The major source of carbon dioxide comes from the burning of fossil fuels. In 2004, the UK emissions of carbon dioxide were over 150 million tonnes. That would cover a football pitch to a height of 157 kilometres!
The Kyoto protocol was an agreement made in 1997, and finally ratified in 2005, that commits participating countries to reducing their greenhouse gas emission. As a baseline level, each country’s 1990 greenhouse gas emissions were chosen. The UK has pledged to cut emissions of greenhouse gases by 60% of 1990 levels over the next 45 years.
The gases included are methane, carbon dioxide, nitrous oxide and fluorocarbons. Currently they do not include emissions from aircraft.