The periods of glaciation are on 100,000 year cycles, driven by natural forces beyond our control. The warmer interglacials last 10,000 to 15,000 years. Importantly, we are now about 11,000 years into our current interglacial period, which may end within the next century or last another several thousand years. In any case, the beneficial interglacial warmth that we are enjoying now will end at some point in the not too distant future (in a geologic sense).

When the next ice age descends upon us, it will be a true climate apocalypse accompanied by crop failures, famine, mass emigration from colder to warmer regions and unprecedented population loss. Looking at the last 4,000 years of climate and history, bad things happen during cold periods, very bad things. Cooler periods brought severe hardship and death, but the descent into a true ice age would be horrific for humanity and there is nothing we can do to stop it.