Removing CO₂ would cause most water in the air to rain out and cancel most of the greenhouse effect
Why might we care about such a hypothetical situation anyway? Aside from Lindzen, there are a number of interesting applications to low solar or low CO2 cases. A concern with “large” climate changes (i.e., on the scale of snowball Earths or runaway greenhouses) is that there’s bifurcation (loosely, tipping points) in the system. This is to say that one can conceivably draw down CO2 from the atmosphere and trigger a snowball, although it would take extremely high values of CO2 (much higher than the original amount) to get back out of this glaciated state. In case skeptics bring it up, this is at least one way to have an ice-covered planet with very high CO2 levels. Indeed, precisely how to escape a full-blown snowball is one of the grand unresolved questions in climate science. Once you're out of a snowball however, you're left with a very hot climate until weathering can d...