Dealing with climate change would not only help the environment but bring a "peace dividend", Environment Secretary David Miliband has said.
David Miliband said a long-term focus was needed
He said the environment historically had played a part in conflicts, while the world's "oil dependence creates real danger".
By moving towards a low-carbon society, he said that "a post-oil economy is not an unrealistic prospect."
He predicted that technology would develop fully electric cars eventually.
Mr Miliband said: "Over a 20-year period, it is possible to imagine the car industry providing the investment and innovation required to move to a post-oil economy, if governments, preferably across a major market such as the EU, can provide a clear long term signal about the regulatory landscape."
He described Sweden's approach to a low-carbon society as "ambitious".
It has announced proposals to reduce petrol consumption by 40 to 50% by 2020.
Mr Miliband, in a speech to the global environment campaign group WWF, said tackling climate change was "our best hope of addressing the underlying causes of future conflict in the world, and is as significant for foreign policy as it is environment policy".
Climate change was more than a threat to nature - "it is a potential humanitarian emergency - since the consequence of failure to mitigate and adapt to climate change will be suffering on a grand scale".
Migration prompted by rising sea levels, water scarcity and the loss of agricultural land represented a major risk, Mr Miliband said, although they would not cause conflict in themselves.
"More often they aggravate tensions that are already there, and act in conjunction with other sources of instability from weak governance, existing armed conflicts, and existing ethnic or religious tensions."
While it was important to focus on the short-term triggers of conflict, "we also need to focus on addressing the long term and underlying causes of conflict, on non-military security solutions, on the material and environmental factors as well as the ideological".
Mr Miliband said it was "right" for a growing movement in the US to push for energy independence in the United States, "focusing mainly on the hidden costs of Middle East oil".
"The cause of energy security can help the world develop the ambition, pace and institutions to move to embrace environmental sustainability."
Declining species, degraded ecosystems and increased water use were all examples of "a society consuming resources at an unsustainable rate".
He said it was hoped that the UK's plans to cut carbon dioxide emissions by 60% would show "the developing world that industrialised countries are prepared to act and break the logjam of distrust where each country will only act if they think others will follow suit."
"By moving early, we can ensure our transition to a low-carbon economy is gradual rather than abrupt and costly, and provide the long-term clarity businesses require for investment."
He said it was possible to give people access to light, warmth, mobility, food and water without damaging the environment.