The Climate on Earth has been changing for millions of years.
For millions of years it was much warmer. Which is why we find dinosaur bones in Montana. Then the planet cooled. It started warming about 12,000 years ago.
We can have effect on parts of the planet. This is called pollution. It caused the river in Cleveland to catch on fire.
The sulfur from coal fired plants in OH & PA caused the rain falling in the Adirondacks to become more acidic than normal. It eventually effected the PH in some lakes.
However, the output from one or two volcanos is probably equal to all the pollutants put into the atmosphere by humans in years. May of these volcanos are under the ocean in places like Antarctica. These volcanos cause the ice to melt.
Petroleum and methane are made by the Earths mantle. These are constantly leaking out of the Earths crust in many places. Especially in the bottom of the oceans.
They ARE NOT FOSSIL FUELS. We need to stop referring to them as fossil fuels. They are carbon based products made by the Earth.
Actually some of those paleontological findings are not as much world climate, but location.
Montana wasn’t at the latitude and longitude it is now. There have been major shifts in tectonic plates. There was Gondwana and Pangea when conitinejts were all together.