Even if a deal is reached among political delegates at the upcoming United Nations Climate Conference in Copenhagen, it is unlikely to set out specific emission targets, says Mike Hulme, author of "Why We Disagree About Climate Change" and a professor at the University of East Anglia in Norwich.

"What we've done with climate change is to attach so many pressing environmental concerns to the climate change agenda that trying to secure a negotiated multilateral agreement between 190 nations is actually beyond the reach of what we can achieve," he argues.

Hulme, who will take part in a debate hosted by the Institute of Economic Affairs in November about carbon emission policies and economic activity before he heads to the Copenhagen conference, discussed his views with Reuters.

Environmental protest group Plane Stupid manage to prevent at least 21 flights taking off when  they  invaded a runway at Stansted airport for five hours on Monday morning.

The group are protesting over the government’s decision to allow the expansion of Stansted Airport with a second runway. The protest also follows the decision last week by Transport Secretary Geoff Hoon to delay the decision on whether to build a third  runway at Heathrow until January.

Plane Stupid is the group that draped banners from the roof of the House of Commons and from a plane on the runway at Heathrow in February.

They say such direct action is vital to get the message across about the danger to the environment of aviation emissions. Do you agree?