g02.    What was the primitive atmosphere like?

The earth’s original atmosphere resembled that of gas giants; rich in H_2, CH₄^–3, and H₂O. Because there was so much hydrogen it was a reducing atmosphere without free or uncombined oxygen. This atmosphere was dispersed when the protosun radiated energy and stripped gases off the inner planets. The evidence for this is provided from the study of inert gases such as helium, neon, krypton, and xenon, which are present in only a fraction of their abundance in the rest of the cosmos. The gases, CO₂, N₂, and H₂O were bound chemically to solid earth materials.  

e16.    What do computer models of greenhouse changes show?

m35.    How can global warming affect biodiversity?

m38.     Why is ozone being depleted?

m41.    How can matter affect the environment?

m52.    What causes air pollution?