It's getting harder to deny that it's actually getting hotter on a global scale. But is it human caused?
Please forgive the click-bait title. I’m trying to refine a line of reasoning, and wanted feedback. Also, if this assists anyone with their discussions, I want to share it.
Climate change deniers have recently mostly abandoned the “it’s not getting any warmer” argument in favor of “sure, it’s warming, but we don’t know if human activity is responsible.” Rather than attack that argument directly, let’s try to simply out-flank it. Suppose, purely for the sake of argument, that we don’t know that our recent climate change is actually human-caused. Suppose that we live in an alternate reality where the Sun is suddenly getting much hotter (and we didn’t notice), or that there’s a massive field of volcanoes in central Iowa spewing gasses into the atmosphere (also not noticed by anybody). If that were true, then we’ve got a rapid climate change event that is entirely “natural” on our hands.
So, what exactly does that mean? Well, every major mass extinction event on planet Earth was caused by a “natural” rapid climate change event. Usually changing to be warmer, but sometimes cooler. Even the asteroid that killed the dinosaurs didn’t kill them with the impact, but the rapid climate change that the asteroid impact triggered.
So rapid climate change is a highly likely trigger for mass extinction. And by mass extinction, I mean ecological collapse. And since the advent of human civilization, ecological collapse really means agricultural collapse. And agricultural collapse really means famine and war at a potentially civilization destroying level. All of this will be “naturally caused” death and destruction.
But humans are, in fact, infamous for battling “naturally caused” death and destruction. Freezing to death is naturally caused, but humans mastered clothing, then fire, then insulated buildings with central heating. Snake bites are naturally caused, but we stock our hospitals with anti-venom. Hurricanes are naturally caused, but we now build our beach houses on stilts and with extra reinforcement. Cancer has natural causes, but we invest billions in medical research and treatment to counter it. Just because the death in our faces is “naturally caused” is no excuse for us to sit quietly and die.
So how exactly should we fight against “naturally caused” climate change? We can’t alter the sun, and we can’t extinguish those magically invisible volcanoes in central Iowa. We need to apply our strength to some other lever to get a counterbalancing effect.
At a global scale, there are only two main levers to pull: planetary albedo and the greenhouse effect. The combination of these two factors are keeping our planet approximately +30C warmer than an airless thermodynamic black-body orbiting at the Earth’s distance from the sun. Since albedo provides a cooling effect, and a greenhouse atmosphere provides a warming effect, the greenhouse effect seems to be the stronger lever as currently applied to our Earth. That means that reducing the greenhouse effect is probably the *cheapest* solution by far.
So how to we apply our strength to the greenhouse effect? Water vapor is the strongest greenhouse gas, by far. But unless we want to cover all the world’s oceans in plastic, that’s a pretty difficult one to control. The second and third strongest greenhouse gasses currently in our atmosphere are carbon dioxide and methane. Maybe we could reduce the concentration of these somehow?
What’s the *cheapest* path to reducing global carbon dioxide concentrations in the atmosphere? Well, since we’re adding billions of tons per year into the atmosphere, the cheapest path to removing some would simply be to not put it there in the first place, right?
So, even in an alternate reality where our current rapid climate change is “naturally caused”, we still have reached the same endpoint that human-caused climate change brings us to. That means that arguing about the cause of climate change is pretty worthless, it’s just a disguised form of obstruction.
