There is a wonderful program on the Science channel called Strip This City. Each episode profiles engineering challenges in major cities around the world, using special effects to "peel" away layers of the city so viewers can visualize skyscraper structure, geology, subterranean transit systems, and sewer systems.
I'm watching the episode on Dubai, a city in the UAE in the Arabian Desert that is home to a series of engineering marvels, including the world's tallest skyscraper.
But the area wasn't always a desert. Five million years ago it was underwater. One million years ago it was a swamp. And thanks to climate change, sand dunes only formed "geologically recently" 18,000 years ago.
Does it look weird seeing "climate change" in reference to something that happened before human civilization? It shouldn't--the climate has always changed on it own, has never stopped changing, and will never stop changing. Welcome to the origin of commonsense skepticism of claims of manmade global warming.
The main argument of those sounding the global warming alarm is that because a) the earth is getting warmer (or colder er, uh, it's changing back and forth), and b) human greenhouse gas emissions are spiking, therefore human greenhouse gas emissions are causing Global Warming. After all, the temperature went up at the same time our emissions increased.
If you've read this far, the thought hopefully occurred to you that if the climate is always changing and has always changed, enough to change Dubai from ocean floor to swamp to desert before humans existed, perhaps it is merely a coincidence that the climate is changing during a time when human pollution was at or near its peak.
Correlation does not imply causation. It is a logical fallacy to conclude that one thing causes another simply because they both increase or decrease at the same time.
Consider the geological history of the Sahara Desert.
At the end of the last Ice Age, the Sahara Desert was just as dry and uninviting as it is today. But sandwiched between two periods of extreme dryness were a few millennia of plentiful rainfall and lush vegetation.
During these few thousand years, prehistoric humans left the congested Nile Valley and established settlements around rain pools, green valleys, and rivers.
If liberals existed back then as the vegetation slowly receded to the desert, they'd freak out that overpopulation and overuse of campfires caused the climate to change, when it was perfectly natural. Yes populations and pollution increased during that time. No, it didn't cause the Sahara to change from a jungle to a vast desert.
Those that over-eagerly believe in man-made Global Warming to the point where it doesn't even occur to them that it all might be a coincidence share the mindset with an ancient or medieval religious zealot who believed that a sacrifice was required to earn rainfall for crops. If a sacrifice is not offered and a drought occurs, see! Causation, not coincidence.
But there are experts who tell us that man is the cause of Global Warming, right? There were experts then, too. Authorities in Ancient Maya, Ancient Rome, Medieval Europe, and everywhere else in human history were sure some sort of sacrifice was required to have some effect. Like them, the modern-day priests of the Global Warming religion tell us we need to make sacrifices in the forms of lower standards of living and higher taxes, or the world will end. Oh and of course, only they can save us. Talk to them about logic and science and they brand you a heretic--a Denier.
You thought you were more evolved than those simple-minded peasants of past eras, eh?
This is not to say that pollution is good or has no effect. It just means the there is a really, REALLY good case to be made against not overreacting about climate change and doing permanent damage to our society.