1 POLS 422 Climate Change The Scientific Consensus International Treaties

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

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 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

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.” [ ° C]  2001: "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.” [ °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.” [ °C]

5 POLS 422 IPCC predictions l CO 2 doubling this century >> 1.5°- 8.6° C warming l Sea level rise: 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

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

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  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)

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

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

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.