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In some ways yes, but in other ways we'll just have to find a new equilibrium. The extent to which this is fixable really depends on how many "tipping points" we've passed over. Lots of systems in the global climate are (at least) bistable, meaning they have at least two dynamical regimes that they can settle into--think two bowls separated by a high wall, with a ball rolling around in one of them. Since different stable states exist, if we push the relevant systems far enough, they'll "snap" into a qualitatively different state, and then won't return to their original state even if the forcings all return to pre-industrial levels. There are a number of big ones that we should be concerned about, but the global thermohaline circulation that drives ocean currents is probably the most obvious and urgent one. With enough of a disruption, the gradients of temperature and salinity (and thus changes in density) that keep the water stably circulating in the oceans can and will either disappear or change enough that most significant currents cease. It's hard to overstate how catastrophic that would be, and if it were to happen no amount of negative emissions would restart it in the short term.

For other systems, rapidly reducing the GHG content of the atmosphere would (almost) certainly work. That's part of why liberals are so gung-ho about carbon capture and sequestration technology research: it would let us rewind things without having to change much about our global economic system in the immediate term. So far, this is as sci-fi as saying "time travel would help." Capturing a trace gas (remember that CO2 concentrations in the atmosphere are on the order of 400 parts per million) is thermodynamically challenging, and we don't have anything like the technology to do this at scale for a reasonable cost of energy yet.