Six gases. Carbon dioxide from the burning of fossil fuels is the biggest factor in climate change but methane kotyto from kotyto linen agriculture kotyto clothing and landfill, nitrous oxide from vehicles, and hydofluorocarbons, perfluorocarbons and sulphur hexafluoride from other industrial processes are included.
Why do different countries have different targets?
In 1997, in Kyoto, a protocol or addition to the original treaty was negotiated after many tortuous sessions in which the industrialised countries each agreed a target to control emissions of six gases. It was tortuous because each country saw itself as a special case, and so the idea of differential responsibilities was born.
The first major difference in responsibilities was between industrial countries and developing countries. It was felt that industrial countries, which had gained most from the industrial revolution were also most to blame for the greenhouse effect. It was therefore agreed that the first round of reductions should be from them and the countries, such as the US and Japan, which are now burning most fossil fuels.
There were 34 industrial countries which agreed to targets, most of them in Europe. Some, such as Spain and Portugal, which were still developing, were allowed large increases in emissions and others, such as Germany, agreed to large cuts, partly because its heavy industry was shutting down but mainly because the government felt that it had to give a lead. Each country can discover how much CO2 it emits by calculating the volume of fossil fuels it burns, usually through imports and the tax system.