Climate records from ice cores indicate that abrupt, global-scale warming events with amplitudes of up to 10°C (in the Greenland region) were reached within as little as 50 years dozens of times during the roughly 100,000 years between the last interglacial (~120,000 years ago) and the current interglacial period (11,700 years ago to present). That’s equivalent to a rate of up to 2.0°C per decade of “natural” global warming. CO2 concentrations remained flat and low (~180 parts per million) throughout these warming (and cooling) periods, which are commonly referred to as Dansgaard-Oeschger events.
... it can therefore be concluded that global-scale warming and cooling events occur naturally at rates and amplitudes several times greater (multiple degrees per decade) than what has occurred since 1850 [~0.05°C per decade], and thus climate change in the modern period does not even come close to falling out of the range of what can and does occur naturally. Also, it can be concluded that CO2 concentration changes have historically not been well correlated with abrupt temperature changes either in the paleoclimate record nor during significant portions of the modern period.
8 New Papers Reveal ‘Natural’ Global Warming Reaches Amplitudes Of 10°C In Just 50 Years With No CO2 Influence (external - login to view)