Global Warming Fundamentals
Bob Runs the Numbers, Episode 13
We’ve all seen the same tired old joke. “Haw haw haw! It snowed somewhere in June! So much for global warming! Hurr durr!”
I don’t think anyone understands 100% of the intricacies of anthropogenic climate change; it gets complicated …
and we should be wary about oversimplifying the complicated things
… but …
there’s also no need to overcomplicate the simple things!
… there are some underlying principles that are very easy for someone with a little high school education to understand.
Four Scientific Disciplines & Four Observations
From four scientific disciplines come four simple observations:
Chemistry: fossil fuels generate atmospheric CO₂
Physics: CO₂ is a greenhouse gas
Earth Science: CO₂ accumulates in the atmosphere
Meteorology: Earth’s temperatures are rising in sync with the rise in CO₂
We can delve into each of these a little more, but spoiler alert: these are four very obvious, very non-controversial, very straightforward observations.
Chemistry
Fossil fuels, composed mostly of carbon, generate energy by reacting with the atmosphere to create water and CO₂.
Coal is about 80% carbon. Gasoline is about 90% carbon. Crude oil is about 85% carbon. All of these, when burned, use oxygen in the atmosphere (two atoms of oxygen for each atom of carbon) and result in about three times as much CO₂ as carbon.
I explored this about a decade ago:
Physics
CO₂ is observed to be a greenhouse gas. This has been confirmed experimentally. You can confirm it experimentally.
Wikipedia describes this radiative forcing. You can also google science projects to see the greenhouse effect with DIY experiments.
Earth Science
Unlike other greenhouse gases like methane and water, CO₂ accumulates in the atmosphere much faster than it can be re-absorbed. Without the artificial addition of fossil fuel-generated CO₂, the natural CO₂ exhalation and absorption used to maintain an equilibrium. But adding so much CO₂ overwhelms the planet’s capacity to absorb CO₂. We have observed this empirically as we measure CO₂ concentrations over decades and centuries.
From Berkeley Earth:
And here is a visualization of the earth’s carbon cycle.
Other greenhouse gases maintain a dynamic equilibrium. H₂O, for example — if extra water vapor is added to the atmosphere it pretty quickly precipitates and levels out the concentration of water in our atmosphere.
Meteorology
Temperatures over the last century or two have risen — and risen much more quickly than ever before — in sync with the increased CO₂ concentration in the atmosphere.
Simple Observations: A Simple Reality
Each of these four observations, from independent disciplines, reinforce each other and support the reality of anthropogenic climate change.
(In some ways, saying this out loud is akin to saying “two plus two equals four” — but in an environment where a substantial minority of Americans refuse to “believe” in climate change maybe it needs to be said out loud. This damning statement about how our species retreats to tribalism is much too complicated and depressing to analyze here.)
But we’re breaking it down to the simple factors, and if you’re gonna deny the reality of human-caused climate change, then start out by addressing which of these four observations is wrong.
The “Tragic Gap” When One Side Denies Reality
If you start a geometric proof without stipulating any postulates, you’ve got nowhere to go.
If you pretend to have a good-faith debate but bounce around denying reality, you’re a bad person. And, worse, it makes it harder for people who have actual good-faith disagreements to work together to find solutions.
This is a huge problem that I’ve looked into before:
Conservatives are ceding the climate-change solution conversation to liberals. Since climate change denial is coming from the conservative end of the political spectrum, the only conversations about solutions are happening within progressive circles. This is harmful — we need to include the full spectrum of solutions, not just those agreeable to liberal orthodoxy. And I’m saying this as someone who’s pretty liberal and generally agree with “liberal” solutions to climate change like conservation and investing in renewable energy like solar and wind.
But solutions that include nuclear energy and industrial-strength geoengineering “fake pollution” like injecting sulfur dioxide into the upper atmosphere need to be in the conversation! Even though these solutions might not be in the wheelhouse of left-leaning politicians.
We need to hear the voices of conservatives who aren’t denying reality.
What’s Complicated & What’s Not
There’s a lot about climate change that is complicated. Some of the feedback models are very compute-intensive. And once you get to mitigation strategies, there are intricate policy implications that are complicated and intertwined. Again, we should be wary about oversimplifying the complicated things.
There are plenty more complicated things: methane liberation from increasingly-misleading-named permafrost may accelerate warming; planetary albedo — as reflective ice disappears, more heat is absorbed by the planet; more water vapor in the atmosphere as the temperature rises. These are positive feedback mechanisms — and we engineers have an ingrained terror of positive feedback loops.
Ocean acidification happens as the sea absorbs more CO₂ than it has in the past. The likely effect on the ocean food chain is still being researched. This complicated thing might have terrible ramifications.
And … to be even more complicated and tangential, does it matter if global warming is anthropomorphic? Maybe for liberals and conservationists, minimizing man’s influence on nature is inherently a good thing. (“Take only memories, leave only footprints” has been a conservationist credo for many decades.) If climate change were happening naturally and humans were not the cause, would there be a movement from the “man conquers nature” crowd to forcibly muscle our climate back into being ship-shape? (And would liberals and conservationists argue to “let nature take its course”?) I don’t know. 🤷♂️ It’s complicated. (Not for nuthin’, I’m in favor of avoiding abrupt civilization-altering climate changes no matter what their cause. Dunno where that data point lives on the liberal-conservative spectrum.)
I’ve mused about the geo-engineering vs. liberal vs. conservative conundrum in the context of a couple recent science fiction works:
But. Again. There’s no need to overcomplicate the simple things! The four interdisciplinary observations we’ve discussed don’t require post-secondary math or science. They’re straightforward and obvious.
Let’s Do This
If you’re “against the global warming conspiracy” or “a global warming skeptic” then it’s worth being rigorous about what you’re against or skeptical about. These four observations in four disciplines are pretty solid observations; if that’s what you don’t believe, then gather some proof! It would be astonishing if any of these four observations in four disciplines turned out to be wrong, and if you’re the one who proves it, a Nobel Prize might be in your future!
If you agree with these four observations in four disciplines, then let’s acknowledge that and move on to balancing the costs and benefits of different solutions.
We can start the policy debate by agreeing about the obvious stuff. Things on the order of “two plus two is four.”
Let’s do this.