It makes sense to keep making the point. As usual, David Roberts does so very well:
So when it comes to the particulate-matter bathtub, the drain is very large. We can reduce the total level of particulate matter in the tub any time we want; all we have to do is turn the faucet down, or off, and the tub will drain rapidly.
Carbon dioxide is not like that. Once it’s in the tub, it stays there for up to 100 years before it drains out. And the drain in the bathtub (so-called “sinks” that absorb carbon out of the air, like oceans and forests) is comparatively small relative to the enormous amounts coming out of the faucet. And by the way, we’re actively making the drain smaller by cutting down forests and carbon-loading the oceans.
This makes for a very different situation. Even if we cut our emissions by a third tomorrow, we would still be increasing the total amount in the bathtub…
We elaborated on this same analogy recently.