Signatories to the United Nations Framework Convention on Climate Change met at Kyoto, Japan in 1997. The resulting treaty was later termed the Koyoto Protocol. The US proposed a scheme to rank greenhouse gases according to their level of destructiveness.
i.e. CO2 = 1. Methane = 11, each called the Global Warming Potential. The treaty committed the industrialised countries to reduce emissions of six gases by an average of 5.2% by the year 2012. The treaty also allowed countries to bank or borrow credits in respect of carbon emissions. (096)