‘Third Heathrow runway would not push up emissions’

AIR QUALITY

A third runway could be built at Heathrow Airport without breaching legal air quality limits, suggests new research by the University of Cambridge.

The study, funded by the National Environment Research Centre, says that increases in nitrogen dioxide (NO2) from higher traffic levels would be more than offset by future reductions in emissions from traffic around Heathrow Airport.

A network of 40 sensors in and around the airport measured NO2 levels over an 18-month period. The findings back up research by the Airports Commission that over the next decade – the timescale of Heathrow’s proposed expansion – the move from Euro 5 to Euro 6 vehicles would mean a significant reduction in NO2, said Professor Rod Jones, who led research at the University of Cambridge.

All new cars must now be compliant with the more stringent Euro 6 EU legislation, which requires lower levels of harmful car and van emissions.

Professor Jones presented his findings at a public meeting last month, and said the results would appear in a scientific paper, which will be peer reviewed before being published as an open access document.

According to the research, most of the NO2 around the airport is not related to “airport activity but from background traffic in the surrounding area”, he said.

The sensors used to monitor pollution are not certified but are calibrated against the measuring instruments already in place, said Professor Jones.

“The sensors enabled us to separate emissions from the airport itself from the background emissions, measuring the NO2. There will be more pollution linked to the airport but it will be against a background of reduced pollution from the wider area, so the general pollution level will drop, we think, below the critical level that we currently have for health impacts.” 

At several sites around the Heathrow Airport, the levels of NO2 are currently above EU limits (40 µg/m3 over a year). But computer modelling carried out by the University of Cambridge predicts the move to cleaner Euro 6 vehicles will lead to CO2 levels “falling significantly”, said Professor Jones. “If that is the case – and I should add that this prediction takes account of the fact that vehicles emit more in real life than laboratories show, then the NO2 level reductions will more than offset the NO2 increase in emissions should the airport get a third runway.”

Professor Jones told LTT: “I am completely agnostic about a third runway at Heathrow. I have no opinion on it. This was about trying out these sensors – the first network of its kind. We did require permission from Heathrow to put in the sensors, but this was independent research funded by the Natural Environment Research Council. We received no money from British Airways or Heathrow.”