By Jonathan Marcus
Diplomatic correspondent, BBC News
The Stern report on the economic impact of global warming is directed principally at governments and the business community.
Africa's drought patterns could worsen catastrophically
But it also represents a warning shot for foreign policy-makers, as global warming looks set to make the world a much more insecure place.
Global warming, by definition, affects everybody.
But different societies will feel its impact in different ways.
And from these differences, the new fault-lines in foreign policy will emerge.
Competition for resources will only increase. In Africa drought patterns could worsen catastrophically, threatening serious hunger and famine.
It is this issue of access to scarce resources - be it water or energy supplies like oil - that is going to drive the foreign policy agenda of the future.
Some will say, what has changed? The security of oil supplies, for example, has long been a major factor in US foreign policy.
But the context is changing dramatically: rising new players like India and China - what some have called the decline of the West and the rise of the East - would be change enough.
But on top of this, you now have to add in the potent factor of global warming.
This matters as much for the developed world as for poorer countries; as much for Europe as for Africa.
Only a few days ago, British Foreign Secretary Margaret Beckett spoke in Germany on the foreign policy implications of climate change.
"If we don't tackle climate change," she warned, "we have to brace ourselves for population shifts on a scale we have never seen before."
She added: "The added stresses of climate change increase the risk of fragile states dropping over the precipice into civil war and chaos. And it edges those countries that are not currently at risk into the danger zone."
And she concluded: "A failing climate means more failed states."
Many experts worry that this cocktail of instability and sharpening conflict over resources could yield a much more turbulent world.