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1 POLS 422 Climate Change The Scientific Consensus International Treaties
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2 POLS 422 The greenhouse effect l Large molecules allow solar radiation in, but not out Understood since 19 th century Goldilocks phenomenon: Earth is “just right” l Greenhouse gases CO 2, H 2 O, CH 4, O 3 (natural and anthropogenic) CFCs, N 2 O (anthropogenic) l Difference between warm intervals & ice ages: 6°C
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3 POLS 422 Fundamental Climate Questions l Are CO 2 concentrations increasing? Yes. u Short-term measurements u Long-term: ice core samples l Is this caused by humans? Yes. 180-280 ppm is natural u Since industrialization, increased to 380 ppm l Is climate changing? Prior to FCCC, unclear Since 1996, IPCC consensus is yes. More dramatically than models predict
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4 POLS 422 IPCC l Background: From UNEP & WMO to UNGA l Predictions 1995: "The balance of evidence suggests that there is a discernible human influence on the global climate.” [+1.0-3.5 ° C] 2001: "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.” [+1.4-5.8 °C] 2007: “There is very high confidence that the net effect of human activities has been one of warming. Evidence shows that natural systems are being affected.” [+1.4-8.6 °C]
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5 POLS 422 IPCC predictions l CO 2 doubling this century >> 1.5°- 8.6° C warming l Sea level rise: + 40-80 cm in 21 st C Could be much larger if Greenland or Antarctic ice sheets melt l More frequent and intense tropical storms Katrina as indicator of the future l “Climate surprises” inevitable Ex: Ocean’s thermohaline circulation system
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6 POLS 422 FCCC (1992) l Objective: “stabilize atmospheric concentrations of GHGs at safe levels” l Principles “Common but differentiated responsibility” Precautionary principle Cost-effectiveness l Obligations Annual GHG Inventories Annex I (IC’s): return GHG emissions to 1990 levels by 2000 (nonbinding) Annex II (western IC’s): financial assistance to DCs
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7 POLS 422 Kyoto Protocol (1997) l 6 GHGs covered: CO2, CH4, N2O, PFCs, HFCs, SF6 l Annex I: differentiated GHG reductions totaling 5% from 1990 levels by 2008-12 U.S. - 7%; EU -8% Aus, Iceland +10% l 5 ways to meet obligations Simply reduce GHG emissions Enhance sinks (forests) Emissions trading among Annex I parties Joint implementation in Annex I parties Clean Development Mechanism (DCs)
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8 POLS 422 What Kyoto means: 3 versions l Meaningful action Annex I emissions projected to rise 30% by 2010 over 1990 levels l Symbolic politics Loopholes will prevent real cuts in GHGs Stage is set for deeper reductions l Meaningless gesture To stabilize GHG concentrations, an immediate 70% reduction in GHG emissions is required u …or 90% by 2030
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9 POLS 422 After Kyoto l 2001: U.S. withdrawal l Bonn surprise (July 2001) Bush withdrawal galvanized action Decisions on capacity building in DCs & E. Europe, tech. transfer, joint implementation Adaptation fund pledged by EU & other ICs u $410 million/year l Russia ratified, bringing Kyoto into force in 2005 l Current negotiations: post-2012 reductions
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10 POLS 422 Beyond International Law l Voluntary initiatives Pew Center: Business Environmental Leadership Council Public utilities: Seattle City Light Individuals: Carbon offsetting l Local initiatives ICLEI: 500+ cities & counties in 67 countries, representing 300 million people u U.S. cities: Nickels’ initiative > 50 million US governors suit against utilities thrown out CA: 1990 levels by 2020; 80% below by 2050 u Emissions trading with U.K.
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