Where can we absorb CO2 in very large amounts, turn it in to carbon and oxygen? What first comes to mind is the Sahara, and with the proper technology that should indeed be a workable solution. But there may be a far better alternative.
There’s a bizarre amount of carbon buried as methane, coal and oil (and other petrochemicals) in the earth’s crust and I don’t see humans stop dragging it out anytime soon. Human use of thee carbohydrates is much like using an addictive substance – using it results in increased pleasure, and effort aimed at using it less creates convulsive withdrawal in subjects. So all that carbon is burned and emitted as heat-trapping gases. But it gets worse – all that heat is fairly certain to trigger runaway effects, in particular by defrosting and summarily rotting the arctic permafrost, as well as by thawing oceanic clathrates. Both emit CO2 and Methane and in amounts that can raise global temperatures well above the most catastrophic 4 degrees Celsius scenarios. That is – the scenarios where the vast majority of animal species and humans on the planet die.
Some people may not care overly much about a billion humans “cooking off” later this century. For the politically right and white, there has always been a certain systemic racism towards people living in equatorial zones, and certain elements in society may thing a die off is long overdue and “practical”. I insist, with mass migration, modern technology, NBC warfare that is no longer the case. If a few tens of million people start dying as a result of climate change, use of any available weapons of mass destruction either as a result of resource wars, migration control or terrorism becomes a 100% certainty.
So having established people will keep emitting CO2 and other climate disrupting, heat trapping gasses, and having established that the consequences of extreme climate change may trigger planet destroying catastrophe either directly or indirectly, we need immediate solutions.
As said, planting trees in the Sahara is doable. We can use sand as building material, and dig canals that take salt water deep into the Sahara desert. We can make these canals run along canyons, and reinforce the canyons with sintered 3D-printed sand, in order to take populations, water and naturally cooled environments deep into the most arid continental regions across the planet. That’s already a developed idea. I am sure I saw designs somewhere. This is a double whammy solution – you create fairly idyllic living environments for humans (Imagine a canyon dug 50 meters deep, a stream running at the bottom, houses set in the canyon walls, running for hundreds of miles through the desert, a monorail running along the artificial canal). Downside it is labour intensive. There are probably far better solutions to using desert surface to capture carbon but I got a feeling that won’t be able to capture all of the CO2 in the atmosphere.
Is there a better alternative?
Yes there is – the oceans. The oceans currently only photosynthesize about 100 meters, and that’s already a generous estimate. So in essence, most of the planet’s water is cold, dead and not at work capturing CO2.
Now we have LED illumination that’s darn effective in terms of energy efficiency. So what if we can illuminate key regions of the world’s oceans, much deeper than that 100 meters? If we do that we trigger photosynthesis in quite substantial three-dimensional regions. I visualise it like this – on the surface of a sea or ocean floats a structure. It is kept moored with cables to the seabed below, let’s assume a sea region in the order of 500 to 1000 meters, but eventually we can go even deeper with this. Along the mooring cables we run electrical cabling, and we suspend pressure resistant glass cylinders. Inside those cylinders we hang LED lighting. The Cylinders need not be particularly intricate – thick glass can be made pressure resistant. You can make these structures shaped in a manner that allows the best efficiency in terms of light output.
Listen – I can imagine all the objections against any such really big projects, be it Sahara or Deepsea photosynthesis or whatever. All these objections come down to this – who is going to pay for such an idea?
The problem of climate change is real, the dangers are real and the need to do something about it. Sooner rather than later we will experience sea levels go up, weather get wilder and large regions of the world become deserts. It’s no longer a matter of decades, we are now clearly seeing the slow motion catastrophe unfold in terms of years. Heatwaves are becoming the new normal as we speak. I have argued before, there’s a lot of reason for rich people to drag their feet in allowing political solutions, because those rich people can perfectly well see that if the world consensus shifts towards affirmation climate change is real, there will be a very big bill due to find solutions to solve it – and they have all the money these days. So rich people, elites know that if we start seeking solutions it’s going to be mostly them footing the bill.
There’s no solving this conundrum. The CO2 and Methane is already billowing in to the atmosphere, where it acts as a thermal battery acid that traps heat instead of electricity. We need approaches to grabbing that CO2 by the throat and turning it into oxygen and biomass really fast. On land the potential to do so is fraught with infrastructural challenges, political hurdles, local instability.
But the sea lays completely barren and mostly lifeless. Right now the sea is by far the biggest absorption medium (or sponge) for atmospheric carbon, and it’s fast losing that ability on account of sputtering halocline currents, ever faster run-off, anoxic regions and ocean acidification.
By claiming all that empty real estate and making oceanic algae do the hard work for us, I really think there’s a credible pathway to tackling the problem. As soon as we evolve as a species in to most robust affirmation of science, facts, yanno “reality” the sooner we can come to terms that, Yes heroin is addictive, yes it is bad for the planet, yes it can get a lot of people dead in a really miserable manner, the sooner we can come to grips with our literal responsibility to actually start giving a damn about, yanno “the future”.
Now the oceans were formless and empty,
darkness was under the surface of the deep,
and the Spirit of Progress and Science was hovering over the waters.
And Humanity said, “Let there be light,” and there was light.
Humanity saw that the light did good
Guys, let’s not waste decades on “studies” ok? Can someone like Elon Musk go out and test this idea?