Rear Admiral Neil Morisetti, special representative to foreign secretary, says governments can't afford to wait for 100% certainty.
|Flooding in Thailand 2011|
Climate change poses as grave a threat to the UK's security and economic resilience as terrorism and cyber-attacks, according to a senior military commander who was appointed as William Hague's climate envoy this year.
In his first interview since taking up the post, Rear Admiral Neil Morisetti said climate change was "one of the greatest risks we face in the 21st century", particularly because it presented a global threat. "By virtue of our interdependencies around the world, it will affect all of us," he said.
He argued that climate change was a potent threat multiplier at choke points in the global trade network, such as the Straits of Hormuz, through which much of the world's traded oil and gas is shipped.
Morisetti left a 37-year naval career to become the foreign secretary's special representative for climate change, and represents the growing influence of hard-headed military thinking in the global warming debate.
The link between climate change and global security risks is on the agenda of the UK's presidency of the G8, including a meeting to be chaired by Morissetti in July that will include assessment of hotspots where climate stress is driving migration.
Morisetti's central message was simple and stark: "The areas of greatest global stress and greatest impacts of climate change are broadly coincidental."
He said governments could not afford to wait until they had all the information they might like. "If you wait for 100% certainty on the battlefield, you'll be in a pretty sticky state," he said.
The increased threat posed by climate change arises because droughts, storms and floods are exacerbating water, food, population and security tensions in conflict-prone regions.
"Just because it is happening 2,000 miles away does not mean it is not going to affect the UK in a globalised world, whether it is because food prices go up, or because increased instability in an area – perhaps around the Middle East or elsewhere – causes instability in fuel prices," Morisetti said.
"In fact it is already doing so," he added, noting that Toyota's UK car plants had been forced to switch to a three-day week after extreme floods in Thailand cut the supply chain. Computer firms in California and Poland were left short of microchips by the same floods.
Morisetti is far from the only military figure emphasising the climate threat to security. America's top officer tackling the threat from North Korea and China has said the biggest long-term security issue in the region is climate change.
In a recent interview, Admiral Samuel J Locklear III, who led the US naval action in Libya that helped topple Muammar Gaddafi, said a significant event related to the warming planet was "the most likely thing that is going to happen that will cripple the security environment, probably more likely than the other scenarios we all often talk about".
There is a reason why the military are so clear-headed about the climate threat, according to Professor John Schellnhuber, a scientist who briefed the UN security council on the issue in February and formerly advised the German chancellor, Angela Merkel.
"The military do not deal with ideology. They cannot afford to: they are responsible for the lives of people and billions of pounds of investment in equipment," he said. "When the climate change deniers took their stance after the Copenhagen summit in 2009, it is very interesting that the military people were never shaken from the idea that we are about to enter a very difficult period."
He added: "This danger of the creation of violent conflicts is the strongest argument why we should keep climate change under control, because the international system is not stable, and the slightest thing, like the food riots in the Middle East, could make the whole system explode."
The military has been quietly making known its concern about the climate threat to security for some time. General Wesley Clark, who commanded the Nato bombing of Yugoslavia during the Kosovo war,said in 2005: "Stopping global warming is not just about saving the environment, it's about securing America for our children and our children's children, as well." More