Yeah. The assumption that the Earth's environment parameters have been stable for billions of years is bunk. (Especially ironic if the person is railing about 'global warming' at the same time.)
Implicit in your sentence is however an assumption that there was any life comparable to today's during the "billions of years" which is false. More than just 500 million years ago there were not even plants on the land:
So it's simply wrong mentioning "billions of years" when humans worry for the environment in which they can live while depending on it.
For most of the "billions" of years on Earth, there wasn't anything on land, and the "life" in oceans was not something we understand as today's life, and the environment could not support our life (as in, there was not even enough oxygen!). The Earth started to "resemble its present state" only less than 400 million years ago:
https://en.wikipedia.org/wiki/Timeline_of_plant_evolution
So it's simply wrong mentioning "billions of years" when humans worry for the environment in which they can live while depending on it.
For most of the "billions" of years on Earth, there wasn't anything on land, and the "life" in oceans was not something we understand as today's life, and the environment could not support our life (as in, there was not even enough oxygen!). The Earth started to "resemble its present state" only less than 400 million years ago:
https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_h...
Human civilizations exists only less than ten thousands of years, during which the climate was very stable (until the recent human influences):
https://en.wikipedia.org/wiki/History_of_the_world