re: Yep, since the start of the Industrial Revolution.
The population in 1850 was 1.2 billion.
Coal and steel production was a tiny fraction of say 1950 and later production levels. Not to mention the lack of cars and non-existence of electrical power
In terms of human emission of CO2 probably the 6+ billion humans of today by merely breathing put out more CO2 then all human activity in 1850.
And in 1850 cutting down trees in order use the land for farming would be difficult- a tree stump is generally a rather stubborn creature. It was done to some extent, but it wasn't wide spread. Tree diseases would have probably kill far more trees.