Your question betrays the fact that you simply don't understand the scale of what's happening.
Imagine a line chart. It displays average global temperature over millions of years. It goes up a little, it goes down a little, it fluctuates over time. That's the natural change. It occurs over thousands and millions of years.
Looking at the last few decades on that chart, you'll see a wall. It's going almost straight up compared to the rest that just meanders lazily. You can see a few other similar peaks on the chart many millions of years in the past, they generally correspond with things like apocalyptic meteorite impacts etc. And even then the change occurs much more slowly than what we're seeing now.
It's honestly insane to me that we're watching the world end and half of people are like "but are we sure this isn't normal?"
Yes we're sure. We double checked. Just look at any "global average temperature" chart and try to predict where it's going. This isn't the stock market it won't just randomly start doing something else. The movement we're seeing is directly correlated to our ghg emissions, and there's a lag - the effects of current emissions won't be fully seen until up to two decades from now. So even if we stopped right now it would continue warming for decades.
Warming also releases more GHGs. As poles and permafrost thaws, enormous amounts of methane are released that was previously trapped, further accelerating warming and acting as a positive feedback loop on top of our steadily rising emissions.
In short were fucked, we know it, and anyone who doesn't know is not paying attention.
