Colorado River Arizona 2002 2003

1000 Years of CO2 and Global Warming Temperature (Northern Hemisphere) CO2 Concentrations Degree Celsius Increase Parts Per Million 1800 2000 1000 1200 1400 1600 1000 1200 1400 1600 1800 2000 Year Year

Worldwide Carbon Emissions 8 Oil (Gasoline) Total Natural Gas Coal 7 6 Total 5 Carbon (109 metric tons) 4 OIL 3 This spike is due to the exponential increase in the use of fossil fuels over the last 150 years. Shown here are emissions of carbon from  gas,  solid,  liquid fuels, and  the total carbon emissions.  2 Coal 1 Natural Gas 1750 1800 1850 1900 1950 2000 Year

Annual Carbon Emissions 8 Atmospheric CO2 average Annual carbon emissions 6 Carbon (109 metric tons) 4 Despite this rapid increase in  carbon emissions, only about  half the carbon can be detected in the atmosphere. The remainder of the carbon dioxide is being dissolved in the oceans or incorporated into trees. It is dissolved into the ocean and trees through phtosynthesis.  2 1955 1965 1975 1985 1995 2005 Year

Historic Los Angeles Temperatures Annual Temperatures 15 16 17 18 19 20 21 22 1880 1900 1920 1940 1960 1980 2000 Year Temperature (°C) Summer Temperatures 18 19 20 21 22 23 24 25 1880 1900 1920 1940 1960 1980 2000 Year Winter Temperatures 10 11 12 13 14 15 16 17 1880 1900 1920 1940 1960 1980 2000 Year The previous graph does not tell the entire story, since temperature changes have not occurred to the same extent during different seasons. For example, in Los Angeles,  temperatures have risen pretty dramatically over the last 120+ years. However,  summer temperatures have not risen as quickly. In fact, summer temperatures  in the 1880’s were about the same as summer temperatures  in the 2000’s. In contrast,  winter temperatures have risen much more consistently and dramatically. Global warming models have predicted that warming will be greater during the winter than the summer. 

2007 Temperature Changes Compared to 1951-1980 -3 -2.5 -1.5 -1 -.5 -.1 .1 .5 1 1.5 2.5 3.4 This is a map of global temperature changes for the year 2005 compared to a base period of 1951-1980. The colors in the reds and oranges represent temperature increases, whereas areas colored with blue represent temperature decreases. As can be  seen here there are few areas of temperature decreases, and nearly all of the dramatic temperature increases have occurred in the far northern latitudes. 