Carbon Cycles by Arvid G. Högbom
For centuries it was commonly believed that the Earth's climate is, and always has been, stable. The idea that the climate, on the contrary, has always changed has its origins with Ignaz Venetz
who, in 1821, laid the foundations of our modern knowledge of the ice ages.
The acceptance of glacial advance and retreat demands acceptance of a mechanism which will cause such events. That mechanism is climate change. The fact that our planet's climate has always changed is now a foundation - and a very sure foundation - of modern climate science.