Recently, a local science teacher sent me an essay written by a climate change skeptic.
Well, okay. I figured that I could skim the essay, look over the data, and briefly explain what the author’s errors were. After all, it’s really important to help teachers understand this topic, because they’re training our next generation of citizens.
And I thought to myself, how hard can this be? After all, I’m a scientist. I felt unconcerned that I’ve never read research papers about climate science before, and that it’s been years since I’ve worked through the sort of differential equations you need for even basic fluid mechanics calculations, and that I’ve never run any simulations on oceanic heat transfer or glacier melting.
Since then, I’ve read a fair bit about climate science. I’ll be honest: I didn’t go through the math. All I did was read the papers and look over the processed data.
This is lazy, I know. I’m sorry. But my kids are at home. At the moment, this is the best I’ve got.
Prominent climate change skeptic Richard Lindzen, an emeritus professor of meteorology, recently delivered a lecture to the Global Warming Policy Foundation. I wholeheartedly agreed with Lindzen when he stressed that the science behind climate change is really, really complicated.
Former senator and Secretary of State John F. Kerry is typical when he stated, with reference to greenhouse warming, ‘I know sometimes I can remember from when I was in high school and college, some aspects of chemistry or physics can be tough. But this is not tough. This is simple. Kids at the earliest age can understand this.’
As you have seen, the greenhouse effect is not all that simple. Only remarkably brilliant kids would understand it. Given Kerry’s subsequent description of climate and its underlying physics, it was clear that he was not up to the task.
Climate science is tricky. In a moment, I’ll try to explain why it’s so tricky.
When people make predictions about what’s going to happen if the average global temperature rises by half a degree – or one degree, or two – their predictions are probably incorrect.
My assumption that I could skim through somebody’s essay and breezily explain away the errors was incredibly arrogant. I was a fool, I tell you! A fool!
But my arrogance pales in comparison to the hubris of climate change skeptics. Once I started learning about climate science, I realized how maddeningly difficult it is.
Lindzen, who should know better, has instead made brash claims:
So there you have it. An implausible conjecture backed by false evidence and repeated incessantly has become politically correct ‘knowledge,’ and is used to promote the overturn of industrial civilization. What we will be leaving our grandchildren is not a planet damaged by industrial progress, but a record of unfathomable silliness as well as a landscape degraded by rusting wind farms and decaying solar panel arrays.
There is at least one positive aspect to the present situation. None of the proposed policies will have much impact on greenhouse gases. Thus we will continue to benefit from the one thing that can be clearly attributed to elevated carbon dioxide: namely, its effective role as a plant fertilizer, and reducer of the drought vulnerability of plants.
Meanwhile, the IPCC is claiming that we need to prevent another 0.5ºC of warming, although the 1ºC that has occurred so far has been accompanied by the greatest increase in human welfare in history.
So. What aspects of climate science can we understand, and what’s too hard?
Let’s start with the easy stuff. Our planet gets energy from the sun. The sun is a giant ball of thermonuclear fire, spewing electromagnetic radiation. When these photons reach Earth, they’re relatively high energy – with wavelengths mostly in the visible spectrum – and they’re all traveling in the same direction.
What we do – “we” here referring to all the inhabitants of our planet, including the rocks and plants and other animals and us – is absorb a small number of well-organized, high-energy photons, and then release a larger number of ill-organized, low-energy photons. This is favorable according to the Second Law of Thermodynamics. We’re making chaos.
And here’s the greenhouse effect: if the high-energy photons from the sun can pass through our atmosphere, but then the low-energy photons that we release get absorbed, we (as a planet) will retain more of the sun’s energy. Our planet heats up.
And, in defense of former senator John Kerry, this is something that a kid can understand. My children are four and six, and this summer we’re going to build a solar oven out of a pane of glass and a cardboard box. (After all, we need stuff to do while all the camps are closed.)
If we fill our air with more carbon dioxide, which lets the sun’s high-energy photons in but then won’t let our low-energy photons out, the planet should heat up, right? What’s the hard part?
Well, the problem – the reason why climate science is too difficult for humans to predict, even with the most powerful computers at our command – is that there are many feedback loops involved.
Some of these are “negative feedback loops” – although atmospheric carbon dioxide causes us to absorb more energy from the sun, various mechanisms can buffer us from a rise in temperature. For example, warm air can hold more water vapor, leading to more cloud formation, which will reflect more sunlight back into space. If the sun’s high-energy photons can’t reach us, the warming stops.
And some are “positive feedback loops” – as we absorb extra energy from the sun, which causes the planet to heat up a little, various mechanisms can cause us to absorb even more energy in the future, and then the planet will heat up a lot. This may be what happened on Venus. The planet Venus may have been habitable, a long long time ago, but then runaway climate change led to the formation of a thick layer of smog, and now it’s broiling, with sulfuric acid drizzling from the sky.
On Earth, an example of a positive feedback loop would be the melting of polar ice caps. As polar ice melts, it reflects less light, so our planet absorbs more of the sun’s energy. Heat made the ice melt in the first place, but then, once the ice has melted, we heat up even more.
And it turns out that there are a huge number of different positive and negative feedback loops. After all, our planet is really big!
For instance, the essay I was sent included graphs of ice core data suggesting that, in the ancient past, changes in average global temperatures may have preceded changes in the concentration of atmospheric carbon dioxide.
But this is just another feedback loop. In the past, there was no mechanism for carbon dioxide to pour into our atmosphere before temperatures rose – dinosaurs didn’t invent internal combustion engines. This is the first time on Earth when carbon dioxide levels could rise before temperatures, and we don’t know yet what the effect will be.
Extra carbon dioxide will probably cause an increase in temperature, but a planet’s climate is really complicated. We have huge quantities of poorly mixed water (otherwise known as oceans). Our topography is jagged, interspersed with valleys and mountains. There are huge forests (only some of which are on fire). The air is turbulent.
We might find that temperatures are buffered more than we thought. The ocean might act like a giant heat sink.
Or then again, the ocean might warm up, accelerate polar ice loss by lapping at the undersides of glaciers, and magnify the changes.
The mathematics underlying fluid mechanics and heat transfer within an enormous, inhomogeneous system are so complex that it’s almost impossible to say. Nobody knows how much detail you’d need to put into a simulation to get accurate results – all we know for sure is that we can’t simulate the world with as much detail as actually exists. All our models are approximations. Some of them contradict each other.
With my admittedly limited understanding, I don’t think anybody knows enough to assert with confidence whether our climate will exhibit either buffered or switch-like behavior. Maybe we can muck about without hurting much. Or we might bring about our own doom with a tiny mistake.
Our planet’s climate is so complex that you could make a similar argument – we really don’t know whether we’re going to be buffered from future changes, or whether we’re at the precipice of doom – no matter what evidence we obtain.
Maybe sea levels start rising – well, perhaps that will somehow reduce the further heating of our planet. Maybe we get more horrible tropical storms – well, perhaps they’re linked to a greater density of sunlight-reflecting clouds.
Maybe things seem to be changing fast for a little while, but then we enter another stable state.
Or, insidiously, maybe it will seem like we’re in a well-buffered system – pumping large amounts of carbon dioxide and methane into the atmosphere without seeing much harm – until, suddenly, we tip over the edge. We often see that sort of behavior from positive feedback loops. Nothing seems to happen, for a while, then everything changes at once. That’s how cooperative binding of oxygen to hemoglobin works in your body.
Another problem is that climate change will probably happen on a very different rhythm from our lives. Weather happens on timescales that we can understand. A decade of droughts. Two years of tropical storms. A few hard winters, or hot summers. But climate happens over hundreds or thousands of years. Most of the time, it changes more slowly than we’d notice.
A two degree shift in average global temperatures, spread out over a few decades? That’s bad, but it’s boring. Which was the main focus of Jonathan Safran Foer’s We Are the Weather.
History not only makes a good story in retrospect; good stories become history. With regard to the fate of our planet – which is also the fate of our species – that is a profound problem. As the marine biologist and filmmaker Randy Olson put it, “Climate is quite possibly the most boring subject the science world has ever had to present to the public.”
Climate science doesn’t fit our culture. Especially not now, when the pressures of surveillance capitalism have forced even the New York Times to run like an advertising company. They earn more from news that gets clicks. Stories need to be sensational. Yes, they run stories about climate change. For these, the polar bears need to be dying, now, and there needs to be an evil villain like Exon lurking in the shadows.
Nobody wants to click on a story explaining that we, collectively, have made and are making a whole lot of small shabby decisions that will cause grizzly bears and polar bears to re-mix and de-speciate.
I got bored even typing that sentence.
Life is incredibly robust.
Our planet has swung through many extremes of temperature. At times, it’s been much hotter than it is now. At times, it was much colder. And life has marched on.
The human species is much less robust than life itself, though. Our kind has flourished for only a brief twinkling of time, during which our climate has been quite stable and mild. A small change could drive us to extinction. An even smaller change could cause our nations to collapse.
Disrupt our food supply – which could happen with just a few years of bad weather, let alone climate change – and there will be war.
So. I tried to learn about climate change, focusing on the work of skeptics. And in the end, I partly agreed with the skeptics:
I agree that climate science is too complicated for anyone to understand.
I appreciate that people are trying. I had fun learning about ice cores, atmospheric modeling, energy absorption, and the like. Well, sometimes I was having fun. I also gave myself several headaches along the way. But also, my kids were being wild. They’ve been home from school for three months now! I was probably on the precipice of headaches before I even began.
Here’s where I disagree with the skeptics, though: given that climate science is too complicated for us to understand – and given that we know that small changes in average temperature can make the world a much worse place to live – why would be blithely continue to perturb our climate in an unprecedented way?
Maybe things will be fine. Yay buffers! Or maybe we’ll reduce the carrying capacity of the planet Earth from a few billion humans to a few million, dooming most of our kind.
I know, I know – eventually our universe will dwindle into heat death, so our species is terminal anyway. We will go extinct. It’s guaranteed.
I still think it would be neat if our great-great-grandchilden were out there among the stars. At least for a little while.
Or even, if they stay here on Earth, it’s nice to imagine them living on a comfortable planet with lots of beautiful trees, and interesting animals to see.
Also, I’m biased.
After all, what are the things that you’re supposed to do if you want to reduce your carbon emissions?
Eat fewer animal products. Live in a smaller home. Drive less. Fly less. Buy less stuff.
Those are all things that I’d recommend to most Americans, for ethical and philosophical reasons, even if we weren’t concerned about climate change. So for me, personally, I don’t need to see much proof that we’ll ruin our climate unless we do these things. I think we should be doing them anyway.
Instead, I think the burden of proof should fall to the people hawking Big Macs. I’d want them to show that a world full of CAFO-raised cows won’t cause climate change, won’t propagate antibiotic resistant bacteria, won’t condemn billions of conscious beings to a torturous existence.
The world is complex. We’re going to err.
I’d rather err on the side of kindness.