“The climate has changed before”. This is the most overused put down of why we should be taking actions right now.

https://sceptical science.com

What matters is what causes the change and consequences – cause and effect – climate change usually involves CO2, and how much , how fast. We have Gone exponential on CO2 output since the industrial revolution only about 250 years ago. And the consequences of global heating – Earth system changes and global mass extinctions.

People get cancer and other illness pathology from smoking cigarettes, even from passive smoking. So we have social rules and regulations. Science is about dealing with evidence for proving quantitative cause and effect.