Question

Which of the following is not a theory supporting global warming?

a.
It is predicted that the average temperature will rise 1.4° C or more over the next 100 years.

b.
Human activity has increased greenhouse gases.

c.
Over the last 100 years the earth has warmed by 0.74° C

d.
Carbon dioxide is an insignificant greenhouse gas.

Answer 1

d. "Carbon dioxide is an insignificant greenhouse gas."

This contradicts the evidence and mechanisms for global warming — CO2 is a significant greenhouse gas and its increase from human activity contributes to warming.