At the Environment Council Meeting on 20 December 2007, the 27 EU Member States overcame their differences regarding the details of plans to include aviation in the EU Emissions Trading Scheme. These included starting dates for the scheme, the amount of CO2 allowances that airlines should receive free of charge and the question of what should be done with the money raised from auctioning allowances. In particular, it was decided that: (i) all airlines flying to and from the European Union would join the scheme in 2012; (ii) airlines would be required to maintain emissions at average 2004 to 2006 levels; (iii) in accordance with the Commission’s proposal, 90 per cent of pollution permits would be distributed to airlines free of charge; (iv) revenue from emission allowance sales should be invested in climate change mitigation measures, although ultimately the decision is left to individual Member States; (v) airlines with very low traffic levels on routes to, from, or within the European Union would be exempt from the scheme, as would public utility air services, and; (vi) 3 per cent of total allowances would be set aside in a special reserve and distributed free of charge to new entrants or very fast-growing airlines. No measures were proposed for dealing with the additional climate impacts caused by nitrogen oxide or other pollutant emissions from aircraft.