Britain should include international shipping emissions in its climate targets to 2050, in an effort to regulate the growing carbon footprint of the sector, a body which advises the government on climate action said Thursday.

The government could decide next year whether to include shipping emissions in its climate targets, after the Committee on Climate Change (CCC) makes a formal recommendation next March, the CCC in a statement.

If the UK did include emissions, it would become the first nation to regulate the carbon footprint from this sector as part of its effort to curb global warming.

It is clear that shipping emissions could well be significant, and so cannot be ignored -- they should be included under the Climate Change Act, said David Kennedy, chief executive of the committee.

The CCC unveiled its first detailed assessment of carbon emissions from ships entering UK ports, showing current emissions are likely to be in a range of 12-16 million tonnes of carbon dioxide (CO2) or higher.

UK law requires the nation to make an economy-wide cut in its greenhouse gas emissions to 160 million tonnes of carbon dioxide equivalent by 2050, which equates to an 80 percent emissions reduction against 1990 levels.

The government is required to take account of the CCC's advice. Parliament must decide by the end of 2012 whether shipping and aviation emissions should be part of the 2050 target and national carbon budgets, which are legally-binding targets that are set over five-year periods.

International shipping and aviation were excluded in the carbon budgets largely due to difficulties in estimating emissions from those sectors.

The CCC projected ships entering UK ports will emit up to 18 million tonnes or 11 percent of the total emissions permitted under the government's Climate Change Act by 2050.

The committee's forecast is 80 percent higher than a previous government estimate of 10 million tonnes, which was based solely on the consumption of bunker fuel.

The CCC's estimate takes into account the miles travelled by, and the carbon intensity, of all ships arriving at UK ports.

The committee has already provided detailed projections for aviation emissions in a December 2009 report, and will provide its advice for both sectors at the same time next March.

OPTIONS

The CCC is weighing three possible options for shipping before it makes its recommendation, because of uncertainties in the methodology used to calculate emissions and legal issues.

The first is to include shipping emissions in the 2050 target and carbon budgets.

Another is to include the sector in the 2050 target and carbon budgets only when progress has been made on developing internationally agreed methodologies for estimating emissions.

The third option is to include the sector's emissions in the 2050 target, but not in the carbon budgets until a later date.

Whether that (third option) is possible from a legal perspective is something we will be looking further in the next three months, Kennedy told reporters earlier this week.

David Balston, a director at the UK Chamber of Shipping, a trade group, welcomed the committee's work and agreed that international shipping should be included in UK carbon budgets.

We do stress, however, that any solution must be global rather than regional to avoid distorting world trade and potentially damaging an industry that is vital to the future prosperity of the United Kingdom, he said.

(Reporting By Jeff Coelho; editing by James Jukwey)