Calculate, map and used of critical loads and exceedances for acidity and nitrogen in Europe

Calculate, map and used of critical loads and exceedances for

acidity and nitrogen in Europe

Professor Harald Sverdrup Chemical Engineering, Lund University,

SwedenHarald.Sverdrup@chemeng.lth.se

The European game planEnvironmental policyand future visions

Internationalworkshops

Homework

Nationalresearch

Nationalenvironmentalresearch funding

ProtocolsProblem solution designs

+

++

++

+

+

R

R

+

Quantitativecause limitation

Ecosystem

Indicator organism

Critical limit

Calculation method

Data

An effect-based methodology

Defining the critical load

• The maximum amount of pollution into an ecosystem that does not cause significant damage to system resources, survival, structure or function

The critical load

QuickTime™ and aSorenson Video decompressorare needed to see this picture.

Contributions toacidity in the system

Contributions toneutralization inthe system

Targets to protectFor Sweden, it is proposed that the aspects to protect are:

1 Tree vitality and growth potential for the major species used in production,2 The potential for natural rejuvenation of the tree vegetation3 Fertility aspect of the soil as expressed by the base saturation,4 Biodiversity of the ground vegetation

For aquatic ecosystems the aspects to protect are suggested to be:

3 The most sensitive fish species native to the waterbody4 Crayfish in those waterbodies it is native to5 The biodiversity of the aquatic community, evaluating the range of organisms native to

the systemTabulated values are available for limiting BC/Al ratios for trees, ground vegetationand crops, as well as their corresponding pH values.

Response was

measured

Norway spruce: BC/Al=1.2Scots pine: BC/Al=1.0Birch: BC/Al= 0.8 Beech, Oak: BC/Al==0.6

Many effect parameters are available

EcosystemType

Ecosystemcomponent

Indicatororganism

Indicatorfunction

Causativeparameter

Limitingvalue

DiagnosticMonitoringparameter

Forestecosystem

Tree cover NorwaySpruce

Root vitality,Growthpotential

(Ca+Mg+K)/AlpH

[Al3+]

1.24.4

0.5 mg/l

Growth,Needle loss, Tree

vitalityNatural

rejuvenation(Ca+Mg+K)/Al

pH[Al3+]

0.73.9

1 mg/l

Rejuvenationrate,

Species longterm survival

Scots pine Root vitality,Growthpotential

(Ca+Mg+K)/AlpH

[Al3+]

1.24.4

0.5 mg/l

Growth,Needle loss, Tree

vitalityNatural

rejuvenation(Ca+Mg+K)/Al

pH[Al3+]

0.6,3.9

1 mg/l

Rejuvenationrate,

Species longterm survival

Models available for critical loads for acidity and nitrogen

• Empirical models– Skokloster model– Empirical nitrogen critical loads

• Simplified models– Simple mass balance (SMB)– F-factor models (lakes)

• Integrated steady state models– PROFILE model

• Integrated dynamic models– VSD model (soils)– MAGIC model family (lakes)– SAFE/ForSAFE-VEG model family (terrestial ecosystems)

The order of the actions

• Static approach first

- Simple mass balance models

- Complex approach; PROFILE

- Create critical loads maps

• Apply dynamic models at sites with enough data

- Single sites - qualitative assessments

- Generate regional approach - representative

information capture and transformation

PROFILE/ForSAFE

Revised critical loads for forests, lakes and streams

meq per m2 och årCLacid ( 5%-tile)

36 0 to 1077 10 to 2062 20 to 40

10 40 to 603 60 to 1004 100 to 2001 200 to 500

meq per m2 och årCLnut ( 5%-tile)

21 0 to 1083 10 to 2060 20 to 40

24 40 to 605 60 to 1000 100 to 2000 200 to 500

Critical Load for acidity and nitrogen in the grid system

Critical loads for ecosystems in Europe, forests, open land and lakes

The best solution is sought for

Critical loadsfor ecosystems

Emissions of pollutants Reduction cost

Transport ofpollution acrossborders

Optimization formaximum protection,minimum reduction cost

The policy for pollution control

1988, kEq per ha and yrExceedance (50%-tile)

20 - to 0.037 0.0 to 0.2

50 0.2 to 0.565 0.5 to 1.0

19 1.0 to 20.0

1988, kEq per ha and yrExceedance (5%-tile)

8 - to 0.021 0.0 to 0.2

38 0.2 to 0.565 0.5 to 1.059 1.0 to 20.0

The Swedish example1988 exceedence was far too much !

Forest growth and vitalityBC/Al=0.6-1.2

Protection of nutrient resourcesAcid input>Weathering

Lakes and streamsmax Al: 0.06 mg/l

Medel: 37 mekv/m2/år

Exceedance depend on the receptor chosen

Exceedence 2010 (50%-tile)meq per m2 och år

149 -300 to 035 0 to 10

6 10 to 202 20 to 401 40 to 600 60 to 800 80 to 150

meq per m2 och årExeedence 1997 ( 5%-tile)

59 -300 to 064 0 to 10

37 10 to 2026 20 to 40

3 40 to 601 60 to 803 80 to 150

Exceedance with the Göteborg protocol

Sulfur deposition 1980-2010

• Green = 3-6 kg S/ha yr• Red > 25 kg S/ha yr

Exceedance of critical loads

• Blue < 3 kg S/ha yr• Red > 25 kg S/ha yr

Critical loads cannot be validated,but the components of it can be testedand validated

Exceedance cannot be robustly tested againstecosystem effects, because ecosystem effectsare not uniquely defined by exceedance

Validation is difficult

Exceedance and effects are NOT simultaneous in time

Critical load isexceeded

Limit is violateddamage possible

Deposition

Limit parameter

TIME

LimitCL

13 NFCs submitted Dynamic Modelling outputs:

Austria, Bulgaria, Switzerland, Czech Republic, Germany, France, Great Britain, Ireland, Italy, Norway, Luxembourg, Poland, Sweden.

Countries now into integrated regional dynamic modelling

What are the model predictions?

• Recovery does not reverse the path of acidification

• Fast effect initially, very slow final recovery

• Recovery is not 100%

Prediction: Lake pH in Scandinavia

7.0

6.5

6.0

5.5

5.0

4.5

4.01850 1880 1910 1940 1970 2000 2030 2060

Svagt buffrat

Starkare buffrat

Median

Simulerat pH-värde i avrinningen

Dynamic simulations:Soil pH in

the long runin Sweden

QuickTime™ and aVideo decompressor

are needed to see this picture.

But BC/Al what we work

with

QuickTime™ and aVideo decompressor

are needed to see this picture.

Soil base saturation, lost ?

0

10

20

30

40

50

1850 1900 1950 2000 2050

NorrMellansverigeSydväst

Markens basmättnadsgrad (%)

Simple messages to policy?

• Critical load (CL)– No significant harmful effects if deposition

don’t exceed CL

• Target load (TL)– Recovery by specified year if deposition don’t

exceed TL

Interpretation of target loads

Will not recover by

2030

Will recover by 2030

TLmax(S)-2030 5th percentile CLmax(S)

20 years with critical loads

• 1968 Acidification put on the official agenda by Prof Svante Oden in Uppsala

• 1979 Convention on long range transboundary air pollution

• 1985 First Olso protocol on flat rate 30% sulfur emission reduction

• 1990 The second Oslo protocol, effects based but settling on 60% sulfur emission reduction

• 1999 The Göteborg protocol, effects based settling for -85% S/-30% NOx

• 2010 revision of the Göteborg effects based protocol

Conclusions

International efforts to prevent acidification have been very successful

Critical oads very extremely successful in linking environmental goals through science to policy

Acidification remains as a large and significant problem in large areas of Europe