1 / 10

Understanding Climate Change: Scientific Consensus and International Treaties

This overview explores the scientific basis of climate change, focusing on the greenhouse effect and major greenhouse gases like CO2, CH4, and CFCs. It outlines the significant role of human activity in increasing greenhouse gas concentrations and the consensus reached by the Intergovernmental Panel on Climate Change (IPCC) since the 1990s. The Kyoto Protocol and subsequent international treaties are examined, highlighting obligations for emission reductions and the challenges of meaningful action. It emphasizes the urgency of addressing climate change to stabilize atmospheric greenhouse gas levels.

telma
Télécharger la présentation

Understanding Climate Change: Scientific Consensus and International Treaties

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Climate Change The Scientific Consensus International Treaties POLS 422

  2. 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 POLS 422

  3. 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 POLS 422

  4. 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] POLS 422

  5. 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 POLS 422

  6. 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 POLS 422

  7. 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) POLS 422

  8. 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 POLS 422

  9. 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 POLS 422

  10. 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. POLS 422

More Related