Ship sulfur emissions found to strongly impact worldwide ocean and coastal pollution

August 19, 1999

PITTSBURGH -- Ship emissions are a dominant contributor to atmospheric sulfur dioxide concentrations over much of the world's oceans and in several coastal regions, researchers from Carnegie Mellon University and Duke University report in a Nature article today.

This news follows the Carnegie Mellon team's initial finding that air emissions from trade-carrying cargo ships powered by diesel engines are among the world's highest polluting combustion sources per ton of fuel consumed, published Oct. 30, 1997 in Science.

The most important finding from this study, according to Carnegie Mellon authors Spyros Pandis, James Corbett, Paul Fischbeck and Kevin Capaldo, and Duke author Prasad Kasibhatla, is that ships affect scientific understanding of climate change.

Ships use the tar-like, sulfur-concentrated remains of petroleum left once the gasoline, oil and all other products have been extracted. This high-sulfur fuel is responsible for the significant environmental impacts of ship sulfur emissions. Regionally, sulfur emissions contribute to acid rain, which can pollute freshwater lakes and rivers, and damage vegetation.

"Ships also have been known to contribute to the formation of clouds over the ocean," Pandis said. "Sulfur emissions have a large role in the formation of aerosols (tiny particles) on which water condenses to form clouds. The interactions of aerosols and clouds have been identified as one of the most important uncertainties in understanding the rate of climate change, or global warming, because clouds reflect energy and thereby reduce the net warming effect of long-lived greenhouse gases."

"Since aerosols have a much shorter lifetime in the atmosphere -- about a week compared to decades and hundreds of years for greenhouse gases -- these effects have been difficult to quantify," Corbett added. "Our study shows that sulfur from ships may be an important factor in solving this part of the global climate change puzzle."

The study also shows that the effect of ship emissions is most evident in the Northern Hemisphere oceans, where greater than 60 percent of sulfur dioxide concentration in the atmosphere and 30 percent of all sulfates can be attributed to ships. Except for the area encompassing Australia, the Southern Hemisphere oceans are almost unaffected. This is because of the heavier shipping that occurs in the north. This is most important for coastal cities that receive the brunt of sulfur pollution from ships.

This study was funded by a grant from the National Science Foundation and the Department of Engineering and Public Policy at Carnegie Mellon.

Carnegie Mellon University

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to