1. A post-Kyoto partner: Considering the ozone regime as a venue to manage nitrous oxide David Kanter A.R. Ravishankara Ian Porter November 13, 2012 MOP 24 – Geneva, Switzerland

2. Outline Preview of forthcoming paper: “A post-Kyoto partner: Considering the ozone regime as a venue to manage nitrous oxide” – under review at the Proceedings of the National Academy of Science Authors: David Kanter (Princeton), Denise Mauzerall (Princeton), A.R. Ravishankara (NOAA), John Daniel (NOAA), Bob Portmann (NOAA), Pete Grabiel, Bill Moomaw (Tufts), Jim Galloway (U. of Virginia) Paper goal: An objective examination of major scientific, legal, technical and policy issues surrounding a potential decision by the Parties to take on N 2 O

4. ODP depends on: amount of sulfate aerosol, chlorine, and T Ozone Depletion Potential of N 2 O ODP of N 2 O = 0.017 To our knowledge, this is the first time ODP of N 2 O was calculated as in the case of the Montreal Protocol gases 4 N2O side event_13Nov_2012. Geneva 2012 Compare 0.017 for N 2 O with: HCFC-123 = 0.02; HCFC-124 = 0.022; HCFC-225ca = 0.025; HCFC-225cb = 0.033

5. A significant part of N 2 O emission is of human origin  Preindustrial level ~270 parts per billion (ppb)  Increases in N 2 O is due to human activity  Anthropogenic sources: agricultural fertilization, combustion, industrial production, etc. 5N2O side event_13Nov_2012. Geneva 2012  Current level ~325 ppb  [N 2 O] increasing at ~0.25% (of total) per year; i.e., ~1% of anthropogenic component per year.

6. Emissions, concentrations, and human- influenced contributions 6  Large Natural Emissions  Even larger natural concentrations- due to lifetime and previous emissions  Anthropogenic concentrations growing rapidly  Very similar to CO 2 ! Current Emissions Current Atmospheric Concentrations Anthropogenic Natural 6.7 TgN/yr 11 TgN/yr 55 ppbv 270 ppbv N2O side event_13Nov_2012. Geneva 2012

7. ODP alone does not tell the story ODP-weighted emission of anthropogenic N 2 O  ODP-weighted-emission of anthropogenic N 2 O was the fourth largest emission even in 1987, i.e., prior to the MP.  Anthropogenic N 2 O is now the largest ozone depletion gas emission  N 2 O’s ODP is small- but its emissions are large  If unabated, it will continues its growth in the 21 st century; even the most optimistic projections shows an increasing N 2 O trend N2O side event_13Nov_2012. Geneva 20127

8. Ozone layer benefit of reducing a GHG 8 N2O side event_13Nov_2012. Geneva 2012

9. Summarizing N 2 O issues 1.N 2 O, when viewed as any other ozone-depleting substance (CFCs, Halons, methyl bromide,…), has an ODP of ~0.02. 2.ODP weighted emission of anthropogenic N 2 O is very large 3.Anthropogenic N 2 O is now the largest manmade ozone-depleting gas emission (a recent development owing to the successful abatement of CFCs and other ODSs under the Montreal Protocol!), and it will remain so for the next century if anthropogenic emissions of N 2 O are unabated. 4.Reductions in N 2 O emissions or stabilization of N 2 O will have climate and ozone layer benefits. 9N2O side event_13Nov_2012. Geneva 2012

10. Why wasn’t N 2 O considered before?

11. Ozone regime’s legal authority N 2 O is largest known remaining anthropogenic threat to stratospheric ozone layer (Ravishankara et al. 2009) Neither VC nor MP define “ozone depleting substance” for purposes of inclusion under ozone regime (Art. 1, MP & VC) N 2 O included in list of substances that “modify the chemical and physical properties of the ozone layer” under VC (Art. 3 & Annex I at (4)(b)) N 2 O could therefore be controlled under ozone regime

12. Legal pathways for N 2 O’s inclusion Amendment to MP (Art. 2(10) – MP) or new protocol under VC (Art. 2, 8 – VC) Historical focus on regulating production and consumption could be useful for managing agricultural N 2 O emissions e.g. fertilizer efficiency standards

13. Interaction with current and post-2012 climate regime Establishing controls for N 2 O under ozone regime consistent with UNFCCC principles & ultimate objective (Article 2-3, UNFCCC). UNFCCC already delegates responsibility (aviation to ICAO, marine bunker fuels to IMO). Legal provisions could limit potential conflicts of authority (Grabiel & Roberts, 2010) Post-2012 climate regime in flux

14. Emissions & mitigation opportunities

15. Non-agricultural N 2 O mitigation SectorPercentage of total anthro. N 2 O emissions Technology and/or practice Mitigation potential Mitigation co- benefits Nitric & adipic acid Production <4%Catalytic reduction >90%NO x Biomass burning 8%-9%Conservation tillage, wildfire prevention education… Highly variableCO 2, CH 4, CO, PM (2.5 & 10), black carbon, sulphates, NO x Stationary & mobile combustion 8%-14%Oxidation catalysts, catalytic reduction… ~70%, ~80% respectively NO x References – SEI (2010), IPCC (2006), EPA (2006), EPA (2012), Winiwarter (2005)

16. Agriculture - Behavior Fertilizer best management practices (Robertson & Vitousek 2009): Crop residue recycling & use of cover crops Precision & split fertilizer application Watershed management Livestock management 4Rs: Right product, right rate, right time, right place (IFA, 2007) Consumer behavioral changes – food wastage, meat consumption…

17. Agriculture - Technology TechnologyMitigation potential Current useMitigation co- benefits Nitrification inhibitors ~35%High value crops, ~12% US corn cropland NO 3 -, NH 3, NO x Controlled-release fertilizer ~40%High value crops, <1% of US corn cropland NO 3 -, NH 3, NO x Genetically engineered crops/breeding ~30%NANO 3 -, NH 3, NO x References – Mosier et al. (2004), Akiyama et al. (2009), O’Brien & Mullins (2009), Shrawat et al. (2008)

18. Nitrification inhibitors in action Ian Porter presentation

19. Existing policies - Direct Non-agricultural N 2 O: UNFCCC Kyoto Protocol EU Emissions Trading Scheme (ETS) US EPA/Dept. of Transportation Australia Carbon Tax & UK Climate Change Act Agricultural N 2 O: Alberta Quantification Protocol for Agricultural N 2 O Emissions Reductions (Canada) Carbon Farming Initiative (Australia) American Carbon Registry US Climate Action Reserve

20. Existing policies - Indirect Reactive N (indirect impact on N 2 O): Water Framework Directive (EU) – NO 3 - Safe Drinking Water Act, Clean Water Act, Clean Air Act (USA) – NO 3 -, NO x, NH 3 Convention on Long Range Transport of Air Pollution (1988 Sofia Protocol, 1999 Gothenburg Protocol) – NO x, NH 3

21. Challenges & opportunities to managing agricultural N 2 O Food security – How to preserve and increase crop yields while reducing N 2 O? Equity – How to allow regions that vastly under-fertilize to increase fertilizer use while globally reducing N 2 O? Nitrogen cascade – Tight coupling of N cycle means that one atom of nitrogen can cascade through a variety of chemical forms, each with a different impact on environment

22. Conclusions N 2 O largest remaining known anthropogenic threat to stratospheric ozone layer Ozone regime’s legal authority and possibility of cooperation with climate regime clear Mitigation opportunities exist across all major sectors Challenges & opportunities exist for any international attempt to manage N 2 O Could mark welcome expansion of sustainable development diplomacy

23. Possible next steps Parties could request TEAP scoping report (“Task Force”) on technical & economic feasibility of specific N 2 O control strategies MLF could look to its experience with MeBr for general lessons on dealing with agricultural sector Implementation strategy could begin with point sources, then expand