As higher temperatures cause sea levels to rise and weather patterns to change, the world faces the prospect of wars over resources such as water and food, according to the document.

There will also be pressure from hundreds of millions of "environmental refugees" fleeing their devastated homelands, said the paper from the Oxford Research Group. And in Britain, police and security services may have to cope with demands for tougher border controls, potentially violent protests against polluting companies and intercommunal tensions.

Resistance to Government measures to mitigate global warming, on top of the additional burden of policing new laws to limit greenhouse gases, is also a possibility.

Author Chris Abbott, a fellow of Bristol University's Centre for Governance and International Affairs, warned that attempts to tackle these new problems using existing strategies are doomed to failure. He called for leadership from politicians to develop new co-operative approaches which focus on preventing and managing climate change.

"If governments simply respond with traditional attempts to maintain the status quo and control insecurity they will ultimately fail," wrote Mr Abbott.

"In today's globalised world, using military force to secure resources overseas, while attempting to create a fortress state at home, will not work - despite the potential attraction of such policies for governments faced with such an uncertain future. The security consequences of climate change will not just manifest themselves 'over there' - there will be domestic security concerns for both developed and developing nations alike.

"Leadership within the police, security services and military will need to use their considerable influence to make this clear to policy-makers and impress upon them the importance of taking steps now to prevent and manage climate change, rather than relying on force to try and control the insecurity later."

It is "almost certain" that, by 2050, droughts, food shortages and flooding will lead to the mass movement of up to 200 million environmental refugees, warned the paper, entitled An Uncertain Future: Law Enforcement, National Security and Climate Change. This will inevitably lead to "kneejerk" demands for tighter border controls which are "unlikely to succeed in the long-term".

The report concluded: "In the long-term, the risks of climate change demand a rethink of current approaches to security and the development of co-operative and sustainable ways of achieving that security, with an emphasis on preventative rather than reactive strategies. While this may seem like a huge task, the seriousness of the threat means that it is wholly necessary, and must be started now."