• EU must act on this unresolved critical aspect of aviation

    It's a sad reflection of how little we have now come to expect from EU attempts to tackle the environmental impact of aviation that we are this month celebrating the miniscule victory of having got the Commission to publish a report.

    The document in question is a proposal on nitrogen oxides emissions from aircraft, but our celebrations won’t have registered on the Richter scale because the report takes us very little further.

    At the time aviation’s entry into the EU Emissions Trading Scheme was being discussed, MEPs on the environment committee rightly noted that the ETS deals only with CO2 emissions, whereas the Intergovernmental Panel on Climate Change had estimated that the effects of NOx (which induces ozone), contrails and contrail-induced cirrus could be two to four times that of CO2. So they asked for the carbon costs paid by airlines through the ETS to be multiplied to take account of Nox.

    This was rejected by officials on the grounds that such a multiplier would have a perverse effect – incentivising further reductions in CO2 but probably increasing NOx emissions, because the two are inversely related. But the Commission had to recognise that the MEPs had a point, so it agreed to introduce a separate measure on NOx by the end of 2008.

    To start the ball rolling, it commissioned a proposal from the Dutch consultancy CE Delft, and this was delivered in October. Despite it being funded by public money and containing nothing confidential, the Commission declined to publish it, until last month, when it realised there were no grounds for withholding it.

    But what of the proposal that was supposed to be agreed by the end of last year? No sign then, and no sign now.
    The issue of NOx from aviation is not straight forward, though that is no excuse for inaction. NOx standards exist, but largely to regulate air quality around airports. NOx has a very different impact at ground-level, where the issue is air quality, compared with cruising altitudes where the issue is climate change. And existing NOx standards are not very strict, which is why aircraft makers have had a greater incentive to reduce CO2 emissions, with the result that NOx emissions have increased.

    CE Delft proposed a number of policy options, none of them ideal, but basically confirming that some precautionary measure could be implemented, such as a NOx charge for cruising altitude based on known NOx emission levels during take-off and landing. But it said this measure should be kept under close review, as the correlation between ground-level and altitude NOx emissions might not be valid for new generation engines, and it would be highly inadvisable to give the wrong signal to engine manufactures.

    This is all reasonable in as far as it goes, but we have been here before. IPCC reports from 10 years ago called for better knowledge of the non-CO2 impacts of aircraft. A committee of experts reported to the International Civil Aviation Organisation (Icao) in 2007 that taking measures to address NOx emissions was almost as urgent as CO2, but Icao played for time by saying further research was needed, and then didn’t commission that research.
    So we now have the European Commission taking no action on its written assurance to MEPs that it would take action on aviation NOx. Furthermore, it is not prepared to push for resolute action on altitude NOx in Icao, and unwilling to spend money on better understanding the science of NOx from aircraft. The most daring thing it does is publish a report it had sat on for five months. And we complain that Icao doesn’t take the environment seriously enough!

    In establishing the NOx study, the Commission noted that aviation NOx emissions are projected to continue growing strongly over the next two decades and unless action is taken, the contribution of aircraft NOx emissions to air quality problems and climate change will increase significantly for many years to come. So it knows. Now it needs to take the appropriate action.