5 October 2007
Citing the “threat of global climate disruption”, California Attorney General Edmund G. Brown Jr. and a coalition of environmental groups represented by Earthjustice petitioned the US Environmental Protection Agency (EPA) to adopt greenhouse gas (GHG) emissions regulations for ocean-going vessels.
Ocean-going vessels, in total, emit more CO2 emissions than any nation in the world except the USA, Russia, China, Japan, India and Germany. The GHG emissions from ships are projected to increase nearly 75% during the next 20 years.
In the petition, Brown asks the EPA to:
- Make a finding that carbon dioxide emissions from ocean-going vessels contribute to air pollution and endanger human health and welfare.
- Set standards for reducing such carbon dioxide emissions.
Brown said that under the reasoning of the United States Supreme Court’s holding in Massachusetts v. EPA, the EPA has the authority to adopt standards for GHG emissions from vessels that enter US territorial waters.
The United Nations International Maritime Organization (IMO) has authority under international treaties to establish pollution standards for vessels but to date has not adopted controls on greenhouse gas emissions. At a recent meeting of the IMO Marine Environment Protection Committee, it was agreed to inventory greenhouse gases by 2009, but no commitment was made to regulate such emissions.
GHG emission reductions from ships could be achieved by such means as development of more efficient engines or reduction of cruising speeds. The coalition’s petition is also asking to require marine vessels to use cleaner fuels. This, however, might be actually a counterproductive measure to control global warming, as refining residual marine fuels requires significant energy input at the refinery which can be reasonably anticipated to globally increase GHG emissions.
Increased fuel efficiency targets may be also conflicting with low NOx emission requirements which are also being developed by the EPA. In the diesel engine, NOx reductions are typically accompanied by a fuel economy penalty. Some electronically controlled large marine engines are already available with two calibrations: one optimized for low NOx emissions and used near ports, and another optimized for fuel efficiency, used in open sea.