Aviation's climate change impact is relatively small. It is responsible for about 6% of the UK’s total CO2 emissions and 1.6% of global greenhouse gas emissions.

Aviation also has non-CO2 related impacts. Aircraft in flight cause water vapour (which leads to the formation of contrails and cirrus clouds at altitude) and nitrogen oxides (NOx – which forms ozone, a greenhouse gas, at altitude). These may more than double aviation’s CO2 impact.  However, other industries also have non-CO2 climate change impacts – the average for all human activities is around 1.5 times the impact of CO2.

Aviation’s contribution to climate change is growing

The Department for Transport’s central case estimate is that aviation will contribute 21% of the UK’s CO2 emissions in 2050. The Intergovernmental Panel on Climate Changes' (IPCC) estimate is that aviation will account for 5% of the global human contribution to climate change in 2050 (including aviation’s non-CO2 impacts).

It is often said that aviation is the fastest-growing source of global emissions – in fact, a quarter of all global greenhouse emissions come from power stations and this has both been the fastest growing source of emissions in recent years and is predicted to grow more than three-fold by 2050.

Airport operations also contribute to greenhouse gases through aircraft emissions on the ground; passengers and staff travelling to and from the airport; vehicles on the airfield; energy used by airport buildings; waste from the airport; and water usage.