Thought of the day, which is said mostly tongue-in-cheek:
If we really must think of a planet to terraform, it seems like the best body in the solar system to work on might be... Earth. There are large swaths of it that are more or less currently uninhabitable in its polar regions, and most changes to the atmosphere we make have their greatest effects in those same polar regions. A 5C increase in global average temperatures might be a 10C or more increase in those polar regions, opening up millions of square miles for human habitation and intensive agriculture. It's even self-sustaining: about a quarter of known fossil fuel reserves are available in the Arctic, and those will become much more accessible with warming temperatures.
Needless to say, there are costs elsewhere on the planet for that kind of intervention, but those are very definitely far, far smaller costs than building floating cities on Venus or reheating Mars' core. Many of those costs could even be recouped by adding a terraforming tax on new residents of polar regions and redistributing them to Bengali refugees fleeing their homes.
Economically, it makes a lot more sense than investing resources in terraforming other bodies in our solar system, though it doesn't offer the same risk mitigation.
Disclaimer: I think terraforming Earth, purposefully or not, is a bad idea. I think it's just a better idea than investing real resources into terraforming other planets.
Huh. That's a very interesting thought. The first thought that pops into my head is the risk. The appeal of trying to terraform Venus (or Mars) is that there isn't a huge existing population of humans. If we mess it up, well...that's unfortunate and expensive, but we didn't just make the only place we currently have uninhabitable.
The second though, pretty related to the first, is the ethical one. Do we have the "right" to do what we want to our planet, including probably causing mass extinction of existing animal life in order to terraform our planet? I'm not sure if I'm even willing to argue that one either way.
Like I said, it's interesting to consider your idea. If we can be sure that anything we do to "terraform" our planet isn't at all risky in terms of human survival, you're probably right!
Longterm, we will have to find some kind of climate control. The last ice age was not too long ago, but mankind has almost entirely lived without. A return of the glaciers would be even worse than global warming (in my estimates), and extrapolating the curves shows that the next ice age is due (were it not for the fact that we changed the atmospheric composition sufficiently to avert that for sure).
Right now we already are playing around with the climate, but very uncontrolled and destructive. I'm also not in favour of using methods designed for climate control in our situation due to the risk (which is different for the different methods, and the failure results are very different also, but still) - the better solution is clearly to stop emitting CO2 - but longterm, we will need the knowledge. Best to test it on another planet first..
>Do we have the "right" to do what we want to our planet
You have a right to make good decisions. Don't sweat about whether we have rights to modify the planet, and instead worry about whether it is a good decision.
At this point there is not enough data or control to ensure success. We are already changing our planet, and we can't even tell if it's good or bad, so this is not the year to make that kind of determination.
The thing about farming in the Arctic is you're gonna have a short growing season no matter what the temperature is. However, you're not going to get that far, because you're talking about an area that is substantially underlaid by permafrost. When that melts, it subsides and usually fills with water, which is why there are millions of boggy lakes on the North Slope of Alaska. Fertile topsoil is not just dirt, it's a complex ecosystem of its own, and it takes a great deal of time to produce. It's probably slightly easier to start farming in the melted Arctic than in your average desert, but it's a pretty near thing, and your 5C difference is going to wreak havoc on current farming areas. The odds of success on this one are not good.
I think there's probably some limit to how much Earth-resources should be used to terraform other planets, but with what we spend on bombs I don't think it'd be a big deal. Terraforming Earth is a spectacularly bad idea, so it would take a lot of spending to be in any sense worse than that.
Desert habitation is actually something I've been really curious about lately- does anyone have links to some good source material I could read into? I'm currently envisioning construction like you'd see in passive homes- hyper insulated, probably powered by solar/wind, and some means of reusing water since it's obviously a limited resource. It's very possible I'm hugely naive though so I'd love to find some hard numbers on the actual viability of what I've described.
I don't have any expertise in this, but off the top of my head:
- wind power would be tough because of sand in the wind. I imagine that would make the tech break down often. Guess it depends on what kind of desert you're talking about.
- Bedouin/Saharan peoples are probably a good reference. They had/have cisterns throughout the desert to preserve water between rainfalls. I think they were largely nomadic but I don't know the motivation for that (trade vs food supply vs ?)
- Bill Gates reports drinking water from human waste tastes fine, you could probably get your hands on the tech his people are developing.
Like... reshaping the Earth in a Earth-like shape! Cool, isn't it? Now, getting the tongue off the cheek, you're right, it makes a lot of (at least an economical) sense to look under our nose at the swaths of unexploited but with a higher promise land and, you know, use them?! Only that the thing is, Venus colonization is more than just a new place that we could find useful to extend into for a current-way of day-to-day human life. It is a lot more! Some may tell you that it is bad to have all the eggs put in the same basket and Venus would be a good second basket, but again it would be a lot more than that. Imagine that so far we haven't had any signs of another life-form living in our universe. As small the chance for this to stay this way as it may be, we can assume for now that the entire universe is ours to extend into. And we need to become capable of doing it. We may "start" doing that by colonizing our own galaxy. For that we should become capable of colonizing planets in some reasonably-close star systems first. And for that it would be desirable for us to learn how to do that using a planet somewhere nearby, in our solar system. And yes, for that we should become capable of colonizing without much struggle harsh places like deserts (in polar or other regions), subterranean and ocean depths here on Earth. And more, those should become self-sustained, to mimic conditions of some far-away colonization prospects. In the long run Venus is just one of the intermediary steps, but an important one. We as a species need that kind of colonizing experience. Of course it won't happen right away, but setting the goal of colonizing Venus is in itself a task that rise awareness and spurs in the meantime other important intermediary necessary goals. Biosphere 2 falls in this category, but we need more, and more - we need context for which these kind of projects would come to make sense.
If we really must think of a planet to terraform, it seems like the best body in the solar system to work on might be... Earth. There are large swaths of it that are more or less currently uninhabitable in its polar regions, and most changes to the atmosphere we make have their greatest effects in those same polar regions. A 5C increase in global average temperatures might be a 10C or more increase in those polar regions, opening up millions of square miles for human habitation and intensive agriculture. It's even self-sustaining: about a quarter of known fossil fuel reserves are available in the Arctic, and those will become much more accessible with warming temperatures.
Needless to say, there are costs elsewhere on the planet for that kind of intervention, but those are very definitely far, far smaller costs than building floating cities on Venus or reheating Mars' core. Many of those costs could even be recouped by adding a terraforming tax on new residents of polar regions and redistributing them to Bengali refugees fleeing their homes.
Economically, it makes a lot more sense than investing resources in terraforming other bodies in our solar system, though it doesn't offer the same risk mitigation.
Disclaimer: I think terraforming Earth, purposefully or not, is a bad idea. I think it's just a better idea than investing real resources into terraforming other planets.