The Scientific Consensus International Treaties Climate Change The Scientific Consensus International Treaties Lecture 10 POLS 384

The greenhouse effect Large molecules allow solar radiation in, but not out Understood since 19th century Goldilocks phenomenon: Earth is “just right” Greenhouse gases CO2, H2O, CH4, O3 (natural and anthropogenic) CFCs, N2O (anthropogenic) Difference between warm intervals & ice ages: 6°C Lecture 10 POLS 384

Fundamental Climate Questions Are CO2 concentrations increasing? Yes. Short-term measurements Long-term: ice core samples Is this caused by humans? Yes. 180-280 ppm is natural Since industrialization, increased to 380 ppm Is climate changing? Prior to FCCC, unclear Since 1996, IPCC consensus is yes. More dramatically than models predict Lecture 10 POLS 384

IPCC Background: From UNEP & WMO to UNGA 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] Lecture 10 POLS 384

IPCC predictions CO2 doubling this century >> 1.5°- 8.6° C warming Sea level rise: + 40-80 cm in 21st C Could be much larger if Greenland or Antarctic ice sheets melt More frequent and intense tropical storms Katrina as indicator of the future “Climate surprises” inevitable Ex: Ocean’s thermohaline circulation system Lecture 10 POLS 384

FCCC (1992) Objective: “stabilize atmospheric concentrations of GHGs at safe levels” Principles “Common but differentiated responsibility” Precautionary principle Cost-effectiveness 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 Lecture 10 POLS 384

Kyoto Protocol (1997) 6 GHGs covered: CO2, CH4, N2O, PFCs, HFCs, SF6 Annex I: differentiated GHG reductions totaling 5% from 1990 levels by 2008-12 U.S. - 7%; EU -8% Aus, Iceland +10% 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) Lecture 10 POLS 384

What Kyoto means: 3 versions Meaningful action Annex I emissions projected to rise 30% by 2010 over 1990 levels Symbolic politics Loopholes will prevent real cuts in GHGs Stage is set for deeper reductions Meaningless gesture To stabilize GHG concentrations, an immediate 70% reduction in GHG emissions is required …or 90% by 2030 Lecture 10 POLS 384

After Kyoto 2001: U.S. withdrawal 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 $410 million/year Russia ratified, bringing Kyoto into force in 2005 Current negotiations: post-2012 reductions Lecture 10 POLS 384

Beyond International Law Voluntary initiatives Pew Center: Business Environmental Leadership Council Public utilities: Seattle City Light Individuals: Carbon offsetting Local initiatives ICLEI: 500+ cities & counties in 67 countries, representing 300 million people U.S. cities: Nickels’ initiative > 50 million US governors suit against utilities thrown out CA: 1990 levels by 2020; 80% below by 2050 Emissions trading with U.K. Lecture 10 POLS 384