This strategy, to get rid of some sunlight, doesn't fix our problem with CO2. In fact, it's likely to make the problem worse.
Our planet has two primary natural methods for lowering atmospheric CO2. One, natural weathering, is not impacted with this strategy.
The other, plantlife, is absolutely affected. If you were to take 10% of sunlight away from Earth, then it logically follows that plants would get 10% less sunlight to convert CO2 into starches and H2O into oxygen. The resource you're trying to constrain, in the name of fighting effects of rising CO2 levels, is the very resource you need in order to fight rising CO2 levels.
Sure, blocking or deflecting some light might lower Earth's temperatures temporarily, but you'd exacerbate CO2 levels semi-permanently.
We, as a community, need to come to the realization that our CO2 problem is not strictly a temperature problem.
Every idea for geoengineering as a solution to climate change is insane. They're either nonsense, like solar chimneys, or they're like this one: way worse than the problem currently is, and WAY worse than not emitting CO2 would be. Take atmospheric sulfate aerosols[1], which I often see touted as the solution, usually by conspiracy theorists. The kind of people who think "big green energy" is money play, and this simple solution is being hidden for some grand reason.
"Atmospheric sulfate aerosols" means spraying sulfuric acid into the air. It's all the joy of this solution with the added bonus of primarily blocking visible light, destroying the ozone layer, and scattering light so that solar panels and plant life don't work as well. Oh yeah, and SPRAYING ACID INTO THE AIR. Intentional acid rain, forever. It's an incredibly foolish, destructive idea that people with zero drive to do basic research support vocally.
The cheapest, easiest and safest way to fight climate change is to stop emitting CO2. It would be so incredibly easy to stop 80% of anthropogenic emissions. These geoengineering plans are worse in every way.
So while I agree with the proposed solution, no one else does, and even then we have to deal with China and India joining the developed world and what that means for CO2 emissions.
> Which is absolutely true, but no one (basically) is doing it.
The UK continues to meet its reduction targets set in Kyoto in 1990, and its reductions are so massive that it now uses less CO2 per capita than it did in 1900. The UK also has had one of the highest per capita economic growth rates over that time period in the developed world, higher than the US for example. France really has no need of cuts, because its per capita CO2 emissions were already so small (about 4/5th lower for each individual than in the US or Australia). This blanket statement is incorrect.
>even then we have to deal with China and India joining the developed world and what that means for CO2 emissions.
Evidence disagrees. Chinese coal consumption is declining ever so gradually (~1% annually) despite their economy growing as normal. In fact their overall co2 emissions are slowly falling as well. Its an open question whether this is going to continue or if this is just a false peak, but if their commitment to renewable and green energy is a predictor then they may fall below the us emission level relatively soon.
Serious question: how reliable are the figures from China? How can we trust they aren't fudging the numbers, either at the local level or the national level?
Its based on energy use etc and I believe satellite spectrometetry, so there are massive margins of error but the general trends are pretty hard to hide.
Continued economic growth at the increased rates that non-renewable energy sources provide, without the external disapproval/sanctions that come with them.
So while I agree with the proposed solution, no one else does, and even then we have to deal with China and India joining the developed world and what that means for CO2 emissions.
agriculture isn't even the majority of methane production even in the US (which has as many cattle as China, but 4.5x fewer people). The single largest source of methane is from natural gas leaks.
Enteric fermentation is still a big problem, but it's a problem for another day- the only reason to solve it now is if it truly is as simple as feeding cows seaweed. That seems highly suspect but I have yet to see anyone accuse it of failing the sniff test.
I don't think it's as easy as you think it is to cut emissions by that much, and it certainly wouldn't be humane.
Biological sequestration is closer to a real solution, since it is analogous to how the hydrocarbons we're burning were created in the first place. It might be easier to irrigate the Sahara and flood it with Salicornia and salt mangrove than to stop China from burning coal.
>I don't think it's as easy as you think it is to cut emissions by that much, and it certainly wouldn't be humane.
No, seriously, it really is that easy. The average cost of a new car in the US is $30k, the model 3 is 35k. Every single passenger road vehicle could be replaced with an electric car for ~$1 trillion. It would cost even less to upgrade the grid to full battery-backed solar power and replace gas heating with electric. Over ten years thats 200 billion annually to eliminate 85% of the co2 released by the US and 50% of the methane.
In terms of threats to the country that barely registers as spending. The iraq war was 10+ trillion dollars, we shipped 12 billion in $100 bills on pallets and lost it. Renewable energy is near price parity to fossil fuels, even if you adopt it stupidly it still isnt that expensive.
You make china stop burning coal by buying them solar panels. Nobody says no to free electricity.
Your comment equates cost with ease, and obviously that's not necessarily going to be the case. Eg something might be relatively cheap but politically difficult.
At some point we as a species are going to have to start taking responsibility for solving the problem or a solution will never happen.
Also, you miss the context of GP's comment by pointing the discussing in this way. They were replying to another comment that claimed cutting emissions was a difficult problem for reasons that are more... physical, I suppose you could say. GP was merely pointing out that technical challenges are not the obstacle holding us in our current predicament.
I don't disagree with you in that the real challenge we face is our species' collective insanity, but I hope you see that in asserting this point that we are both in agreement with GP here.
> Also, you miss the context of GP's comment by pointing the discussing in this way. They were replying to another comment that claimed cutting emissions was a difficult problem for reasons that are more... physical, I suppose you could say. GP was merely pointing out that technical challenges are not the obstacle holding us in our current predicament.
I don't agree with that. I don't see anything in the comment indicating that they saw the problem as anything other than easy to deal with. Have a look at the reply they made to me, where they said "if we would collectively stop chewing our cuds, it would be cheap and simple to do those things". That's still trivialising the social/political component, making it out as if somehow it's just a matter of making a choice as a society. You can't just wish for society to change its attitude, and while it's easy to talk about making such changes, there's the very difficult process of actually making those changes happen.
You might as well say "if we would collectively invent an infinite, completely clean source of energy, it would be cheap and simple to solve the problem." Well, sure. But that's just stating a goal. It doesn't mean it's easy to reach that goal.
The space sail idea is already designed for a scenario in which global warming becomes an even clearer and more urgent existential threat, causing countries to get together and devote a trillion dollars and a team of scientists to a radical solution. Given that context, I think it's reasonable to point out that in a scenario with money and collective will, we should stop polluting, whatever other steps we take.
Well yeah, thats why its in the subjuctive. To express that if we would collectively stop chewing our cuds, it would be cheap and simple to do those things. My intended point is about the simplicity of scaling production, the abundance of the necessary resources, and the low cost of existing technology.
In multiple comments, you've point blank said it would be really easy. If it's really hard to get the political will to spend the money to do the technically cheap and easy thing, then actually the task is hard.
Political will is not an engineering complication. It applies to any solution to global warming. Im comparing cutting co2 to other solutions, not as a problem in general.
My frustration comes from seeing cutting co2 as somehow harder than seeding chemicals into the atmosphere over the entire planet, or building a tube to the stratosphere, or lanching a sunshield into space. Those solutions are an insane level of difficulty above cutting co2.
I'm not ignoring the political difficulty here, that's specifically what I'm complaining about. Its obviously hard on some level or we would have done it already, like how the ozone layer is being repaired. These unworkable solutions destroy the political credibility of CO2 reduction.
Saying "the problem is easy besides the political component" is not the same as saying the problem is easy. It's an intensely hard problem but the focus needs to almost entirely be on politics, because the rest is easy in comparison. I'm not drawing attention away from the political difficulty by emphasizing how easy the technical side is, i'm drawing attention to the difficulty of the political side.
You think electricity is not made with CO2 ? no country is 100 percent nuclear or solar and batteries are not made using a clean process either. There is absolutely no free lunch and pretending thIngs are easy is ignorant at best.
I said converting the grid to battery-backed solar. Batteries are clean. Cobalt is a heavy metal but when mined sustainably and built with renewable energy the pollution from a producing a battery is very little.
There are plenty of countries whose power is 100% or close to it "made without CO2", usually with help from hydroelectric (e.g. Norway). Solar panels are becoming cheaper and cheaper and cheaper. The situation is closer to free lunch than you imply!
Over medium time scales people switching to smaller vehicles won't really show up as additional demand and thus won't drive any increase in supply.
If people downsized in large numbers it might even move some buyers away from new large vehicles (if the anticipated resale value of large vehicles dropped).
replacements over ten years means replacing cars at end of life. Additionally, 90% of a car's total life cycle CO2 emissions are due to fuel use[1], so its actually very quickly worth replacing a car. With the current grid it's between 30-60k miles, with a fully green grid it's as low as 7k miles.
The economy makes benefit of cheap fossil fuels. We are shifting away from them, but other forms of energy are more expensive, or they are inconsistent, and usually both. Increasing the cost of fuel and power would mean making everything more expensive. For most first-world countries, we can take the cut. But it would absolutely lead to more poverty and starvation in the third world.
You're being hysterical about acid--- using a scary sounding word, even though it isn't. (You're not far off from the people who think that any chemical they don't understand must be bad, even though they never took an organic chem. class!) Volcanoes naturally put sulfur in the air, so what we'd be doing wouldn't all that different.
Honestly I think a big change that human industry will have to make over the next century is becoming comfortable with intermittent peak power. Some stuff will happen when it is sunny, or windy, and not otherwise. It's not crazy to say "maybe we should only smelt during peak solar hours", and probably not even crazy to say "maybe our bulk freight should only be moving during peak solar hours".
Once you get rid of the need to do energy intensive stuff at night, the power storage problems become a lot easier.
There is a bunch of options being explored for shorter and longer term energy storage.
One example i ran into recently were concrete blocks that would be heated during periods of excess production, and then the heat converted back into electricity during slumps.
Never mind that smarter, nation wide, grids can allow electricity to flow in either direction depending on where the production and need is.
Yes, and we'll need all of the energy storage we can get, both for applications that do require continuous or on-demand power and for applications which require dense, portable power.
But every transformation you put your energy through between harvesting it and harnessing it has a cost, whether you are converting your electricity between DC and AC willy-nilly, storing it as chemical energy, or converting it to mechanical motion and storing it as gravitational potential. If you have a list industrial application that is not time sensitive, and is running at night from an 80% efficient storage mechanism (effectively, even if off the grid), you can boost your efficiency by 25% by running when it is sunny! Who wouldn't do that?
> Never mind that smarter, nation wide, grids can allow electricity to flow in either direction depending on where the production and need is.
Larger grids are also more vulnerable grids. We should learn from the lessons provided by, e.g. the 2003 blackout in the northeastern U.S. We don't need bigger, more vulnerable, more tempting targets for the bad guys. We need more compartmentalization to limit potential damage and make systems easier to understand and repair.
80% would be electrifying all road transport and making grid electricity renewable, and converting processes to electricity (primarily converting home heating). Road+heating+residential electricity is about 70% of co2 in the us and 50% of methane. The remainder is industrial use of electricity.
NB that this claim is in response to a proposed solution of building a gun to shoot a sun shield into space. The difficulty is relative. One is incredibly easy compared to the other.
Electricity isn't an energy source. Right now the US generates ~65% of electricity from burning coal and natural gas[1]. This is a common misconception with hydrogen fuel cells as well, which are chemical batteries, not energy sources.
While I agree with your general sentiment in this thread, simple electrification isn't enough; we also have to roll out major renewable energy generation and storage (which is still far wiser than building a gun to shoot a sun shield into space).
mistyped and left out 'renewable' grid electricity. In my defense, I have norovirus right now and my brain is currently flowing towards a water treatment facility somewhere.
Even converting all of those sectors to electric/renewable, you don't remove all greenhouse gases, you cut them down. In the case of personal transportation we see estimates of ~53% reduction in carbon footprint. I don't know what the improvements would look like if all utilities were forced to go renewables but we would certainly see large increases in price.
I think he means its easy from a technology standpoint. There are still a ton of politics at play here.
We know how to build solar, wind and nuclear plants, do that and just shut down coal power plants. That is like half. Then keep working to get old inefficient cars off the roads. Tax SUVs and give tax breaks to electric buyers.
None of these things are politically easy, but technologically require nothing new and might leave us with a stronger more economy because of the amount of new players and innovations in the fields affected.
But the current political discourse is functionally stalled on the issue because people don't care until it unambiguously affects them. That works great for many smaller issues but for this by the time it affects the average voter we are fucked.
This is a pretty naive view. There are no electric replacements for some of the big consumers of oil (trucking, shipping, airlines, construction equipment, etc).
There are already plans in various places to equip highways with overhead wires that will allow trucks to operate like trams for the duration.
Never mind that diesel engines, used in most heavy machinery, is not as picky about its fuel as a gasoline engine is. As long as it goes bang under pressure, a diesel engine can potentially run on it. what is not needed is to electrify anything, but that CO2 in vs CO2 out sums to zero (or a lot damn closer to it than it currently does).
Electrifying all of the highways and roads trucks drive on would basically be building an entire grid again. That doesn't really fall under the technically feasible category.
Interesting historial fact: the reason the USA was able to engage the Japanese relatively quick after Pearl Harbor is because the shit bunker fuel ships use doesn't burn easily at all so the ship fuel reserves were left intact.
There will be soon enough. And even if there was no way to match liquid hydrocarbon fuels for some applications then we just need to make those fuels from renewable sources.
Trucking can easily be electrified and the majority of transport related co2 including airplanes, trains, and cargo ships is from personal light road vehicles. Cargo ships are less than 2%, trains are less than 1%. Airplanes are around 7%. Around 30% is trucking. Construction vehicles are all electric/hydraulic already but more importantly are an insignificant source of co2.
Long distance semi tractors drive 500-800 miles a day. That doesnt require a huge battery.
>Long distance semi tractors drive 500-800 miles a day. That doesnt require a huge battery.
You're joking right? Do you realize how much weight they tow compared to the weight of a Tesla? On top of that most of the Tesla weight is the battery itself.
Battery powered semis for long haul is absolutely not a solution.
Those wouldn't need electricity, however, if you decide to run them off of some kind of renewable bio-fuel or even just natural gas from renewable sources. The main thing is to switch them off of fossil fuels ASAP, then you can move from there to whatever future tech comes along later.
Reducing emissions is strictly a moral argument that has not been won. We don't have to cut CO2. But we should because it is the right thing to do. All the economic hocus pocus of the last couple of decades has not convinced people of that fact.
We don't really have any concept of how to do it, and it will be a hammer blow to an already depleted biosphere. the cynic in me also suspects that it would lead to war.
You're criticizing that solution based on the name instead of based on its flaws and then you proceed to make absolutely baseless claims like the one about the acid rain, which completely disregard that the amount of sulphites needed is far less than what we already dump into the atmosphere on a yearly basis.
Please do more research before stooping down to sensationalism and fear-mongering.
> which completely disregard that the amount of sulphites needed is far less than what we already dump into the atmosphere on a yearly basis.
Nonsense. The cooling is less effective at higher altitudes, and all the sulfate currently in the atmosphere provides a forced cooling of .4 W/m^2 vs the greenhouse gas warming of 2.4 W/m^2. The cooling relies on atmospheric water which decreases the higher you go.
We would need to dump way, way more sulfates/sulfites into the air than we do currently.
It's sub-sea permafrost and it's possibly we have already damaged it so badly all the methane will leak and there's little we can do and there's little we know -- Russian Artic seafloors are in every which way pretty hostile to scientific research. (And also oil drilling, if you want to know more Google for Exxon Kara Sea and ponder what it means the Russian-awarded ex-CEO of Exxon is now the Secretary of State)
As far as I am aware, most (all?) discoveries were made from surface vessels, often seeing a foaming sea, foaming methane. It's real bad.
It's depressing that there's nothing any of us can do about it. All we can do is hope for some sort of miracle scientific solution. I hate the idea of geo engineering but the alternative seems impossibly worse
Because it is based on an aggregation of publications. The executive summary is approved line-by-line by all of the governments in the UN so it's much tamer than the report would suggest, but the synthesis of global data and studies is quite reliable.
It's all data-driven rather than opinion and while it paints a dark future, there is strong agreement in the scientific community that we have not yet triggered unavoidable positive feedback on a catastrophic scale. Even if we stopped emissions dead right now the future wouldn't be roses and perfume but it's not a nightmare. For the near and medium term the most important factor is still the amount of CO2 we emit, which far outweighs the current feedback loops and the ones that are likely to activate soon.
For instance siberian/canadian permafrost, clathrates and arctic albedo have all been triggered to some extent, but the releases have been outpaced by anthropogenic emissions. This will change, first with arctic sea ice, but at this point we are reasonably certain they won't pick up exponentially until we expect them to.
Amount of sunlight is not the limiting factor on plant growth in most places. In fact, it's often the opposite - plants shut down respiration during midday to limit water loss because it's too hot.
I imagine "most places" refers to most places on land, which is less than 20% of the range of where plants grow. Ocean-based plantlife is the workhorse on this planet, and I would argue that the lion's share is absolutely constrained by available sunlight.
Further, there's a substantial difference between "respiration" and absorption of sunlight. Pineapple plants, for instance, only "breathe" at night.
Plant life in the oceans is mainly limited by minerals, especially iron. That's why the oceans aren't green and slimy. Dumping iron powder in will usually cause an algae bloom, which eventually die and take the carbon they fixed to the bottom, so seeding the oceans with iron is a potential way of reducing CO2 in the atmosphere. Of course, like any large-scale meddling, there will be collateral damage.
> will usually cause an algae bloom, which eventually die and take the carbon they fixed to the bottom
It works so well that this could even be how the current "icehouse earth" conditions got started in the first place. The Azolla bloom of 49 ma dropped atmospheric CO2 levels from 3500ppm to 650ppm in less than 1 my, and CO2 has been in that lower range ever since.
A quick, non-biologist's googling suggests that nitrate and ammonium are the limiting factors for most oceanic algae.
I recall there being experiments for areas are iron limited, so they spread iron sulfate and created algae blooms.
I suppose intuitively, if you scoop up a bucket of ocean water, it is not green. If light were the limiting factor you would expect the water to contain lots of light absorbing algae. This does happen in nutrient rich waters, like the sewage lagoons and creeks I grew up near.
You can't assume that a reduction in sunlight reaching the top of the atmosphere means a reduction in total sunlight reaching plants on the earth's surface, because of complex feedback effects involving cloud cover.
Moreover, as multiple posts in this thread point out, sunlight is not the limiting factor in plant growth.
Maybe the diffractive elements the paper proposes could deflect wavelengths not used by plants. This would reduce total insolation on Earth but leave photosynthesis and CO2 absorption untouched.
There isn't going to be one single solution, but reducing incoming sunlight by a small percentage (1-2%) could be a cost effective part of a multi-layer approach.
Look, even as a scientist it is incredible hard for me to have a solid opinion on the CO2 influence. (Is it causing warming? Is warming a good or bad thing? etc.). But climate change is the rule in earth history, not the exception.
But I kindly ask you to have a look at this link:
https://www.nasa.gov/feature/goddard/2016/carbon-dioxide-fer...
You could definitely reflect ex. infrared without affecting photosynthesis. I think your response is a little quick to brush off these ideas. There are many possible venues for geoengineering that could have fantastic benefits, even beyond affecting climate change. Brushing them off as ideas akin to "playing god" is both unprincipled and potentially harmful to both mankind and the planet.
Astute observation, but the problem is easily fixable. Plants use particular wavelengths of light (IIRC mostly from the visual spectrum) for photosynthesis. If the proposed spacecrafts were to block mostly UV and infrared, letting most of visible spectrum through, it'd do plants no harm at all.
The relevant technology is already available and widely used. For example typical car's windshield consists of two or more layers of special UV/infrared absorbing foil sandwiched between glass panes for structural support.
In case of a spacecraft, all you'd have to do is spin the fuselage at low RPM to keep the foil extended.
EDIT:
my only contention with any sun-blocking spacecrafts is that they'd have to be carefully engineered to prevent use as a weapon for attacking ground & orbital targets with focused beams of light.
That beings said (though, I am CERTAINLY no proponent of this idea), were we to make this geostable "sunshade" out of some sort of solar power generation device (since all of this is ridiculous conjecture, I don't have to think about the logistics) it could cool the (already) elevated global temperatures while reducing green house gas emissions. Though, that would create it's own long term issues to be solved, but all of these fanciful odeas tend towards band-aids, instead of solutions =) still, fun thought experiments
This one for one ratio that you mention of blocking the sun out would not logically follow. Any plant life losing sunlight that does any significant amount of carbon absorption would die. Where are they planning to throw some shade Antarctica?
I'd argue that the more energy you use, the more comfortable your life is.
I'd also argue that energy use (at the moment) is pretty linked to how much CO2 you emit.
A lot of the biggest emitters live in democracies.
So, how do you get the majority of the population to vote in politicians who are going to make their lives less comfortable (by taxing / controlling / lessening the amount of CO2 they use)?
Frankly I reckon we, as a civilization, are going to dither and procrastinate up until the point it's far far far too late to do anything meaningful, and then people will try jump on the geoengineering to hack things into place. There was a nice piece in the book "This changes everything" where they were talking about geoengineering. I'll paraphrase, but basically someone said "we'll just alter things in this way", and someone else said "that'll mean droughts in my country". Fun times ahead.
If you haven't read it yet, I recommend "Sustainable Energy Without the Hot Air" [0] to get an idea of just how much less energy we need to use if we want to get by with just renewables. I really hope we can get there!
If it were to become apparent that dangerous changes in global climate were inevitable, despite greenhouse gas controls, active methods to cool the Earth on an emergency basis might be desirable. ... It seems feasible that it could be developed and deployed in ≈25 years at a cost of a few trillion dollars, <0.5% of world gross domestic product (GDP) over that time.
The "few trillion dollars" part is a problem. Not because it represents a particularly high cost scheme for neutralizing the warming part of AGW, but because it's so all-or-nothing. If you invest "only" $10 billion in this scheme the marginal abatement effects are going to be pretty close to zero, because so much of the cost is front-loaded into enabling technologies that will eventually deliver direct benefits.
I refer the interested reader to the classic The Political Economy of Very Large Space Projects:
I am not particularly convinced that this requires a few trillion dollars. Is there some hard evidence that sunshades are impossible to deploy with less than $10 billion?
I'm not against geo-engineering as a general concept, even though I don't personally buy into the most alarmist of the climate change scenarios. If we do do some kind of project like this, I would want to have a counter in place in case it does more harm than good, as a general rule of thumb. I would want that factored into the cost and preparations in place for just such an eventuality before committing to such a course.
In this case, though, it seems relatively trivial - it seems like it's more work to keep them in place then to have them scatter to the (solar?) winds. Once they've moved out of the Lagrange point, then they become a non-issue. All we've lost is the money to put them there and the materials. Compared to some of the other ideas I've heard, this appears to be much safer.
If you're going to put 20 million tons of perfectly identical gram-sized craft into orbit somewhere, it seems a lot more sensible to launch a factory to the Moon rather than launch all that mass from Earth. The CO2 added to the atmosphere from burning 2 billion tons of rocket fuel cannot be negligible.
This is addressed in the paper. It's even addressed in the abstract of the paper.
Edit: Second is a concept aimed at reducing transportation cost to $50/kg by using electromagnetic acceleration to escape Earth's gravity, followed by ion propulsion. The paper says that if there are rockets involved, they will be used outside of the atmosphere.
> It's even addressed in the abstract of the paper.
Where?
edit: located below (italics added) thanks. The environmental costs of launch are considered. I can't see the environmental impact of manufacture considered explicitly, though.
Abstract:
If it were to become apparent that dangerous changes in global climate were inevitable, despite greenhouse gas controls, active methods to cool the Earth on an emergency basis might be desirable. The concept considered here is to block 1.8% of the solar flux with a space sunshade orbited near the inner Lagrange point (L1), in-line between the Earth and sun. Following the work of J. Early [Early, JT (1989) J Br Interplanet Soc 42:567–569], transparent material would be used to deflect the sunlight, rather than to absorb it, to minimize the shift in balance out from L1 caused by radiation pressure. Three advances aimed at practical implementation are presented. First is an optical design for a very thin refractive screen with low reflectivity, leading to a total sunshade mass of ≈20 million tons. Second is a concept aimed at reducing transportation cost to $50/kg by using electromagnetic acceleration to escape Earth's gravity, followed by ion propulsion. Third is an implementation of the sunshade as a cloud of many spacecraft, autonomously stabilized by modulating solar radiation pressure. These meter-sized “flyers” would be assembled completely before launch, avoiding any need for construction or unfolding in space. They would weigh a gram each, be launched in stacks of 800,000, and remain for a projected lifetime of 50 years within a 100,000-km-long cloud. The concept builds on existing technologies. It seems feasible that it could be developed and deployed in ≈25 years at a cost of a few trillion dollars, <0.5% of world gross domestic product (GDP) over that time.
> The CO2 added to the atmosphere from burning 2 billion tons of rocket fuel cannot be negligible.
The quote from the abstract that addresses it:
> Second is a concept aimed at reducing transportation cost to $50/kg by using electromagnetic acceleration to escape Earth's gravity, followed by ion propulsion.
More detail later in the paper:
> Because of its enormous area and the mass required, shading from space has in the past been regarded as requiring manufacture in space from lunar or asteroid material and, thus, as rather futuristic. Here we explore quantitatively an approach aimed at a relatively near-term solution in which the sunshade would be manufactured completely and launched from Earth, and it would take the form of many small autonomous spacecraft (“flyers”).
To make carbon-neutral rocket fuel, synthesize methane from CO2[1] that is extracted from the air. Both SpaceX[2] and Blue Origin[3] are currently developing methane-fueled rocket engines.
When you build them on earth, you aren't using "a factory", you're using a supply chain with thousands of factories and millions of people. A factory that can go from regolith all the way to spacecraft is still very speculative.
As for 2 billion tons of rocket fuel, it's not trivial but it's something less than 5% of one year's current CO2 emissions, and we're talking about spreading it out over a couple decades.
Since stopping CO2 levels from rising is nigh impossible, the only option left it seems is something drastic like this (I'm reminded of Futurama where they drop a giant ice cube into the ocean every once in a while). It has the added benefit of being able to be done without depending on everyone else changing their habits.
I have a feeling that there are a bunch of these "plan B" solutions to our global climate change problem. It's that they are mostly just giving us more time before we have to actually deal with the problem. If the Atlantic Meridional Overturning Circulation ever comes to a halt then we are really screwed, so if there's anything which could prevent that from happening it might be worth the risk.
The total amount of CO2 in the atmosphere, and the amount produced and consumed by plants is very high compared to the amount produced by humans. Long term the solution is absolutely to reduce the CO2 produced by mankind through renewable energy, and reducing CO2 produced by agriculture. In the short term though carbon farming can sequester large amounts of carbon by growing on land that was previously desert, or the method mentioned in the linked page. Hopefully this slows down global warming enough to give humanity enough time to come up with a sustainable solution
Just so you know, fossil fuels are a renewable energy on a large enough timescale. It's the massive rate of consumption and waste of them which is the issue.
Switching to biofuel or solar or wind at the same massive consumption rate will not fix the issue.
> fossil fuels are a renewable energy on a large enough timescale
No they're not, at least coal isn't because it was formed from trees and other heavy cellulose based plant matter that wasn't broken down by microbes millions of years ago, but would be broken down today. Oil and Methane may be "renewable" but not in a timeline worth considering.
Switching to other methods of generation would fix the problem of climate change caused by the release of CO2. Other issues are definitely important, but not on the same level as unchecked global warming.
Do you mean that there do not exist any energy sources which are renewable at the rate we require, or that using such sources at the current / future rate would still be irresponsible for some reason?
Unless you can stop the marine ecosystem from cratering (virtually a given if CO2 levels continue to rise unabated) it's all for naught. Enjoy your lack of oxygen.
On mobile so I'll let you search for it, but start at Wikipedia for anoxic oceanic event. You don't have to stop much photosynthesis for the oceans to produce huge amounts of deadly hydrogen sulfide
The wiki does not support 'huge amounts', and makes some tenous connections to some localized events and worldwide extinction event ones, as do most of the people who bring this up. It makes it hard to have the same conversation if they are conflated.
However, note the end of the wiki, where they state that the oxygenated state of the ocean currently is likely not the 'default' state of things if extrapolated beyond human history. It is certanly a concern. However there are ways to stimulate blooms, which may help serve to sequester carbon, and add oxygen in one fell swoop. Perhaps it is time to investigate the feasibility of such an action.
Agreed, these types of solutions are really just a stopgap (and a relatively short one at that). But that's always been the case. I mean, there's no beating entropy. Eventually the heat-death of the universe will make it, literally, all for naught.
The difference between end of all time in however many tens of billions of years vs the economic collapse of human society in a handful of generations is a fairly major scale difference.
Yeah, we've got less than two billion years before the Sun expands enough to cook off our atmosphere. I suspect we will be extinct before that, however. As a collective, we're not very bright.
Really we should just be focusing on building a time machine and re-populate the pre-human past. I imagine that no matter what happens, we could just populate infinite timelines (But we are more likely to already be on that exact timeline)
That seems a bit of a long-shot. I'm not sure if it is less likely than us causing our own extinction, however.
I don't watch a lot of movies, and I recall even fewer, but there is an appropriate line in The Matrix about how a human can be smart but humans are pretty dumb as a whole. It seems to be remarkably true.
"A person is smart. People are dumb, panicky dangerous animals and you know it. Fifteen hundred years ago everybody knew the Earth was the center of the universe. Five hundred years ago, everybody knew the Earth was flat, and fifteen minutes ago, you knew that humans were alone on this planet. Imagine what you'll know tomorrow."
The problem with geo-engineering solutions to global warming is that they would require global consent. Anything else would be a drastic violation of human rights, and potentially a cause for massive conflict. We all have to share the same planet, and some peoples might be drastically opposed to (potentially) irreversible processes such as the scattering of chemicals in the atmosphere. Any "for the good of mankind" justification is almost beside the point.
Unfortunately, yes? Nobody made the decision to contribute to global climate change; it just kind of happened as an emergent consequence of the discovery of oil. Whereas a single country deciding to permanently tint the sky is not going to go over well with the global community, probably to the point of tanks on borders and missiles at ready.
So altering the climate is fine, if it's a side effect of making money. It's just doing it at a financial loss that's a problem.
Maybe we should focus on ocean fertilization with iron as a way of increasing fish yields. Who can begrudge some poor fishermen trying to bring home more fish? It's not their fault if it also sequesters CO2.
Solar radiation management also offers possibilities though. We already spew lots of soot and other pollutants into the air without anyone rolling out missiles. We just need to figure out industries with the right kind of pollution and we're good.
Sure, but I think it'll be very difficult to get the US, China, and Russia to agree on something as drastic as this before catastrophic climate-related events start taking place. (And let's not forget all the other nations with nuclear missiles. The playing field is a lot more level these days, for better or worse.)
If the USA, Russia or any other nuclear power does it there won't be a war. Nuclear is the key word here, Those wars are much more costly than any amount climate change.
Isn't Drastic violations of human rights the other name of the USA and also all other nations around the globe ?
This view is also a specist one, what about all the other lifeforms on the planet that we could not have life favorable condition on earth ? insects, plants, ocean life, corals, etc.
Switch from compete to cooperate mindset and there would be a lot less lifeforms rights violations.
Also instead of having the USA lifestyle as a model we try try to reach and have for ourselves, we should aim for the India lifestyle so we could all live on earth without destroying the planet.
Most good engineers are wise enough to ignore the public and philosophers like you. :-P If you look at medical history, it is littered with Doctors who discovered something crucial and revolutionary who were met with resistance. The same story goes with astronomers.
How about this: Are people allowed to act in a way that will save themselves, even if it sames everyone else on the planet, and has some side effects? I think the answer is an emphatic yes!
> How about this: Are people allowed to act in a way that will save themselves, even if it sames everyone else on the planet, and has some side effects? I think the answer is an emphatic yes!
Who decides which ways will save and are therefore allowed?
That's not feasible. Even the most isolated nation-state in the world (i.e. N. Korea) has a hard time getting its high tech projects finished if all of the other countries are working against it. And they have the advantage of a fanatical following and oppressive control of the military and media.
Something on this scale would be pretty much impossible to pull off if all the G-8 countries put you/your company on an embargo list for high tech materials.
North Korea is making Nukes to threaten the world with. And is a tiny shithile country with an already destroyed economy.
It helps to be claiming to be acting in humanity's best interest instead of obviously being a despot. Think about the political aftermath of interfering with someone claiming that they are trying to save the world and having a reasonable argument that is the case.
Someone attempting this would likely be in a major country and would likely have the approval of most of the countries. If the USA attempted no amount of embargos could stop them, the same with Russia and maybe a few other countries.
It is even possible that Germany, France, Israel or South Africa could pull it off with a little politics and clandestine dealings. They could delay politically and pester larger nations and demand UN actions while continuing development.
If the US and Russia were dead set on stopping they could with a few bombing runs from aircraft carriers. I don't think that is likely because neither of these countries is crazy and would love to be saved at no cost while having a political bogeyman they can use in the future.
EDIT - Have an upvote for a thoughtful and reasonable reply though.
So, just to be clear, you want to impose your will on the planet, as a whole. You don't care about any form of democracy. You don't care what anyone else thinks. You think you're right, and anyone who opposes you is wrong. And since you're right, you're justified in doing whatever you think is necessary.
Vast tragedies throughout history were perpetrated by people who thought they knew better than everyone else, that their ends justified imposing their means on the rest of the human race.
Your attitude is dangerous, because you can use it to justify anything (e.g. you think you're about saving lives). It is evil, because it places you above everyone else and leads to death (e.g. you think you're saving civilization, which requires destroying the bad parts of it).
You either have not learned from history, or have learned the wrong lessons from it and are following in the footsteps of millennia of anti-heroes.
I think a really hard limit on the max CO2 acceptable that most everyone would agree to would be where outside air starts to feel stuffy to humans. I have not found a good study on this but indoor air quality people say around 1000 ppm CO2 and you should start trying to increase ventilation. If the atmosphere gets too high it will be hard to keep indoor air below that without CO2 scrubbers. Over 750ppm(?) CO2 in the atmosphere and one gets the horrible situation where one goes inside a CO2 controlled space instead of outside to get "some fresh air".
We're at 400 ppm CO2 right now. So your feeling is that we'll probably start reducing carbon emissions once we double the amount of carbon in the air?
450 ppm is often held up as a catastrophic point of no return. I don't know if that's alarmist. Let's say it is! Maybe we'd have to get all the way to 600 ppm before it was genuinely a catastrophe. But I'm pretty confident that if we reach 700 ppm, we're fucked.
The Earth's orbit is too circular and our axis isn't tilted enough. We're at the maximal energy absorbing posture. In 100,000 years, we'll need this greenhouse blanket to keep our ice planet warm.
I'm a layman, but my mental model suggests that tidal-lock would be the relationship that raises the energy most on the receiving body. An example of that concept would be Mercury.
A tidally-locked body would have nearly 50% of its area "cold," in other words it is not radiating any heat from the primary heat source out into space. Only heat reaching the cold side from atmospheric convection or internal conduction would be able to reach space. In Mercury's case, the lack of significant atmosphere reduces the flow of heat from the warm side to the cold side.
A spheroid with any given amount of surface area exposed to equal heat / cold has the highest chance of preserving equilibrium. If that logic is true, correcting Earth's axis tilt should slightly increase the amount of energy radiated away. That would also produce more consistent temperatures between the equators and poles (raising sea levels by reducing the amount of frozen water proportionally). Needless to say that would have nearly incalculable side effects.
The other day I had a random urge to Google why sea levels are actually rising, and I learned that it's not a result of melting ice. Melting ice and rising sea levels are both the result of rising temperatures. The sea absorbs the heat and expands.
However, the loss of ice does accelerate the warming because less light is reflected from the earth.
Yes, there is a simple puzzle that makes use of this. When carrying coffee back to the office, how do you insure that the coffee will be the hottest, by putting in the cream at Starbucks or back at the office?
A hotter object loses heat faster than a cooler object.
It's actually a fourth power relationship to temperature. See Stefan-Boltzmann Law for the details.
I'm all for exploring solutions, but I also wonder about the behavioral economics at play when people "feel" like a geo-engineering solution is inevitable.
In other words, how much does believing we will inevitably engineer our way out of the problem keep us from making the hard choices that may be necessary.
Who is the "us" that needs to make hard choices? Those that are seriously impacted by climate change and those that stand to benefit from the status quo are very disjoint sets, and the latter have shown quite an aptitude for persuading the former not to worry about it. The time for making those hard choices is quickly passing by without any significant motion. It's not time to give up yet but it's also not a good idea to just assume people are going to come around on this.
That's what stratospheric sulfate aerosols[0] are. Same stuff the industry already dumps into the atmosphere but dumped way higher in low amounts and easy to reverse: you can just shut it down and the effects fade over the course of the following year.
this would be simpler for sure but it would require very difficult things to attain such as having people relinquish their air conditioning, stopping capitalism and consumerism, changing the global industrial process, diminishing our energy consumption, replacing the current political systems with democratic ones, returning to ways of producing food that do not cause soil infertility.
Exactly like polar ice. The problem as you point out is that polar ice is reducing which just makes it worse.
And obviously this whole discussion about technological solutions is due to the fact that all those things you list seem to be impossible or happening too slowly.
I doubt artificial ice is the easiest solution, but e.g artificial clouds could be perhaps.
I saw something on TV a few years ago about a project to make boats which would spray a fine mist high into the atmosphere, ie. create artificial clouds to reduce the heating of the earth.
$50/kg to Earth orbit would be fantastic. One could get to a much higher exit point than the 5.5 km elevation (18,000 feet) they propose for even more efficient system. Seems like a great mega-project for China. They have the resources, drive, ambition, tech, and access to many 8 km+ mountains to build a launch tower on. Hopefully this would spur the US to partner with Chile and/or Argentina to build one on one of the ~7km peaks in South America. Denali is probably out of the question, but as military project, maybe it could be done.
Umm... I'm not sure it is politically feasible to build a rocket launching facility on Denali. That is gonna make a whole lot of people angry. You should see what happened when they put wind turbines on the much smaller mountains of Maine.
Sort of related, I happen to like the looks with said turbines. There are still untainted vistas.
From US soil? Not sure the US would put 10's to 100's of billions into a launcher and not have it in the US. Maybe the Panama Canal land grab route would be what would happen instead of Denali.
We'd probably use the current facilities. I suppose we could also try for Hawaii or Puerto Rico. The land grab is also an option, given the likely political climate if it reaches this point.
My understanding is that closer to the equator is better, with some caveats.
> My understanding is that closer to the equator is better, with some caveats.
For this project, I don't think it matters. They even said they will orient the launcher vertically.
The reason you normally want to be closer to the equator is that you get some sideways velocity from the rotating earth, and that is faster nearer the equator. This is important for low earth orbits because the sideways velocity is very high.
However, in this case they don't really care much about sideways velocity. They want to reach escape velocity. As you go higher, the sideways velocity needed to stay in orbit gets smaller, until finally it's practically zero. So, any gain they would get from being near the equator wouldn't be needed.
I'm still pretty skeptical about them putting it on Denali. It just seems really unlikely - and insanely difficult. It's also considered sacred by some of the natives, as I understand. I am imagining the outrage.
Yeah, still seems really unlikely. There's a reason we don't do nuke testing like we used to. People get pretty mad about certain things. I suspect that launching rockets from Denali would be one of those things.
> It seems feasible that it could be developed and deployed in ≈25 years at a cost of a few trillion dollars, <0.5% of world gross domestic product (GDP) over that time.
Much more optimistic numbers than I had previously guessed.
It's also been speculated that the same idea could be used to have the opposite effect on Mars. A cloud of small satellites trying to push more sunlight towards the planet, thereby heating it up.
It's all space-nerd talk for the moment, but none of the technology needed to achieve these goals is very far from reach today.
In that case, neither is fusion, which is essentially free energy forever.
It opens up the avenue for many more warming and CO2 mitigation techniques that are a reality today (e.g. desalination on a global scale and massive reforestation of Africa and the Amazon)
As well as the ability to stop burning fossil fuels much quicker than transitioning to solar/wind.
It's interesting how you think it's possible to do massive reforestation in Brazil and Africa. Think about massive reforestation of Europe or the eastern USA and I think you'll see the fundamental problem with it. That land has already been put to other use (mostly agricultural use) and cannot simply be reforested. The government would have to repurchase the land from each individual land owner to do that which is not at all practical.
This project requires millions of square kilometers of high tech satellites. If we could make millions of square kilometers of high tech satellites then we could probably make millions of square kilometers of solar panels here on earth, and not put CO2 into the atmosphere in the first place.
Regarding deflecting light, for a long time white roofs have been pushed as a reflection mechanism[1] to deflect and lower energy costs thus reducing emissions. Though white roofs may actually increase warning in the way it reflects light onto other particles and doesn't help block it from coming into the atmosphere. Solar roofs capture it better and may be a better emissions lowering tool.
Seems like a better idea to do it from space, unless of course it goes too far and is difficult to control.
Deflecting is still better than absorbing on the roof top, since roof top means 100% warmth absorption and deflection always less than 100%, probably only a fraction of that.
No. As an a example, I'm assuming that hot roofs absorb 70% of the incoming energy and reflect 30%, where reflectig roofs absorb 10% and reflect 90%. These numbers can be a bit different, but I'm pretty sure that hot roofs absorb a multiple of energy compared to reflecting roofs. Makes sense?
This is why we need a space elevator! Costs would be reduced from $40k / kg to ~$400/kg.
I spoke to an engineer at a space-focused company about space elevators. He, unfortunately, burst my bubble. While the elevator itself might be feasible, he thinks that countries would never let an asteroid large enough to act as a counterweight, with thrusters large enough to move it attached, enter Earth's orbit. The potential of it being used as a catastrophic weapon is just too dangerous.
We'd also need to advance material science and logistics quite a bit. It sounds like carbon fiber has the tensile strength, but we can't make it in near the length nor quality we'd need for a space elevator.
The elevator would need to avoid or divert space junk.
And we haven't actually practiced asteroid capture, much less orbit keeping on a scale that large.
Would it possible to aim to have these satellites shade only one or both of the poles? That could solve the problem of reduced sunlight for plants. (Among other issues.)
ISTM it would be difficult since the sun isn't a point source. Fortunately, as other comments have mentioned, sunlight is not the limiting factor for plant growth in most situations.
Can somebody who understands the subject (or have read the paper more carefully than me) say how the moment of the shadow on the earth would be? Would it be fixed on a part of the earth or move, and if it moves, how fast and in what "orbit". I.e, would some part of the earth get more (much more?) cloudy days if this would to be implemented?
The inner Lagrange point is always between the sun and the earth (by definition), so the "shadow" would always be centered on local "noon" and would pass the each longitude at the same time every day.
But the sun isn't a single point, it is big! In the same way that a pencil can have a sharp shadow but an office building will have a blurry shadow, the satellites would produce blurry shadows.
I'm not sure of the dimensions of the inner Lagrange point-- I agree that the shadow would be centered on astronomical noon, but I think it would be so blurry, and have such a wide blur radius, as to be unnoticeable except as a change in absolute light.
I don't have the technical background to know if this is a pie-in-the-sky kind of thing, but it seems like an amazing idea. It reminds me of the "Icarus array" from the book "Echopraxia" by Peter Watts. Of course, this wouldn't harvest energy but just absorb it.
So, now the most egregiously greedy/evil plans from the Simpsons are being considered?
>'The Sun Blocker was a device developed by Charles Montgomery Burns. As the name suggests, it was created to literally blot out the sun outside, in order to ensure Mr. Burns' electricity was sold in a monopoly, covering Springfield in perpetual darkness otherwise.
The machine was extremely infamous alongside the theft of Springfield Elementary School's oil well for riling the Springfieldans' hatred of Mr. Burns, enough to want to murder him, especially Smithers, who had earlier been fired by Mr. Burns when the former protested against the plot and cited it was too heinous of a plan for even him to nominally support.
[...]
According to Mr. Burns, the Sun Blocker was conceived due to Mankind overall having an innate desire to destroy the sun, and that, due to the infeasibility of actually doing such an act, he settled for "the next best option."'
February 2001, "Ice and Mirrors", by Brenda Cooper and Larry Niven. Swarm of small mirrors used to cool a planet. Mentioned in this Nature article complaining about the cost: https://www.nature.com/news/2006/061030/full/news061030-6.ht... Predates Echopraxia by 13 years.
This is the space version of fusion, "just 20 years away" or "within our grasp" for the last 60 years.
In fact, it may be even less feasible. Not to sound too much like a skeptic, but my bet is on terrestrial methods of mitigation, solar/wind/tidal, reforestation and, hopefully one day, fusion.
Most people underestimate by several orders of magnitude how hard it is to launch something into space correctly.
I remember a quote from a US geo-engineer to the effect of "half of my job is not to come up with geo-engineering solutions that will be used, but to show people that plan B is soooo extreme that they start taking plan A much more seriously"
"They would weigh a gram each, be launched in stacks of 800,000, and remain for a projected lifetime of 50 years within a 100,000-km-long cloud. The concept builds on existing technologies. It seems feasible that it could be developed and deployed in ≈25 years at a cost of a few trillion dollars, <0.5% of world gross domestic product (GDP) over that time."
Oh FFS. If we have a few $trillion to devote to global warming, we can enormously reduce it using known technologies.
There is an important clue in this spectacular self-own to the emotional allegiances of the people who get excited about ideas such as this one.
How about just invest in a solar powered way to make something useful from CO2 in the atmosphere. Like say a brick. We could make roads and buildings out of it.
If I was given a few $trillion to solve atmospheric CO2/CH4, I would move mining to the moon, and move manufacturing and agriculture into orbit. Then smother the Earth-side economy with cheap/free stuff to discourage the remaining entrenched industry, and offer habitat space to anyone who prefers doing physical work for a living, over living in a highly regulated paradise on UBI + patreon.
For perspective, Gerard K. O'Neil gave a ballpark estimate of $31B (correction: $31B in 1972 dollars, $172B in 2013 dollars) for a v1 O'Neil cylinder made of steel. http://www.nss.org/settlement/physicstoday.htm
Any form of geoengineering that is outside of earth mskes me nervous. Removing or altering its effect might be precluded if society breaks down (e.g.after a nucleur war)
I don't understand why people are still obsessed with "global warming". The political proponents of it have already changed it to "climate change" after global temperature stopped rising for a decade and it's been almost two decades now. I would be much worried about "global cooling" i.e. another ice age.
A couple of degree increase over the next hundred years (which is their worst case estimate based on the most advanced models, even though no model has been able to predict anything, only fit historical data) will change nothing. Sea levels will probably rise by a few feet and people living in their beach houses will have to find another vacation spot in 20 years after they notice that the sea has been coming closer to their house since the last decade.
Ice age is just as unpredictable (except they don't even have a make-believe explanation for it) and could start any time giving us very little time to prepare. If we want humans to suffer less because of it, the least we should do is try to give over a billion people who have no access to electricity some way to make sure that they will be able to heat their houses if it's cold, like most of the developed world can... in addition, meanwhile, they can enjoy clean drinking water, washing machines, industries etc.
Most of your assertions here are incorrect. You don't need a particularly complex model to show that if more energy is absorbed by the earth than is radiated, which is the case due to greenhouse gasses in the atmosphere, the temperature will rise until it returns to a steady state at a higher temperature. This means that even if CO2 emissions stop immediately (which obviously they won't), the temperature will continue rising for a period of time (some decades).
A 2 degree rise is considered to be the absolute limit without likely catastrophic consequences. It is certainly not the worst case.
If you're being honest about your introduction, that you don't understand why people are concerned about climate change, then that's a start. If you're instead trying to convince people of your point of view, please provide evidence for your assertions.
>If you're instead trying to convince people of your point of view, please provide evidence for your assertions.
That is useless. People follow it like a religion, I am merely trying to have a conversation to few reasonable ones so I can understand their point of view if they have anything interesting to say apart from repeating the same tired tropes.
>You don't need a particularly complex model to show that if more energy is absorbed by the earth than is radiated, which is the case due to greenhouse gasses in the atmosphere, the temperature will rise until it returns to a steady state at a higher temperature.
Do you have reference to a graph that shows the amount of CO2 in the air vs how much heat is absorbed? Has this been isolated? Can't be that difficult to create a green house and study the relation by varying CO2 concentration. Could it be that the temperature rise is an independent phenomena which is the cause for CO2 rise, not the effect of it? None of the political arguments seem to be questioned ever and no scientific studies seem to come out of it. Given that most research findings are false (http://journals.plos.org/plosmedicine/article?id=10.1371/jou...), there ought to be some research findings that show evidence against climate hysteria, even if they are wrong, but those don't seem to surface. It is as if any questioning of political propaganda is systematically silenced (https://www.youtube.com/watch?v=GujLcfdovE8).
If you're asking for references that CO2 absorbs and radiates IR radiation, I imagine you'd have to look to a textbook or papers from the early 20th century. That's established fact. As far as evidence that increased CO2 in the air reduces the radiation of heat from the earth back into space, yes, there is also plenty of evidence showing that. Here's an article that does a good job of explaining the science and links to several sources: http://www.ucsusa.org/global_warming/science_and_impacts/sci...
This paper from back in 2001 demonstrates that the changes in spectra radiated from earth as detected by spacecraft match expectations given the effects of CO2 and other greenhouse gasses in the atmosphere: http://www.nature.com/nature/journal/v410/n6826/abs/410355a0.... It also links to a number of papers around the supporting science.
Those are just the first two good examples I found. There are plenty more. I don't agree with your argument (as I understand it) that most research is wrong, and therefore the fact that there's no research supporting your position somehow itself supports it. Rather, while of course not all scientific research is done well, and scientific understanding is always evolving, that does not mean that it is impossible for anything to be known. The great deal of evidence supporting human-caused climate change, and the lack of robust evidence of the contrary, should reasonably lead one to the conclusion that it is a real phenomenon.
>If you're asking for references that CO2 absorbs and radiates IR radiation, I imagine you'd have to look to a textbook or papers from the early 20th century. That's established fact.
Hmm... the "established facts" for thousands of years in textbooks and everywhere was that the earth is flat. I guess I should believe in that too. Anyways, I will link you to an article which argues that CO2 acts as a coolant: http://www.biocab.org/Overlapping_Absorption_Bands.pdf
So, Given that plants grow better at higher CO2 concentrations (as experienced by indoor growers https://university.upstartfarmers.com/blog/why-and-how-to-su...), it seems like it is good to try increase CO2 concentrations higher and see if we can achieve the desired cooling effect while we are at it. Meanwhile, we will also be solving world hunger, preventing deaths due to unclean water, freeing up time used by people of poorer countries in farming, processing food, washing etc. using industrial machines and letting them enjoy the same standard of living as the western countries... all of this can be done by letting them use fossil fuels... taking the taxes and international restrictions away from the industry.
I read the article and it seems to be posted on a site for "Union of Concerned Scientists", which it seems is an advocacy group for what they think is "scientific". I think that is a very closed minded way to view science but let's examine their claims:
>CO2 has caused most of the warming and its influence is expected to continue
Anyways, in the report, they compare various chemicals and how much heat they trap. What they don't compare is how much heat 280 ppm of CO2 captures vs how much 1500 would capture. My guess is not much because a 40% rise in CO2 changed the average temperature by a couple of degrees in the last few hundred years. So, it seems like the relation is either very weak or that there is no relation at all. It can't be that hard to create two greenhouses next to each other, fill them with different levels of CO2 and note the difference and it is very surprising that nobody has done it... but given how modern science works, what is much more likely is that the experiment didn't come in their favor and hence it was never published.
>that most research is wrong
I am not the one claiming that. There have been multiple studies in the fast few years which have shown that most modern scientific publications don't hold up on peer review... and most scientists don't spend their time on peer review. It seems that it is not in their interest to review a study that someone else published. Making new and extraordinary claims with doctored data seems to get all the attention from journalists (and hence more funding), so that is all everyone seems to be interested in doing.
>The great deal of evidence supporting human-caused climate change, and the lack of robust evidence of the contrary, should reasonably lead one to the conclusion that it is a real phenomenon.
100% of Nazi scientists believed that Jews were an inferior race. Maybe scientists are biased by politics of the countries they work in, among other things? Can you name one other "scientific fact" that has not been politicized but still "settled"? Let me help you: it doesn't exist. Science doesn't "settle". It's always open to enquiry and new evidence can always change it.
> 100% of Nazi scientists believed that Jews were an inferior race.
May I direct you to https://en.wikipedia.org/wiki/Godwin%27s_law which suggests that at this point you have likely lost this thread. Don't worry, you can come back in a few weeks and will likely be able to put up more FUD about how the climate isn't changing and there's "no way to tell" whether putting more CO2 in the atmosphere will trap more infrared sunlight.
Nevermind that this property of CO2 is an established fact, and we have Venus as an example of what a runaway greenhouse effect looks like in real life. Also ignore the advice of the 95% of scientists who have studied this for years.
> the "established facts" for thousands of years in textbooks and everywhere was that the earth is flat
Most people (including scientists/philosophers) didn't believe that the Earth was flat. The Greeks used the theory that the Earth was spherical to determine the circumference of the Earth thousands of years ago (https://en.wikipedia.org/wiki/Eratosthenes). And sailors recognized that the Earth had to be spherical from early observations with spyglasses as well. The controversy was between religious leaders who wanted to continue to push the official "Geocentric" model (that is that the round Earth is the center of the universe) in spite of evidence to the contrary.
Of course, the fact that the Earth is round didn't affect most people's daily lives at the time the way climate change will today, which is why they didn't care much either way. A luxury we do not have.
Many U.S. coast cities will become submerged when sea-levels rise by several feet.
This is not the omly effect, particularly countries in the middle east will dry out, leading rural inhabitants to gravitate towards in excess of their capacities, leading to destabilised countries.
This has already happened with Syria and millions if refugees, now wait for the remaining countries to follow with hundreds of millions of refugees in the next 100 years.
Naturally, even heavier hurricanes, more devastating floods will happen.
Keep in mind, a rise of only 6 degress fahrenheit, means a rise of 20 degrees fahrenheit in some areas and less in others. This is catastrophic for the areas that are among the ones with bad luck and will induce mass migration/fleeing.
> there is no fundamental reason why launch from Earth by linear acceleration to escape velocity of 11.2 km/sec should not be possible
ok... even if you build it 5km in the sky, a 1km long launch rail would still apply 6,000 Gs of acceleration. Good luck designing a spacecraft that can survive that.
Or don't waste 5km and make the tube 5km. The acceleration drops to 1282G. Digging a 1km hole drops it to 1000G or so. Not really that much. About the acceleration a woodpecker head gets, less than a baseball being hit by a bat, or what a wrist watch can withstand. Under 1/10th that of the electronics in an artillery shell.
Does anyone have links to a good recent research paper on climate change? With modeling details and dataset. I've looked around but it's difficult to find the best/most recent knowledge.
One option is to find a way to decrease human population voluntarily. That will reverse human related climate change in more natural and comprehensive way.
From the article, the L1 Lagrange point isn't stable, it's a saddle.
In the plan described here, the craft would be actively controlled to adjust how much light they're diverting and at what angle in order to stay balanced at the Lagrange.
If the steering system is turned off all the reflectors would harmlessly blow away.
What idiot called this "Feasibility of cooling the Earth with a cloud of small spacecraft near the inner Lagrange point" instead of "Solar Eclipses As A Service?"
This is how big a shadow the Moon makes on the Earth. On a good day. https://twitter.com/WWUPlanet/status/896177474517716992 And the Lagrange point is 4x further away than the Moon. You can cut the total amount of light hitting the earth, but you can't aim it like that.
I'm sure we don't have the technology to do this today, nor will we have it this century, but if TFA is ever practical then the weaponization thereof will be soon after. At that point artificial-light agriculture will probably be less expensive than today, but still more expensive than the outdoor kind.
You'd have to create a lens instead of just a shade. The proposal already uses translucent pieces, so if you align them it might be focusable. Anyway I'm not convinced this will be used as a weapon, because there are cheaper ways of killing crops than launching stuff to L1.
I remember a quote from a US geo-engineer to the effect of "half of my job is not to come up with geo-engineering solutions that will be used, but to show people that plan B is soooo extreme that they start taking plan A much more seriously"
With regard to stability, just use L4 and L5! Park some anchor objects at L4 and L5, and stretch a big tape-like net between those things, in the middle of which is the shading device. Problem solved! :)
Our planet has two primary natural methods for lowering atmospheric CO2. One, natural weathering, is not impacted with this strategy.
The other, plantlife, is absolutely affected. If you were to take 10% of sunlight away from Earth, then it logically follows that plants would get 10% less sunlight to convert CO2 into starches and H2O into oxygen. The resource you're trying to constrain, in the name of fighting effects of rising CO2 levels, is the very resource you need in order to fight rising CO2 levels.
Sure, blocking or deflecting some light might lower Earth's temperatures temporarily, but you'd exacerbate CO2 levels semi-permanently.
We, as a community, need to come to the realization that our CO2 problem is not strictly a temperature problem.