 The current estimate for global temperature rise by 2100 is 3.5C. This is a devastating conclusion that underlines why many people, including myself, believe global warming represents the biggest threat to mankind. The international consensus that has emerged is that: global temperature rise should be limited to 2C; that emission policies should be determined at regional (eg. European), national and city level; and that the United Nations should monitor and co-ordinate these.  While a limited deal was reached at Durban, securing a comprehensive, global agreement is unlikely soon. a key problem is that governments are focused upon immediate issues such as financial fragility. There is  