Trends in air pollution and emissions projections Sean Beevers, Emily Westmoreland, Hrishi Mittal And David Carslaw
Talk summary The problem with emissions forecasts? What the problem could be? What can we do about it? What are the implications?
Tonnes/a annum 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 2002 2003 2004 2005 2006 2007 2008 2009 2010 Year Artic Rigid LGV Bus Taxis Car Motorcycle PM 10 Road transport emissions PM 10 emissions (exhaust + Tyre and Brake wear) by vehicle type in the LAEI between 2002 and 2010.
PM 10 Air Pollution concentrations Normalised PM 10 /SO 2 /CO annual rolling mean concentrations.
Long range transport? we have looked at roadside in isolation (Fuller and Green, 2006). 50 Central London 40 PM 10 concentration (µg m -3 ) 30 20 10 0 Transect (North - South) across London
50000 40000 Artic Rigid LGV Bus Taxis Car Motorcycle NO X Road transport emissions Tonnes/ann num 30000 20000 10000 0 2002 2003 2004 2005 2006 2007 2008 2009 2010 Year NO X emissions by vehicle type in the LAEI between 2002 and 2010.
NO X Air Pollution concentrations Normalised NO X /NO 2 /O 3 annual rolling mean concentrations.
Not long range transport 400 NO -3 X concentration (µg m ) 300 200 100 Central London 0 Transect (North-South) across London
Is resuspension important? Harrison, 2004 doesn t suggest so but cannot be excluded from further study. Met. effect in 2007? Index (1999 = 1) 1.26 1.26 1.24 1.24 1.22 1.22 1.20 1.20 1.18 1.18 1.16 1.16 1.14 1.14 1.12 1.12 1.10 1.10 1.08 1.08 HGV 1.06 1.06 Total vehicles 1.04 1.04 1.02 1.02 1.00 1.00 0.98 1999 2000 2001 2002 2003 2004 2005 2006 0.98 1999 2000 2001 2002 2003 2004 2005 2006 0.96 0.96 0.94 Year 0.94 Year Index (1999 = 1) London traffic changes from 1999 to 2005/6. Index (1999) = 1. Total vehicle changes taken from LEZ monitoring report (TfL, 2008). Index (1999 = 1) 1.26 1.24 1.22 1.20 1.18 1.16 1.14 1.12 1.10 1.08 1.06 1.04 1.02 1.00 0.98 0.96 0.94 LGV 1999 2000 2001 2002 2003 2004 2005 2006 Year Index (1999 = 1) 1.26 1.24 1.22 1.20 1.18 1.16 1.14 1.12 1.10 1.08 1.06 1.04 1.02 1.00 0.98 0.96 0.94 0.92 Car + Taxi 1999 2000 2001 2002 2003 2004 2005 2006 Year Index (1999 = 1) 1.26 1.24 1.22 1.20 1.18 1.16 1.14 1.12 1.10 1.08 1.06 1.04 1.02 1.00 0.98 0.96 0.94 0.92 Bus and coaches 1999 2000 2001 2002 2003 2004 2005 2006 Year
0.5 10 PM 10 emissions (g km -1 ) 0.4 0.3 0.2 0.1 NO x emissions (g km -1 ) 9 8 7 6 5 4 3 2 E2 LGV Primary Emissions - exhaust? 0.0 0.5 0 10 20 30 40 50 60 70 Average speed (km hr -1 ) 1 0 10 9 0 10 20 30 40 50 60 70 Average speed (km hr -1 ) Driving dynamics Modal models PM 10 emissions (g km -1 ) 0.4 0.3 0.2 0.1 0.0 0 10 20 30 40 50 60 70 Average speed (km hr -1 ) NO X emissions (g km -1 ) 8 7 6 5 4 3 2 1 0 E3 diesel car 0 10 20 30 40 50 60 70 Average speed (km hr -1 ) Vehicle tests Emissions over an hour?
Non-exhaust emissions from transport? Much of the effort has been put into exhaust, yet increasingly nonexhaust emissions are important (toxicity). Very difficult to test and no standard method. No technology in the emissions model (i.e. change in brake wear rates/composition etc). Doesn t really depend on how much braking you do (1Hz speed)
Within-City Spatial Variation in OP
Particle Exposure Model Spike with Conc. Antioxidant Solution 200 µm AA/UA/GSH (ph 7.4) 37 o C 0h 4h 0h 4h 0h 4h 0h 4h Control Carbon black ROFA PM 2.5 & 10 All incubations at 50µg/ml
Toxicity (traffic): Quinones and Metals
What are the consequences of not getting it right? Taken from the GLA report - LAEI 2004 model forecasts.
What are the consequences of not getting it right? Taken from the GLA report - LAEI 2004 model forecasts.
DEFRA research: What are we doing to study the problem? Creating a hourly emissions inventory in London Using ATC data, MCC data (12 and 24 hour) and ANPR Trends between 2003 and 2007 c.f met. normalised measurements Looking at diurnal profiles of emission and measurements by day of week weekday and Sunday effects Trends by day of week Weekday vs weekend analysis provides an emissions ratio, by vehicle type
What more can we do? More traffic measurements please! Specific air pollution measurements - EC, metals (Cu, Antimony) Direct measurements of brake particles Dave/Gary s PM mass closure model LEZ supersite measurements Look at London s ANPR data and specifically at what is changing within vehicle categories (vehicle weight/size/diesel vehicle(%)) Better assessments of when vehicles are using their brakes.
Thanks for your attention Thanks to: DEFRA, Transport for London (TfL)/Greater London Authority, DfT and the HEI Emily Westmoreland, Hrishi Mittal, David Carslaw, Frank Kelly, Ian Mudway, David Green and Gary Fuller