Suddenly we discuss tailpipes and atmosphere.
First of all, a gigaton is one billion metric tons. One metric ton (2,200 lbs.) is what a cubic meter of water weighs. One billion metric tons is what one cubic kilometer (one billion cubic meters) of water weighs, and it is called a gigaton.
Next, remember atmospheric CO2 includes two oxygen atoms, and weighs 3.7x the carbon feedstock. So if there are 70 gigatons of carbon in the Amazon, for example, burning the remaining Amazonian carbon will release 2.7x that many gigatons of CO2 into the atmosphere (ref. Amazon Ecology Project). So far, tropical deforestation alone has resulted in the release of about 475 gigatons of CO2 into our atmosphere.
So how many gigatons of CO2 are we contending with, anyway…?
Suddenly we discuss water.
…it turns out that the energy required to lift a cubic kilometer of water 2,000 feet is 248 megawatt-years.
What if that water were desalinated in plants located on the coast?
So how much water is in a Sverdrup after all?