Air Quality in 2050

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Air Quality in 2050

• Professor Martin Williams
• Burntwood Lecture
• Institution of Environmental Sciences
• 14 November 2007

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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, its
• just one thing after another..

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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 didnt 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 OCasey died
• Philip Larkin and Leonard Cohen(!) published
  books
• Gareth Edwards almost signed for Swansea Town

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Time Series of SO2 Emissions (Mtonnes)
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Trend in Black Smoke at Lambeth 1961-98
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Trends in UK PM10 1992-2003
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Trends in Particulate sulphate 1987-2003
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Trends in SO2 and SO4 at Eskdalemuir1977-2002
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EMEP
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EMEP
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EMEP
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Maximum 1-hour mean Ozone in UK
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Annual Mean Ozone at Urban and Rural sites in
London and SE England (µg/m3)
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Future Projections UK SO2 and NOx Emissions
(kt/yr)
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But how will the polluted atmosphere
respond?Will emissions remain decoupled from
economic growth?Will we still quantify economic
growth in the same way?
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Relative Annual Means London, 1997100
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EMEP
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EMEP
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EMEP
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Future Ozone Controls
Future Ozone Controls
Future Ozone Controls
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E.g. Szopa et al., 2007 Downscaling from global
to regional modeling Benefit of current emission
controls counterbalanced by the global increase
Impact on air quality
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How will the tropospheric ozone baseline change?
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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

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Temperature dependency of total isoprene
emissions from Mediterranean vegetation (Owen et
al., 1998)
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The Future some drivers

• Demographics
• Energy
• Sociology
• Politics
• Health/disease

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Global migration to cities, changes emission
configurations, urban air quality and health
impact
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NOx emissions from human sources by world region
for the B2 scenario Markus Amann IIASA
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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

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Chemical Components Background Fine Fraction
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Chemical Components Roadside Fine Fraction
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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
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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

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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

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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?

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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)

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• 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

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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.

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X GWPBC(T100years) ?xBC / ?xCO2
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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 earths climate
• S removal from fuels comes with a fuel
  consumption penalty at the refinery
• Geo-engineering?

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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

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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

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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?

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Air pollution problems in general are at a
turning point

• Most technological solutions are or soon will be
  embedded in policy
• Euro 56 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?

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What will future air quality science be
addressing in 2050?

• Monitoring?
• Health issues?
• Bioaerosols?

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SCIAMACHY Tropospheric NO2
Ensemble of individual events (episodes)
aggregated into 3 years
Andreas Richter University of Bremen
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A more rational way to manage air quality in the
future?
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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?

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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?

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

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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!