[angiosperm]

We have also pumped a very large amount of long-lived fluorine compounds into the air, that will last for centuries. They have from 2500x to 25000x times the "greenhouse gas warming potential", kg for kg. They are mostly refrigerants (CFCs, HFCs, and soon their successors) and transformer insulation gas (SF6). Volcanoes do emit some amount of fluorine compounds, too.

We also have a great deal of methane leakage, which is usually cited as 25-100x, and we may soon have a lot of hydrogen leakage, at >100x. Rocket launches are installing water vapor, another one, into the stratosphere like never before.

So even if we got CO2 down to a pre-industrial level, we would still have heat forcing from the fluorine- and other compounds.

Capturing CO2 is kind of pointless until we get emissions under control. I.e., a dollar spent preventing emissions buys much more than a dollar spent capturing. Solar panels and wind turbines directly displace mass emitters of CO2.

[mytailorisrich]

I don't know about all compounds but CFCs stay in atmosphere for about a century only and we've already banned them, and methane has a very short lifetime of about 12 years. So we 'only' need to control emissions of those to solve the problem.

On the other hand, as said, CO2 stays for centuries if not 1,000+ years so at this point net zero is only half the job though probably the hardest part.

[zdragnar]

Methane, at least, breaks down to CO2, no?

[angiosperm]

HFCs are not banned yet. They are responsible for 2500x CO2 forcing. Your car is leaking those right at this moment.

[specialist]

Yes and: I understand that we want to prevent the non-human emissions from becoming a positive feedback loop. Meaning that at some tipping point, the thawing tundra, burning forests, and acidic oceans will continue to get worse, even if/when human emissions completely stop.