Doctors warn climate change is "greatest threat to public health"

Medical experts have urged policy makers to take concrete steps to tackle climate change, warning that failure to do so poses an immediate, grave and escalating threat to the health and security of billions of people around the globe.

More than 100 medical and military professionals, including Dr Hamish Meldrum, chairman of council at the British Medical Association and Lord Michael Jay, chairman of medical relief charity Merlin, yesterday backed a statement declaring climate change the greatest current threat to public health.

The statement outlines how rising temperatures and weather instability will lead to more frequent and extreme weather events, loss of habitat and habitation, water and food shortages, the spread of diseases, ecosystem collapse, and threats to livelihood, potentially triggering mass migration and conflict within and between countries.

It also warns that humanitarian crises will impact on military resources and that the human and economic cost of climate impacts "will be enormous".

It urges the EU to urgently adopt a 30 per cent CO2 greenhouse gas reduction target for 2020 and for the United Nations to commit to restricting the global temperature rise to 2°C as agreed at the Copenhagen and Cancun Summits.

Opening the meeting, Energy and Climate Change Secretary Chris Huhne urged national governments to limit the impact of climate change to deliver "a cleaner, healthier, safer future".

Professor Hugh Montgomery, director of the UCL Institute for Human Health and Performance urged politicians to tackle the tangible risks posed by global warming.

"It is not enough for politicians to deal with climate change as some abstract academic concept," he said.

"The price of complacency will be paid in human lives and suffering, and all will be affected. Tackling climate change can avoid this, while related lifestyle changes independently produce significant health benefits. It is time we saw true leadership from those who would profess to take such a role."

Other signatories included Professor Sir Ian Gilmore, former president of the Royal College of Physicians, David Kidney, the former MP who is now head of policy at the Chartered Institute of Environmental Health, and the leaders of Norway and Sweden's Medical Associations.

The statement was released as startling new research predicted sea levels are likely to rise by 75 centimetres by 2100 as a result of climate change.

Aslak Grinsted, researcher at the Centre for Ice and Climate, the Niels Bohr Institute at the University of Copenhagen, yesterday published a set of projected changes in sea level for the next 500 years.

The two most realistic scenarios, calculated based on greenhouse gas emissions and pollution levels stabilising in the coming decades, predicts sea levels will still rise by about 75cm by 2100 and two metres by the year 2500.

The most pessimistic scenario, where emissions continue to increase, predicts sea levels could rise 1.1 metres by 2100 and 5.5 metres by 2500.

Even in the most optimistic scenario, requiring extremely dramatic climate change goals, major technological advances and strong international cooperation to cut greenhouse gas emissions, the sea would continue to rise by around 60cm by 2100 and 1.8 metres by 2500.

Grinsted said the changes would occur because ice caps and sea levels react slowly to changes in emissions.

"Even if we stabilise the concentrations... and stop emitting greenhouse gases into the atmosphere, we can see that the rise in sea level will continue to accelerate for several centuries because of the sea and ice caps long reaction time," he said.

"So it would be 2-400 years before we returned to the 20th century level of a 2 mm rise per year."