From today until December 18, the United Nations' Climate Change Conference will be held in Copenhagen, Denmark. Leaders and environment ministers and officials will meet to put together a successor to the Kyoto Protocol.

The Kyoto Protocol was signed in 1990 to slow down global warming and climate change. It ends in 2012. Copenhagen is the last chance for the parties of the United Nations Framework Convention on Climate Change (UNFCCC) to meet before deciding on a new agreement.

The aim is for that new agreement to come into force before the first commitment period of the Kyoto Protocol expires. Representatives from 170 countries are now gathered in Copenhagen. Let's look at the major players and what they bring to the table.