Launched in 2000, the Carbon Disclosure Project (CDP) is a disclosure and reporting framework used by 3,000 of the world's largest companies to report their greenhouse gas emissions and climate change strategies.

CDP data can be viewed by investors, corporations, policymakers and their advisors, public sector organisations, government bodies, academics and the public.

The initiative is part of both port operators’ global sustainability programme to reduce their environmental footprints.

Charles Haine, global environment manager at DP World, said: "Energy consumption and carbon emissions in the transportation supply chain is a critical global issue with significant social and environmental implications, and all of us need to be part of the solution.”

Going forward, DP World has set a goal to reduce total greenhouse gas emissions at its terminals by 27% by 2013 under its five-year plan, while APM Terminals plans to cut CO2 emissions from terminal operations worldwide by 15% by 2012.