This book spells out, in more detail than usual, what can and should be done to avert the real risks of disaster. It summons us to an endeavour worthy of the resources and ingenuity of the 21st century, towards bold initiatives with big costs, and much bigger benefits. It explores the interconnected issues of climate and development, laying the groundwork for such a new deal. It presents a challenging agenda, and highlights the needs and perspectives of developing countries which may be unfamiliar or uncomfortable to readers in high-income countries. The unfortunate truth is that any large country, or group of mid-sized countries, can veto any global climate solution by refusing to participate, so a solution will only work if it works for everyone.