"When the Pentagon and Greenpeace are on the same page, you know things are getting serious."

"Picture a map of the world. Picture the areas we’re most concerned about; where poverty, instability, and conflict meet. Parts of the Middle East and North Africa. Pockets of sub-Saharan Africa. Delicate borders on the Asian subcontinent. Now picture the areas where climate change will strike hardest. The overlap is uncanny – and unnerving."

Chris Huhne, UK Secretary of State for Energy and Climate Change, gave an speech today in which he pointed out the systemic nature of the threats posed by climate change. Rather than directly causing problems, climate change exacerbates existing threats, making food more difficult to grow, water more difficult to distribute, public health more difficult to manage, infrastructure and lives more vulnerable to extreme weather events and, crucially, where tensions already exist in the geopolitical system, generally taking us closer to violence. It was not a ground-breaking address, but summarises why climate change is not "just" an environmental problem.

Huhne concludes with these words:

"Desperate people take desperate measures. Instability is now a national problem; soon it will be a regional one. Migrants surge outwards, searching for survival.

"This is the nightmare scenario. Yet it is already tragically familiar. We have already seen civil wars compounded by water stress, in Darfur. Regional conflicts fuelled by resources in the Democratic Republic of Congo. Food prices prompting riots in Bangladesh.

"Climate change is the force that threatens to unify and magnify these pressures. It will focus and concentrate existing tensions, fracturing states and destroying societies. So far, we have not done enough to stop it. We still have time to mobilise: but that time is rapidly running out. Doing nothing is not an option."

Full speech available here.