The world's environment ministers, government officials, diplomats and campaigners are preparing for the biggest poker game of their lives - the COP15 conference in Copenhagen in December 2009.

It's one of the most complicated political deals the world has ever seen but third world countries are holding the cards.

In Environmental Research Letters, the paper 'Tripping Points: Barriers and Bargaining Chips on the Road to Copenhagen' lays bare the main tripping points – those political barriers and bargaining chips – which need to be overcome for countries to reach a consensus on how to address global climate change. 

One of the key issues delegates will face in their attempt to agree on mitigation, is that what some countries see as barriers, others perceive as bargaining chips. While many developed countries, including the UK, favor extending mitigation actions to developing countries, many developing countries will be using finance and technology transfer as a deal breaker for their consent to the overall deal.

And India, Mexico and China produce a lot of carbon dioxide so without their buy in,  the COP15 Copenhagen conference is just a bad vacation with lousy weather.

Bluffing is expected to be similar to the 'chicken and egg question', like whether actions depend on financing or financing will depend on actions. Researchers predict that  countries will be delaying decisions until the last hours of the conference when all the bargaining chips will be on the table and parties cannot wait any longer to see who will show their hand first.

Other barriers delegates will face in their bid to reach an agreement on a post-2012 framework are issues evolving around the reduction of emissions from deforestation and forest degradation, and how to implement adaptation to climate change.

Even if some consensus is reached in Copenhagen, there is no guarantee a deal will be agreed on.  President Clinton agreed to Kyoto in 1999, an easy decision because he knew he did not  have treaty authority so it was politically no risk.

The researchers write "Regardless, however, of the perspective from which one frames the discussions, success in Copenhagen and beyond will depend on parties' ability to negotiate past the tripping points […] by finding ways to match barriers with bargaining chips in envisioning how the details of any future agreement can be hammered out in the months and years to come."