements to be enforced by the year 2020. Scenario 1 had a slightly stronger aerosol-induced effective radiative forcing (ERF) from shipping than the present-day scenario (−0.43 W m−2 vs. −0.39 W m−2) while reducing premature mortality from shipping by 69% (globally 34 900 deaths avoided per year). Scenario 2 decreased the ERF to −0.06 W m−2 and annual deaths by 96% (globally 48 200 deaths avoided per year) compared to present-day. Our results show that the cooling effect of present-day emissions could be retained with simultaneous notable improvements in air quality, even though the shipping emissions from the open ocean clearly have a significant effect on continental air quality. However, increasing ship fuel sulfur content in the open ocean would violate existing international treaties, could cause detrimental side-effects, and could be classified as geoengineering.

Final-revised paper