Good morning John. 

It's been a very busy science week, and I feel as if a particular science story that's been totally missed, but may be, in fact, the biggest one of all of them. Like, bigger than maybe room-temperature superconductors, bigger than maybe a really powerful solid tumor cancer treatment. It's hiding and nobody's talking about it, and it is that we might now understand what caused this: Which is a graph of the temperature of the surface of the North Atlantic Ocean. Many different years, uh, and that this year in red, which isn't particularly fun to look at. Like, it's scary times here on planet Earth. But before I jump into all of this, John, I just want to say thank you for your lovely Esther Day video. I love you too. It's been quite a year, though I am happy with the current trajectory at least.

So geoengineering is this fairly controversial idea that you could intentionally change the climate of the planet. Now, that is different from when you accidentally change the climate of the planet, which is just the last hundred years. This conversation is gonna be a big deal, it's gonna be a bigger and bigger and bigger deal over the next few decades as we have to make really hard decisions about what to do about the actual impacts we are experiencing from climate change. We have very clearly been doing a lot of accidental and reckless and haphazard geoengineering over the last hundred years. The biggest piece of that is dumpin' a whole lot of carbon dioxide into the atmosphere and thus decreasing the amount of heat that can radiate back out to space. That means more heat in the system and a hotter planet.

But there's also a lot of other pieces of geoengineering that we've been doing. For example, we release a lot of sulfur dioxide when we burn dirty fuels like coal and fuel oil. And sulfur dioxide actually temporarily, for a very short period of time, much shorter than the impacts of carbon dioxide, can decrease the temperature of an area of the planet. It does this because it's good at seeding clouds, and it does that by combining with moisture in the atmosphere to form droplets of sulfuric acid, which, y'know, you don't really want in the air. But it does create more and fluffier clouds. This is a known effect. This is not new information. This happens when volcanoes erupt and sulfur dioxide comes out. It can cool the planet with the dust and with the sulfur dioxide.

Now, one really big source of sulfur dioxide is those big ships that carry cargo containers from one continent to another. They burn the kind of oil that's left over after everybody's done taking the fraction that they want out of it. It's like the worst cheapest oil. That's what they use. It has a lot of sulfur in it. They burn it, and that sulfur dioxide goes in the atmosphere and it seeds clouds. You can actually see them from space. They're called ship tracks, and they are clouds that are created by sulfur dioxide being spat up from the stacks of these big ships.

Now, I don't know if you already see where I'm going with this, but this is absolutely wild. But because sulfur dioxide is bad for people and animals and the Earth, the UN's International Maritime Organization passed a new rule that said you have to burn low sulfur fuels in these big ships. That rule went into effect in 2020, and over the last few years, there have been significantly fewer ship tracks.

Scientists have been looking at this really carefully and their models are showing that, like, almost all of the new warming of the North Atlantic surface of the sea can be attributed to just new light hitting it that wouldn't normally be hitting it. Now, that's mostly because of ship tracks and partially because this year, there was just less dust from the Sahara (for I think unrelated reasons).

So in one way, this is very bad news, like, it turns out global warming is worse than we thought it was. We were just being shielded from some of its effects by other pollution that we were throwing up into the atmosphere. But in another way, and I think a bigger way, in the long term, this is good news because the experiment that we just ran here is priceless and also impossible to pull off. Like, if we had wanted to run this experiment, it would have been so expensive that we never could have done it. But it also would be politically impossible to pull off because geoengineering is such a hot button issue. Instead, we got a perfect experiment showing us the effects of local geoengineering on this area, and the thing is you don't have to use sulfur dioxide to seed cloud. There's other ways to do it that don't involve a bunch of acid rain and giving people asthma.

One of the ways is to just shoot sea water into the air. There's a bunch of seawater around, you shoot it up into the air with, like, misters that make it like super tiny so it can float in the atmosphere just like any other particle. Most of the water evaporates, leaving behind little crystals of salt that then can seed clouds and then falls back down and the ocean's like, "Yeah, that was the salt that was here in the first place."

Some people say that we can't discuss geoengineering because people will see it as an excuse to continue just burning fossil fuels. I don't think anybody's gonna see it that way in 10 or 20 years. It's gonna be very hot. It's gonna get hot enough that we're gonna see a lot of marine extinctions. It's gonna get hot enough that we're going to see a lot of humans dying. Those stories are gonna be very big in other parts of the world, but they're also gonna be, like, local stories in the U.S. Like, we're gonna have people here dying of heat. And we have to do, like, three things at the same time. We have to stop putting new carbon dioxide in the atmosphere. We have to start taking old CO2 out of the atmosphere. And we have to deal with the impacts of the current warming which exists now and we cannot avoid.

We are entering into the overlap period, the period during which the problem is big enough that we can't ignore it anymore and when we still can do things to solve it. And that means all three of those things. So to have a natural decades-long experiment like this is priceless. And maybe even more than that, we can see that we're already doing it. Instead of saying, "Should humanity take this giant step forward and begin geoengineering the planet?" What we're saying is, "Should we take a giant step forward and do it, instead of accidentally and haphazardly and in the most reckless manner possible, do it intentionally and carefully?"

John, I'll see you on Tuesday.

Intentional and careful is also a lot of what the Awesome Coffee Club is doing. So, a lot of places and a lot of people just sort of look for the certifications, but we've actually gone to talk to and visit with the people who make this coffee because coffee is one of the great joys of life. And this coffee is amazing because it's extraordinarily high-quality because it is taken care of from the moment the tree is planted in Colombia to the moment that it's shipped out of our warehouse in Missoula, Montana.

There's a link in the description or you can just google Awesome Coffee Club. You know how the internet works.