There is one potential negative feedback loop that I am now curious about, since we recently learned that Antarctica is/was highly volcanic. If the continent deforms as the mass of ice melts off of it, causing the volcanoes go off in a mega-eruption, could the atmospheric particulates shade the Earth enough to trigger an ice-age in the near future, say, 50-100 years? And if so, could we conceivably modulate the level of the particulates in order to manage the ice age?