2. Climate data collected over time help scientists analyze trends in the atmosphere.
What evidence of climate change do scientists see?
What type of evidence would indicate weather or temperature changes?



3. There are many sources of global warming.

a. List three human-caused sources of global warming.
What are things humans do that affect the atmosphere?


b. List three natural or astronomical sources of global warming.
What are things that happen naturally on Earth that affect the atmosphere?




4. Describe the effects of increased greenhouse gases in the atmosphere on the
following properties of our environment.
Think about what happens to each property as climate changes.