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The Greatest Global Warming Thread


42 replies to this topic

#26
Driver

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Like Krawlie said-- just caused it failed before doesn't mean it always fails.

I get your point though.

As for why do anything if it seems insurmountable-- again, the initiatives aren't just about reversing the damage they are also about lessening our impact for the future and finding ways to adjust to the damage we live with.
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#27
pavonis

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Here's a brief summary, that isn't locked behind a paywall (at least for me). Here’s a related article.

The physical model that relates power and temperature is the Stefan-Boltzmann law. It relates energy flux, j, to temperature, T, through the Stefan-Boltzmann constant, s.

 

j = sT4

 

The total power emitted is then the energy flux multiplied by the area.

 

P = A*j

 

A black-body of a certain temperature radiates at a particular power, and vice-versa, an object radiating a certain amount of power must be at a particular temperature T.

 

The world uses about 17 trillion watts annually (with about 1-2% annual growth historically). A 2% annual growth rate is about an order-of-magnitude increase over a century. So by the early 22nd century, we could be using up to 170 trillion watts. Right now our energy flux from our own energy production is about an average of 0.03 W/mbut by the 22nd century it would be up to 0.3 W/m2

 

The sun provides about 240 W/m2, averaged over the course of the year and the entire surface of the Earth. Granted, it may not seem like we produce much comparatively (what’s 240 versus  240.03 or even 240.3?) but it builds up. To maintain a constant temperature, every watt received has to be re-radiated out into space. If the sun is delivering 240 W per square meter, and we’re adding another .03 – 0.3 W per square meter, the atmosphere will warm. Let’s say half of it goes into the ocean, which has a much larger heat capacity than air. All that really does is to introduce a delay into the passage of the energy out to space. Almost every joule has to pass through the atmosphere on its way to space; less than 1% of energy used is able to directly radiate into space without warming anything on its way out of the Earth’s atmosphere.  So just the waste heat from our civilization’s energy production and consumption can raise the atmospheric temperature a fraction of a degree over the course of a century. So, what’s a fraction of a degree? World leaders have been trying to reduce the warming trend so as to prevent more than 2 C of warming over the next century. If we’re trying to prevent just two degrees of warming, every fraction is noticeable.

 

Now, this model hasn’t even accounted for carbon dioxide levels, which will have a much stronger effect over the short term.  From my physicist perspective, all fossil fuels (coal, oil, natural gas) are just carbon compounds (there are, of course, many more details to it, but who wants to read that post?) Suffice it to say that every gram of carbon from a fossil fuel creates about 3 grams of CO2.

 

From the databases I have found, I’d estimate the coal and natural gas consumed at 135 billion tons of oil equivalent, with another 113 billion tons of oil consumed since 1950 to now. That’s about 250 billion tons of fossil fuels consumed over about six decades, which should be about 7 x 1014 kg of CO2 (I’m necessarily working on estimations rather than detailed calculations, as nightly’s readership isn’t likely to care about the fine details, and I’m already regretting sinking this much time into a post). That is about 90 parts per million CO2 added to the atmosphere from fossil fuels over the 20th century. We’re at about 400 ppm this year. Pre-industrial CO2 levels were under 300 ppm. So the CO2 levels in the atmosphere have roughly risen in accordance with straightforward high-school chemistry predictions.

 

At this point, I’d have to demonstrate the ability of carbon dioxide molecules to absorb and re-radiate infrared wavelengths, and that would involve discussion of molecular dynamics that I’m not keen on getting into, and I don’t expect anyone will care about those details anyway.

 

Perhaps some of my calculations are off – that happens. I make mistakes. Being able to identify and correct those mistakes is a virtue of the scientific method. Having been wrong in the past isn't a sign that everything is wrong always. If that were the case, we wouldn't have computers and telecommunications systems to have this discussion on. If we're more wrong now than we've ever been, then all our modern technology is apparently running on black magic. Being willing to be wrong is the only way to make progress. Maybe some of my estimates are off, but they’re estimates, not decrees from God or Trump. I favor a back-of-the-envelope approach to these types of problems, both in class and on message boards, because the detailed calculations are much too much work to bother sharing with anyone who doesn't really care about the details, as I suspect Poe and Tex don't. I have no idea what their backgrounds are, and have no interest in getting into a pissing contest over credentials. Besides, faculty promotion review boards don’t see posting on message boards as a favorable path to tenure. I only have so many hours in the day to produce work, and sharing it with nightly’s denizens, much as I love you all, doesn’t get me up the career ladder. 


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#28
Ms. Spam

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So you're saying that during the Trump years I should invest in coal?  :flirt:

 

That's a jokey post by the way.

 

And I totally get that math you just threw out! OMG!



#29
Poe Dameron

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The world uses about 17 trillion watts annually (with about 1-2% annual growth historically). A 2% annual growth rate is about an order-of-magnitude increase over a century. So by the early 22nd century, we could be using up to 170 trillion watts. Right now our energy flux from our own energy production is about an average of 0.03 W/m2 but by the 22nd century it would be up to 0.3 W/m2.

 

Actually, I read a similar article to that before just to make sure I wasn't talking out of my butt and would end up looking silly.  I'll just say that I read what you had to say, except the CO2 stuff since that may have been relevant to Tex, but has nothing to do with what I'm discussing, and understood it.

 

Your own article calls the amount of current human consumption of energy "nothing" compared to the energy the sun provides.  What your article then does is make a (rather unrealistic) assumption of a continued 2% increase in non-solar energy consumption in perpetuity to the point of predicting a 300x increase in non-solar energy consumption.  It's literally borrowing a theoretical problem from the future.

 

Now, granted, you took it back down to a more manageable timescale of roughly the 2130s before it starts to factor in as a fraction of a degree, but then you're, at best, nibbling on the edges of being relevant.  As of now, with our current energy needs, and in any timescale that could possibly matter to policies we set today, waste heat is a non-factor, at least on a global scale.  There was no reason to bring it up as the lead on why warming is a real thing to Tex as you did.

 

Now, without an air of superiority, tell me what I'm getting wrong here?  Don't tell me about expertise or how apolitical the laws of thermodynamics are.  Because it appears to me that even in the article that you bring up it is stated not be any more than a trivial driver of any warming that is happening.


I favor a back-of-the-envelope approach to these types of problems, both in class and on message boards, because the detailed calculations are much too much work to bother sharing with anyone who doesn't really care about the details, as I suspect Poe and Tex don't.

 

That attitude right there is why I'm on your case, just so you know.



#30
Brando

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This was split from the election thread, so if I missed anything, let me know. That's also why it reads a little funny.



#31
pavonis

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Even if per capita energy consumption remains flat, as long as the population increases the energy consumed must increase, too. And I am not certain why we should assume per capita energy consumption won't grow, either. The rest of the world is likely going to continue aiming for western-style lifestyles. Economic growth is still strongly correlated with energy consumption. Economic activity requires energy, no? But if the 1-2% annual growth in energy consumption doesn't seem realistic to you, even though it is based on historical trends, then what numbers would you predict? Are world economies likely to settle for 0.5% growth?

The model I've provided is rough, mainly because posting more sophisticated calculations here isn't easy, and I'm not sure what the gain would be. After a certain length and depth, such a post would just be better off published in a journal rather than a message board. At least then I'd get feedback from colleagues. For instance, I'm not sure what your background is, Poe. Why should I discuss more detailed calculations when you're quite ready to dismiss what I say just because you read a blog that said something different? What is my incentive to discuss with you when I'm not certain what I'll gain from the exchange? I'm willing to learn from people who know more about something than I do, and I've demonstrated that here at nightly over the last sixteen years. Are you willing to learn from others? I haven't seen any evidence that you are.

The bottom line is that there is a limit to everything. Thermodynamics sets out where the boundaries are. Maybe they're sufficiently wide for us now, and maybe energy consumption will fall over the next few decades. Why might it fall though? A population can't grow exponentially indefinitely. Are we looking at a population crash, or maybe a living standard crash, in the future?
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#32
Odine

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Whats bemusing  to me is you can tell someone you believe climate change is a thing, and humans play a massive part in it, that science backs you up on it, and people will look at you ****-eyed like you're an idiot. 

 

Tell some one you hold "The belief that some invisible cosmic Jewish Zombie can make you live forever if you symbolically eat his flesh and telepathically tell him that you accept him as your master, so he can remove an evil force from your soul that is present in humanity because a rib-woman was convinced by a talking snake to eat from a magical tree" and they'll smile at you, say "me too" and its all good. 

 

I'm all for belief in magic and stuff (my tag name is a feminine spin on Odin for crying out loud), but I'll sure as hell listen to the science people when **** starts getting real and they start advising. 



#33
Driver

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This whole time I thought you were a dude.



#34
Odine

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I am a dude.. I just like to bend it a little bit.


Edited by Odine, 15 November 2016 - 01:25 PM.


#35
Driver

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I was kidding. :)

#36
Odine

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Right on. But seriously, climate change. It's the number 01 cause for civil unrest in China. They have to choke on that ****. London is pretty bad, but not that bad. I'd prefer Greenland not to melt into the sea. I'd prefer the Gulf Stream to keep flowing up the coast of the UK and Europe so we don't turn into a fridged waste, thanks.

#37
Driver

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If there's an argument against throwing US dollars at climate change, that's it right there. We can clean up our **** as much as we want but China is destroying the air quality faster than they can bootleg some purses. 



#38
Poe Dameron

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Economic growth is still strongly correlated with energy consumption. Economic activity requires energy, no?

 

Not really.  In the short-term it's correlated such as dropping with recessions and such.  But United States energy consumption has actually dropped since 2000 and per capita energy consumption is at the same level it was by the end of the 1960s (see Table 1).  We still drive cars, run ACs, and have the same major appliances (actually a whole lot more of us do now than back then), they're just all more efficient. 

 

Granted, a part of that is due to off-shoring some industries (I'm isolating a single country), but a lot of it is an increase in efficiency.  And, I personally believe improvements in efficiency will do more to lower energy consumption than anything.  As I mentioned before, just imagine how much energy will be saved once driverless cars are perfected and the traffic light is abolished.

 

 

 

Why might it fall though? A population can't grow exponentially indefinitely. Are we looking at a population crash, or maybe a living standard crash, in the future?

 

Exponential population growth is a myth.  The total fertility rate has been cut in half in the last 50 years from 5 to 2.45 babies per woman and falling.  Approximately 2.1 babies per woman is the replacement rate where population stabilizes in the long run.  Essentially, we've gone from every woman making 2.9 more babies than needed for replacement, to making just 0.35 more than needed in a very short time.  We'll probably see the total fertility rates drop below replacement within our lifetime, and I doubt it will go back above it in any timescale that's worth speculating about.

 

Barring an immortality plague, exponential population growth is not going to happen.  The trendlines say we're going to keep growing for awhile. But sometime during the 22nd century, our population will begin to shrink.

 

A little bit of irony.  Africa is the only reason we're not below replacement already.  If they were to ever become prosperous, their total fertility rate would likely plummet even as their per capita energy usage would soar.  Fertility rates are inversely correlated with prosperity.

 

 

 

The model I've provided is rough, mainly because posting more sophisticated calculations here isn't easy, and I'm not sure what the gain would be.

 

I'm not seeing the necessity of more sophisticated calculations at all.  The calculations were already made in the article you presented and I'm not disputing them or asking you to re-run them for me.  I'm interpreting what is in front of me and the information says that it's a trivial problem in the moment.

 

Just to go back to the beginning.  Tex asked you for proof about global warming and waste heat was what you led with.  You answered in a rather arrogant manner that implied that it was a simple matter of the laws of thermodynamics that could explain warming.  As I think has been demonstrated, it's not a driver of any warming that is happening today, or at the level it's currently being generated, will have any appreciably negative environmental effects for all reasonable purposes of an environmental policy discussion ever.

 

Tex wasn't asking for proof of something that isn't a problem now, but can be speculated that it might barely start moving the needle over a hundred years from now when the problem would be 10x worse.  He asked for proof for something causing warming now, not will cause warming.  That's so far into the future that we don't have even the foggiest idea what tools we'd have to combat it by then.

 

So I called you out on that error.  And instead of you simply saying, "You're right, that was a silly point about something that I read might be a problem in the future," I, time and again, get this:

 

 

 

I'm willing to learn from people who know more about something than I do, and I've demonstrated that here at nightly over the last sixteen years. Are you willing to learn from others? I haven't seen any evidence that you are.

 

Now where have I ignored any evidence from you?  Exactly what did I say that was factually incorrect?  What did I misinterpret and demonstrate an inability to understand anything that you said?  Where did I have difficulty grasping the science that you seem to believe is only understandable to someone of your expertise?

 

What we have here isn't you vs. the ignoramus.  It's you vs. your own bias.  You've lived with this same argument for so long about how climate deniers should listen to the scientists instead of their own wishes, that you failed to grasp that maybe a layman (who isn't even a climate denier in the first place) is capable of pointing out your legitimate error.

 

I've got news for you: The basic concepts and conclusions here aren't all that difficult to grasp.  I may not be able to run the numbers myself, but I could take the information presented and interpret it to mean that I was correct in the first place and the science does not back up waste heat as a driver in warming.  And instead of being willing to learn from other people as you claim above, you have consistently tried to shout me down by claiming superior knowledge without ever actually proving me wrong on anything that I've said.

 

From the beginning, this has been your arrogant attitude in weaponizing the neutrality of science as a political cudgel:

 

Look, I work hard to understand the situation, and it's irritating to be dismissed by someone with an inferior understanding. Human knowledge is too vast to be able to manage without experts. Why do so many people dismiss expertise?

 

I'm the one here that's actually reading what the other person has to say.  I'm the one responding to your actual points instead of going on and on about how the other could never understand and how bothersome it is that you have to explain it to someone beneath your level.

 

And, btw, to those reading pavonis and clapping.  Perhaps you should re-read the thread and how we got here with an actual open mind as well.  Anyone is welcome to point out where I'm going wrong in any of this.



#39
Marc DuQuesne

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I think irrigation has a lot more impact on warming than the models are predicting. They always look at water vapor as a feedback greenhouse gas, I think it has a lot more of a direct effect. We may find that aside from aquifers going dry the water had a negative effect when it was redistributed.

#40
pavonis

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And, I personally believe improvements in efficiency will do more to lower energy consumption than anything.

 

 

That's nice. Personal belief is very nice. That's how things get done, after all. By wishing really hard! So, how many years of continued efficiency improvements do you foresee? Based on what models or data? Can we build motors that are 99% efficient, or 99.9%, or even 99.999%? How about 105% efficient? That'd be impressive. 

 

Engines can only get so efficient. There's a limit, and we're not far from it already. 

 

 

Exponential population growth is a myth

 

 

It's not a myth, it's happened. If our historical growth curve isn't exponential, what function would you say best describes it? 

 

 

350px-Population_curve.svg.png

 

Will human population continue to grow exponentially? Apparently not over the next few decades. Ruling out continued exponential growth, leaves the following options: for the population to level off and remain constant indefinitely (unlikely if not impossible), to decline linearly (more-or-less what will happen in the near-term), or to exponentially decay (which isn't ruled out over the long term). Which model do you expect to match reality? 

 

Anyway, the growth rate is still positive for the near term, so we can expect the population to level out around 9 or 10 billion. I don't expect those 10 billion to all live Western-style lives, but I do expect a lot more of them to achieve it, and many more to still want it. I expect total energy demand to only increase, whatever per capita consumption does. Would you disagree? 

 

 

 What we have here isn't you vs. the ignoramus.  It's you vs. your own bias.  You've lived with this same argument for so long about how climate deniers should listen to the scientists instead of their own wishes, that you failed to grasp that maybe a layman (who isn't even a climate denier in the first place) is capable of pointing out your legitimate error

 

 

You called yourself the ignoramus. I didn't. I don't want to get banned for flaming! Do you often insult yourself on the behalf of others? 

 

Is the climate changing due to increased carbon dioxide in the atmosphere, released into the atmosphere by the burning of fossil fuels? Climate skeptics want data and models to answer that question, and can be convinced by data and discussion. Climate deniers just say "no". Which one are you again?

 

Will the shift over to "clean" energy solve any problems? Not really. They'll just delay them. Anyone who's just interested in the immediate future is fine. Anyone with a long enough view of history is fine, too, because the whole universe is going to end someday. Either way it's all good because it's all going to end. It's the intermediate future that's at stake, say the next couple of centuries (where we'll all be dead, but our civilization will still be around and dealing with these problems, maybe). That's the interesting time frame to examine. 



#41
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If there's an argument against throwing US dollars at climate change, that's it right there. We can clean up our **** as much as we want but China is destroying the air quality faster than they can bootleg some purses. 


Thing is though it got so bad they're doing something about it. They're modernising their industry and power sources making the switch to green energy. And they're doing it faster than any other developed nation. So sure, they ****ed their own air. But now they're doing more to reverse the problem than most.

#42
Poe Dameron

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That's nice. Personal belief is very nice. That's how things get done, after all. By wishing really hard! So, how many years of continued efficiency improvements do you foresee? Based on what models or data? Can we build motors that are 99% efficient, or 99.9%, or even 99.999%? How about 105% efficient? That'd be impressive.

 

Engines can only get so efficient. There's a limit, and we're not far from it already.

 

That's rather smug from someone who just lost two essential assumptions in his case.

 

I demonstrate that efficiency is already happening, and it has largely decoupled energy consumption from economic growth, and this is your response.  You accuse me of wishful thinking for pointing out something that has already happened and which I suggest will continue happening in the future, including giving a specific example of the type of efficiency (logistical) that will increase energy savings into the future.

 

Your response about how engines can’t get much more efficient indicates you didn’t even understand what I said.

 

 

 

It's not a myth, it's happened.

 

And this is the other core assumption that you've lost.  You didn't say it was a historical trend where the exponential growth ended decades ago and today we’re fairly close to a stable birth rate with a tempo effect largely accounting for increases in population.  You asked if exponential growth would occur indefinitely.  Future, not past.

 

 

 

Ruling out continued exponential growth, leaves the following options: for the population to level off and remain constant indefinitely (unlikely if not impossible), to decline linearly (more-or-less what will happen in the near-term), or to exponentially decay (which isn't ruled out over the long term).

 

Exponential growth is the exact opposite of the problem we’re facing in the long run.  It’s impossible to know exactly where the total fertility rate will eventually stabilize (a lot of it depends on how long African fertility rates remain significantly higher than the rest of the world).  But if it stabilizes with the relatively high 1.8 the angloshere has maintained, the population would decline over 10% each generation once that cohort starts passing away.  The human race would lose billions of people within the short span of a few generations and continue losing several hundreds of millions each generation through any timespan that we can predict from here (exponential decay for the record).

 

Of course, if Africa stays at its current rate, it would reverse the trend eventually.  But that assumes that Africa remains unprosperous and uses relatively little energy.  In which case, per capita energy usage would drop.

 

 

 

I don't expect those 10 billion to all live Western-style lives, but I do expect a lot more of them to achieve it, and many more to still want it. I expect total energy demand to only increase, whatever per capita consumption does. Would you disagree?

 

Of course not.  But the amount of growth in energy consumption we're talking about has certainly been curtailed.  Can you still claim to expect us to use 10x as much energy a hundred years from now?  That figure seems rather dubious, does it not?

 

Remember 10x is where you essentially took the problem of waste heat from trivial to minor.  A fraction of a degree.  Well, take that fraction and make it even smaller fraction.

 

And then take into account a rapidly falling population (or lower prosperity) as efficiency will no doubt continue even along the margins, and you’d actually find that the, at best minor, problem is actually becoming less of a problem.  Not more over time.

 

Once again, by all means tell me where I’m wrong in any of this.

 

 

 

Do you often insult yourself on the behalf of others?

 

Remind me, which one of us is the cool, detached, and learned man of science here?  Because your arguments have become less scientific and more base message board gotcha nonsense.

 

 

 

Is the climate changing due to increased carbon dioxide in the atmosphere, released into the atmosphere by the burning of fossil fuels? Climate skeptics want data and models to answer that question, and can be convinced by data and discussion. Climate deniers just say "no". Which one are you again?

 

I’ve answered that several times already.  I’m not a climate denier.  I’ve not said a word disputing anything about CO2.

 

 

 

Will the shift over to "clean" energy solve any problems? Not really. They'll just delay them.

 

Excuse me, but that premise is in tatters.  If we were to shift completely to alternative energy without CO2 tomorrow, the problem would essentially be solved.  Waste heat will never become a significant problem in the space of the next few centuries.

 

You’ve completely failed to put forward a compelling case for how it would increase enough to do significant damage in that timeframe.

 

One does not need to ignore the laws of thermodynamics to see this.


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#43
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Well said Poe



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