Experts estimate that the current atmospheric concentration of carbon dioxide is how much higher than it was 250 years ago?
A)7 percent
B)12 percent
C)30 percent
D)43 percent

Question

Quizplus · Accepted Answer

The current atmospheric concentration of carbon dioxide is approximately 43 percent higher than it was 250 years ago, largely due to human activities such as the burning of fossil fuels and deforestation.

Experts Estimate That the Current Atmospheric Concentration of Carbon Dioxide