g13.    What makes up earth's climate? 

The troposphere traps heat through the greenhouse effect. The amount of heat in the troposphere depends on the concentrations of greenhouse gases and the length of time they are trapped. The most common gases, H₂O and CO₂, are controlled by the hydrological cycle and the global carbon cycle, respectively. Solar output varies by 0.1%, which can cause temporary warming or cooling. Changes in amounts of polar ice affect global temperatures (See Figure 07: Climate Zones).

e08.    What are bioregions and biosphere reserves?

e15.    What was early life like?

e16.    What do computer models of greenhouse changes show?

m18.  To whom are rainforests important?

m25.    How is solar energy used?

m26.    How is hydroelectric power used?

m27.    How is electricity from wind used?

m33.    How does global warming affect climate?

m35.    How can global warming affect biodiversity?

m36.    How could human health be affected by weather extremes?

m34.    How could food production affect the environment? 

m39.    How does ozone affect life?

m52.    What causes air pollution?

m53.    How does air pollution affect organisms?

m64.    How much ionizing radiation are we exposed to?

m78.    How do droughts and floods impact populations?