quantitative constraints on natural and anthropogenic...
TRANSCRIPT
Quantitative Constraints on Natural and Anthropogenic Mercury: Implications for Policy
Noelle E. Selin*, Shaojie Song, Amanda Giang *Assistant Professor of Engineering Systems and Atmospheric Chemistry Massachusetts Institute of Technology Mercury 2013, Edinburgh, 1 August 2013 [email protected] http://mit.edu/selin http://mit.edu/selingroup
Questions
o What constraints do we have on the global biogeochemical cycle of mercury?
o Are these constraints enough to quantitatively evaluate global policy effectiveness?
For more information: N.E. Selin, “Global Change and Mercury Cycling: Challenges for Implementing a Global Mercury Treaty,” Forthcoming in Environmental Toxicology and Chemistry, 2013 E. M. Sunderland and N. E. Selin, “Future trends in environmental mercury concentrations: Implications for prevention strategies." Environmental Health, 12(2), doi:10.1186/1476-069X-12-2 Also presentations at ICMGP by Amanda Giang (Friday); Shaojie Song (poster, Monday)
Global Biogeochemical Cycle of Mercury
[Selin, Ann. Rev. Env. Res., 2009]
Previous estimates of natural and anthropogenic fractions
o Pre-industrial constraint: Factor of 3 enhancement (Selin et al. 2008)
o Pre-industrial mercury ≠ Natural (Amos et al. 2013)
Current-day anthropogenic
Natural
Historical
exact fractions uncertain…
Increasingly available observational data
EMEP
CAMNet
AMNet
http://www.emep.int/; http://www.on.ec.gc.ca/natchem/Login/Login.aspx; http://nadp.sws.uiuc.edu/amn/
Constraints from Inverse Modeling
Ø For natural/re-emissions, the average uncertainties are reduced from 100% to ~ 64%.
Ø Better ability to constrain anthropogenic emissions, particularly in Asia
(e) Asia emission
Ocean Ocean Soil
From S. Song et al, presented in poster at ICGMP on Monday
Emissions in the Minamata Convention
o Emissions to air, releases to water/land o Emissions controls:
n New Sources: Best Available Technology, 5 years
n Existing Sources: menu of choices, 10 years o Releases: must take measures to control
releases
For more: Policy session on Friday AM at ICMGP
Emissions and Deposition to 2050
Sunderland and Selin, 2013; Selin, forthcoming
BAU
Minamata
o Minamata “BAT” provisions likely to roughly correspond to “B2” scenario
Very optimistic
Modeling of Future GBC under Policy
A
Surface ocean: 7000
Geo
geni
c: 2
00
Depo
sitio
n: 2
200
Rivers: 200
Depo
sitio
n: 3
700
Evas
ion:
260
0
Anth
ropo
geni
c: 1
900
2900
4200
100
Land
em
issio
n:12
00
Surface soil: 110,000
Long-term soil: 860,000 Intermediate ocean: 160,000
Surface ocean: 3800
Deep ocean: 270,000
Atmosphere: 5000
270
A
Surface ocean: 7000
Geo
geni
c: 2
00
Depo
sitio
n: 2
200
Rivers: 240
Depo
sitio
n: 3
700
Evas
ion:
270
0
Anth
ropo
geni
c: 1
670
3300
4500
700
Land
em
issio
n:13
00
Surface soil: 130,000
Long-term soil: 880,000 Intermediate ocean: 180,000
Surface ocean: 4000
Deep ocean: 280,000
Atmosphere: 5000
280
(a) (b) (c)A
Surface ocean: 7000
Geo
geni
c: 2
00
Depo
sitio
n: 3
900
Rivers: 290
Depo
sitio
n: 6
300
Evas
ion:
400
0
Anth
ropo
geni
c: 4
700
3800
6400
790
Land
em
issio
n:15
00
Surface soil: 150,000
Long-term soil: 880,000 Intermediate ocean: 200,000
Surface ocean: 5800
Deep ocean: 280,000
Atmosphere: 8700
280
+5%
+12% +18%
+8% +4%
-12%
Present
Policy (2050)
Selin, ETC, forthcoming 2013
+75%
+150%
+116%
+25%
+53%
+25%
+85%
+100%
+36%
No policy (2050)
0%
Conclusions
o Globally, future changes on order of 1-2%/year from Minamata Convention; mostly avoided increases
o Scientific knowledge not sufficient at present to attribute causes
o Increased role for measurement, modeling, effectiveness evaluation
o Additional benefits not accounted for from policy
Acknowledgments
Funding: “CAREER: Understanding Chemistry, Transport and Fate of Mercury and Persistent Organic Pollutants through Global Atmospheric Modeling," U.S. National Science Foundation Atmospheric Chemistry Program, Award #1053648, 3/2011-3/2016 MIT graduate students Shaojie Song, Amanda Giang Student participants in trip to Mercury negotiations (INC5, Geneva, January 2013) Questions?
http://mit.edu/selingroup