 External costs , also referred to as hidden costs , are <unk> of the environmental and climate impacts of air transport . Whilst setting a financial value on all such impacts is difficult to do precisely , figures have been produced for the most significant . In 2000 the government valued the annual cost of climate change induced by greenhouse gas emissions from UK air transport at £ 1 @.@ 4 billion , rising to £ 4 @.@ 8 billion per annum by 2030 . The impact of noise was costed at around £ 25 million per annum in 2000 , and for the same year the impact on air quality was costed at between £ 119 million and £ 236 million per annum . Based on figures produced by the European Environment Agency the AEF has calculated a much higher total external cost for 2000 of around £ 6 billion . 
