[magduf]

Warning: I am not a climate scientist.

However, I have to disagree that humanity has to leave the planet, or that it's impossible to fix. I will agree that it's very unlikely to be fixed or mitigated to a decent amount before disaster happens, but that's because of politics and human stupidity, not because it's not possible.

More CO2 in the atmosphere doesn't have to equal higher average global temperatures. CO2 holds in energy from the Sun. So the answer is simple: decrease the amount of sunlight. There's already ideas of how to do this, such as "solar shades". Basically, put a bunch of things in orbit that block some of the Sun's light, so less of it strikes the atmosphere. Now, even with the higher levels of CO2, less energy is entering the system that will be retained by the greenhouse effect. Of course, planetary engineering ideas like this are megaprojects and would require huge amounts of money to do, and probably international coordination, which seems unlikely given the terrible state of world politics at the moment.

[robomartin]

You misunderstood. I didn't say we have to leave the planet. What I am exposing in the data is that we know how atmospheric CO2 would decrease if we did (and took all of our toys with us).

The answer is simple: We cannot fix this. Because any attempt would require energy and resources beyond planetary scale. Which means we are far more likely to kill everything on this planet than to fix it.

I am not a climate scientist either. I am, however, an engineer, and I have a pretty solid handle on Physics. Conservation of Energy alone says we cannot fix this.

BTW, by "fix this" I mean, any faster than the natural rate of about 50,000 years for a reduction of 100ppm.

If you take the time to read the Google paper I linked you'll find the statement that sent me on a path to truly try to understand this many years ago. They said, paraphrasing:

"Even if we convert all energy generation on the entire planet to the most optimal forms of renewable energy, not only will we not see atmospheric CO2 levels decline or level-off, they will continue to rise exponentially".

This was a conclusion exactly opposite what the researchers went into this "knowing". I appreciate they were honest enough to publish this and actually expose just how confused we've become about this concept of saving the planet. It simply isn't going to happen. Not in a generation, not in a hundred, not even in a thousand.

You see, it's that pesky bit of data: 50,000 years for a reduction of 100 ppm. Without humanity.

This means that if humans stay on the planet, even if population growth stopped, and we magically --because it would require magic-- became carbon neutral, it would still take at least 50,000 years to drop 100 ppm, or, more than likely, 100,000 or 200,000, pick a number.

This is equivalent to trying to remove smoke from your kitchen with a small fan while you continue to burn the food you are cooking on the frying pan. You just can't do it. You have to stop cooking and then wait for the small fan do do the job over a couple of hours. If you want it done faster you have to stop cooking and use a much larger fan (more energy). If you, on the other hand, continue to burn your food and install a bigger fan, you may or may not clear the smoke. If you do, it will likely take just as long or longer.

This isn't difficult stuff to understand. It's actually the most common sense science I've seen in a long time. The graphs tell a story. All we have to do is see it, read it and understand it.

[magduf]

The entire problem with your logic is that you're assuming that humans will not and cannot do anything at all to change carbon levels, aside from relying on natural processes. That's completely ridiculous. Any attempt to fix the problem has to involve artificial actions: carbon sequestration, solar shades, etc.

Your entire mentality is "it took X years for nature to do this, so it'll take X years to undo it by natural processes, and oh yeah, we have to actually undo it so everything goes back exactly the way it was, instead of just making the end result satisfactory". This isn't helpful at all. As I pointed out before, we can reduce the amount of sunlight using solar shades; we don't actually need CO2 levels to go back to pre-industrial levels. We just need to prevent the temperature from rising so much, while we figure out how to deal with the CO2.

>This is equivalent to trying to remove smoke from your kitchen with a small fan while you continue to burn the food you are cooking on the frying pan. You just can't do it.

Yes, you really can. With a fan powerful enough, and a vent hood, you absolutely can. It really doesn't take that much, and it depends on how much smoke you're producing, but you seem to think you need a turbojet engine to clear the air in a small kitchen from a small cooking fire, and you really don't.

>If you want it done faster you have to stop cooking and use a much larger fan (more energy).

Here's the part you're not getting. The amount of energy you need to run a vent fan isn't anywhere near the amount of energy unleashed by your cooking fire. Even better, if you constrain the air supply, the fire burns itself out quickly, or at least is prevented from producing as much smoke.

>It's actually the most common sense science I've seen in a long time.

I've noticed that people who throw around the term "common sense" a lot do so because they really don't understand things very well, and think their intuitive understanding suffices, when in fact it doesn't.

[robomartin]

Thanks for the personal attack at the end. Class act.

Don't take the kitchen analogy literally, that's not what an analogy is for. I won't discuss it, because it is purely a tool not a precise model of planetary-scale dynamics.

You also misunderstood my point entirely. And, BTW, don't tell people things like "that's completely ridiculous" unless you are in a position to irrefutably prove what you are saying. Also, it's rude.

Anyhow, my point is very, very simple:

If it takes in the range of 50,000 years for atmospheric CO2 to come down by 100 ppm without humanity around, any solution that claims to be able to do this a thousand times faster has a massive burden or proof equivalent to magic and divine intervention, combined.

Politicians toss around all kinds of proposals and plans that are equivalent of the famous "and then a miracle occurs" cartoon. They want to destroy entire economies just because they say so. And all of it is nonsense.

Now, let's think about what it means that it took 50,000 years for a 100 ppm drop (which is about what we need).

Well, it involved massive amounts of rain, hurricanes, cyclones as well as massive amounts of trees and vegetation growth. Please stop and think about the energy it took for, year after, year, for 50,000 years to drop so much water and grow so many trees and vegetation to capture the CO2 and drop it by 100 ppm. The scale is almost inconceivable.

Can we find a more efficient way to do it? OK, let's assume we can (which I think is a fair assumption). A thousand times more efficient? I don't have to do the math to know that even if we were 1,000x more efficient it would still require an astronomical amount of energy and resources. I would not be surprised if an improvement in efficient CO2 capture in the order of a million times better than the natural process still required so much in terms of resources and energy that it would be just about impossible.

And yet we are missing the forest for the trees. What I am talking about mostly is what the zealots and politicians are parading around. With the reality I presented, which is irrefutable --unless someone wants to challenge ice core data-- it is easy to prove how ridiculous their proposals actually are:

Switch to renewable energy sources: Nope, CO2 levels will still continue to rise exponentially. This has already been studied.

Stop coal plants: Nope, even if we left the planet it would take 50,000 years.

Outlaw all forms of petroleum-powered transportation: Nope, even if we left the planet it would take 50,000 years.

On, and on, and on.

What you are saying about blocking the sun is another one of those ideas. First of all, anyone who has spent a reasonable amount of time in aerospace and gotten into the physics of the matter understands the unbelievable amount of energy it would require to launch millions of solar shades and put them into orbit. I mean, it takes energy to create the fuel and oxidant to put into a rocket. And these processes are not clean. On top of that, that many rocket launches would only add to the problem. And then we are talking about meddling with a planetary scale ecological system that is the result of billions of years of adaptation under existing solar conditions. There is no way whatsoever to predict what could happen. Again, we could succeed at killing absolutely everything on this planet. The only people who believe simulations are those who wrote the code, for the most part we have no clue what <doing x> will produce 10 years from now, much less 50 or 100.

It's hubris to think we can actually do this when everything we touch is far more likely to cause more pollution and require hyper-planetary scales of energy and materials.

I know lots of people --politicians!-- have a lot of sunk costs and interest in not challenging --even a little-- the status quo. And so I fear we are going to do a whole bunch of really stupid things. And I can't do a thing about it. Nobody can, because that train is already on the tracks in more ways than one. In that sense and more this conversation is a complete waste of everyone's time.

[zekrioca]

In the article mentioned by parent comment, they suggest extracting CO2 from atmosphere and storing it somewhere safe. There is (at time of article's writing) no technology capable of doing so. I guess it is would be "safer" than creating a "solar shade"? I am not a climate scientist either..

[robomartin]

The questions nobody answers when it comes to all of these so-called solutions are:

    How much energy will this require?
    How will we generate it?
    Will generating that energy produce CO2 or other problems?
    What resources are we going to need (chemicals, etc.)?
    How are we going to extract or produce them?
    How much energy is that going to require?
    How are we going to produce that energy?
    Will generating that energy produce CO2 or other problems?

Conservation of Energy is an ass. It does not care one bit. Which means we can't solve a problem with less energy than what went into creating it in the first place.

A common misconception is that humanity added a bunch of CO2 in a couple of hundred years. That's not true. It took millions, if not billions of years. Sure, in therms of use using petroleum, yeah, we did it in a couple of centuries. However, the reality of this fuel is that it took billions of years to create. THAT is what we burned; billions of years of stored energy.

That was the other revelation I had during my research. We are looking at this with the wrong time scale. In a couple of hundred years we burned millions or billions of years worth of stored energy. And to clean-up that mess you need far more energy than what it took to produce the mess in the first place.

Imagine how many trees, plants, animals and solar energy went into creating the petroleum we burned. That's the start of the scale of the problem we are trying to fix. In other words, we can't fix it. Not without making a much larger mess.

[philipkglass]

In a couple of hundred years we burned millions or billions of years worth of stored energy. And to clean-up that mess you need far more energy than what it took to produce the mess in the first place.

That would be true if the only way to remove CO2 from the atmosphere were to run "combustion in reverse" to turn carbon dioxide back into hydrocarbons.

That is not the only way, though. Enhanced silicate weathering is attractive because it turns atmospheric CO2 into chemically stable condensed phase compounds, without the huge thermodynamic cost of reversing combustion. The energy cost of enhanced silicate weathering (though still large in absolute terms) is greatly reduced compared to combustion-reversal because it's just accelerating the kinetics of a thermodynamically favorable natural process.

MgSiO3 + CO2 => MgCO3 + SiO2

This is a sketch of the geological carbon cycle [1], the same thing that eventually (100,000 years from now) would remove the excess CO2 from the atmosphere. The idea is to accelerate the drawdown by pulverizing silicates so the above surface-area-limited reaction goes faster.

See e.g. "Enhanced weathering strategies for stabilizingclimate and averting ocean acidification"

https://csas.earth.columbia.edu/sites/default/files/content/...

[1] "The Global Carbon Cycle: Geological Processes" Section 3.6

http://geosci.uchicago.edu/~kite/doc/Wallman.pdf

[robomartin]

In my research of the domain I did come across this. It is one of the scariest proposals out there. These people risk causing irreversible damage to the oceans and all life within them. It's hubris to think we can do something like that and actually control it at a planetary scale. Also, refer back to my questions about the energy and resources required to do this, to do anything.

While you are right in that the process is not combustion in reverse, the reality of the matter is that it much worse than that. Massively worse.

We haven't even gone to the other elephant in the room: Australia. I hope someone eventually publishes an honest accounting of the CO2 that was released into the atmosphere through these fires. My guess is it easily negates decades of clean energy and other mitigation technologies.

I didn't get into it in my original comments. There are two questions everyone should ask when looking at the 800,000 year CO2 concentration chart:

1) How/why did CO2 levels rise?

2) How/why did CO2 levels drop?

These are fundamental questions anyone with a science background should ask almost immediately. The answers, at a basic level, are simple:

1) Massive continental scale fires burning for thousands of years. Remember, no fire dropping helicopters.

2) Storms, rain, water, hurricanes and, yes, trees and vegetation growing over thousands of years.

So, stuff burned for approximately 25,000 years for a 100 ppm increase and stuff grew and rain fell for about 50,000 years to capture the CO2 that was created.

The bottom line is that anyone claiming that we can do 1000x better than if humanity left the planet they are going to have to explain, in great detail, how it is that they know Zeus so intimately that he will grant them magical powers. And I don't think this is an understatement at all.

BTW, the only intelligent proposal I've seen is to plan trees like our lives depend on it. Seriously. Simple tech. We know how it works. We know what it does. And, if we have the water, we know how to grow them. This won't solve the problem any faster but it is likely to make things better. All we have to do is figure out how to prevent our massive new forests from burning, because, in that cases, once again, we will have made the problem een worse. Here's an article on that one:

https://www.livescience.com/65880-planting-trees-fights-clim...

[philipkglass]

Originally you said "Conservation of Energy is an ass. It does not care one bit. Which means we can't solve a problem with less energy than what went into creating it in the first place."

Enhanced silicate weathering is a way to draw down atmospheric CO2 with less energy than went into creating the problem. Still, perhaps it will never be deployed on a large scale if people find the proposal too scary.

That's one of the most depressing things about curbing climate change. There are a number of changes that we could have implemented to prevent the problem from getting as bad as it is now. But all of them scared enough people that they didn't go forward on a scale that was large enough, fast enough. That could be fear of physical safety (opposition to nuclear power), fear of unemployment (coal miners against cleaner power sources), fear of lost profits (businesses against carbon taxes)...

Since the scale of the problem is vast, the scope and scale of any actual solutions will be vast as well.

[robomartin]

My point is that you can't just look at chemical reactions. How much will it take in energy and resources to make it happen? That's where Conservation of Energy becomes an ass.

In other words, it's easy to talk about a solution, any solution, in isolation of what it would really take to deploy it at a scale massive enough to affect planetary level changes. Think about all of the equipment, transportation, processing, people, energy, etc. We literally can't think about things at these scales.

To go back to my super-simple argument about how the planet behaved without us polluting it further. It typically took absolutely massive storms for tens of thousands of years to reduce CO2 by 100 ppm. I use 50,000 years as an average of sorts, but the reality is that the range extends all the way out to 100,000 years for 100 ppm.

Now imagine taking all of that and proposing that we are going to do the same in 50 or 100 years, without leaving the planet, without shutting down every form of transportation, without killing every industry on the planet and without reducing population to medieval levels. That is a tall order. It's one thing to run a little microscopic test (when compared to planetary scale everything is microscopic), quite another to have the audacity to claim we know what will happen if we take it global. We could create quite an ecological mess.

The things you mention we could have done. I don't think they would have made any difference. I mean, not in terms of atmospheric CO2 concentration. Human life, definitely. One of the things I learned --and I can't remember it accurately-- is that CO2 in the atmosphere "sticks" and is hard to mitigate. The idea is that anything we do at ground level will have zero impact past a certain altitude. We can certainly burn stuff and have the CO2 go up and circle the globe but we can't easily pull it down from 10, 20 or 30 km of altitude.

That's what a lot of these simplistic conversations miss. When I say it will take an astronomical amount of energy and resources I am thinking about a process that has to reach out and grab CO2 going up tens of kilometers into the atmosphere all around the globe. We just can't do this by installing solar panels, sprinkling the beaches with chemicals, banning coal and gasoline powered vehicles and devolving into the middle ages. This is a very tough problem and one that likely has no human-scale solution, both in terms of time and resources.

That said, I don't think this is reason for depression. Imagine for a moment if we agreed on this idea that we just can't fix it. What would our conversations turn to then? Improving human life? Developing technologies to help us live with the coming changes? Cleaning-up our act to improve life locally? That and more.

I would imagine the narrative would change radically. For one thing, we would stop hearing from ignorant politicians, celebrities, deniers and zealots. Researchers would be able to work on real research rather than having to get on the bandwagon for fear of never having access to research grants and opportunities. There is no telling what advances we might make if we just stopped the insanity this has become and allowed facts, reason and real unencumbered science and engineering to float to the top. Utopia, I know.