Id like to start out my case by clarifying the topic is...
global warming is real
Id like to start out my case by clarifying the topic is about humans causing global warming. Definitions: glob"al warm"ing noun a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants. Contention 1: 75% of the 20th century increase in the atmospheric greenhouse gas CO2 is directly caused by human actions like burning fossil fuels. CO2 levels were 389ppm (parts per million) as of Apr. 2010 - the highest they have been in the past 650,000 years. [2] [1][4] Contention 2: Human-produced CO2 is warming the earth, not natural CO2 released from the ocean and other "carbon sinks." CO2 from fossil fuel combustion has a specific isotopic ratio [5] that is different from CO2 released by natural "carbon sinks." 20th century measurements of CO2 isotope ratios in the atmosphere confirm that the rise results from human activities, not natural processes. [3] The vast majority of scientist believe it. Here's a graph of global temperatures that proves we have a problem. Conclusion: My opponent only made one point and failed to cite his evidence, therefore his point is invalid. I on the other hand cited all my points, and have presented significant evidence for man made global warming. This is why I believe you should vote pro. 1. National Research Council of the National Academies, "Surface Temperature Reconstructions for the Last 2,000 Years" (3.6 KB) , www.nap.edu, 2006 2.National Aeronautics and Space Administration (NASA), "Global Climate Change: Evidence - How Do We Know," www.climate.nasa.gov (accessed Apr. 26, 2010) 3.Intergovernmental Panel on Climate Change (IPCC), "Climate Change 2007: Working Group I: The Physical Science Basis" (19 MB) www.ipcc.ch, 2007 4.National Oceanic and Atmospheric Administration (NOAA), "Global Climate Change Indicators" (249 KB) , www.ncdc.noaa.gov, Apr. 13, 2010 5.Robert Andres, PhD, and Gregg Marland, PhD, et al., "Carbon Dioxide Emissions from Fossil Fuel Consumption and Cement Manufacture, 1751-1991" (6.5 MB) Oak Ridge National Laboratory, May 23, 1994