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  • 1. Climate Change: Science and Ethical Implications Bill Riley Earth Sciences Division Lawrence Berkeley National Laboratory Acknowledgements: IPCC and UCS
  • 2. Discussion Outline • Global Climate Change – What is climate change? – Observations – Predictions and impacts • Ethical and Political Issues
  • 3. Intergovernmental Panel on Climate Change (IPCC) • Established by the UN and World Meteorological Organization in 1988 • Assess the scientific, technical, and socio-economic information relevant for the understanding of the risks of human-induced climate change • Assessments based on published and peer-reviewed literature
  • 4. Source: OSTP
  • 5. Source: OSTP
  • 6. The natural greenhouse effect keeps the earth about 60°F warmer than it otherwise would be. Without the greenhouse effect, life as we know it would not be possible. Source: OSTP
  • 7. Burning of fossil fuels CO2
  • 8. Deforestation CO2
  • 9. Greenhouse Gas Concentrations are Increasing Carbon dioxide: +31% Methane: +151% Nitrous oxide: +17% Source: IPCC TAR 2001
  • 10. Observed Variations of the Earth’s Surface Temperature* *relative to 1961-1990 average Source: IPCC TAR 2001
  • 11. Observed Variations of the Earth’s Surface Temperature* *relative to 1961-1990 average Source: IPCC TAR 2001
  • 12. • Clear correlation between atmospheric CO2 and temperature over last 160,000 years • Current level of CO2 is outside bounds of natural variability •Rate of change of CO2 is also unprecedented Source: OSTP
  • 13. If nothing is done to slow 2100 greenhouse gas emissions. . . • CO2 concentrations will likely be more than 700 ppm by 2100 • Global average temperatures projected to increase between 2.5 - 10.4°F
  • 14. Main Findings of WG I • Extensive and wide-spread evidence that the earth is warming; we are already seeing the first clear signals of a changing climate. • Human activities are changing the atmospheric concentrations of greenhouse gases. • New and stronger evidence of a human influence on climate.
  • 15. Numerical Modeling • In many scientific disciplines, numerical modeling is the way – we develop “understanding” of system behavior • Particularly useful when experiments are impossible or difficult to perform, e.g., – The Big Bang – Climate change – Evolution
  • 16. Numerical Modeling • Modeling is a synthesis of the physical, chemical, biological, etc., processes important in a system’s functioning – Often enumerated in mathematical relationships between the various ‘state’ variables of the system
  • 17. General Circulation Model • Numerical model of – Atmospheric momentum, energy, and mass transport – Land surface trace-gas and energy exchange with the atmosphere – Oceanic water movement and energy exchange with the atmosphere – Designed to run >100 year simulations • GCMs differ because they represent these complex interactions in different ways • The models do a reasonable job simulating our current climate (e.g., seasonality) and reproducing known changes from past climates
  • 18. Temperature Projections • Global average temperature is projected to increase by 2.5 to 10.4°F from 1990 to 2100 • Projected rate of warming is unprecedented for last 10,000 years Source: IPCC TAR 2001
  • 19. Variations of the Earth’s Surface Temperature - 1000 to 2100 • 1000 to 1861, N. Hemisphere, proxy data • 1861 to 2000, Global, instrumental • 2000 to 2100, SRES projections Source: IPCC TAR 2001
  • 20. Projected Changes in Annual Temperatures for the 2050s The projected change is compared to the present day with a ~1% increase per year in equivalent CO2 Source: The Met Office. Hadley Center for Climate Prediction and Research
  • 21. Sea-Level Rise Projections • Global average sea level is projected to rise by 4 to 35 inches between 1990 and 2100 • Sea level will continue to rise for hundreds of years after stabilization of greenhouse gas concentrations Source: IPCC TAR 2001
  • 22. Precipitation Projections • Global average water vapor and global mean precipitation will increase • Larger year to year variations in precipitation
  • 23. Extreme Events Change in Phenomenon Confidence in projected change* Higher maximum temperatures, Very likely more hot days Higher minimum temperatures, Very likely fewer cold days and frost days Increase of heat index Very likely, over most areas More intense precipitation events Very likely, over many areas Increased summer continental drying Likely, over most mid-latitude & associated risk of drought continental interiors Increase in tropical cyclone peak Likely, over some areas wind and precipitation intensities *Judgmental estimates of confidence by IPCC: very likely - 90-99% chance, likely - 66-90% chance. Source: IPCC TAR 2001
  • 24. Potential Climate Change Impacts Health Weather-related mortality Infectious diseases Air-quality respiratory illnesses Agriculture Crop yields Climate Changes Irrigation demands Forests Temperature Change in forest composition Shift geographic range of forests Forest health and productivity Precipitation Water Resources Changes in water supply Water quality Sea Level Rise Increased competition for water Coastal Areas Erosion of beaches Inundation of coastal lands Costs to protect coastal communities Species and Natural Areas Shift in ecological zones Loss of habitat and species Source: EPA
  • 25. Main Findings of WG II • Climate change is underway and the early impacts are already visible. • Climate change and its impacts over the next 100 years will be much more significant than what we’ve seen over the past 100 years. • Natural systems are the most vulnerable to climate change because of their sensitivity to climate and limited capacity to adapt.
  • 26. Main Findings of WG II (cont) • More frequent and more intense weather extremes are projected; hence, more severe impacts from these events can be expected. • Developing countries in general and poor communities within developed countries are most vulnerable. • Adaptation can help reverse adverse impacts; but these are costly and some damages are inevitable. • Win-win options are available, if action is swift.
  • 27. Ethical and Political Issues • National and international • Individuals
  • 28. The United States has 4% of the world’s population, but produces 25% of the world’s CO2 emissions
  • 29. Responsibility • Some argue that wealthy countries should make sacrifices because they – have an ethical responsibility for historic use of “climate space” – have self-interest – have the means to invest in and develop clean technology • Developing countries are most vulnerable, yet have benefited least from industrial activity
  • 30. A 1 m rise in sea level would flood 20% of Bangladesh and displace 14.8 million people Globally, over 200 million people would be displaced or require sea walls Huq et al. 1995 Nichols and Mimura 1998
  • 31. “If climatic change makes our country uninhabitable, we will march with our wet feet into your living rooms.” - Atiq Rahman, Bangladesh spokesman in climate negotiations, 1995
  • 32. Kyoto Protocol • Kyoto Protocol signed 1997 • Calls for industrial countries to reduce emissions to 5% below 1990 levels by 2010 • After 2012 developing countries to join in • Kyoto still unratified so not yet in force as international treaty
  • 33. US Climate Policy • Reject Kyoto Protocol • Effectively rejects climate change research conclusions • Voluntary, not mandatory, emissions reductions • Focus on reducing emissions intensity, not total emissions • Support further research, including carbon sequestration
  • 34. Environmental Scientists • What motivates scientists to choose their topic? – Curiosity about how the world functions – Economic, social, inertial (as in other professions) – Desire to work in a field that “improves the world”
  • 35. Environmental Scientists • What are the ethical responsibilities of scientists? – No institutionalized guidelines – Scientists are therefore guided by personal ethics – Many scientists would say that their strongest ethical responsibility is to fairly and completely report their data and conclusions • “If it’s out there, we should be able to discover and report it” • Should there be institutionalized ethical guidelines? – E.g., Hippocratic oath, Professional Engineer, therapist
  • 36. Summary • Extensive and wide-spread evidence that the earth is warming • New and stronger evidence of a human influence on climate • Potential consequences are severe and persistent • Developed countries have a responsibility to address climate change by reducing emissions, etc., but the U.S. opposes such measures • Despite the important implications of scientific work, there is no ethical code of conduct for scientists