John Ashton, UK’s climate-change ambassador, told a conference in London global warming isn’t a threat in the conventional sense. Investment in weapons will not help, he said, but everyone still must realize climate change has “a security dimension.”

Ashton made his remarks as China is poised to overtake the U.S. as the world’s biggest emitter of the greenhouse gases that cause global warming. The conference on climate change and security is focusing on Asia.

Ashton cited drought-related conflicts in Kenya and Sudan, and noted that Ugandan President Yoweri Museveni had called climate change an “act of aggression” by rich nations against poor ones. World wheat prices, moreover, are up 40 percent from two years ago because of drought in Australia due to global warming.

“We have to do far more than we have done so far to help those most impacted by climate change,” Ashton told the meeting.

India and China, whose carbon-gas emissions are surging, reject calls to cut emissions saying that the problem has come from the developed world. The U.S. has likewise rejected emission caps, arguing it would be economic suicide unless booming developing economies were similarly bound.