Linking ammonia emission reduction and air concentrations and depositions of reduced nitrogen in Europe

Transcription

1 Linking ammonia emission reduction and air concentrations and depositions of reduced nitrogen in Europe Albert Bleeker ECN Air Quality & Climate Change

2 Outline Background of this (trends) study Results previous trends study - Data on emissions and concentrations/depositions - Conclusions drawn What happened since that study? - Did it bring new insights?

3 Background of this trends study Builds on previous study by Sutton et al. (2000) - Background document for the UN/ECE Ammonia Expert Group (AEG) Reason for update of the old study - Additional 5 years of information - New studies on emission/concentration/deposition relations Input to new background document to be presented at the December meeting of UN/ECE AEG

4 Why is this study important? Emission/transport/deposition of reduced nitrogen (NH x ; NH 3 and NH 4+ ) will eventually lead to eutrophication and acidification of ecosystems and contribute to local air quality Recognizing this, together with the transboundary nature of the problem, the UN/ECE developed protocols on: - Limiting NH 3 emissions - Reducing SO 2, NO x and VOC concentrations - Setting national emission ceilings to be reached in 2010 (Gothenburg Protocol, 1999) In parallel: European Union agreed on the National Emissions Ceilings Directive (NECD), setting targets for e.g. NH 3 emissions binding in European Law.

5 Why is this important? (II) Evidence needed for effective NH 3 emission reduction: - Achievable - Measurable NH 3 emissions mainly from agricultural sources, thus: - Abating NH 3 will be in agricultural sector - Reduction in animal numbers - Reducing fertilizer consumption - Implementing technical measures Since reducing sector activity was not an option, there is a need to demonstrate the effectiveness of technical measures

6 Challenges Quantify the link between NH 3 emission changes and monitored atmospheric NH x in situations where emissions have definitely changed - Note: not only NH x issue. Many questions regarding linearity between SO 2 and NO x emissions and NH x concentrations Assess the effectiveness of NH 3 emission abatement policies

7 What has been done? 2000 trends study brought together information about the link between NH 3 emission and measurements (concentration and deposition) from different case studies: - link between agr. sector activity and atm. NH x - Hungary, Slovakia, Former East & West Germany, Russia, Switzerland & North Carolina - link between NH 3 emission abatement and atm. NH x - Netherlands - Denmark

8 Emissions: are they true? NH3 emission (kt yr -1 ) (CH, DK, D[E], HU, NL, SL) NH3 emission (kt yr -1 ) (D[W], RU) Denmark Germany (E) Hungary Netherlands Slovakia Switzerland Germany (W) Russian Fed

9 Hungary NH4 + conc. (μg m -3 ) Jan-81 Jan-81 Jan-82 Jan-83 Jan-84 Jan-85 Jan-86 Jan-87 Jan-88 Jan-82 Jan-83 Jan-84 Jan-85 Jan-86 Jan-87 Jan-88 Jan-89 Jan-89 Jan-90 Jan-90 Jan-91 Jan-91 Jan-92 Jan-92 Jan-93 Jan-93 Jan-94 Jan-94 Jan-95 Jan-95 Jan-96 Jan-96 Jan-97 Jan-97 Jan-98 Jan-98 Jan-99 Jan-99 Jan-00 Jan daily measured 30 day mean 1 year mean 53% emission reduction no clear trend in either NH 4 or NH NH3 conc. (μg m -3 ) NH4 + in pptn. (mg l -1 ) & wet deposition (g m -2 year -1 ) SO2 & aerosol SO4 2- conc. (μg m -3 ) ammonium in rain ammonium wet dep. ammonium 3 yr mean suphate aerosol suphur dioxide

10 Slovakia monthly values 1 year running mean Poly. (monthly values) 44% emission reduction ~20% reduction of NH 4 between NH4+ in precipitation (mg l -1 ) Jan.78 Jan.79 Jan.80 Jan.81 Jan.82 Jan.83 Jan.84 Jan.85 Jan.86 Jan.87 Jan.88 Jan.89 Jan.90 Jan.91 Jan.92 Jan.93 Jan.94 Jan.95 Jan.96 Jan.97 Jan.98 Jan.99

11 Netherlands NH3 conc. ( g m -3 ) % emission reduction 10% reduction NH 4 wd 29% reduction NH 4 aerosol 6 NHx wet dep. (kg N ha -1 yr -1 ) NH4 + conc. ( g m -3 ) Again: part of the explanation - parallel changes in SO 2 and NO x emission But also: overestimation of effectiveness of measures Measurements Model

12 Netherlands effect of changing SO 2 and NO x ammonium wet deposition ammonia concentration SO 2 and NO x emissions and actual emissions increase in NH 3 conc. and decrease in NH 4 wd

13 Overall conclusions many difficulties involved in evaluating changes in NH 3 emissions by using monitoring networks - need for long time series - interaction with other components (SO 2 & NO x ) - models used not always complete caution when measured values do not follow expectations: - limitations in the models - limitations in the monitoring - ineffectiveness of the abatement techniques

14 What happened since? Ongoing discussion on trends (in relation with meeting the NECD targets) - Additional measuring programmes - Evaluating/updating models - Emissions - Transport/deposition Updated information; 5 additional years - Emissions - Concentrations/depositions New studies - United Kingdom - Netherlands - EMEP

15 Updated EMEP emissions for Europe Countries Hungary Greece Czech Slovakia Slovenia Servia Poland Cypres Latvia Lithuania Portugal Italy Netherlands Finland East Germany West Spain Ireland Great Brittain France Denmark Belgium Austria Change in emission (in %)

16 The Netherlands ammonia emission (kton/year) ammonia concentration (ug/m3)

17 The Netherlands (II) x 500 m emissions 5000x5000 m emissions 20 y = 0.68x R 2 = OPS ( ug m -3 ) % difference Emission uncertainties Dry deposition parameterization 0 y = 0.56x R 2 = passive sampler ( ug m -3 )

18 United Kingdom Question to be answered: - Can we detect NH 3 emission changes after the outbreak of foot & mouth disease? Study motivated by Dutch & E. European experience of difficulty to see trends following emission reductions

19 UK (II) Measured Unaffected Measured Affected Modelled Unaffected Modelled Affected 03/04/ /06/ /08/ /10/ /02/ /12/2002 NH3 concentrations (ug N m -3 ) 01/10/ /04/ /06/ /08/ % 160% 140% 120% 100% 80% 60% 40% 20% Measured Modelled Trend was detected: - Only by comparing affected and unaffected sites simultaneously 03/12/ /02/2002 Affected normalized NH 3 as % of unaffected

20 Annual mean load (mol/ha) (µgn/m3) Switzerland '92 '85'86'87'88'89'90'91'92'93'94'95'96'97'98'99'00'01'02'03'04'05 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 Dübendorf Payerne Chaumont Rigi Rigi Magadino Sion Magadino Lugano Chaumont Basel NH 4 +NH 34 Concentrations -N in rain Lägeren Tänikon Lausanne Dübendorf Härkingen Zürich Chaumont Rigi Bern Payerne Payerne Davos Lausanne Jungfraujoch Payerne Basel Lägeren Tänikon Dübendorf Härkingen Zürich Rigi Bern Davos Jungfraujoch Sion Magadino Lugano

21 Slovak Republic Agriculture Industry Traffic NH 4 -N Concentration NH 3 emission (t/year) Concentration (mgn/l)

22 EMEP - Europe NH 3 +NH 4+ decrease more as a consequence of SO x reductions Less effect on conc. in precip: less scavenging of NH 4 + compensated by more of NH 3 Tendency for air concentrations to decrease more than wet depositions model predicts this to be caused by the SO 2 emission reductions

23 USA North Carolina NH3 emissions (kt/yr) NH4 + conc. in precip. (um) NH3 emission from pigs NH4 in precipitation NH4 wet deposition NH4 + wet deposition (kg N/ha/yr) Year Comparison of NH 3 emissions in the coastal plain region of North Carolina, USA, against NH 4+ precipitation concentrations and wet deposition at the NADP monitoring site NC35 in Sampson County (Aneja et al., 2006)

24 USA National Trends Network (NTN)

25 SO 4 2- NH NO 3 -

26 SO 4 2- NH NO 3 -

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43 SO 4 2- NH NO 3 -

44 Overall Much effort put in trying to get a grip on the linkages between emissions and concentration New studies (again) showed relevance of having insight in: - Adequate emission estimates - Adequate model parameterizations - Need for long-term good quality measurements - in contrasting areas (evaluating abatement measures) If all this can be brought together, valuable evaluations on the effectiveness of NH 3 abatement measures can indeed be made However, further discussion needed on reasons behind observed (lack of) trends in emissions and concentrations

45 UN/ECE Expert Group on Ammonia 4 6 December 2006, Edinburgh (UK) Datasets on trends of NH x still welcome, to be included in the background document - Not only Europe; also other experiences are needed to get the full picture Contact: a.bleeker@ecn.nl