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.

Over the past 200 years, which human activity has led to a global temperature increase?

A.  generating electricity from rivers, winds, solar energy, and geothermal energy

B. mining iron, copper, and other metals

C. burning fossil fuels

D. replacing wild grazing animals with cows, sheep, and other farm animals

Explanation:

C. burning fossil fuels

For the past 200 years, the burning of fossil fuels has released huge volumes of carbon dioxide into the atmosphere. Carbon dioxide is a greenhouse gas that acts to trap heat near the surface.