We are just over a month away from the UN Climate Change Summit in Copenhagen. And top of the agenda is agreeing on a process to reduce greenhouse gas emissions. Current provisions, as laid out in the Kyoto Protocol, run out in 2012. Environmentalists are deeply worried because current levels of carbon dioxide are now at their highest for more than half a million years.

But just weeks away from the conference there's deadlock. A final five-day session of preliminary low-level talks have been taking place in Barcelona this week to try to end the stalemate before Copenhagen; but hopes of reaching a global climate change treaty are fading. Instead the US now says a deal is more likely late next year

Inside Story, with presenter Shiulie Ghosh, discusses the consequences of the failure to strike a deal in Copenhagen