Using ice core samples and analyses, researchers have discovered ...

[Starlight]

Using ice core samples and analyses, researchers have discovered that over the past 800,000 years
 
  A) glaciers were greatest when greenhouse gases increased the most.
  B) the Earth has gradually been warming and sea levels have been rising.
  C) there is a strong correlation between global temperatures and greenhouse gases.
  D) atmospheric levels of methane and carbon dioxide have steadily been increasing.

Question 2

Scientists use proxies to study climate in order to measure
 
  A) current levels of carbon dioxide.
  B) changes in temperature over the past 100 years.
  C) changes in the ozone layer over the past 30 years.
  D) climates hundreds and thousands of years ago.

[IAPPLET]

Answer to Question 1

C

Answer to Question 2

D