Do you really think the climate hasn't changed?
Why has the Earth been warming recently?...and by "recently," I mean the last 18,000 years, since well before man started doing anything...before there were 10 million humans on earth...some estimate far fewer, possibly 1 million or less.
The oceans have been rising all that time. England & Ireland were "recently" part of mainland Europe, and Alaska was a part of Asia (the "land bridge" was a thousand miles wide. Again, all of that before an industry by man.
This is well settled historical science.
The sun didn't suddenly start up, but the tilt and changing orbit might have been a factor in how the sun's energy affected Earth. Ice cores show that the earth's climate has never been in a steady state.