Global Warming is a theory, not a proven fact. It cannot be proven. We have no idea what normal short-term (less than a few thousand years) climate change is. Humans have only had thermal measuring equipment since the 1800’s. 150 years of data relative to 10,000+ year climate cycles is hardly enough to draw conclusions.
Given that we’re 18,000 years into the interglacial Holocene period I’d be more worried about mankind surviving the next 100,000 year ice age than worrying about a 3*C rise over the last 100 years. (Interglacial periods typically only last 15,000 to 20,000 years.)
The reason for ice ages is typically attributed to the 100,000 year cycle of variation of the Earth’s elliptical orbit. There is also a 41,000 year cycle of the wobble of the Earth’s rotation.
Yeah, the Earth’s warmed quickly recently. But mankind’s burning of fossil fuels for 100 years seems kind of insignificant compared to all the other forces at work in the true cyclical climate changes.