Climate Solutions: Is It Feasible to Remove Enough CO2 from the Air?
e360.yale.edu
e360.yale.edu
But what chance does this sort of ambitious effort have when more and more states don't even want to deal with the ordinary problem of reducing CO2 output?
It seems to me that anyone caring about climate change needs to have a generally pro-science position politically.
We may, however, get there via improved economics and technology happening in renewable energy right now. With an unreasonable amount of luck, we might buy ourselves enough time to make peace with the human condition and find a replacement for global capitalism that does a better job of integrating the reality of our needs and the planet’s.
> But what chance does this sort of ambitious effort have when more and more states don't even want to deal with the ordinary problem of reducing CO2 output?
There are cheaper geo-engineering methods that don't attempt to directly reverse the problem, just (locally) mitigate some of the consequences, that could be done unilaterally by a state. E.g. stratospheric aerosol injection (less glamorous but a much cheaper than parking sunlight-filtering-satellites between the earth and the sun).
> Unlike the control of greenhouse gas emissions, which must be undertaken by all major emitting nations to be effective and is likely to be costly, geoengineering could be undertaken quickly and unilaterally by a single party, at relatively low cost. Unilateral geoengineering, however, is highly likely to impose costs on other countries and run risks with the entire planet’s climate system.
i agree that e.g. aerosol injection proposals seem rather stupid, won't actually fix the problem, but may just mitigate some of the many consequences of the problem, and also cause entirely new problems.
on the other hand, i suspect it is much more likely that geoengineering proposals will actually happen in preference to hypothetical negative emission technology, as geoengineering doesn't need a group of countries to agree on doing it, and (some of them) are relatively cheap and easy to do using existing technology.
Imagine standing outside in sunlight. Above the clouds in the course of the sun is a faint band a bit wider than the sun. Specks, motes. Thousands of them. Across the band some glitter, some are dark - like dark specks. Those covering the sun are almost all dark. If you carefully look at them through a filter that let's you see the sun's disk, you can make out a fuzzy outline not too unlighy the continents, with a few extra spots in between. Earth has a ring. An artifical one, much wider than the ones Saturn has - more like a ribbon, actually. The motes are each large flat reflective surfaces. Flat disks made of reflective plastic films. Microns thick with as much area as is practical to make launch and unfold at scale. They orient themselves using current flowing around their rim using electricity generated from solar power on their main body. The current in the rims orient them relative to earth's magnetic field. They also act like solar sails when needed, using solar wind for minor maneuvering and they use small micro ion drives for positioning. Each is a pixel. It can reflect sunlight completely away from the surface of the earth. Or to a targeted spot on it. They can match their rotation to their orbit and cast a variable shadow: from a slim wisp to their full area. All in all. All of them together can dim the sunlight falling on the earth by up to 2%, but with precise control per region. Many targeted on the same spot can boil (or slowly evaporate) large bodies of water or heat large volumes of air within specific control. They can be weapons. Terrible ones: melting metal and rock for small focused regions. But mostly they are tools - gardening tools. Weather, and more importantly climate is something that they are used to steer. After wrecking the sort of balance we found when we started here we were responsible for establishing a new balance.
Most of their work is reducing the incident solar radiation falling on the earth's surface. They dim the radiant energy on the surface in line with the current climate control program. For the continents they mostly just reduce incoming energy. Over the ocean some areas are dimmed less to help cloud formation. This extends their influence immensely as we then increase the earth's albedo using the extra cloud cover, reflecting a lot more light than ocean does. They fiercely shield whatever glaciers we could save. The ones on the night side are used for controlled lighting in a few cases. The baby drone-planted forests are sometimes given extra sunlight. And a few cities are given the occasional extra light when safe. The ones not positioned for blocking sunlight focus light and heat to manage weather systems. Parts of the garden's weather systems can be managed. On the one side of a continent clouds are formed by heating the ocean. These clouds are shielded and shepherded through shielded corridors and allowed to condense and rain in the interior. In places large inland water bodies were made. In other places river like canals were melted through rock. The natural forests and areas we could save are given special status:Bonsai, and we try to keep them vaguely in line with what they originally were, at great cost. But much desert is farmable and a lot of previously rough terrain is being manicured. Some spots of the garden are never tame and recalcitrantly fights back. There is a degree of success in using them to manage ocean currents, but it's difficult and doesn't always work. They don't have the strength and finesse required to do that at scale. We need other tools for that. Wind currents are easier. They follow simple temperature gradients and with trial and error and a lot of computer modeling these are mostly directly managed. Weather is at a coarse (and often fine) level controllable within the constraints set by climate regulation control. A new stable balance against the current level of atmospheric composition can be maintained - within reasonable constraints. We still need to spend decades or centuries cleaning up our carbon dioxide mess. New forests, huge atmosphere altering factories and sublimation pits help, but it is a long term project.
Our current situation is sort of a consequence of:
Imagine a world where beasts of burden don't toil under the hot sun - where machines powered by refined oil products allow for the cultivation of crops, feeding millions. Where machines relieve people of brutish work, freeing them for more satisfying and valuable pursuits. Where durable and strong materials can be made cheaply from petroleum-based products that millions of households can enjoy. Where hundreds of millions of people can be fed using more efficient agriculture that uses chemically produced fertilizer....
And so on and so forth...
> [...] humanity has not yet come anywhere even remotely close to the death tolls of the major mass extinctions of the past half-billion years ... yet. In the past 400 years, there have been documented extinctions of some 800 species. This is a tragedy, to be sure, and likely a massive undercount, but when divided by the 1.9 million species known, 800 extinct species amounts to an extinction of less than one-tenth of 1 percent - a far cry from the End-Permian, during which, generously rounding up, almost 100 percent of complex life on earth was killed.
re: the End-Permian mass extinction
> "Five hundred million years is a really, really, _really_ long time. And [the End-Permian mass extinction] is the single worst event in the last 500 million years of earth history. So your scenario should not be sort of a bad-day scenario. [...] It's closer to a one-in-a-billion event."
> [...] End-Permian sites across the planet from the ancient ocean [...] similarly recorded a carbon cycle jackknifing. Where did all this extra light carbon in the atmosphere come from? One way is to kill all the plants, plankton, and animals in the world. [...] But the carbon isotope swing at the End-Permian mass extinction is so severe that many other scientists think that the collapse of the biosphere isn't enough to explain it.
> [...] At the end of the Permian, Siberia briefly turned inside out as the Traps covered Russia in more than 2 million square miles of lava.
> [...] "Basically the entire global economy rests on how quickly we can get carbon out of the ground and put it in the atmosphere", Ridgwell told me. "That's basically the global enterprise. And there's a lot of people doing it. Geologically, it's a really impressive effort."
> But as exceptional as humans are, estimates of the carbon released in the End-Permian mass extinction range from an utterly catastrophic 10,000 gigatons of carbon -- twice as much as we could ever burn -- up to a mind-meltingly unfathomable 48,000 gigatons.
> [...] "So taking the modern ocean and adding 40,000 gigatons of carbon -- like in the End-Permian -- it would take you from, say, 300 ppm to 30,000 ppm CO_2," Payne said. We both started laughing. This number is incomprehensible.
> [...] For now, typical estimates place End-Permian atmospheric carbon dioxide somewhere around 8,000 parts per million [...]
> [...] In the long term the oceans can keep up with a huge buildup of carbon dioxide in the atmosphere, as long as it happens slowly enough. The gradual process of weathering breaks down rocks on land, washing them into the ocean and, in doing so, buffer the seas against acidification [...]"
> "Well, the rate at which we're injecting CO_2 into the atmosphere today, according to our best estimates, is ten times faster than it was during the End-Permian. And rates matter. So today we're creating a very difficult environment for life to adapt, and we're imposing that change maybe ten times faster than the worst events in Earth's history".
For reference, the human endeavour is injecting roughly 40 gigatons of CO_2 into the atmosphere every year.
Geologist here! That's a good quote. On geologic timescales, a million years is short! Accordingly, a lot of our effects on the environment are scary more because of their rate than their absolute magnitude (so far). I think humanity as a species has been doing a pretty good job of implementing that old facebook motto "move fast and break things". We'll see how that works out for us.
You can't be serious with "something that would not decompose". Entropy literally disfavors it. The point is to tamper the rate, not to completely turn all C into diamond and jettison it into the sun.
Scientists agree: Climate change is terrifying, climate change is human caused, and climate change is here now today, threatening to be the effective end of our species in a number of decades you can count on your hands. On top of which, it only takes mildly pessimistic scenarios to reach time spans you will probably live to see.
Right now the ruling class of big oil is setting the fraction of gases in the atmosphere, and doing a terrible job of it.
But at least it isn't the government?
This seems like a particularly bold claim given that we currently live in a political climate where we can’t even seem to agree on basic matters of reality.
At or below 150 ppm of CO2 in the air, all land-based plants would go extinct.
At or above 1,000ppm, or 2.5x current outside levels, human performance starts to decline. People will complain of drowsiness and stuffiness. Those levels can occur in buildings already. I don't look forward to a future where opening a window for fresh air delivers stuffiness, and inside buildings rise commensurately.
Who knows how many pollinating species will go extinct, and at what levels, as they can no longer breathe enough to fuel their activities.
Wait a second. For the last few million years CO2 levels have been in the 180-300 ppm range (except for recently where they have gone above that).
What makes you think that plants that initially evolved hundreds of millions of years ago in very high CO2 environments did not continue evolving as CO2 levels changed, so that the plants we now have find 180-300 ppm to be ideal?
Yes, CO2 is what plants eat, but it doesn't tend to be the limiting nutrient very often on Earth today. For the ocean (where 50-85% of photosynthetic oxygen production, and equivalently carbon burial, happens [1]) there are actually maps of this [2], and you may note that CO2 does not appear. On land, it's usually water, nitrogen, or phosphorus [e.g., 3].
Accordingly, there have been many studies on CO2 fertilization, but since it's not the limiting nutrient it doesn't tend to have much of an effect [e.g. 4]. At best there are benefits for some plant species in areas where water is the limiting nutrient, since higher CO2 means plants can keep their stomata closed more [e.g. 5], but even this is a bit of a mixed bag since dry places tend to get hotter and drier under global warming.
[1]https://en.wikipedia.org/wiki/Phytoplankton#Oxygen_productio... [2] https://media.springernature.com/m685/nature-static/assets/v... [3] https://nph.onlinelibrary.wiley.com/doi/full/10.1111/j.1469-... [4] http://www.pnas.org/content/early/2016/12/07/1610156113.shor... [5] https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.124...
All scientific, controlled experiments with plants demonstrate conclusively that they thrive (faster growth, larger leaves, increased biomass, larger fruits, less need for water, etc.) at higher CO2 levels than what we have today and than we had before the Industrial Revolution. I encourage people who are intellectually curious and honest to look up the scientific papers on the topic and read them for themselves (you don't have to be a biologist or a geologist to understand the experiments, the parameters, or the outcomes).
And that apparent silver lining's actually got a downside, too. Plants working hard to draw up water is a Good Thing, because that water is the only source of nitrogen and other elements needed to make proteins and vitamins.
CO2 just gets turned into carbs; it makes plants grow big and tall but less nutritious. This won't be a problem for us overfed gluttons in the West, but it is going to exacerbate malnutrition issues in poorer regions of the world.
See e.g.:
https://www.nature.com/scitable/knowledge/library/effects-of...
Anyone who studies the biology and evolution of plants, as well as the actual constraints of their growth processes, will understand why this gigantic transformation has been happening. There are similar measurements of major increases in ocean plankton over the last decades.
[1] https://www.nasa.gov/feature/goddard/2016/carbon-dioxide-fer...
My apologies if that isn't what you were doing.
My question is, if photosynthetic carbon capture is nutrient limited, what happens when we are adding both CO2 and phosphorus to the environment? Does everything grow better? And what's the next limiting nutrient?
Nitrogen limitation is one common one, which can apply either on land or in the oceans in different areas. We're adding quite a lot of that to the environment too though, up to a 200% increase in reactive nitrogen availability over pre-Haber-Bosch times [1]; accordingly about half the nitrogen in your body may come from the Haber-Bosch process [2].
In the ocean, there are already a good number of places that are Fe limited (Fe is needed to make chlorophyll, among other things [3]), so they'll stay that way unless we go with Fe-fertilization or increase dust input [4].
Si limitation is another possibility in the oceans -- particularly for phytoplankton that make silica tests like diatoms [5] (though as an interesting aside, a surprising number of plants need silica to make their phytoliths [6])
On land, there's plenty of Fe and Si (from soil), so if we're supplying P, N, and CO2 then we're mostly left with water or light (photon) limitation.
If all nutrients are superabundant (particularly in aqueous settings), then we end up with runaway growth and eutrophication, which is dangerous in its own way [7]
[1] https://en.wikipedia.org/wiki/Human_impact_on_the_nitrogen_c... [2] https://en.wikipedia.org/wiki/Haber_process#Economic_and_env... [3] https://www.tandfonline.com/doi/abs/10.1080/0190416840936323... [4] https://en.wikipedia.org/wiki/Iron_fertilization [5] https://www.sciencedirect.com/science/article/pii/S096706370... [6] https://en.wikipedia.org/wiki/Phytolith [7] https://en.wikipedia.org/wiki/Eutrophication
[1] https://en.wikipedia.org/wiki/Milankovitch_cycles [2] https://www.geocraft.com/WVFossils/ice_ages.html
For instance, when oceans change, such as el nino, la nina, reversals of enduring currents, or even new connections between seas due to tectonic transformations, that is properly a cause of climate change -- regardless of how much that change is, in fine, mediated by the atmosphere. Atmospheric changes are demonstrably not the only, nor the ultimate causes, of climate change.
It's surprising to me that in a technologically astute and optimistic forum like this one, there would be so much resistance to the idea that engineering solutions to heating would be easier than engineering solutions to cooling. Because anthropogenic or not, the climate is going to change, and keep changing, so either we adapt, we engineer it, or we die.