Greenpeace flies a hot air balloon with the message "Rescue the Climate" over the ruins of the ancient Mayan city of Chichen Itza, as delegates prepare to meet for UN Climate Negotiations COP16 in nearby Cancun. Greenpeace is sending the message that even the most advanced civilizations can collapse, and urges that if we do not act, climate change could have devastating consequences for humanity. It is not too late. Simply by making the right choices at this meeting, governments can - and must - set us on the path to a safe future - by making climate change history.