Air Quality in 2050 : Air Quality in 2050 Professor Martin Williams Burntwood Lecture Institution of Environmental Sciences 14 November 2007


Can we learn from history?What is history??: Can we learn from history? What is history?? In the words of Rudge, the truculent and somewhat reluctant sixth former in The History Boys by Alan Bennett, it’s ‘……just one ******* thing after another…..’


Can we learn from history? 1964:: Can we learn from history? 1964: Harold Wilson became Prime Minister Liverpool won the League, West Ham United won the F A Cup Lynn Davies and Mary Rand won the Long Jump Olympic Golds in Tokyo The Beatles dominated the charts Dylan toured the UK and didn’t get shouted at Death penalty for murder abolished, Dorothy Hodgkin, Martin Luther King and Jean-Paul Sartre won Nobel Prizes The Daily Herald (left-wing newspaper) was replaced by The Sun Vietnam war continued Mary Poppins premiere Ian Fleming and Sean O’Casey died Philip Larkin and Leonard Cohen(!) published books Gareth Edwards almost signed for Swansea Town……


Slide4: Time Series of SO2 Emissions (Mtonnes)


Trend in Black Smoke at Lambeth 1961-98: Trend in Black Smoke at Lambeth 1961-98


Trends in UK PM10 1992-2003: Trends in UK PM10 1992-2003


Trends in Particulate sulphate 1987-2003: Trends in Particulate sulphate 1987-2003


Trends in SO2 and SO4 at Eskdalemuir1977-2002: Trends in SO2 and SO4 at Eskdalemuir 1977-2002


EMEP : EMEP


EMEP : EMEP


EMEP : EMEP


Maximum 1-hour mean Ozone in UK: Maximum 1-hour mean Ozone in UK


Annual Mean Ozone at Urban and Rural sites in London and SE England (µg/m3): Annual Mean Ozone at Urban and Rural sites in London and SE England (µg/m3)


Future Projections – UK SO2 and NOx Emissions (kt/yr): Future Projections – UK SO2 and NOx Emissions (kt/yr)


But how will the polluted atmosphere respond?Will emissions remain decoupled from economic growth?Will we still quantify economic ‘growth’ in the same way?: But how will the polluted atmosphere respond? Will emissions remain decoupled from economic growth? Will we still quantify economic ‘growth’ in the same way?


Relative Annual Means London, 1997=100: Relative Annual Means London, 1997=100


EMEP : EMEP


EMEP : EMEP


EMEP : EMEP


Slide21: Future Ozone Controls Future Ozone Controls Future Ozone Controls


Slide22: Impact on air quality E.g. Szopa et al., 2007: Downscaling from global to regional modeling: Benefit of current emission controls counterbalanced by the global increase


How will the tropospheric ozone baseline change?: How will the tropospheric ozone baseline change?


UK Air Quality in 2050: UK Air Quality in 2050 High hourly/8 hourly ozone levels may become more frequent, with potential adverse effects on health The role of Biogenic emissions is likely to be crucial Urban annual mean levels will certainly increase towards the tropospheric background The tropospheric background may also increase How significant is this for human health? A key issue for the health effects community is the question of a ‘no-effects’ threshold for ozone


Slide25: Temperature dependency of total isoprene emissions from Mediterranean vegetation (Owen et al., 1998)


The Future – some drivers: The Future – some drivers Demographics Energy Sociology Politics Health/disease


Slide28: Global migration to cities, changes emission configurations, urban air quality and health impact


Slide29: NOx emissions from human sources by world region for the B2 scenario Markus Amann IIASA


UK Air Quality in 2050 : UK Air Quality in 2050 With optimal measures on climate change and air quality, it is possible to achieve improvements in air quality significantly greater than incremental measures on each Williams(2006) estimated future UK air quality in 2050 resulting from an aggressive pursuit of the UK long-term goal of a 60% reduction in CO2 emissions Made assumptions of significant penetration of zero-carbon energy generation and in the transport sector Concluded that with optimal win-win policies for climate change and air quality, PM2.5 and NO2 urban background levels in London could decrease by ~55% compared to current levels


Chemical Components Background Fine Fraction: Chemical Components Background Fine Fraction


Chemical Components Roadside Fine Fraction: Chemical Components Roadside Fine Fraction


But that was an optimistic analysisThe realities will be more complex, but it does show what could be achievedSo what are the complexities?The trade-offs and the win-wins: But that was an optimistic analysis The realities will be more complex, but it does show what could be achieved So what are the complexities? The trade-offs and the win-wins


THE STERN REPORT RECOGNISED THE WIN-WINS AND THE CONFLICTS: THE STERN REPORT RECOGNISED THE WIN-WINS AND THE CONFLICTS Chapter 12 ‘ Policies to meet air pollution and climate change goals are not always compatible. But if governments wish to meet both objectives together, there can be considerable cost savings compared to pursuing both separately’


WIN/WIN POLICIES: WIN/WIN POLICIES Measures which reduce fuel use – energy efficiency, less transport activity Lower carbon intensity energy generation – ‘pure’ renewables (ie not biomass/biofuels), nuclear Low emission vehicles (hybrids…) Hydrogen economy IF generation of hydrogen is low carbon Carbon Capture and Storage Reducing aviation NOx ? Reducing global ozone


TRADE-OFFS?: TRADE-OFFS? Most aftertreatment techniques – FGD, particulate filters, (but note SCR can give the opportunity to optimise fuel consumption) Production of low sulphur fuels Diesel vs Petrol (Black carbon and CO2 issues) Combined Heat and Power Biofuels and biomass burning Shipping emissions reduction?


TRADE OFFS AND CONFLICTS-DIESELS: TRADE OFFS AND CONFLICTS-DIESELS Diesel vehicles – lower CO2 vs higher Particulate and higher NO Two areas of concern: -dieselisation of the fleet and –trade offs of increased fuel consumption vs pollution abatement Mazzi and Dowlatabadi(2007) showed that from 2001 to 2020 the additional mortality due to increased diesel use in the UK would be 1850 deaths (910 due to Euro 3 and 940 due to Euro 4)


Slide41: But there are climate benefits from reducing Black Carbon-quantifying this is at the forefront of science at present Estimates suggest GWP(100yrs) is ~680 But BC is short lived so GTP may be a better metric, then the effect is smaller over the longer term, but still a warming, so good climate reasons to remove particles from diesel exhausts Boucher et al at the Hadley Centre UK, estimate a 100yrs GTP for BC ~10 times smaller than the 100yr GWP So ‘civilising’ the diesel with control technologies for PM and NOx will reduce the conflicts between air quality and climate change goals


Metrics for short-lived GHGs/Air Pollutants need to be agreed: Metrics for short-lived GHGs/Air Pollutants need to be agreed Shine et al. (2005) introduced the GTP concept. The absolute GTP is defined as the global change in surface temperature at a time horizon induced by a pulse emission. It has unit of K.kg-1 and unlike the absolute GWP is an end-point rather than a cumulative measure of climate change.


X = GWPBC(T=100years) xBC / xCO2: X = GWPBC(T=100years) xBC / xCO2


TRADE OFFS AND CONFLICTS-SULPHUR REMOVAL FROM STACK EMISSIONS AND FUELS: TRADE OFFS AND CONFLICTS-SULPHUR REMOVAL FROM STACK EMISSIONS AND FUELS Europe and North America have reduced sulphur emissions by large amounts since the 1970s This has greatly reduced the acidification problem and reduced harmful exposures to people But sulphate aerosol exerts a cooling influence on the earth’s climate S removal from fuels comes with a fuel consumption penalty at the refinery ‘Geo-engineering’?


POTENTIAL TRADE OFFS STILL TO BE QUANTIFIED AND MANAGED - CHP: POTENTIAL TRADE OFFS STILL TO BE QUANTIFIED AND MANAGED - CHP CHP – Combined Heat and Power Significant energy savings are feasible But we will be reversing the trend we began in the 1960s of moving energy generation out of urban centres and bringing the generation back into cities So the air quality impacts will need to be quantified and managed


POTENTIAL TRADE OFFS – BIOMASS/BIOFUELS : POTENTIAL TRADE OFFS – BIOMASS/BIOFUELS While the use of biomass (wood) is potentially a low carbon form of energy there are problems: The carbon savings may not be as large as expected and vehicle pollution may not improve There are potentially biodiversity problems and related effects from wholesale cultivation practices, second generation biofuels more attractive? Wood burning is a potential air quality problem especially in smaller scale/domestic use Even if air quality does not deteriorate, the large potential improvements in air quality may not be realised


Shipping and Aviation: Shipping and Aviation Still much to be done here – but will IMO and ICAO move fast enough? Action at national level can only have limited effectiveness for these sectors so a different approach is needed-how well can the EU influence these international organisations?


Air pollution problems in general are at a turning point: Air pollution problems in general are at a turning point Most technological solutions are or soon will be embedded in policy Euro 5&6 will soon be agreed – DPFs and SCR? Euro VI will be proposed soon (this year?) LCPD will potentially require SCR in 2016 Smaller combustion plants may be included in a revised IPPC There are still some emission reductions to squeeze out of technical measures, but- Will it be possible to convince decision makers to take further action on air quality grounds alone?


What will future air quality science be addressing in 2050?: What will future air quality science be addressing in 2050? Monitoring? Health issues? Bioaerosols?


Slide50: 25


SCIAMACHY Tropospheric NO2: SCIAMACHY Tropospheric NO2 Andreas Richter University of Bremen Ensemble of individual events (episodes) aggregated into 3 years


A more rational way to manage air quality in the future?: A more rational way to manage air quality in the future?


The Future: The Future ‘Pure’ air pollution policies will be increasingly difficult to justify Air pollution policies will need to be increasingly co-ordinated with those addressing climate change and sustainable development, and shaped by energy futures The global dimension will be increasingly important-for science and policy What changes do we need to make to our current institutional systems to cope with these changes?


The Future: The Future What do we need to do to make these things happen? One step could be in revising the Gothenburg Protocol/NECD Step one is likely to be an ‘incremental’ revision, discussing ceilings for, say, 2020, with reductions of the order of ~0-10% or thereabouts, and maintaining the geographical coverage of CLRTAP A further imaginative step however could be to set aspirational ceilings for air pollutants for ~2050 related to a ~60%(or greater?) reduction in GHGs-if reductions in carbon of that order are aspired to, then there could be major reductions in air pollutants Should Europe play a stronger role in stimulating Global Nitrogen Management?


Slide56: CONVENTION ON LONG-RANGE TRANSBOUNDARY AIR POLLUTION 50 Parties in Europe, North America and Central Asia


Concluding messages: Concluding messages Synergies of Air Quality policies and outcomes with those of Climate Change and Energy futures provide a great opportunity for significant further reductions in air pollution-even in the developed world, but certainly in the developing countries Future air quality will be shaped by climate change and energy supply issues – in the absence of any geopolitical or economic shocks But the related impacts on air pollution –in both directions - issues will need to be recognised, quantified and managed from a position of knowledge-scientific, technological, economic and social in a way that has not been achieved before Environmental science will need to broaden its scope!


Acknowledgement: To the sterling work of the Air Quality team in the Department for the innumerable discussions which have shaped the ideas, and to the researchers, who along with the Divisional team have produced most of the results which made this talk possible. The views expressed in this talk are those of the author and do not necessarily represent those of Defra.Thank You!: Acknowledgement: To the sterling work of the Air Quality team in the Department for the innumerable discussions which have shaped the ideas, and to the researchers, who along with the Divisional team have produced most of the results which made this talk possible. The views expressed in this talk are those of the author and do not necessarily represent those of Defra. Thank You!