Even tossing a few billion tons of sulfur dioxide in the atmosphere to mimic a volcanic eruption and thus deflect a fair bit of sunlight, depressing temperatures for a decade or two, which they did in the 2060s to great fanfare and/or gnashing of teeth, was not enough to halt the warming, because the relevant heat was already deep in the oceans, and it wasn’t going anywhere anytime soon, no matter how people played with the global thermostat imagining they had godlike powers. They didn’t.
