We need to cool the planet, or at least the populated areas. It’s necessary because the freak week with 50 Celsius in Germany is no longer unimaginable. People will die, plants and animals will all be slowly cooked. The reason for the fast warming seems to lie in the oceans no longer being able to absorb more heat. The imbalance is reported to be 1 Watt/m2, which is double from what it was only a decade ago. This means heat is building up in our atmosphere and it has no way to escape.
Geoengineering is a big term that has been made very scary such that it causes a pavlov reaction just like “communism” and “holocaust” even if they are used wrongly
In order for Earth not to turn into Venus, due to runaway processes like methane release and widespread forest fires and oxydation of soil carbon, drastic measures are needed. The economy is not capable of it because its goal is to maximize fossil credit cashflow (as discussed in other posts). So what measures -can- be taken without too much obstruction?
Shading : SpaceX is developing rockets that can hurl hundreds of tons of cargo to orbit or anywhere in space really. We need shade, because the cooling effect also enhances the carbon capturing power of plants on land. This could take the form of gigantic stretches of Mylar or some other material, maybe even sourced from the moon or other places. By the time this kind of initiative gets going it will all be automated, designed and run by AI. The stratospheric sulfur meme is still around (has been since the damn 50’s) but we moved on from that (I hope).
Maybe the starlink constellation can add a few % solar occulsion in due time. Plants get plenty of light and warmt to grow. Shading during the day and not blocking outgoing radiation during the night can double the effectiveness.
But what about bringing the heat from the ground up to the edge of space. The atmosphere will, as it warms up, of course rise higher because the warming gas molecules want to occupy more space. This is already noticable to satelites that experience more (atmospheric) drag in their orbit than before. But this heating and expanding will be a stale business after a while (and winds will actually die down as we all swelter and then broil in our atmosphere). It is better to break this so called “stratification” or layering.
Stratification has a history of being a problem. Oceans have stratified several times, meaning they developed a nutrient poor but solar intense hot top layer over a nutrient rich and dark rest. Of course this put the tools for life in the wrong place, and oceans that reached that state have often remained dead for thousands of years. Only tectonic shifts could change currents and mix the layers again, giving a new chance to life. There are many stratified “dead zones” in the oceans today and it makes sense to mix the waters there as well. I have written about that before.
But what would happen if we created a piece of land, preferably the middle of a desert, where we concentrated a lot of heat on purpose (like with a solar tower) and caused convection (maybe even aided by turbines). The air would rise due to relative boyancy, and would be able to cool against space. At ground level air would be drawn into the region, maybe humid because it passed over water, and carry that humid heat to the top of the atmosphere where it would cool removing the heat from the ground.
It seems we have a natural version of this, called the hurricane tornado or cyclone. The best version is the huricane that is over hot water, where it loads up with heat energy which is then turned into the movement of air and water (and cows and sheds) and dispersed, also partly into space. Hurricans die over land, because the land does not store or give off heat that easily. I have written about this process, which start by breaking a saturated layer of air above the water (stratification again) which prevents more evaporation. Once that happens more water evaporates, causing an upwards convection which in turn breaks the saturated layer : The genie is out of the box.
I have written about an actual solar tower in Spain, which has been in operation between 1985 and ’94 or something, generating power by heating air which would rise through a chimney, which would then drive a wind turbin in that chimney. It worked fine, but the fossil industry killed it like it has killed so many answers to the menace we experience today.
As you can see from the above picture, to get energy from the updraft you need a chimney, if your goal is merely to cause convection you don’t need the chimney. You can probably use some of the case study calculations to see how much convection you get. The ground below it was made black but a lot of heat would still radiate back. The advantage of this design is that the air gets heated gradually. It would be interesting to see if there was any cooling effect in the region.