A Skeptic's View on Climate Models
I like to think that I'm a good skeptic. I've read every word of Carl Sagan's timeless Demon Haunted World. I almost always ask for evidence. I employ the scientific method to guide my actions. I try to think critically. I'm willing to admit when "I don't know". I question bold and crazy claims. And most importantly, I try not to let my ideology sway which claims I question. That's why, as a skeptic, and as a firm advocate of science, I simply cannot accept the following claims without some level of incredulity:
“The next few decades offer a brief window of opportunity to minimize large-scale and potentially catastrophic climate change that will extend longer than the entire history of human civilization thus far.”
"The forest as we know it would effectively be gone."
"We will have very few humans on the planet because of lack of habitat."
Each of the preceding statements are bold, apocalyptic claims concerning climate change, and there are many more like them littered across the Internet. But just because they are widespread and originate from respectable, legitimate scientists, that does not mean I can simply switch off my skepticism. I must subject these claims to the same scrutiny that I would acupuncture, chiropractic, or demons. And when I do, I can only conclude that most claims of catastrophic, apocalyptic climate change are bogus.
That is not to say that climate change isn't real. It absolutely is. A basic education in Earth's carbon cycle is more than sufficient to convince any ardent skeptic of that irrefutable fact. The planet is warming and humans are the primary drivers.
But when it comes to portending doom and gloom, the tools scientists use -- namely atmosphere and oceanic general circulation models -- are woefully insufficient to render specific predictions about the future. The Earth is big, with so many moving parts it would make your head spin. Modeling its climate is a monumental task, and frankly, it's impossible to do so with complete and total accuracy. Climate scientists try their best, taking into account variables such as cloud cover, albedo, water movement, radiation, and surface pressure. Unfortunately, as climate scientists alter their models to take into account more variables, some of which are poorly understood or difficult to measure, they introduce more sources of uncertainty.
To see if their models work, climatologists validate them against past data, figuring that if they match the past, they can predict the future. But there probably has never been a situation in the history of our planet where carbon dioxide has been the primary culprit of climate change. In other situations (most commonly volcanic eruptions) numerous other greenhouse gases also greatly increased the rate of heating. It's really hard to build a model for a situation for which there is little historical precedent.
What does all of this mean? It means that anyone who says they know that climate change will result in (insert apocalyptic scenario here) is not making claims based on solid evidence.
However, just because climate models suffer from inherent flaws, that doesn't mean that they are useless. Averaging them helps correct for uncertainties, which gives us a more broadly accurate picture. What this exercise shows is a clear warming trend, and more and more, this predicted trend is being confirmed by actual data. Globally, almost every year for the past two decades has been one of the hottest ever recorded.
Basically, climate models can tell that the Earth is warming, but they can't conclusively predict that the forests will disappear or that humans will go extinct. When scientists make wild and unwarranted conclusions like these, which are gleefully reported by hype-loving media outlets, they end up amounting to white noise that can be readily tuned out. Not only does this feed the narrative of a click-baiting, commercialized press, it leads to political and public inaction on a pivotal issue.
Climate change is occurring, and personally, I favor actions to avert it. But my opinion is not based upon the apocalyptic assertions of certain climate scientists. That's because their extraordinary claims are not backed by extraordinary evidence.