Communicating and Learning About Global Climate Change: Opening Remarks John P. Holdren Director, The Woods Hole Research Center Teresa & John Heinz Professor of Environmental Policy, Harvard University President, American Association for the Advancement of Science Global Climate Change Town Meeting Annual Meeting of the AAAS San Francisco, 17 February 2007

The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society. Accumulating data from across the globe reveal a wide array of effects: rapidly melting glaciers, destabilization of major ice sheets, increases in extreme weather, rising sea level, shifts in species ranges, and more. The pace of change and the evidence of harm have increased markedly over the last five years. The time to control greenhouse gas emissions is now. from the Climate Change Statement of the AAAS Board, released 2-18-07

Global climate change is the most dangerous environmental problem humans have ever created. It is also the most difficult environmental problem humans have ever created. But there is much that individuals, firms, & governments can do to reduce the danger.

Climate change: complex & interdisciplinary SCIENCE what climate is and how it works; how global climate has been changing and why; how it’s likely to change in the decades ahead; what the impacts are likely to be on farms, forests, fisheries, health, property, ecosystems… TECHNOLOGY the role of humans & their technology in causing climate change; technological options for mitigating climate change; technological options for adapting to it.

Complex & interdisciplinary (continued) ECONOMICS population growth & economic growth as climate-change drivers costs of abatement, adaptation, and impacts consequences of alternative regimes of action & inaction for economic growth, employment, trade POLITICS & POLICY policy options and their impact on outcomes actors and interests in the climate debate…and the evolution of perceptions & interests over time finding a global climate-policy framework that is adequate, equitable, and attainable uncertainty and prudence in public policy on climate

The physics & geometry of Earth’s orientation to the sun Climate change as a teaching opportunity The physics & geometry of Earth’s orientation to the sun

PHYSICS: Interaction of electromagnetic radiation with matter Climate change as a teaching opportunity PHYSICS: Interaction of electromagnetic radiation with matter www.livephysics.com

Physics: energy flows in the atmosphere Climate change as a teaching opportunity Physics: energy flows in the atmosphere

Physics: water, ice, and sea-level rise Climate change as a teaching opportunity Physics: water, ice, and sea-level rise

Climate change as a teaching opportunity CHEMISTRY carbon in fossil fuels and combustion coal ≈ CH oil ≈ CH2 natural gas ≈ CH4 + a bit more so, e.g., burning oil entails… CH2 + 3/2 O2  CO2 + H2O

Climate change as a teaching opportunity BIOCHEMISTRY photosynthesis 6 CO2 + 12 H2O  C6H12O6 + 6 H2O + 6 O2 (Trees are made of CO2 and water!) respiration C6H12O6 + 6 O2  6 CO2 + 6 H2O anaerobic decomposition C6H12O6  3 CO2 + 3 CH4

Earth science: the carbon cycle Climate change as a teaching opportunity Earth science: the carbon cycle

Geography: remote sensing Climate change as a teaching opportunity Climate change as a teaching opportunity True color MODIS composite image – late March 2000 Geography: remote sensing

Geography: land-use & deforestation Climate change as a teaching opportunity Geography: land-use & deforestation Mato Grosso State, Brazil, 2004

Earth science: winds & jet streams Climate change as a teaching opportunity Earth science: winds & jet streams

Earth science: ocean currents Climate change as a teaching opportunity Earth science: ocean currents

Earth science: how hurricanes work Climate change as a teaching opportunity Earth science: how hurricanes work

Earth science: climate & life over geologic time Climate change as a teaching opportunity Earth science: climate & life over geologic time

Probability and statistics of climate & weather Climate change as a teaching opportunity Probability and statistics of climate & weather

Ecology: interaction of organisms with a changing environment Climate change as a teaching opportunity Ecology: interaction of organisms with a changing environment

Geography: climate-related health impacts Climate change as a teaching opportunity Geography: climate-related health impacts World Health Organization estimates of climate-change-related increases in mortality for the year 2000

Engineering: technology for CO2 capture Climate change as a teaching opportunity Engineering: technology for CO2 capture

Geology: formations that can store CO2 Climate change as a teaching opportunity Geology: formations that can store CO2

Systems analysis / integrated assessment Climate change as a teaching opportunity Systems analysis / integrated assessment

Sociology: public-opinion polling Climate change as a teaching opportunity Sociology: public-opinion polling Source: National Science Board, Science & Engineering Indicators 2004, Ch 7.

Political science: leadership Climate change as a teaching opportunity Political science: leadership