Question: Click here and open the atmospheric CO₂ data from Mauna Loa. By dragging the green handle or entering the date, you can find the atmospheric CO₂ concentration in ppm. Use this to calculate the slope of the graph between 1988 and 2009. Check below to see if your calculation is correct.

Question: Why do you think the yearly increase in atmospheric CO₂ given by the slope of the graph is different than the yearly amount of anthropogenic CO₂ added to the atmosphere, which was calculated on the previous page?

Anthropogenic CO₂ emissions are changing the balance of the carbon cycle. We are releasing CO₂ from long-term storage at a significantly faster rate than long-term carbon sinks can take it in. However, the oceans and other short-term carbon sinks provide a buffer, absorbing a large portion of the CO₂ humanity is releasing into the atmosphere. As a result, the amount of CO₂ building up in the atmosphere does not reflect the amount of CO₂ emitted by human activity.