What the reports say
What this means in terms of ‘confidence’
Total population in area exceeding the annual mean objective of 40 μg m-3, London
Climate change won’t affect underlying meteorology
“In the longer term (e.g. in 2030) there is also the potential additional uncertainty due to the influence of climate change on meteorology. Whilst the influence of climate change on UK meteorology is highly uncertain, nevertheless there are suggestions that it could become windier during winter months. This potentially would have the effect of increasing the importance of aircraft sources compared with road transport.”
“Calculation of annual-mean concentrations ‘[of NOx] using the dispersion modelling methodology recommended by the PSDH requires an hourly sequence of meteorological data for the relevant year, which of course is not available for a future case. The procedure adopted is to assess the future case as if the weather in the future year is the same as that in a historical year. Information on year-to-year variability can be obtained by repeating the calculation for other historical years. Of course, this procedure cannot account for the potential influence of climatological shifts (eg from global warming), which might be relevant when looking at very long time horizons, but for the time horizons of interest this is not expected to be larger than the current inter-annual variation.”
Atkins (2007) Demonstrating confidence in the PSDH air quality work, Sec. 4.1.3.
AEA Emissions Methodology for future LHR Scenarios, para. 2.5
The model has not included the effects of climate change. Including the longer term impacts of climate change could increase the importance of aircraft sources compared with road transport.