Okay, I was staying out of this, but I'll bite: the earth warms and cools based on activity on the sun. Scientists know this. Man's impact is little to nothing. Want proof? Look at New England. The mountains of New Hampshire (and Vermont, and New York...) were created by glaciers melting. That means that, at some point, New England was covered with ice. OTOH, in Connecticut, there are dinosaur "remnants"--tracks, fossils, bones. THAT means that, at some point, New England was warm enough to support dinosaurs--sub-tropical or similar.
Obviously, both of these event happened eons ago. But, it shows that the earth has been warming and cooling to extremes for millions of years--and long before man ever walked upright. Only man would be arrogant enough to think that HE caused this--and worse, that HE can change/fix it.
That said, I think we should be good stewards of the earth, and be mindful about using her resources and treating her wisely. I don't think that creating global panic and spending billions of resources are the way to do it. I'm also old enough that I've been through any number of climate panic fads, from "global cooling" to "the ozone layer is disappearing" to "greenhouse gases". They are meant to create panic so people "do something!!!" It's funny how they always say "we only have 10 years to fix this before we hit the tipping point!", and then 10 years go by, and...crickets.
Yes, the earth has been cooling *and* warming for billions of years. It's the pace of warming that is the problem. There have been periods before humans where CO2 levels were nearly 10 times higher with much higher temps, but it took tens of thousands of years for that to happen, from 10,000-150,000 years.
One of the most intense global warming events, and most studied to compare with what is happening now.... was the Paleocene-Isocene Thermal Maximum (PETM)....in which the earth warmed very rapidly....5-8 degrees celsius with carbon levels almost ten times higher than we have now. The "rapid warming" was likely triggered by an increase in volcanic activity. The rapid warming period was at least 3,000 years....to get to the peak, where it stayed for over 100,000 years. We've gone up by 1.2 degrees Celsius in 150 years, since the dawn of the industrial revolution, most of that coming in the last few decades. That doesn't give you pause....make you consider that we're possibly contributing to the warming?