By Larry Bambrick
Day One: Monday, August 10 — It Gets Hot, Hot, Hot
It’s the beginning of the end.
It’s another big challenge. We’re trying to answer the question — what happens to the Earth, when the sun gets old?
Usually… answering questions like that becomes almost entirely theoretical. This is what happens to the sun. Here’s the science of it. But it’s hard to give it a human scale. When we think about the size of the sun, the scale of the nuclear reactions inside — especially when it’s billions of years into the future — it’s hard to give it any human dimension.
Because the life-cycle of the sun is billions of years long. By the time the sun dies, life on Earth — if there is any — will look vastly different from today.
To try to explain the science — but give it a different look — we’re going to put the Earth — as we know it now — in the path of a rapidly aging sun. What would happen to New York, for example, if the city — as it is now — had to face a sun that was 500 million years older? And then 1 billion years older. And then 5 billion years older.
It was fascinating to learn more about an aging sun. Most importantly, as the sun ages, it actually gets hotter. You would think that as it consumes more and more of its fuel (hydrogen), that the sun would get cooler. But the exact opposite happens.
To understand why, we had to learn more about what creates heat in the sun. Several times a second, hydrogen atoms in the sun’s core collide. This nuclear “fusion” creates tremendous heat and light. As it travels out, that heat and light eventually get to the earth — allowing life on Earth to flourish.
We live now in the so-called Goldilock’s zone. Just far enough from the sun so we’re not roasted like Mercury. But close enough so that we’re not frozen, like Mars.
But as it ages, the hydrogen at the sun’s core eventually gets compressed by the weight of the gasses on the outside of the sun. Under pressure, more and more of the hydrogen atoms collide. More heat gets created, not less. More light is produced, not less. As the sun ages… the Earth would get hotter and hotter.
So here we are, back in Hamilton, after finding a gorgeous brownstone that looks like it’s New York. We want to be able to find a way to show — in stages — the effects of a gradually hotter planet.
The fact is — we have a very small tolerance as human begins. If our body gets just ten degrees hotter, our brain starts to die. In the first stage of this episode, the sun is five percent hotter on average than it is now. If that happened, the changes would be catastrophic. It’s far worse than the worst predictions for global warming. Ice shelves would melt. Ocean levels would rise. And we’d struggle to survive.
There are already examples of what happens to people during heat waves. Several years ago in Chicago, the temperature stayed over 100 degrees for a week — and hundreds of people died. How would we cope if a change like that was permanent?
It’s humbling to think that we’re living on Earth now that it’s in this perfect sweet spot. Too much hotter would be bad. Too much colder would be bad. Life on earth depends on the mercy of the sun.
Day Two: Tuesday August 11 — An Apple Orchard a Day
If humans exist in a narrow band of temperatures, plants and animals are even more quickly affected as the sun ages.
Today we’re in an apple orchard to explain what exactly would happen. As the temperature of the sun climbed — the impact on plants and animals would be tremendous.
Not all plants are created equal. Some plants — so called C3 plants, mostly the ones that are predominant in North America, maples, oaks fir trees, etc. — can’t handle too much more heat.
And it’s not the heat precisely. As the heat rises, more water evaporates. As it does, more rain falls. What goes up, must come down. As the rain crashes down, it erodes the rocks more quickly. And as the rocks erode, more raw ore is exposed. And as THAT happens, more CO2 is absorbed by the rocks. It would all take hundreds of thousands of years. But as we hugely accelerate that timeline, we’ve got to bring that science to life.
It’s complicated stuff. But ultimately what it means to plants is that as the world’s temperature climbs, there’s less CO2 in the air. And plants need CO2 to breath.
But… not all plants are created equal, which brings us back to the apple orchard, and our C3 plants.
So called C4 plants — palms, bamboos, long grasses —need less CO2 to survive. In a world where there’s less CO2, the vegetation of the world would be transformed. Parks across North America would be replaced with thick ropey vines. Palm trees. It would look more like Ankor Wat in Cambodia than Central Park.
Again, our challenge in this episode is to give this sort of transformation a human scale. So we’ve put a human “farmer” into this apple orchard. It would be five percent warmer, so our ability to stay outside for long periods would be challenged. But we could survive. The plants that we know would disappear though. And as the sun gets older, we wouldn’t be able to survive.
We’ve got a way to try to tell that part of the story too — it’s a bit of a leap in our imagination, but I think it’ll work.
Naked Science‘s “Swallowed by the Sun” premieres Thursday July 22 at 10P et/pt.