The Carbon Bathtub

I saw a cool little article and graphic in National Geographic that's very helpful in understanding the dynamic nature of the level of CO2 in our atmosphere. In the analogy of filling a bathtub which has a slow drain, it is very easy to see that even if you turn down the faucet (i.e., reduce the production of CO2), the level in the atmosphere can continue to rise (as long as the in-flow rate exceeds the out-flow rate).