Climate Physics and Chemistry Natural and Fossil Fuel CO2 in the Ocean Ocean and Atmospheric Chemistry Goals for this part of the subject (I) • The Global Carbon System: – Inform the class of relevant facts and figures concerning fossil fuel CO2 emissions and their fate so as to be able to think and act in science and public discourse – Understand the basic processes that govern movements of CO2 in the earth surface environment – Develop an understanding of how these processes are incorporated into models that predict future atmospheric carbon dioxide levels Ocean and Atmospheric Chemistry Goals for this part of the subject (II) • Atmospheric Chemistry: – Develop an understanding of gas phase reactions in the atmosphere – Understand the sources and sinks of CH4, N2O, and CFCs – Evaluate the past and future evolution of these gases Direct measurements of CO2 in the atmosphere for the past 47 years Spatial variability of atmospheric CO2 Atmospheric CO2 concentration (microliters per liter) 360 360 Barrow Alaska (71.3o North) 350 350 340 340 330 330 320 1973 360 1977 1981 1985 1989 Mauna Loa, Hawaii (19.5o North) 320 1973 360 350 350 340 340 330 330 320 1973 1977 1981 1985 1989 American Samoa (14.3o South) 1977 1981 1985 1989 1985 1989 South Pole (90o South) 320 1973 1977 1981 Seasonal cycles of atmospheric CO2 concentrations are illustrated by measurements from four monitoring stations where the National Oceanic and Atmospheric Administration takes continuous readings. Analysis of the measurements shows that seasonal cycles in the Northern Hemisphere-which reflect the dominance of photosynthesis in the summer and plant respiration in the winter-seem to be increasing in amplitude. This may be a result of global warming. The dots represent monthly averages. The data are from Peterson et al. 1986; Komhyr et al. 1989; Thoning, Tans and Komhyr 1989; Waterman et al. 1989; and Gillette et al. 1987. Atmospheric CO2 vs. latitude and time “And in my judgment, we need to set aside whether or not greenhouse gases have been caused by mankind or because of natural effects, …” and focus on the technologies that will enable us to live better lives and at the same time, protect Global CO2 emissions from fossil-fuel burning, cement production, and gas flaring Global Oil Production Annual Oil Production (Billions of Barrels) 30 25 20 World U.K. and Norway Former Soviet Union 15 World Outside Persian Gulf Persian Gulf 10 U.S. and Canada 5 0 1930 1940 1950 1960 1970 1980 1990 2000 Global CO2 emissions by area: CO2 emissions by region: GREENHOUSE GAS CO2 emissions from Europe have stabilized, but those from North America have risen sharply Billions of metric tons1 OECD North America 7 Former USSR 6 OECD Europe 5 4 3 China 2 1 OECD Pacific Asia2 0 1980 82 84 86 88 1990 92 94 96 98 00 1. Emissions from fuel combustion only 2. Excluding China. OECD = Organization for Economic Cooperation & Development Atmospheric CO2 growth rate Pg Carbon/year 8 Annual emissions from fossil fuels 6 Atmospheric CO2 growth rate 4 2 0 Linear average CO2 growth rate 1955 1965 1975 1985 1995 2005 Going up. Annual global rates of CO2 accumulation in the atmosphere and CO2 emission from fossil fuel burning since 1958. The Revelle Factor Ocean uptake of fossil fuel CO2: two limiting cases and the real situation Western North Atlantic Potential Temperature Section Practical implications of ocean vertical thermal gradient • This experiment, which seem’d first but mere food for curiosity, became in the interim very useful to us. By its means we supplied our cold bath, and cooled our wines or water at our pleasure; which is vastly agreeable to us in this burning climate. Ellis (1751) Stommel and Arons Deep Ocean Circulation Scheme: western boundary currents, slow interior recirculation