How are pristine conditions of the atmosphere determined? a. ...

[asmith134]

How are pristine conditions of the atmosphere determined?
  a. Research conducted prior to the Industrial Revolution
  b. Seawater samples from deep within polar ice packs
  c. Sediment samples
  d. coral skeletons

Question 2

The sun's radiance usually has a ____ variation.
  a. 1
  b. 10
  c. 20
  d. 40

[tdewitt]

Answer to Question 1

ANS: B
There was no research done before the Industrial Revolution. The changes from this time period were
already found all over the world in the ocean. Information can be found in the section Marine
Pollutants May Be Natural or Human Generated.

Answer to Question 2

ANS: A
There was less than 1 variation in radiance over a period of 11 years, but the sun can have an impact
on temperatures on Earth. The Maunder Minimum period occurred when sunspots were rare. The
temperatures for the winters during this time were very bitter cold in North America and Europe.
Information can be found in the section Human Activity is Causing Global Oceanic Change

[asmith134]

Gracias!

[patma1981]

Thanks for the timely response, appreciate it