Abrupt Climate Changes
	• Real - they happened • Large - 1/3 to 1/2 of glacial/interglacial changes • Global (as far as we can tell) • Rapid - in as little as 10 years (meaning big changes every year) • Repeated - not unusual with the long view • In warm times, not just ice ages • No satisfactory theory for them • Our models (the ones we rely on to predict the future) do not generate them • Societies have often not survived them