What is a greenhouse gas?

  1. What is a greenhouse gas?
  2. When and why is carbon dioxide considered a pollutant?
  3. How do scientists know that humans are responsible for the increasing levels of carbon dioxide in the atmosphere that lead to climate change?
  4. What are the consequences of increases in the concentrations of carbon dioxide and other greenhouse gases?
  5. What are some options suggested to help combat this issue?

In your Individual Post, label your answers #1-5 so it is clear which question you are answering. Be sure to cite and reference your sources in APA format