The environment changes with time. Weather erodes the landscape and the oceans rise and fall. The planetary temperature changes with the release of carbon… and humanity releases the carbon, well, some of it.
We do our best to destroy our planet because that is our nature- to shit on our own doorstep. I believe we are speeding along the effects of climate change but it was always going to happen- it’s part of the history of our world as recorded within the planet’s geology. We can slow the effects… but we can’t stop it… it’s inevitable… and a necessary function for the preservation of our world.