If negative effects are worse than expected, it can’t be reversed.
I agree that MCB can be reversed faster, but still being able to reverse in a few years is pretty responsive. There are strong interactions with other GCRs. For instance, here’s a paper that argues that if we have a catastrophe like an extreme pandemic that disrupts our ability to do solar radiation management (SRM), then we could have a double catastrophe of rapid warming and the pandemic. So this would push towards more long-term SRM, such as space systems. However, there are also interactions with abrupt sunlight reduction scenarios such as nuclear winter. In this case, we would want to be able to turn off the cooling quickly. And having SRM that can be turned off quickly in the case of nuclear winter could make us more resilient to nuclear winter than just reducing CO2 emissions.
I agree that MCB can be reversed faster, but still being able to reverse in a few years is pretty responsive. There are strong interactions with other GCRs. For instance, here’s a paper that argues that if we have a catastrophe like an extreme pandemic that disrupts our ability to do solar radiation management (SRM), then we could have a double catastrophe of rapid warming and the pandemic. So this would push towards more long-term SRM, such as space systems. However, there are also interactions with abrupt sunlight reduction scenarios such as nuclear winter. In this case, we would want to be able to turn off the cooling quickly. And having SRM that can be turned off quickly in the case of nuclear winter could make us more resilient to nuclear winter than just reducing CO2 emissions.