In 1992, when the world met to discuss an agreement on climate change, equity was a simple concept: sharing the global commons—the atmosphere in this case—equally among all. It did not provoke much anxiety, for there were no real claimants. However, this does not mean the concept was readily accepted. A small group of industrialised countries had burnt fossil fuels for 100 years and built up enormous wealth. This club had to decide what to do to cut emissions, and it claimed all countries were equally responsible for the problem. In 1991, just as the climate convention was being finalised, a report, released by an influential Washington think tank, broke the news that its analysis showed India, China and other developing countries were equally responsible for greenhouse gases. Anil Agarwal and I rebutted this and brought in the issue of equitable access to the global commons. We also showed, beyond doubt, that the industrialised countries were singularly responsible for the increased greenhouse gases.