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Earth’s carbon dioxide levels reach highest point in 800,000 years (therecord.com)
149 points by lisper on May 6, 2018 | hide | past | favorite | 88 comments



I thought this bit was interesting:

"As a scientist, what concerns me the most is not that we have passed yet another round-number threshold but what this continued rise actually means: that we are continuing full speed ahead with an unprecedented experiment with our planet, the only home we have," Katharine Hayhoe, a climate scientist at Texas Tech University, tweeted Thursday"

We really are going ahead full speed. Global emissions have been rising in recent years, not falling.


And even countries like Germany who say they take climate change seriously are revising their CO2 goals because they are having trouble meeting them due to their abandonment of nuclear power. https://euobserver.com/environment/140475

At this point if you are opposing nuclear power, you aren't taking climate change seriously, even if you say you are.


I have a feeling that one of the biggest blockers to actually doing something about climate change is how easily the conversation gets derailed. Almost everyone agrees on clean energy, but once you get into specifics people lose their cohesion(people are pro- or anti-nuclear power, or for or against wind energy(birds, off-peak power, etc.)).

I think people get too focused on any one particular solution, and cannot see that a mixture of things probably is best. Nuclear for places that can tolerate it plus wind or solar for peak times. Hydro and solar/wind for places that can't.

I have heard for years, and at various times expounded myself, of the virtues of nuclear. But the public in most industrialized countries cannot stand the thought of it near them, so looking at a more balanced approach makes sense.


> I think people get too focused on any one particular solution, and cannot see that a mixture of things probably is best. Nuclear for places that can tolerate it plus wind or solar for peak times. Hydro and solar/wind for places that can't.

I agree that a mixture is necessary. With that being said, the examples you give are entirely technological, which I think is likely insufficient to solve climate change. I think we need a combination of technological, psychological, and political approaches.

For example, as a cyclist, I'm continually disappointed by the reasons people tell me they'd never be able to adopt cycling for transportation. I'm told that they wouldn't be able to do X, Y, or Z, or that they'd feel very restricted, etc. But when I tell them that most cyclists do X no problem and they could rent a car if they wanted to do Y and Z (which are done infrequently), they aren't convinced. It seems to me that many people face a false dilemma here because they see cycling as far more difficult than it actually would be. If you design your life to make cycling possible, it's perfectly acceptable, even preferable in my case because I want the exercise. Most people pick where they live based at least in part on their driving commute, so it would only be fair to do the same for a cycling commute.

Population reduction is another area which you could mention as part of a combination of solutions. In my experience those conversations are often counterproductive. But it seems clear to me that population can't keep increasing if we only have one planet, and we might prefer to have less people with a higher quality of life. (My views on population ethics are not fully formed for what it's worth.)

My view is that climate change is a lost cause, so instead I'm focusing on adaptation to the new normal.


> My view is that climate change is a lost cause, so instead I'm focusing on adaptation to the new normal.

I hate this attitude. You may be doing everything possible as an individual to prevent further climate change, but the majority of people I hear spouting this attitude do not.

It's based on the premise that there will actually be some sort of "new normal" that is worth surviving for. The ongoing impact of our actions is indeterminable - we could end up with something so inconceivably bad that all your adaptation efforts are pointless, or that you simply cannot live a life of any value when compared to the early 21st century.

Also, it smacks of "F*ck you, I've got mine". You assume that the impact of climate change are survivable, apparent by the fact that you want to focus on adaptation, but this attitude ignores the fact that there are billions of other people on the planet. Maybe climate change can be survived by us in our situation with all our first world advantages, but there are millions, possibly billions, who don't have that choice.

Focus on adaptation for all you like, but please don't forget that prevention is greater than cure and that it's not too late.


> it smacks of "F*ck you, I've got mine".

You're projecting. Parent's attitude is completely rational.

> prevention is greater than cure and that it's not too late

Not sure exactly what you think it's not too late for, however it is delusional to believe we will stabilise, let alone reduce, greenhouse gas levels.


Last time I checked we breezed past the symbolic point-of-no-return at 400 ppm CO2... so it kinda is too late. We can try some damage prevention if you feel like it.


We might as wel try though. It's possible that if we had a carbon tax someone might come up with:

  * very cheap energy
  * a somewhat effective way to sequester carbon
We'd obviously lose a massive amount of energy putting back all the energy we burned but that would be the price of survival.

I don't know if this is possible. But we should at least try. Currently our lack of carbon pricing isn't giving us full incentive to try.


Well, here is the thing- our cooperate overlords have created the perfect system to shirk regulations by shifting production to whoever is the most desperat.

My money is not on goverments or companys here. My money is on some plague drastically reducing the number of humans capable to produce carbon dioxide. It looks containable now, but contain something like Ebola with millions on the move and the UN-Institutions collapsing under this circumstances.

You can not enforce quarantine, if a whole country decides to walk.


It seems over negative as well. There are a couple of simple things that may help with CO2:

1) Exponential improvements with wind solar and batteries. They are all getting like 50% better / year. Project that and you can fix things

2) Re the confusion over different approaches, we have a solution and its called the market. Just have a global $50/ton tax/credit on emissions/sequestration. Politically hard but otherwise would likely fix rising CO2.


> I hate this attitude. You may be doing everything possible as an individual to prevent further climate change, but the majority of people I hear spouting this attitude do not.

I don't like it either, but I think it's intellectually honest.

I live a fairly low carbon life, probably in the bottom 20% for people in the US. My main contribution is probably from flying a few times a year, which I don't intend to maintain long term. I don't own a car, avoid eating meat, and generally try to use less power when I have the opportunity.

From the left I hear a lot about how climate change is a major issue, but I see few efforts being made to actually address the problem. I don't count planning, by the way. We need action now, and we're not seeing it. And I also don't count efforts to make other people change their lifestyles when those promoting those efforts won't change themselves. That reeks of hypocrisy.

> It's based on the premise that there will actually be some sort of "new normal" that is worth surviving for.

No, it's not. It's based on the premise that the expected return for my effort would be higher for adaptation than trying to convince others to change their habits, making new technology to "solve" climate change, etc. That's not to say that the situation will be good in either case, just that one is better than the other.

I have little to no control over what others do, but I can control my own situation. I fully recognize that others may suffer enormously, but as far as I can tell I have few options to change much of that.

In focusing on adaptation, by the way, I'm thinking about things like offering engineering solutions to our changing world. This is not necessarily geoengineering, which by large won't work best I can tell. It might be things like flood resistant buildings, for example. As a mechanical engineer, I can help design things that will help others.

> prevention is greater than cure

I agree completely.

> that it's not too late.

This is debatable. As far as I'm concerned, the climate will change independent of any efforts I make. Some analyses suggest we're already beyond the point of no return. Even if that's not true, as far as I can tell there's been no practically significant slowing of greenhouse gas emissions, just mostly talk. Talk is cheap.


Nuclear was a fantastic solution, then we wasted a lot of time, and they take a long time to come online, and renewables got a lot better. If it makes sense then go for it, but I doubt it makes sense any more.


Not an expert, but I was convinced to switch from "nuke is a bad idea" to "nuke asap is a less bad idea than any other current option" when I was pointed to the ridiculously messy situation we have and the transmission problem

1) the situation now is that, as longterm as nuke waste is, it pales in comparison to the long-term of coal and natural gas extraction, transport, and burning.

2) renewables are great and where we want to go...but the tech is not at a place where we can get 100% yet and we have no efficient way to transmit power long distances nor store power, so we can't have solar in a desert in Arizona power Fargo Minnesota.

Why do you think nuke power likely doesn't make sense anymore?


A nuclear power plant will take 10 years to come online, and will last for about 50 years. You then have the transmission problems, toxic waste problem and risks. I'm willing to largely ignore the toxic waste and risks because they are addressing a far bigger problem. So let's call them negligible (even though they aren't) and I still think nuclear today is a hard case to make. Getting these approved are large capital expenditures of around $9 billion that come online all at once. Then you have the transmission problems as mentioned.

I have not done the math but it seems that it would be faster, and more politically tenable to use decentralised solar virtual power plants and wind such that individual households become largely responsible for their own power and act in concert as the grid supplier and battery.

The main thing preventing this seems to be capital investment, regulation and political will.


The difference of not using nuclear power in Germany is less than 1% of the planned 40% reduction, even if we assume that only the worst coal plants are used to substitute. This is a larger problem, sadly. (That said, by now I'm all for keeping the nuclear plants running a few years longer, but that is not enough by far.)


The debate is not about nuclear power. Whether we keep existing reactors or not is not going to have a significant effect on future greenhouse gas levels. Very few new nuclear power stations are being built globally, so it won't be part of the solution. I agree that it could be - if we were really worried, as we should be. Realistically, we just need the US on board. Then things will change. But a decisive majority of the US population is in a strange anti-science place these days, and the world's future rests on their shoulders. That's a scary thought...


The debate should not be about existing nuclear plants. The debate should be about using modern passive safety designs for plants yet to be built.


How do you debate designs that haven't been built yet?

Historically, nuclear power plants take years or decades to build, and at great cost. The risk to investors is so high that they only proceed with some kind of state-funded insurance.

If there really was a modern nuclear reactor design that would compete in the energy market with wind and solar, everyone would be building them already.


From my understanding a lot of the reason for this is it only really makes sense to make large scale reactors; mostly due to approval processes and regulations already in place. There's a massive up front cost no matter the scale of the operation, so it makes most sense to do larger projects vs smaller ones.

https://newatlas.com/small-modular-nuclear-reactors/20860/


Solar is a great solution for so many countries! In India, unfortunately, the governments audacious energy generation announcements for 2020 seem to be getting slowed down by its own bureaucratic hurdles (and possibly lobbying by big Energy corps).

Given the lower ppp of Indian consumers, the Solar panels still aren't cheap enough (add to it the cost of wiring/batteries/accessories) and the government isn't providing enough subsidy (especially on imports). I can only hope that some Silicon Wafer manufacturing lands in India soon; otherwise the Energy transition will take forever.


Those plants have to be built, but we don't have time for that anyway. Now we must focus very closely on self-preservation. But how many people have the means to leave Earth and survive apart from it for however long it will take for Earth to return to habitability? Moreover, how can I find people who are able to work on that specific problem without convincing themselves it's not their personal responsibility and subsequently forgetting themselves?


There is nothing we can do to Earth that will get the survivability level even close to any other option out there.


It's merely that it's going to be safer to be far enough away.

edit: i cant reply so quickly due to rules so to clarify for what you asked me in response, I'm talking about being a certain radius away from a killzone. You need more information to verify this.


Where would you deem safer and why?


> Global emissions have been rising in recent years, not falling.

It's been said that (a) every living creature is influenced by environment, and (b) humans tend to do things harmful to themselves near an "end".


the only thing that stresses me out more than the story, is the likelihood that someone very smart is working on something that will take 99% of us all out in a last ditch effort to save the planet.



That is haunting.


And that, sadly, as a last ditch effort, would be a very good thing for humanity, but probably not for the planet.


If I know anything about humans it's that a "last ditch, requires 99% participation in an all out effort" isn't doable. 99% of people can't agree on anything especially if the results aren't immediate and miraculous.


http://earthguide.ucsd.edu/virtualmuseum/climatechange2/07_1...

On a geologic timescale, CO2 levels were many times higher than they are today.

>In very general terms, long-term reconstructions of atmospheric CO2 levels going back in time show that 500 million years ago atmospheric CO2 was some 20 times higher than present values. It dropped, then rose again some 200 million years ago to 4-5 times present levels--a period that saw the rise of giant fern forests--and then continued a slow decline until recent pre-industrial time.

CO2 levels over the past ~5 million years are at the lowest point in over 200 million years. On a geological timescale, CO2 levels are returning to normal, not going away from it.


Okay, this comes up sometimes in climate-related topics, usually because of a combination of misunderstanding and a need to be the clever contrarian that's thought of something nobody else has.

The question isn't whether Earth will survive these CO2 levels. Earth will (probably) be just fine. It's common knowledge, especially among the scientists that publish claims about rising CO2 levels, that Earth has had much higher levels of CO2 and other greenhouse gases in the past, and that at those times, there was lots of life.

The question isn't necessarily even whether humans will survive much higher CO2 levels. We're resourceful, we have the ability to shape our environment. Some people will survive.

The question is how much we're going to enjoy all of the adverse effects of this global climate change. It is going to cause or contribute to a lot of natural disasters: hurricanes, tornadoes, extreme storms, droughts, flooding, massive wildfires. There are going to be migrations. Wars. There are some solid arguments that climate change contributed to the Syrian civil war [1]. Many species are going to disappear as they fail to adapt quickly enough to the changing environment; it will take much longer for new species to take their place. We will see, for example, an environment with fewer butterflies and more mosquitoes -- many more.

Nobody is going to get out of this unscathed. It's going to cause widespread political and economic instability and unrest. Even if you manage to find yourself a nice little spot untouched by the most direct effects of climate change, it's going to cause enough suffering in enough other parts of our globally interconnected human society that you'll see the costs somewhere. The US spent a record $306 billion on disaster response last year. Where do you think that money comes from?

[1]: https://www.scientificamerican.com/article/climate-change-ha...


I think your framing of the question is very fair and absolutely how the topic should be considered. But at the same time, I think you're assuming much more from the average person than is realistic when you state that whether Earth (and implicitly humanity) will survive or not, is not the question. People are becoming radicalized in everything. And radicalism tends to be intrinsically connected with ignorance.

See the top of this thread (well currently at least) for a line of discussion where somebody not only thinks climate will imminently lead to earth becoming uninhabitable but wondering how and where people could survive [away from Earth] until the planet does become habitable again. Or consider the fact that the comment you're responding to, though factually accurate and contextually relevant, is being downvoted for stating facts that mitigate this sort of hysteria. Sure, it's a sample of one - but I'm sure a survey of the views in this thread will show the question is indeed far more elementary than the nuanced and accurate view you're discussing!


People are becoming radicalized in large part, maybe even entirely, because of forums like this one. A really good article along these lines was submitted to HN, but unfortunately didn't get much traction: https://www.rollingstone.com/politics/news/all-american-nazi...

I think people can handle nuance just fine. Since everyone's gotten it into their heads that policing online discussions is exactly the same as censorship and limiting free speech, it's up to us, the participants, to restrain ourselves from the radicalizing shouting matches that usually happen on so many topics.

> See the top of this thread (well currently at least) for a line of discussion where somebody not only thinks climate will imminently lead to earth becoming uninhabitable but wondering how and where people could survive [away from Earth] until the planet does become habitable again.

I'm not seeing that anywhere in the comments on this article. Can you link to it?

> Or consider the fact that the comment you're responding to, though factually accurate and contextually relevant, is being downvoted for stating facts that mitigate this sort of hysteria.

Well, no. I disagree that it's relevant, and hope at least some of the downvotes are for that reason alone. "Stating facts" doesn't automatically make something relevant; good statements of relevant facts would have been, "the researchers didn't take ____ into account during the 800,000 period they're talking about", or, "there's another paper by respected researchers that disagrees with this one", or, "I know a lot about this field and I think I see an error in their methodology", or, "this is all correct but there's no cause for alarm because [body of evidence that global warming is somehow beneficial]" (it's not).

It's also not mitigating hysteria. There are good reasons to be extremely alarmed for our future generations. That's not a hysterical position. Some people may be couching it in alarmist statements, but given the opposing number of people who still believe that all of this data is an outright lie anyway [+], that's sort of unavoidable for political topics.

[+]: Including HN, during the CRU email breach a few years ago, where the popular opinion was that climate researchers were fabricating data so that they could get more money for further research.


I'm not seeing that anywhere in the comments on this article. Can you link to it?

This [0] seems pretty close to that description.

There are good reasons to be extremely alarmed for our future generations. That's not a hysterical position.

Very few people "believe" strongly enough to invest based on that belief. Why hasn't Bezos or Soros or whoever started buying lots of land in northern Saskatchewan, or shorting land on the coasts?

[0] https://news.ycombinator.com/item?id=17008013


Ah, thanks. Yeah, not sure I'd agree totally with that particular comment.

> Why hasn't Bezos or Soros or whoever started buying lots of land in northern Saskatchewan, or shorting land on the coasts?

Because (a) it's complicated (https://www.bloomberg.com/news/features/2018-05-02/the-u-s-c...) and (b) investors are famously short-term thinkers and as is evident in some of the discussion here, the effects of global warming are just slow and opaque enough to fool a lot of people into thinking they don't exist.

...and this is granting that investor interest is a good way to evaluate how sound the science is on some subject, and I don't think that's a position I'd agree with.


>It's common knowledge, especially among the scientists that publish claims about rising CO2 levels, that Earth has had much higher levels of CO2 and other greenhouse gases in the past, and that at those times, there was lots of life.

This isn't common knowledge at all among non-scientists. Most people have no clue that CO2 levels were many times higher than today, and that earth and the ecosystem in general were just fine. Scientists may be aware of this fact, but why don't they inform the general public of this? Take the submitted article for example. Instead of publishing an article stating, "CO2 levels are higher than 800,000 years ago; but are likely lower than they were at any point from 20-200 million years ago" they only leave in the scary, doomsaying first part and neglect to inform the second part. It is the equivalent of looking at a 24 hour geological clock and only telling people about the past minute while neglecting datapoints from minutes or hours ago. Why aren't scientists informing the public of the historical data?

I understand why the climate change community may not want to bring up this point (it detracts from other issues) but people should be aware of this fact. Humanity, and life in general, will survive increased CO2 levels.

>The question isn't whether [X], it's whether [Y].

I am paraphrasing, but that's largely what your comment is saying. The article premise and its title, is about [X], where [X] is CO2 levels. It seems like the response to historical CO2 levels is to change the topic.

Edit: I don't want to reply to several comments, so I'll respond here.

Why do I believe the discussion should inform people about historical CO2 levels? Largely because I firmly believe CO2 emissions will not decrease through 2040. The incentives to cut emissions are just not there. Petroleum is simply too useful as a resource. The current projections I have seen predict 500ppm by 2050, and likely 600ppm by 2100. Given those numbers, I ask myself the question, how likely is it that humanity will face extinction in the next century? How should I interpret these numbers?

Given the geological data, I find it reassuring that biology and life on earth survived for hundreds of millions of years with CO2 levels between 1000-2000ppm. It means that increased CO2 levels will not cause the extinction of humanity.


>. Humanity, and life in general, will survive increased CO2 levels.

In the few past instances when temperatures increased this fast there were mass extinction events.

Yes, life can exist on a warmer earth just fine. But rapid change kills a lot of things.

Scientists don't focus on informing people that the earth used to be much warmer and it was fine, because they are focusing on the fact that rapid change is dangerous.


The sun is also measurably brighter and hotter than it was when CO2 levels were significantly higher, meaning we should expect greenhouse effects to be more severe. CO2 levels aren't the only thing that contribute to climate. Additionally, while in the past the levels have been much higher, the rate of change in CO2 levels was never nearly this swift in the geological record--it's the sudden change that has many people worried.


I did not bring global temperatures into the discussion as I don't believe they pose as serious a threat as increased CO2 levels. Wikipedia has a nice graph showing estimated global average temperatures over time https://en.wikipedia.org/wiki/File:All_palaeotemps.svg . Please note the log-time scale.

The graph shows that between 10-250 million years ago, global temperatures were 1-12° C higher than they are today. Given that current projections, which include the 2% relative gain in solar irradiance, expect 3-4°C warming by 2100, the geologic temperature record suggests such increases are not detrimental to life on earth. Let us recall that life was thriving during the Jurassic and Cretaceous periods, when temperatures were 5-10°C higher and CO2 levels between 1000-2000ppm. Global temperatures today are actually lower than than average, on a geological timescale.

>the rate of change in CO2 levels was never nearly this swift

No, you can't conclude this. You cannot show there was no other a period in Earth's geologic history where CO2 levels rose by 150ppm (or 150%, whichever is not relevant) in less than 200 years. The geologic record is not detailed enough to make such a claim. It is unknowable if there was a series of major volcanic eruptions that caused CO2 levels to rise rapidly.

And sudden change has always been a part of climate and evolution. Rapid change can occur in just a few decades. For example, the Sahara wasn't even a desert 10,000 years ago. Also see punctuated equilibrium.


> You cannot show there was no other a period in Earth's geologic history where CO2 levels rose by 150ppm (or 150%, whichever is not relevant) in less than 200 years

That assumes the CO2 is also gone just as quickly. But I doubt that would happen unless you can show a natural process that could not only increase the CO2 level by 150ppm but also decrease it by 150ppm just as quickly.


Your argument seems to be that everything is OK because things always change and conditions have been much more extreme in the distant past. And other people are arguing that these sorts of extreme changes may have very real consequences that can dramatically effect human civilization and stability and we're doing very little to prepare or blunt the blows.


People are concerned mainly about how CO2 will affect humans + our current ecosystem. On that measure, 800,000 years is a relevant timeframe: it covers when our civilizatiom arose, when humans left africa, etc

I do think it would be good if people knew that CO2 was even higher in the past. But, that doesn't make this article wrong. An article can't cover every single topic, and earlier CO2 in the non-human era is just tangentially related.


Alright, I want to point-by-point rebut your comment, but I'm going to take a step back instead.

What is your goal here?

Every argument has some kind of goal, some position or point of view that it wants to express. Yours appears to be, "CO2 accumulation is no big deal as long as at least a few people survive". (Contextualizing your own statement that, "Humanity, and life in general, will survive increased CO2 levels".)

But I don't want to assume that that's your argument, because it would be a wildly irrational one to make. So let's bring your actual position out into the light.

--

edit in response to your edit:

> Largely because I firmly believe CO2 emissions will not decrease through 2040.

Maybe. But they could, except for all of the politics and arguments around this that is still preventing large-scale efforts to reduce global emissions.

> Petroleum is simply too useful as a resource.

It has been useful. Humanity likely could not have reached its current state of technological development without easy access to vast amounts of energy in the form of coal and oil.

But its usefulness is waning. Countries and organizations are more often using it to influence the economies of other countries. A lot of suffering is happening in Venezuela right now, and oil is a major contributor to that; a lot of damage was done to Gulf Coast not long ago, and even if you place no value at all on natural ecosystems, it also impacted a lot of livelihoods that depended on fishing and tourism in the area. Depending on your point of view, the most recent Iraq war killed, maimed, or displaced a lot of people for the sake of controlling oil. Tensions between Europe, US, and Russia right now can also trace their causes back to the distribution of natural gas.

And none of this is taking into account the predicted effects of a warming global climate. Many -- many! -- more people are going to suffer and die.

> I find it reassuring that biology and life on earth survived for hundreds of millions of years with CO2 levels between 1000-2000ppm. It means that increased CO2 levels will not cause the extinction of humanity.

There are a lot of different conditions that satisfy "survival", and many of them are pretty awful.

--

Since global warming / climate change is such a politically charged topic, let's try reframing it.

Let's say there is a hypothetical global disease for which nobody has a natural immunity. We'll use some variant of the Black Plague for this gedankenexperiment. Right now it is responsible for killing an estimated few hundred thousand people a year worldwide [1], and costs several hundreds of billions of dollars each year worldwide [2]. We could be committing more resources towards reducing the impacts of this disease, but right now, this is a level of suffering and expense which enough people are totally okay with.

This disease is expected to gradually worsen though, and in the not very distant future, begin killing millions and harming millions more. We may still be able to mitigate a lot of the effects of the disease in the future, but we'll still have the same costs for developing new technology to fight it, plus we'll have much higher costs for dealing with the effects of it.

The Black Plague killed 30% to 60% of Europe's population in the mid-1300s [3], and now it's coming back, just more slowly.

Would your position then be, "it's no big deal, we survived it once before"?

[1]: https://www.thedailybeast.com/climate-change-kills-400000-a-...

[2]: https://news.nationalgeographic.com/2017/09/climate-change-c... -- this doesn't include worldwide numbers; I'm using a conservative extrapolation here.

[3]: https://en.wikipedia.org/wiki/Black_Death


> Humanity [...] will survive increased CO2 levels.

I don't know that we can take this as a given. It would have been easier two or three hundred years ago; now we have industrial civilization and 7.3 billion people, the combination giving us an unprecedented ability to do damage to the ecosphere. I can imagine a scenario in which climate change leads to political unrest which leads to wars — we may already be seeing some of this, and it could get a lot worse — that eventually spirals out of control into thermonuclear war. Unlikely? I sure hope so! But I don't think we can rule it out completely.

Sure, the cockroaches will survive. But that's not much consolation.

I think we need to figure out a way for all of humanity to work together on this problem. If we fail to do that pretty soon, I don't think it will bode well for our doing it in the future either. Continued denial and fractiousness will make the nightmare scenario more likely.


Humanity may survive, but our civilization likely won't. It relies on cheap energy and a stable climate, both are under threat. Good luck manufacturing a MRI machine when you're struggling to grow enough food for next year.


> It seems like the response to historical CO2 levels is to change the topic.

How does a detailed discussion about CO2 levels 100m years ago help push us toward drastically cutting emissions now?


The article talks about this being the highest point in the last 800K years, but you're right that geologically speaking the levels are quite low for our planet.

The problem is life takes a long time to adapt, including us silly humans who build our cities on the coast. Just because CO2 levels have been higher before does mean the process will be a pleasant one.

It may well involve the extinction of large numbers of species, and large numbers of humans (never all humans as some people seem to be fond of saying.) It could even possibly trigger collapse of civilization in extreme enough scenarios where methane from the oceans and tundras is released in a feedback loop.

So yeah, you're factually correct, but missing the point.


No, the article says the CO2 levels are at their highest in the last 800,000 years. Its literally right there in the title of the post.


Yeah but Pilfer's point is the levels in the last 800,000 years are abnormally low in the last 200 million year period.


If I’m interested in the survival of human civilization, which has been around for less than 10,000 years, how is it useful to consider that CO2 levels were much higher 200 million years ago?


Yes, the Cambrian explosion indeed was an even wilder change in environment and ecosystem than what we're going through now. A hypothetical human time traveler, however, wouldn't survive a hypothetical time travel back to that.


>A hypothetical human time traveler, however, wouldn't survive a hypothetical time travel back to [the Cambrian explosion].

I assume you are referencing about CO2 levels. Yes, around ~500 million years ago, CO2 levels reached 10,000ppm, which would be hazardous (but not fatal) to a human traveler. However if you pick a point between 300 million years ago and today, when CO2 levels were at 1000-2000ppm, a human traveler would have no problem surviving in that environment. Heck, it is even possible to hit those CO2 levels in a modern day warehouse or office that is poorly ventilated.

Increased CO2 levels are very survivable and do not mean the end of the human race.


The question isn't whether some humans will survive or not, but where they will survive, and how expensive it is to adjust to that change.


Which is moving the goalposts and changing the question. He's asking if a "hypothetical human time traveler" could survive hundreds of millions of years ago, and based off historical CO2 data, it could be possible.


You are picking pedantic arguments instead of focusing on the actually important themes, which isn't productive or useful

Let's get everything on the table. Are you actually okay with dozens of millions to hundreds of millions of people dying -- and many others suffering immense drops in quality of life -- as a result of human-caused climate change? Despite the fact that we have the capacity to heavily mitigate such risks?


obtuse levels are high here. goal posts moved on a goal post already moved. goal post was being moved back


I think that's true although it's also true that rapidly increasing CO2 now seems a dangerous experiment with our only planet.

As an aside noting the downvotes on the above comment I sometimes question if that stuff is a good idea. I can see the point that mentioning high CO2 levels may not be a problem could be dangerous as the masses will keep burning CO2 but trying to drum up panic isn't working that great as illustrated by the "highest point in 800,000 years" thing. From an engineering kind of view point I feel you should look at things as neutrally as possible though I guess from a political view point maybe not.


From the same site:

> All we can say is that, over the last 400,000 years, there seems to have been a positive feedback at work: whenever the climate became warmer, carbon dioxide and methane rose and helped make the climate even warmer.


Fair, but that doesn't detract from the point that CO2 levels maintained 1000-2000ppm for over 100 million years. This was during the Jurassic and Cretaceous periods, when life was thriving on earth.

Present CO2 levels are low on a geological timescale.


Due to stellar evolution, the solar constant is at its highest on a geological timescale.

https://archive.org/details/nasa_techdoc_19820009158

Back in the Mesozoic Era, the Sun was about 2% cooler than it is today. The extra CO2 back then added a helpful (for most life) greenhouse effect. Now, both the relatively high CO2 level and the rapid rate of increase are unhelpful.


That link performs a calculation based on some fairly back-of-the-envelope physics assumptions. Its conclusion:

Roughly one-half of the solar luminosity increase occurs during the last 2 billion years but there is no evidence for a parallel increase in the Earth's mean surface temperature. Indeed, isotopic studies of the Precambrian samples by Knauth and Epstein (ref. 12) indicate that the mean surface temperature has been decreasing during this time. Clearly, there is a need for further studies of the effects of crustal movements and volcanism, biological activity, etc. on the long-term evolution of the Earth's climate. At present, it appears that the effects of solar evolution are still buried in the "noise" due to other uncertainties in paleoclimatic models.

Is there anything since 1981 with more definitive conclusions? Is there any study that has attempted to measure sun output directly or indirectly, rather than simply calculating output based on the sun's age?


Thank you. Nothing annoys me more than people who bring up the fact that CO2 used to be much higher without mentioning that the sun was cooler. It leads to a very misleading picture.


How well would that work for humans? 2000 ppm is well above the threshold when we start to find negative cognitive effects. And I imagine CO2 in buildings would be more like 3000-4000 ppm.

This is leaving aside sea level rise hurting infrastructure, crop failures due to shifting weather, and areas becoming regularly above 35 degrees wet bulb.


That doesn't change the fact that there are adverse effects we are noticing, which CO2 is a contributor to.

Its also worth noting that a lot of what has scientists concerned is the rate at which we are seeing these changes.


That is a true statement. Another true statement is that Earth's greenhouse gases are basically a trace compared with Venus's. Another true statement is that the current human causal rate of CO2 emissions will rapidly change our environment to one unsuitable for human life.


Source on that last one? Even the worst climate change predictions don't create an earth unsuitable to human life. Hostile changes, sure. Unsuitable? No.


You're right, I shouldn't have said that. Unsuitable for human civilization is what I should have said.


That would only be in the worst case scenarios, and even then only a transitory condition. You can't keep humans down forever, sooner or later we'd rise again. It's debatable what it would take for civilization to collapse, and how long it would take to recover. But I think there's little doubt that recover it would.


The sad truth is nobody actually knows what's going to happen. We can only read the signs.


But it's just talking about the past 800,000 years.


Can you expand on that?


Do we have a good grasp on what that means? I'm not trying to deny climate change but if I'm honest I don't know what it means for the carbon dioxide levels to by the highest in 800,000 years.

Is the temperature response linear?

Are there other dangers involved in changing the composition of our atmosphere?

Is the response likely to self regulate or avalanche out of control?

Is being the highest in 800,000 actually a significant point or is it just a bad sign?


Answers in order:

We dont' know. 5 times.

The rapid and huge increase in CO2 is to my knowledge unprecedented. We did have similar CO2 levels in the past but never in such a rapid incline, only after thousands if not millions of years time for everything else to respond.

We could be causing a The-Day-After-Tomorrow-Scenario. Or something like 2012.

Or Mad Max. We simply don't know but considering the parts we do know, it's likely that whatever happens is not good. A 400ppm Level of CO2 was considered a symbolic point of no return and we have passed it a while ago.


My concern is that we are experimenting with a precious and unique system.


Is there a way to build a closed loop system that would suck CO2 and make methane from it for example? Methane can be used for further energy production but again with closed loop, capturing all produced CO2.


Garbage incinerators with CO2 capture and geological storage; that is a net CO2-negative process, and you can recover energy in the form of domestic heating, too. This is not a fantasy technology; everything needed to do this already exists and can be purchased. An extra bonus is that you also vastly reduce the pollution problems associated with landfills.


Plants and algae convert co2 to hydrocarbons such as starch and cellulose, which can be used as fuel or further refined into biogases, ethanol, or biodiesel etc. Industrial processes also exist and can be solar powered , but probably are less efficient.


VW is currently working on this through the Audi eFuels programm. The goal is the synthesis of disel and gasolene from atmospheric CO2. iirc they have recently produced 60l of synthetic gasolene for testing purposes.


> and make methane from it

That part's easy. Where's your energy source?

The whole issue is not Co2, it's energy.


> That part's easy. Where's your energy source?

Solar + methane itself fed back into the loop.


The problem is, again, thermodynamics. You are going to get entropy, i.e. conversion of useful energy into unusable energy without getting work out of that process.

This means you are going to need to pump more energy in than you produce. Which begs the question GP asked.

Put another way, perpetual motion machines are impossible. What you propose is that.

Put some nice nuclear batteries on this and you might have a chance. But net power in is greater than net power out, again due to thermodynamics. So ...


If you have solar power, why are you reforming Co2? Just use the solar power directly and don't emit the Co2 in the first place.


You aren't controlling all emissions.


If there's enough power (solar or otherwise) there won't be any emissions.


A company called Algenol was researching CO2 -> ethanol using algae and I thought it might be the answer but they seem to have kind of given up for now. It worked but not cost effectively. There's a bit of a post mortem here https://www.greentechmedia.com/articles/read/lessons-from-th...


It's a topic of active research: https://en.wikipedia.org/wiki/Power-to-gas

Efficiency is a problem though. With all the steps involved, the laws of thermodynamics become very punishing.


On an unrelated note, I'm impressed that the Waterloo Record's webiste is surviving the HN hug.




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