Which part of the phrase isn't accurate?
That's at best hyperbolic. It's inflammatory and unhelpful in a rational discussion.
And to be clear, it's also inaccurate. Climate change will not cause the end of civilization as we know it, unless as we know it means "exactly as it exists right now", in which case twenty or thirty years from now would be the end of civilization as we know it even with absolutely no climate change, just due to how technology and culture progresses.
"perhaps the most serious flaw in The Bomb was that it was much too optimistic about the future" - Paul Ehrlich, 2009
"I do not think my language was too apocalyptic in The Population Bomb. My language would be even more apocalyptic today." - Paul Ehrlich, 2015
The message remains constant, in spite of contrary evidence, but the mechanism of apocalypse changes over time.
When you're faced with contrary evidence, do you change your mind or double down?
Yes, climate change can cause significant problems. Yes, human civilization affects climate. However, adaptation with our ever-increasing scientific and technological capability appears most likely to maximize well-being.