Which of the following best describes the pattern in the atmospheric CO, concentration data over the past 200,000 years? A The concentration of CO2 fluctuated between 150 ppm and 250 ppm.
B
The concentration of CO, fluctuated between 150 ppm dild 250 ppm until recently, when the concentration rose exponentially.
c) The concentration of CO2 remained constant at first from 200,000 years ago until 50,000 years ago, and then began a steady decline.
The concentration of CO, rose exponentially to 400 ppm and leveled off at carrying capacity.