The Netherlands is mulling over whether to build into its new controversial environment tax a specific levy linked to climate-changing nitrogen oxide (NOx) emissions.

The move to differentiate its contentious new air passenger tax according to an aircraft's NOx emissions on landing and take-off will be considered at Cabinet level on 7 May before the Dutch government makes a formal response to its Parliament, where the idea was first mooted.

Details of the move, which are due out within days, form part of Dutch national plans to introduce an "eco tax" this summer, under which passengers will be charged 11.25 euro ($17.30) on flights to EU countries and 45 euro on flights falling outside a 2,500km zone.

The tax has been fiercely challenged by airlines and airports, but a Dutch court recently threw out a legal challenge by a trade organisation, the Board of Airline Representatives in the Netherlands (BARIN), that sought an injunction against the tax. BARIN claims the tax breaches the Chicago Convention and European rules on free movement of goods and has lodged an appeal at The Hague which will be heard on 3 July.

The issue of emissions differentiation is becoming increasingly important. "It means that a passenger flying in the EU with an aircraft that emits a lot of NOx will have to pay more than the same passenger flying with a cleaner aircraft," says one expert.

Within current EU legislative plans to include aviation within the EU Emissions Trading Scheme, MEPs want the value of carbon credits bought by airlines doubled in the absence of specific new legislation to deal with the additional climate impact caused by NOx. And Flight has learned that the European Commission has now commissioned a study to identify and evaluate measures to reduce aircraft NOx emissions to accompany the carbon trading scheme.

The EC says: "One of the goals of the study is to identify and evaluate cost-effective options for further European action to limit or reduce aircraft NOx emissions."

The study comprises a two-stage consultation process with stakeholders - engine and aircraft manufacturers, airlines, airports and their trade associations, and non-governmental organisations.

In the first stakeholder consultation, the advantages and disadvantages of potential policies were discussed. In a second - due to take place in Brussels in a few days' time - discussions will cover the climate impact of NOx, instrument choice, design and development, and future EC legislative proposals.

Source: Flight International