They're going to need to figure it out at some point. Just throttling hydrocarbons isn't going to cut it anymore. I mean, it's not exactly a surprise, we've known what was going to happen for more than a century. Selectively volatize all the carboniferous hydrocarbons[0] and that's gonna happen.

Big industrial cooling methods will be needed[1].

Earth's been a lot warmer. That's not the problem. It's the rate of heating that's the problem from a systems perspective. So you want to buffer that without hitting the rate of photosynthetic production too hard. Any cooling will kill off crops, but you can seek the optimum for the lowest level of disruption from either heat or famine. That kind of precision really asks for direct control of total insolation - dumping piles of dust doesn't give you that kind of fine tuning.

I personally like "The L1 Space Parasol", but realistically . . . it'll probably boil down to extremely-poorly-thought-out biotech spraying[2]. I think megaprojects like the L1 Parasol are going to be beyond us for a while. Not beyond China though I bet. Maybe they'll save the world and charge the rest of us rent.

[0] If only we stuck with horrible garbage coal for our cars and airplanes and ships, maybe the poisonous dust would have helped with total insolation. WINK.

[1] Alongside hydrocarbon throttling, or else you're in a worse situation, with less photosynthesis and even more carbon. Sure, it's colder, yay, but you're going to be dialing the temperature down over and over since the carbon's still jacking the heating up.

[2] Or the thermonuclear bonfire, as equatorial populations force existential geopolitical conflict. Which would have the same effect as taking a guy dying of a 105/41 {deg} fever and dropping him in a swimming pool filled with ice. Good news! He doesn't have a fever anymore.