Why was the concern over global cooling replaced with a concern over global warming?
a. the science community needed a cause to frighten the general population.
b. steady surface temperature increases were noted between the 1970 s and 90 s.
c. air pollution only became a concern in the 1980 s.
d. scientists observed severe ocean acidification.

What is the primary justification of the hypothesis that the early earth environment was void of oxygen? ( 2 points) data showing the concentrations of gases extracted from rocks fossil evidence regarding the origin of eukaryotes generally accepted atmospheric conditions molecular evidence based on evolutionary traits.

Why does physical weathering speed up the processes of chemical weathering? a) physical weathering requires abundant water, as does chemical weathering. b) physical weathering produces fresh surfaces for chemical weathering to attack. c) chemical weathering can occur only on small surfaces, not large ones. d) chemical weathering requires salt, which is provided by salt wedging.

Amountain created from tectonic activity would be considered which type of landform ? a) primary landform b) secondary landform