Ocean shipping companies made reductions in the levels of carbon dioxide they emit per journey in 2011.
New data shows they achieved a drop of more than five per cent in terms of grammes of carbon dioxide emitted per kilometre travelled by cargo at sea when compared with 2010.
The figures have been released by the Clean Cargo initiative, a ten-year-old industry programme that measures and reports on the environmental impact of companies in the shipping sector.
Its data covers 13 of the world’s leading ocean container carriers, which operate more than 2000 ships and account for around 60 per cent of ocean container capacity worldwide.
Improvements were made in both categories measured – non-refrigerated cargo, where emissions fell by 5.7 per cent on 2010, and refrigerated cargo, where emissions dropped by 5.3 per cent.
This is the third year that Clean Cargo has publicly released such data, with emissions for non-refrigerated cargo falling by 9.4 per cent across the reporting period – from 75.2 grammes of carbon dioxide emitted per kilometre travelled in 2009 to 68.1 grammes in 2011.
However, the figures for refrigerated cargo have been less impressive, reflecting historical difficulties in modifying refrigeration technology. There was actually a rise in emissions from the transportation of refrigerated cargo from 2009 to 2010, and over the three year data period, emissions have fallen by just under one per cent on the 2009 baseline.
Clean Cargo points out that the decline in emissions from 2010 to 2011 is due to 'improvements in carrier fleet efficiency' rather than any slowdown in global trade, as the data measures emissions per journey rather than an absolute figure.
Cannie Farag, Clean Cargo project manager, said: 'The priority now is to support efforts to standardize emissions calculations across the entire logistics supply chain.' She added that while good progress had been made by companies in measuring their emissions, it is now 'critical' to move from measurement and reporting 'to real performance improvement over time'.
According to the International Chamber of Shipping, the global shipping industry should be able to reduce carbon dioxide emissions per tonne of cargo transported by 20 per cent between 2005 and 2020 through a combination of technological and operational developments, as well as the introduction of new and bigger ships that perform better on energy efficiency.