The Greenhouse effect. Without the greenhouse effect, the earth would be a frozen ball. http://www.gov.mb.ca/agriculture/soilwater/climate/images/indexfig1.jpg. Total U.S. Greenhouse Gas Emissions by Economic Sector in 2010. http://epa.gov/climatechange/ghgemissions/sources.html.
The Greenhouse effect • Without the greenhouse effect, the earth would be a frozen ball http://www.gov.mb.ca/agriculture/soilwater/climate/images/indexfig1.jpg
Total U.S. Greenhouse Gas Emissions by Economic Sector in 2010 http://epa.gov/climatechange/ghgemissions/sources.html
Short History of Climate Change 1824 - Joseph Fourier discovered the greenhouse effect. 1859 - John Tyndall discovered that H2O and CO2 absorb infrared confirming the Fourier greenhouse effect. 1896 - Svante Arrhenius proposed human CO2 emissions would prevent earth from entering next ice age (challenged 1906). 1950’s Guy Callendar found H2O and CO2 did not overlap all spectra bands, therefore warming from CO2 expected (countered the 1906 objections against Arrhenius). 1955 - Hans Suess identified the isotopic signature of industrial based CO2 emissions. 1956 - Gilbert Plass calculated adding CO2 would significantly change radiation balance.1957 - Revelle/Suess suggested oceans would absorb less CO2 causing more global warming than predicted. 1958/60’s - Charles David Keeling proved CO2 was increasing in the atmosphere. 70’s/80’s SukeManabe and James Hansen began modeling climate projections. Current: NCAR, GISS, Hadley, CRU, RSS TLT, UAH, MSU, Glacier Melt, Sea Level Rise, Latitudinal Shift all confirm models. http://www.ossfoundation.us/projects/environment/global-warming/climate-science-history
The Intergovernmental Panel on Climate Change (IPCC) History • Established in 1988 by two United Nations Organizations, the World Meteorological Organization and the United Nations Environment Programme to assess “the scientific, technical and socioeconomic information relevant for the understanding of the risk of human-induced climate change.” • Led to the United Nations Framework Convention on Climate Change (UNFCCC) • Produces Assessment Reports
TheUnited Nations Framework Convention on Climate Change (UNFCCC) • Treaty established in 1992 to stabilize greenhouse gas concentrations in the atmosphere. • Adopted Kyoto Protocol in 1997 • Industrialized countries ("Annex I countries") commit themselves to a reduction of four greenhouse gases (GHG) • Never ratified by US since there are no requirements on underdeveloped nations • Top-ten emitters 1. China: 7,711 million tonnes (MT) or 25.4% 2. US: 5,425 MT or 17.8% 3. India: 1,602 MT or 5.3% 4. Russia: 1,572 MT or 5.2% 5. Japan: 1,098 MT or 3.6% 6. Germany: 766 MT 2.5% 7. Canada: 541 MT or 1.8% 8. South Korea: 528 MT or 1.7% 9. Iran: 527 MT or 1.7% 10. UK: 520 MT or 1.7% http://www.guardian.co.uk/environment/2011/apr/21/countries-responsible-climate-change
http://www.pmel.noaa.gov/co2/gif/globcar.png GTC: gigatons of carbon
http://www.epa.gov/climatechange/science/futuretc.html Climate Models • Accounts for positive feedback • Ice melts due to warming • Ice reflects sunlight • Less ice, les reflection, more warming • Account for negative feedback • Clouds form due to warming • Clouds reflect sunlight, less warming • Models’ predictions under different scenarios • Models are extremely complex and must account for scores of factors • Base on AOGCM, Atmosphere-Ocean General Circulation Model • Climate Science is still evolving
IPCC Special Report on Emissions Scenarios (SRES) • Over 40 scenerios • A1F1: • High global economic growth and continued heavy reliance on fossil fuels, • Close to Business as Usual (BAU) • A2 • Used most often • Middling scenario, with less even economic growth and some adoption of alternative and renewable energy sources • B1 • Assumes a major move away from fossil fuels toward alternative and renewable energy
Surveyed scientists agree global warming is real http://www.cnn.com/2009/WORLD/americas/01/19/eco.globalwarmingsurvey/index.html • Based on the opinions of 3,146 scientists • Vast majority of the Earth scientists surveyed agree that in the past 200-plus years, mean global temperatures have been rising and that human activity is a significant contributing factor in changing mean global temperatures.