Science Based Policy for Addressing Energy and Environmental Problems Robert Sawyer Class of 1935 Professor of Energy Emeritus University of California at Berkeley 32nd International Symposium on Combustion McGill University, Montreal 6 August 2008 Science for Policy Decisions— Three Key Areas • Air Pollution • Global Warming • Fuel Resources GLOBAL WARMING Global Average Radiative Forcing IPCC Fourth Assessment, 2007 Keeling Curve, CO2 at Mauna Loa Red line is 57% of fossil fuel CO2 emissions Paleoclimate CO2 and Temperature from Ice Core Data Four Global Warming Questions • 1) Is global warming occurring ? (science) • 2) What is the cause? (science) • 3) What are the likely consequences? (science based prediction) • 4) What should we do about it? (policy) Global Warming is Occurring • Historical records of land and sea temperatures • Satellite measurements Global Warming is Occurring Mean Land and Ocean Temperatures Annual Mean Global Temperature Greenhouse Gas Warming is Moderated by Negative Forcings We Are the Cause of Global Warming • Anthropogenic contributions dominate radiative forcings that control earth’s temperature • IPCC Fourth Assessment: “There is a very high confidence that the global average new effect of human activities since 1750 has been one of warming, with a radiative forcing of +1.6 [+0.6 to +2.4] W/m2” The Consequences of Global Warming are Uncertain • Some effects are already observable – Arctic ice is shrinking more rapidly than predicted – Tundra melting, increased Greenland ice cap summer melt, breakup of West Antarctic shelf • Model based projections match historical temperature data 2007 Minimum Sea Ice Extent September 1979-1983 Average September 2002-2006 Average Universität Bremen Sea Level Rise Impact Implications for Combustion Global Warming • Improve efficiency of combustion and enduse devices (efficiency, efficiency, efficiency) • Carbon capture and sequestration presents challenges and opportunities • Control of more frequent large forest fires • Lower carbon alternatives to petroleum FUEL RESOURCES Fossil Fuel Resources far Exceed 1750–2004 Consumption 1400 1200 ? ** IPCC Proven reserves* Gt C 1000 800 600 Methane Hydrates Emissions (CDIAC) *Oil & gas from EIA 600 500 400 EIA ** Unconventional oil & gas; uncertain, could be large 300 200 400 Shale Oil 200 Tar Sands 0 Oil Gas Coal Other Source: Hansen 2006, www.columbia.edu/~jeh1/agu_communicating.pdf 100 0 CO2 (ppmv) Reserve growth Production Costs and Supplies of Liquid Transportation Fuels Farrell and Brandt Greenhouse Gas Emissions, New Passenger Cars Fossil Fuel Use Trends note different scales Implications for Combustion Fuel Resources • Lower carbon alternatives to petroleum • Electricity begins to displace combustion fuels in surface transportation • Hydrogen a long term (mid-century) option • Prepare for a phase down of carbon fuels Beijing AIR POLLUTION Los Angeles Guatemala Air Pollutants • • • • • • • CO SO2 NO2 O3 Pb Particulates Air contaminants/air toxics Adverse Health Effects Evidence • Human clinical exposures • Animal studies • Epidemiology – Large samples (statistical strength) – Relevant, real-world exposures – Uncertain exposures • Shift from pulmonary to cardiovascular effects Air Quality Goals Particulate Matter • • • • • TSP: total suspended particulate PM10 PM2.5 PMx Nanoparticles Mortality Relative Risks from 10-µg/m3 Increase in PM2.5 Jarrett, et al. Implications for Combustion Air Pollution • Industrialized countries have reduced combustion generated pollutant emissions [gm/MJ] by about 98% – Total emissions diminished by growth – Transfer to developing countries • Urgent public health need to reduce cooking and heating emissions in agrarian and developing societies