Representatives from almost 200 countries are gathering in Paris from 30th November to 11th December. They are taking part in the 21st Conference of the Parties to the UN Framework Convention on Climate Change, or COP21.The high-profile meeting in the French capital aims to give nations from across the world the opportunity to agree on an international strategy for tackling climate change.Many governments have published their own, national pledges to combat climate change ahead of time, keen to avoid the disappointment of previous climate summits such as the Copenhagen conference of 2009.So, are climate experts optimistic that there will finally be a significant international agreement?What measures will need to be taken to curb greenhouse gas emissions?And what role does China play when it comes to the global climate?