Why the colors of the sky can save us from the climate change apocalypse
The sky is supposed to be blue, dammit. I mean come on And if not? That’s a sign.
Earlier this month, a monster Midwestern thunderstorm called Derecho — 60 miles wide, gusting up to 90 miles per hour — bathed the skies over South Dakota in a sickly, ectoplasmic green. The internet did its WTF?! Thing; Images from social media went viral and then hit the news, followed by the explanations needed. Everything was moving even faster than the storm itself — just like two years ago, when massive wildfires slightly darkened the skies over San Francisco Golden Gate Orange. People freaked out. And why not? It was really weird. Apocalyptic strange.
Orange of San Francisco and green of Sioux Falls – along with the neutral taupe of Dubai during one of its recent mega-city-sized sandstorms – are unparalleled sights in terms of vibrancy and heaviness. Derechos and wildfires and sandstorms have all happened before, but not like this. The difference: climate change, our stupid anti-terraforming of the earth. untimely, greaterand more dangerous are hallmarks of the new world, where the city sky is matched to the color of a dead planet (apologies for William Gibson’s “Neuromancer”).
So you might think it’s even weirder that I think that’s great. We’ll owe a debt of gratitude to Earth’s scary new color combinations—and the evolutionary quirks of our eyes and brains that let us see color in the first place. Climate change has been going on for a century and a half. Most of the time it was so subtle that people couldn’t see it or ignore it. But our color vision is tailored for survival. When the sky turns green, we notice it. I hope that the eerie skies will inspire people to fight the coming climate catastrophe better than any dictionary-sized international science report ever could.
The colors we see
Ask what a color is – not what some colors are, like “red” or “purple” but what kind of color is, like what it’s made of — and you’ll get a different answer depending on where you point the question. A physicist would say that color is photons, subatomic particles, or energy of different wavelengths. A neuroscientist would say color is what happens when large molecules at the back of your eye called photoreceptors absorb those wavelengths and convert them into electrical signals your brain can understand.
You are both right. It is this system this allows us to see a thin slice of the vast electromagnetic spectrum – the part we call “visible”. It works exceptionally well, even if we sometimes disagree on things like the name of the color we’re actually seeing, or if a particularly strange dress is blue or white.
Some animals see color even better than we do—birds and beetles, for example, can see ultraviolet. Back in deep evolutionary time, our primate ancestors had only two types of photoreceptors for color; a mutation in one gave us three—that’s trichromatic vision, capable of distinguishing between millions of hues from red to violet. Kind!
But different languages have different names for these colors. For example, Russian has basic words for dark blue and light blue that English doesn’t have. Scientists will long argue what these language differences tell us about how human brains work, but one hypothesis I like is that humans are more likely to name names Colors that are useful to them, cultural. That said, although color vision evolved on a world lit by a whitish-yellow sun, with an atmosphere full of water vapor that scatters blue in the sky, amidst plant life that mostly reflects green, that’s not always the case Colors people have found most striking.
The colors we pay the most attention to—the ones we noticed and named first as our languages evolved and evolved—were the ones most important to our survival. Warm colors like red and yellow that alert us to food or warn us of predators. Not the usual, expected colors that make up most of our world, like blue (sky, water) or green (plants). We consider all this as background.
That means, in a way, we stop noticing it. Our brains are quirky that way. Things that don’t change, or things that change very, very slowly, don’t register. The technical term for this is “Shifting Baseline Syndrome.” New normals overtake old ones like paint fades on a wall. This is even true for existential threats like the climate crisis, when the first 150 years of change are hard to see. Earth and human civilization changes, if gradual enough, might go unnoticed until we are too late on the brink.
seeing is believing
Because of this, the sudden and dramatic change in sky color could prove to be our salvation. At first it was so bright cyberpunk orange in San Francisco, when soot from unusually large wildfires — caused in part by drought and heat induced by climate change — absorbed the blue wavelengths of sunlight and allowed the red-orange through. Then a layer of the Bay Area’s famous fog crept underneath, scattering the light in all directions. It was super scary and people noticed.
Then last week that derecho – pimped swept across South Dakota by an atmosphere pumped full of thermal energy thanks to climate change. The sky turned green over Sioux City, straight out of Dr. strange. No one is sure why thunderstorms sometimes turn green. It’s probably a combination of water vapor scattering blue light, which then combines with the yellowish-orange light of a sunrise or sunset. But whatever the science, people noticed once again. The same eyes and brains that evolved not to notice blue skies suddenly switched to green and orange emphasis mode. We might not be made to care about every small spike in climate change, but we are made to notice (finally!) when the planet we evolved for no longer exists. The new world, no better, is right before our eyes.
It will probably need that if anything is going to change. People think that the Cuyahoga River, which caught fire in the mid-20th century, was a spur to the modern environmental movement. But the river had caught fire dozens of times before Time magazine was printed a photo of the river on fire. People had to see it for themselves, so to speak, before they would stop rampant industrial pollution.
Around the world, people live in countries on the front lines of the climate crisis and its impacts – especially in poorer countries of the Global South – report more fear about the climate as a whole. You see the evidence more clearly. In the US, only young people and those who identify as Democrats think that dealing with climate change should be a top priority Pew Research polls. About half of Americans believe that humans are only partially or not at all responsible for climate change. But we are. It is real. If a single recalcitrant Democratic senator (and all Republican) can prevent even the most fundamental policy changes to avert a planetary cataclysm of our making, it will take pressure from all of us to change course. It is up to us. We now know. just look up
At least that’s my hope. Painting the apocalypse with a different palette will make it stand out in a whole new way for us. That the new colors of the sky are so startling will spur us to action. We’ll see the signal for what it is – and finally do what it takes to make them blue and boring again.
Adam Rogers is senior correspondent at Insider and author of Full Spectrum: How the Science of Color Made Us Modern.