The MIT Climate Research Unit indicates that the ‘safe’ level of CO2 in the atmosphere is roughly 280-350 parts per million (ppm), the level at which all of human civilisation throughout history has existed.

Question

What is the current estimated level of CO2 in the atmosphere?

A.
150ppm

B.
350ppm

C.
417ppm

D.
1000ppm

Answer 1

The current estimated level of CO2 in the atmosphere is approximately 417 ppm. So, the correct answer is:

C. 417ppm.