Doctors must take a leading role in highlighting the dangers of climate change, which will lead to conflict, disease and ill-health, and threatens global security, according to a stark warning from an unusual alliance of physicians and military leaders.

Writing in the British Medical Journal on Tuesday, a group of military and medical experts, including two rear admirals and two professors of health, sent out an urgent message to governments around the world. "Climate change poses an immediate and grave threat, driving ill-health and increasing the risk of conflict, such that each feeds upon the other," said the authors, Lionel Jarvis, surgeon rear admiral at the UK's Ministry of Defence; Hugh Montgomery, professor of human health at UCL, London; Neil Morisetti, rear admiral and climate and security envoy for the UK; and Ian Gilmore, professor at the Royal Liverpool hospital. "Like all good medicine, prevention is the key."

The threat to national security and health from global warming have been addressed separately in the past, but the BMJ editorial urges governments to treat them together. "It might be considered unusual for the medical and military professions to concur," wrote the authors. "But on this subject we do."

The authors urge doctors to use their position of trust in society to build support for action on climate change. "Although discussion is good, we can no longer delay implementing tough action that will make a difference, while quibbling over minor uncertainties in climate modelling. Unlike most recent natural disasters, this one is entirely predictable," they warned. "Doctors, often seen as authoritative, trusted, and independent by their communities, must make their voices heard in calling for such action."

Prof Montgomery told the Guardian that doctors should take up the climate challenge just as they did with the harm from tobacco. "Many doctors see suffering and death first-hand on a daily basis. They recognise that prevention is far better than waiting for disease, when cure may not in fact be possible. They are also uniquely able to translate abstract harm into a vision of real suffering- just as they were with cigarette smoking and lung cancer," he said. "Now, as then, they must play their part - impressing upon their governments the immediacy and gravity of climate change and its impacts on their citizens, and those of other countries."

Prof Gilmore added that doctors could have an influence both as a body and in their individual work: "Some of the things that are good for health are also good for the climate, like exercise and a diet that is lower in meat. That's a win-win situation."

But doctors could also influence government policy, and the NHS's policy on greenhouse gases, he said: "We have a responsibility to steer the government towards more climate-sensitive policies."

Such a call is likely to be seen as controversial by many in the medical profession, and beyond it, particularly in the light of last year's "climategate" controversy in which many scientists found themselves under attack from commentators and bloggers.

While medical journals have highlighted the problems of climate change in the past, few physicians have spoken out on the issue.

The warning from medical and military leaders came as government officials from around the world met in Bangkok in the latest round of the long-running talks under the auspices of the United Nations Framework Convention on Climate Change (UNFCCC). The Bangkok conference, which is a preliminary session to the major meeting in Durban this December, is low-key and not expected to produce a breakthrough.

Christiana Figueres, executive secretary of the UNFCCC, told the conference that Bangkok was an opportunity to consolidate the gains made at last year's Cancún climate conference, when several important issues - including forestry - were broadly resolved.

"Here in Bangkok, governments have the early opportunity to push ahead to complete the concrete work they agreed in Cancún, and to chart a way forward that will ensure renewed success at the next UN climate change conference in Durban," she said. "If governments move forward in the continued spirit of flexibility and compromise that inspired them in Mexico, then I'm confident they can make significant new progress in 2011."

But several major issues remain to be resolved, she acknowledged, including the future of the Kyoto protocol and building the institutions necessary to deliver greenhouse gas emissions cuts and financing.

The BMJ's warning, carried in an editorial in the magazine, drew on several sources, including the Pentagon's 2010 Quadrennial Defense Review to Congress, which highlighted the national security aspects of climate change, and statements from the UK's ministry of defence and the foreign secretary, William Hague, who called global warming "perhaps the 21st century's biggest foreign policy challenge". The BMJ authors found that climate change would exacerbate "poverty, environmental degradation, and the further weakening of fragile governments".

But the scale of the challenge is such that the involvement of doctors and tough actions on emissions are necessary, according to the authors. "We must adapt our cities and their infrastructure to cope with these challenges through combining engineering design and public health initiatives – for example, developing resilience in clean water and drainage systems, using human and food waste for energy generation, and building roads to act as flood pathways. At the same time we need to ensure that the military can still operate effectively to sustain security in this changing environment. As with prevention, effective adaptation will require an approach that encompasses the whole of society and international collaboration."

The editorial was published ahead of an open meeting on climate change, medicine and security, scheduled to take place on 20 June at the British Medical Association in London.