A larger-than-expected historic reduction in this non-dimensionless quantity is explained by Sarmiento and Toggweiler’s three-box model. Increases in this quantity explain the dip in two isotopic signatures in the Suess effect. This quantity is buffered on long timescales via a negative feedback loop in which increases in this quantity raise the rate of silicate weathering. Measurements of this quantity at the Mauna Loa Observatory are graphed (10[1])on the Keeling (10[1])curve. This quantity dipped (10[1])by 90 parts-per-million during the last glacial maximum because colder oceans are better sinks. Climate sensitivity is defined as the global temperature increase in response to a doubling of this quantity. Ocean acidification is caused by increases in, for 10 points, what quantity that measures the amount of the primary greenhouse gas emission? ■END■