"Terraform Earth" is a great slogan for a 'bright green' viridian approach to our interlocking ecological crises.
We're already doing it, after all. But we don't think about it in those terms, and we aren't getting the kind of results which we might, if we did.
What you're proposing we can call silviforming, and it's a good idea. We spend too much energy making Earth more like Mars (dry and barren) or like Venus (a roiling greenhouse of carbon dioxide inimical to life); let's make Earth more like Earth instead.
And it's really an economic puzzle, the life-forms work automatically (4Byr old self-improving nanotech).
The Syntropic Farming guy grows the best cocoa beans on the planet at 3x the yield of comparable-quality conventional farms with no fertilizer nor irrigation, and he's getting other crops out of the same "food forest" too. The production is there, it's a matter of getting the word out and engineering the economics.
I think a combination of Small Plot Intensive (SPIN) farming with the soil-building "Grow Biointensive" system makes a good "wedge" for small holders to make money, which you can then parley into food forests. (A food forest takes a few years before it starts to really cook, the SPIN/GB market farm covers the gap.)
Bruce Sterling tried, with some success, to promulgate a technologically-oriented and optimistic approach to the climate crisis, around the turn of the millennium.
That article, conveniently enough, contains a link to one on "bright green environmentalism", which bruces considered similar enough that he closed the chapter on the Viridians.
Which, I wish he hadn't. But I can't fault him for finding other things to do with his time.
Now that you mentioned terraforming Earth, let me mention my favorite forgotten mega projectL Antlantropa (https://en.wikipedia.org/wiki/Atlantropa). Peel away the colonialism, ties to Lebensraum, and lowering the Mediterranean by some 200m, the man-made lakes to irrigate Sahara is an interesting idea, I think! Boosts Africa's untapped potential. On a similar vein also see the Qattar Depression Project (https://en.wikipedia.org/wiki/Qattara_Depression_Project)
I like how nature environments have "untapped potential" if they're inhospitable to humans, even though they have tons of interesting/diverse creatures and fauna. Like, all the earth is here for is to squeeze out a few more acres of corn to raise beef
While Atlantropa is a silly idea, and lowering the level of the Mediterranean Sea is an invitation of disaster, the current through the strait of Gibraltar is quite substantially powerful, and most of the energy involved is currently dissipated. Without damming the strait or lowering the level of the Mediterranean, and with limited disruption to the ecosystem an enormous amount of stable hydropower could be generated there. The geography of the Mediterranean basin is really an incredible opportunity, that concentrates the Sun’s energy throughout the whole basin at the Strait.
Deserts are great at shedding heat into space (high albedo in the visible, high emissivity in the infrared, low humidity). Climate feedback loops are complicated.
I'm skeptical that the net effect of a desert is better than the net effect of a forest. I understand exactly why deserts are useful, but I can't imagine they're more useful than forests.
Forests continuously sequester carbon as trees grow, live, die, and the microbes which feed off the dead trees ones grow, live and die. The cycle of carbon utilization is never totally efficient, and the carbon that is "lost" in the cycle blackens the soil.
No, you are correct, it's just complicated and broad applications of afforestation will require very accurate modeling. The perceived benefit will depend on what timescale you care about.
Changing the albedo and local transpiration has an immediate effect (which can be positive or negative, depending on the existing albedo, downstream effects, etc). CO2 sequestration, on the other hand, takes time.
If you plant trees, let them grow for 30 years, then remove a high fraction of that carbon from the cycle (e.g. lumber), then the break-even point can be pretty short (decades, probably, but I don't have a good number). This will depend on a lot of climate feedback effects, like heat leaking out of your forest through moisture evaporation (which otherwise would have been shed back into space), what the existing carbon uptake rate was of the location you planted (did you replace scrubland, grassland, desert, ...?), etc.
If your permanent sequestration is primarily due to carbon cycle efficiency loss, maybe multiply that timescale by a factor of 10-50.
Trees chemically capture some of the incoming sun energy. Are you certain the radiation cooling through that infrared atmospheric window takes away more energy than what’s trapped in carbohydrates? We have technology to keep that energy trapped for hundreds of year (wood paint).
(Culturally, it's not coming from a colonist mindset. This is about regenerating land that never should have been desert in the first place. Jordan wasn't always desert, for example.)
We are on a trajectory to increase the average temperature of the planet by as much, if not more, than from the last ice age to now, when so much of the oceans were frozen than the sea level was 120m lower than it is today and northern Europe and America were covered with several kilometers of ice. And so within one century. When we reach that point forests won't even be able to grow. That's the scale of problem we should be facing. The ideas you propose are just a distraction.
I don't understand, maybe I'm misinterpreting your position.
Based solely on the scale of the problems yourself presented, you must surely agree that (mega)engineering is the most factible solution in terms of time. Greening the desert might be the best idea but the scale certainly sounds right.
The only solution is to stop releasing CO2. There is nothing else that will save us. How much desert would we need to "green" to compensate the emissions? Where do we find the resources to do so, knowing that we must also cease to emit more CO2?
That's certainly part of the solution, but not the whole picture. Even if you stopped pumping CO2 today, 1) global weather processes have already started,. 2) the rest of the already pumped CO2 is not going to magically dissapear. It will take time, time we don't have.
The only actual solution is to engineer many solutions, supported by reducing the pumping CO2 at a minimum, hopefully zero.
My smartphone can't establish a connection with my Bluetooth headset if a phone communication is already taking place.
Leaders of some of the largest and richest countries on earth denied there was a Covid problem and still deny - or fake to deny - the climate crisis.
There's going to be a transition to something else but our specie or civilization isn't ready to make it smooth and I have little hope we can handle global scale projects like terra-forming.
Most likely there won't be any significant terraforming initiative and small scale local solutions will be enforced when it's too late for anything else.
It may be economically feasible if land in the Sahara were sold, under some reasonable terms like not polluting it beyond some reasonable level, on a 500 year lease to wealthy individuals who want some "effectively sovereign" land to try experimental forms of government.
I'm having a hard time interpreting your comment as anything other than "Let's sell kingships to the wealthy," and am not seeing how that would solve any problems at all.
It's not a kingship because it's only a 500 year lease. It could probably be shortened to 200-250. Enough time for very long term returns on investment.
500 years is longer than most royal dynasties lasted. In China, none of the CE dynasties lasted that long, in Ancient Egypt, no dynasty lasted longer than 300 years, and in Western Europe, off the top of my head, I can think of only the Capets and the Habsburgs who lasted longer.
The duration is not the issue that I have with the idea. Jonestown only lasted for 3 years, but caused some rather big waves with its experimental forms of government.
Effectively sovereign is pretty much already the deal in some countries if you're rich enough..
The only problem with Sahara is that no one will bother - there's also not much to govern except sand. If people wanted to spend billions to seed the place I don't think any of the government in Africa is going to say no, it's just that nobody is doing it.
The solar radiation at the poles is much smaller than at the equator, so the contribution of polar ice to the total radiation-weighted albedo of the planet is much smaller than the contribution of equatorial deserts.
When the radiation happens, the sun ain’t shining anyway. What matters is the surface temperature, and the difference doesn’t look too bad, around 15%: 300°K in tropics, 250°K in arctic.
High albedo is important because of its effect on the net reflectivity of the planet, not its effect of the radiation of the surface.
Emissivity is the material property involved in radiation loss, and ice is highly emissive, but so is almost anything non-conductive. Also radiation loss depends on T^4, so that 15-20% difference ends up being closer to one being double the other.
The Sahara has grown something on the order of 10% over the last century [1]. So ~200 million of its 2.2 billion acres are new. Wouldn't we just be restoring the albedo to what it was?
Yes but there are many knobs to play with, and if you make one change it better be a calculated one.
Mao thought that sparrows ate people's grain, so ordered to kill them all. What Mao did not know is that those sparrows ate vermin such as crop-eating insects. Those insects ate all the crops triggering the Great Chinese Famine, and the ecological disaster that requires farmers to pollinate plants by hand.
No, I'm seriously you guys.
We have just figured out that we can (re)make forests out of deserts, let's do that. Let's do the hell outta that!
"How to Grow a Forest Really Really Fast" https://news.ycombinator.com/item?id=9074473
Search on "Greening the Desert" E.g. https://en.wikipedia.org/wiki/Desert_greening
"Celebrating 10-Years at the Greening the Desert Project, Jordan" https://www.youtube.com/watch?v=yI9wMtTvWps
This is a regenerative process: the forest produces the seeds, fauna, and materials needed to create more forest.
We can totally do this, and many people are, the tricky bit is getting the economics to work.