A document that nearly all countries are parties to is called the UN Framework Convention on Climate Change (UNFCCC). This document was signed at the Earth Summit, a famous international event held in Rio de Janeiro, Brazil, in 1992. The UNFCCC’s objective is “stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic [i.e., human-caused] interference with the climate system.” There have been many meetings called Conference of the Parties meetings, or COP meetings. Each COP meeting attracts thousands of attendees and lasts about 12 days. COP 13 was held in Bali, Indonesia, in December 2007. I was there. Two months earlier, the world had learned that the 2007 Nobel Peace Prize was to be awarded equally between Al Gore, the American politician, and the IPCC, the Intergovernmental Panel on Climate Change. The outcome of the Bali meeting was deeply disappointing, but not surprising. Governments and businesses worldwide, and ultimately, humankind as a whole, will determine what actions will be taken. Climate science, however, is able to provide highly useful input to this policymaking process.