Tougher controls on aircraft smog emissions introduced by UN aviation agency

As part of its effort to reduce aircraft emissions that affect local air quality and the increase in global warming greenhouse gases, the United Nations aviation agency has adopted more stringent standards for controlling a pollutant that can contribute to the reddish-brown smog often seen over urban areas.

By unanimous decision of its 36-member Council, the International Civil Aviation Organization (ICAO) adopted new oxides of nitrogen (Nox) standards which are 12 per cent more stringent than previous levels for applicability in 2008.

Nox is the generic term for a group of highly reactive gases, all of which contain nitrogen and oxygen in varying amounts. Many of the nitrogen oxides are colourless and odourless. However, one common pollutant, nitrogen dioxide (NO2), along with particles in the air can often be seen as smog. Most Nox emissions from aircraft have been found to occur in approach, take off and climb in a height range up to 3,000 feet.

Since 1981, ICAO has issued progressively stricter Standards and Recommended Practices (SARPs) for aircraft engine emissions, as well as exploring ways to reduce emissions through operational and market-based measures.

In close cooperation with international organizations concerned and the air transport industry, ICAO aims to limit or reduce the number of people affected by significant aircraft noise, the impact of aviation emissions on local air quality and the impact of aviation greenhouse gas emissions on the global climate.

The entry into force last month of the Kyoto Protocol to the UN Framework Convention on Climate Change (UNFCCC) aimed at further reducing greenhouse gas emissions reaffirmed ICAO’s leadership role in environmental matters related to civil aviation.

Specifically, the Protocol calls on industrialized countries to work through ICAO to pursue the limitation of greenhouse gas emissions from international civil aviation.