the UK. Whilst these carriers have been perceived to democratise air travel, providing the opportunity for lower income groups to travel more often, the main result is actually that middle and higher income groups travel more often, and often for shorter trips. Researchers have been raising concern about the globally increasing hypermobility of individuals, involving frequent and often long distance air travel and the resulting environmental and climate effects. Capacity The availability of airport capacity has been identified as an important constraint on the ability to meet the increasing demand for air travel. In many cases airport capacity is already fully used in meeting current demand. At Heathrow and Gatwick airports the runways are full for "… virtually the whole day". In 2003 the runway at Birmingham airport was expected to reach full capacity by 2009 at the latest, whilst terminal capacity at Edinburgh airport had reached its limit. Government forecasts that year predicted that by 2030 the number of passengers could rise to between 400 million passengers per annum (mppa) and 600 mppa, representing a two to threefold increase, and a figure of 500 mppa by 2030 was regarded by the government as robust. In 2006 the government reported that at 228 mppa the demand for air travel the previous year was in line with the 2003 forecast, but also revised the forecast demand for 2030 downwards to 465 mppa as a result of capacity constraints, even taking into account proposed airport developments. Government and regulation The law governing aviation in the UK is defined by the Civil Aviation Act 1982, which is updated periodically with amendments, the latest being the Civil Aviation Act 2006. The government department responsible for legislating changes in national policy and long term strategy relating to aviation is the Department for Transport (DfT). At the operational level the independently run Civil Aviation Authority (CAA) regulates economic, safety, and consumer protection aspects, as well as airspace policy, although these responsibilities are being increasingly ceded to the European Aviation Safety Agency (EASA). International aspects of air transport are regulated by agreements made within the International Civil Aviation Organization (ICAO) as established by the Chicago Convention, whilst most new legislation is now made at the European level through the European Civil Aviation Conference (ECAC). As a consequence, other than in airport development, there are few aspects of the air transport industry in which the government can act