2. 2. Land-Use Change (primarily tropical deforestation) 1. Burning of fossil fuels http://eces.org/gallery/ How Are We Increasing the CO 2 Concentration?

3. Fossil fuels still provide ~80% of the world's total energy needs http://eces.org/gallery/ CO 2 & Global Change

5. Atmospheric Carbon Dioxide (CO 2 ) Concentrations (1750 to present) Data Source: C.D. Keeling and T.P. Whorf, Atmospheric CO2 Concentrations (ppmv) derived from in situ air samples collected at Mauna Loa Observatory, Hawaii, Scripps Institute of Oceanography, August 1998. A. Neftel et al, Historical CO2 Record from the Siple Station Ice Core, Physics Institute, University of Bern, Switzerland, Sept. 1994.