Read the following 2 articles in the Web Resources about the debate about global warming:
Global Warming Pro: U.S. Global Change Research Program: Global Climate Change Impacts in the United States.
Global Warming Con: Heartland Institute: Climate Change Reconsidered: 2011 Interim Report.
Do you think that global warming is a credible threat or not? Explain your position based on what you read in the 2 summary articles. Use specific facts to defend your position.