Acid Rain Revisited

Hubbard Brook Research Foundation

Science Links

Bridging the Gap betweenScience and Policy

Outline

• Patterns of Emissions and Deposition

• Forest Ecosystem Effects

• Ecosystem Response to Management Strategies

• Conclusions

Patterns of Emissions and Deposition

Time (years)

allowances allocated for that yearall sourcesPhase I sources

Phase II sources

SO2 Emission Reductions under the Acid Rain Program

9.4 9.3 8.7

5.3 5.44 5.47 5.29 4.94

7.527.817.51

7.076.57

7.036.7917.3

11.210.6 10.2 10.6

0

2

4

6

8

10

12

14

16

18

20

1980 1985 1990 1995 1996 1997 1998 1999 2000 2001 2002 2003

Em

issio

ns (m

illio

n to

ns) s

9.4 9.3

5.3 5.35.55.4

8.7

4.9

12.513.113.012.5

11.9

15.716.117.3

11.210.6 10.2 10.6

0

2

4

6

8

10

12

14

16

18

20

1980 1985 1990 1995 1996 1997 1998 1999 2000 2001 2002 2003

Em

issio

ns (m

illio

n to

ns) s

SO2 Allowance Price Index

$0

$50

$100

$150

$200

$250

Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04

Source: Cantor Fitzgerald

0

5

10

15

20

25

1995 1996 1997 1998 1999 2000 2001 2002 2003

SO2 Emissions and the Allowance Bank, 1995- 2003

8.7

11.7 13.5

15.0

16.6

21.6

18.818.1

19.9

Allowances allocated that year

Unused allowances from previous year (bank)Actual emissions from affected sources

SO

2 Em

issi

ons

(mil

lion

ton

s)

1990 emissionsPhase I (1995-1999) average emissionsPhase II (2000-2003) average emissions

scale: 1990 emissions in Ohio were 2.2 million tons

SO2 Emission Reductions, by State

projected emissions level in the absence of Title IV

8.1

1990 emissionsPhase I (1996-1999) average emissionsPhase II (2000-2003) average emissions

scale: 1990 emissions in Ohio were 500,000 tons

NOx Emission Reductions, by State

1965 1970 1975 1980 1985 1990 1995 2000

SO

2 E

mis

sio

ns

Mill

ion

sh

ort

to

ns

2

4

6

8

10

12

14

16

with Canadian Emissionsw/out Canadian Emissions

Year

1965 1970 1975 1980 1985 1990 1995 2000

NO

x E

mis

sio

ns

Mill

ion

sh

ort

to

ns

0

2

4

6

8

Source Area Includes: VT, MA, NY, NH, CT, RI, ME, OH, PA, DC, MD, NJ, DE, MI, VA, WV, QUE, ONT

SO2 Emissions - 24 hr source area (Million metric tons)

0 2 4 6 8 10 12 14 16

Hub

bard

Bro

ok

Pre

cipi

tatio

n S

O4

(eq

/L)

0

20

40

60

80

Y= 3.82X + 5.73r ²=0.764

NOx Emissions - 24 hr source area (Million metric tons)

0 2 4 6 8

Hub

bard

Bro

okP

reci

pita

tion

NO

3

(eq

/L)

0

5

10

15

20

25

30

35

Y= 7.31X - 24.99r ²=0.393

Forest Ecosystem Effects

Soil Acid Rain Effects

• Soil S and N enrichment

• Nutrient cation (Ca2+, Mg2+) depletion

• Al mobilization

Aquatic Effects

Summary (n=1469)

No. of Lakes (%) Surface area (ha) (%)

pH < 5.0 352 24 2,000 8.4

ANC < 0 µeq/L 388 26 2,650 11

Ecosystem Response to Management Strategies

Critical Chemical Indicators for Ecosystem Response to Acidic

Deposition

TerrestrialSoil and soil water

Ca/Al < 1

Soil base saturation < 20%

AquaticSurface waters

pH < 6.0ANC < 50 eq/LAl > 2 mol/L

SO

4 (

eq/L

)

45

90

135

180

NO

3 (

eq/L

)

20

40

60

80

100

AN

C ( e

q/L)

-40-30-20-10

010203040

pH

4

5

6

Year

1983 1985 1987 1989 1991 1993 1995 1997 1999

Ali

(m

ol/L

)

02468

101214

Ali

(µm

ol/L)

pH

AN

C

(µeq/L

)N

O3 (

µeq/L

)SO

4 (µ

eq/L

)

Num

ber of

Lak

es w

ith

Sig

nific

ant Tre

nds

and

Direc

tion

of T

rend

-20

-10

0

10

20

p < 0.05p < 0.10

Adirondack Lakes6/1982-12/2000

n=16

SO4 NO3 S+N CB ANC pH Ali DOC

Num

ber of

Lak

es w

ith

Sig

nific

ant Tre

nds

and

Direc

tion

of T

rend

-50

-40

-30

-20

-10

0

10

20

30

40

50

p < 0.05p < 0.10

Adirondack Lakes6/1992-12/2000

n=48

SO4 NO3 S+N CB ANC pH Ali DOC

pH

4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0

Nu

mb

er o

f F

ish

Sp

ecie

s

0

2

4

6

8

10

12

14

20001982-83

pH (2000)

4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0

Cha

nge

in N

umbe

r of

Fis

h S

peci

es

1982

-200

0

-6

-4

-2

0

2

4

6

Model Predictions of the Response of Soil and Water

to Acidic Deposition:

Past and Future

Climatic data•Solar radiation•Precipitation•Temperature

PnET Water balance Photosynthesis Living biomass Litterfall

Net Mineralization

BGC – Surface water Aqueous reactions

Uptake

Deep water flow

Shallow water flow

Weathering

Wet Deposition

Dry Deposition

BGC• Aqueous reactions• Surface reactions

• Cation exchange• Adsorption• Humic binding• Aluminum dissolution/precipitation

Policy or ProposalNOx

(million short tons)

SO2

(million short tons)Deadline for

Implementation4

Pollutant?

1990 Clean Air Act 4.6 8.9 2010 No

Jeffords Bill S.556 (as amended)

1.5

66% reduction from 1997 levels

2.25

75% reduction fromPhase II levels of 1990 CAAAs

2008 Yes

Smith Bill S.2815 (Clear Skies)

2.1 by 2010

1.7 by 2018

67% of current levels

4.5 by 2010

3.0 by 2018

73% of current emissions

2010 and 2018 3 pollutant

Carper Bill S.843

(Clean Air Planning Act of 2003)

1.87 by 2009-2012

1.7 after 2013

4.5 by 2009-2012

3.5 by 2013-2015

2.25 after 2016

2009, 2013, 2016 3 pollutant

Clinton Bill S.588 Approx. 2.1 in

2004-2006

56% reduction from 1990 levels

Approx. 1.38

70% reduction from 1990 CAAAs levels

Approx. 4.45 by 2007

50% reduction from 1990 CAAAs levels

2004-2006:

2007

No

SO2 Cap and Trade Program:Expected Annual Costs by 2010