Lucas is a Green star performer

As the Kyoto Treaty finally comes into effect, Dr Caroline Lucas, Member of the European Parliament for the Green Party, sets out the 'green' view on aviation, calling on the industry to meet its social and environmental obligations and pay for the wider impact of the industry on the global community

Climate change represents a bigger threat to our way of life than terrorism - and it is being fuelled by the untrammelled emission of CO2 (carbon dioxide) and other so-called greenhouse gases by human activity. The aviation industry bears more than a heavy share of responsibility: current scientific research into climatic change, and on the contribution of aviation to global concentrations of greenhouse gases, point to the need for a radical change in public aviation policy - for both economic and ecological reasons.

Aviation is the single most polluting mode of transport and the fastest growing source of greenhouse gas emissions. In addition to being a pollution-heavy means of transport, aircraft emit a very large proportion of their pollutants directly into the upper troposphere and lower stratosphere, where the pollution is disproportionately damaging. Research suggests that aircraft pollution from NOx (nitrous oxide) effectively doubles the contribution to global warming from aviation's share of the main greenhouse gas, CO2 itself. Moreover, the ground traffic associated with airports is also a great contributor to climate change.

Airlines claim that they contribute around 3% of total greenhouse gas emissions. The Green Party, however, estimates that the aviation industry currently accounts for just over 3.5% of total CO2 emissions. Moreover, a recent report by the Intergovernmental Panel on Climate Change suggests that emissions from aircraft could be responsible for up to 15% of the overall global warming produced by human activities by 2050 (IPCC, Special Report on Aviation and the Global Atmosphere) at current rates of increase. Unless current attitude's to aviation policy are radically changed, aviation's CO2 emissions will have increased by 588% between 1992 and 2050, and its NOx pollution by 411%.

Aviation's adverse environmental consequences are thus well documented - less well recorded is the economic downside of climate change.

The costs of aviation to the environment, health and taxpayers are huge. Any projected benefits of aviation expansion will be countered by the massive job losses resulting from climate change. Job losses from scaling down of aviation are much exaggerated - the industry is just as likely to accelerate job losses through the outflow of employment to the rest of the world outside the European Union (EU) as it is to bring them in.

In addition, the costs of aviation's contribution to global warming are not borne by the industry alone but by society as a whole, in terms of climatic change and pollution-related ill-health.

In spite of this, the aviation industry is markedly under-taxed and is characterised by artificially stimulated demand by the use of direct and indirect subsidies. The aviation industry is subsidised by all taxpayers - not just those who fly. For instance, the Green Party estimates that UK aviation is subsidised by tax breaks amounting to £9.2 billion ($17.2 billion) a year.

The only way to make the aviation industry accountable for its pollution is to end these tax breaks. By removing subsidies and building the full cost of a flight into the ticket price, using the so-called "polluter pays principle", artificially high demand would be curbed. This can be achieved by different methods including fuel charges, landing charges and seat/ticket charges. Other measures could include a ban on night flights and a moratorium on airport expansion, in addition to ending the EU-wide exemption on aviation fuel tax and pushing for a European-level charge on aviation, based on emissions.

Moreover, a system of emissions charges, such as the one currently in place in Zurich airport in Switzerland (outside the EU), could be introduced. This scheme penalises highly polluting aircraft, encourages the development of cleaner technology, and raises revenue for investment in environmentally sound projects.

In addition, local authorities themselves should be allowed to apply additional "air traffic congestion charges" or emissions levies in a bid to reduce demand for air transport.

Emissions charges are only part of the solution. Congestion fees, extending tax to air tickets, raising landing costs, and campaigning to overturn the unethical Chicago Convention are other initiatives that need to be implemented to make transport environmentally responsible. In short, the aviation industry must bear its social and environmental responsibility and work towards internalising all the costs that are now being externalised.