More data requested on Tarim Basin hidden water

[mistermack]

The mechanism that they are describing would be an extremely slow process, not worthy of the terms "sucking" or "sink". Firstly aerobic soil respiration needs air by definition. The oxygen supply deep below is going to be very restricted so the production of CO2 would be very slow. Then it needs significant water movement, otherwise the existing water will become saturated and not take any more CO2. High C02 levels also inhibit bacterial growth. But this region is desert, and groundwater movement is not going to be very substantial. Then of course, you are only moving carbon from A to B. From soil to water.  If the basin is old, then it's probably at capacity, so what water is going in at one end is probably leaving at the other. Which means that the natural outflow of this "sink" will be giving off CO2 as soon as it escapes.  

Basically, instead of soil-generated CO2 very slowly working it's way to the surface, some of it is taking an alternative route.