Global Warming

[Dragonlord]

Good post, Gothmog! I agree completely....

 

[thestonesfan]

Enivronmentalism is the best mentalism.

It's a good religion for people who are innate cynics.

 

[BasketCase]

What your graph does show is how stable global temperatures have been for the last ten thousand years,

Precisely. Stable within a range of a little under 2 degrees C. The increase we've seen in the last century is entirely within the stable area.

Again, the earth system is chaotic. We understand the variables that affect it, but not how they all interact.

Then we can't be sure what the actual results are going to be. And we also can't be sure that our climate models and simulations are accurate.

 

[betazed]

Well, another report on global warming.

http://www.msnbc.msn.com/id/6863557/

This was also there on yesterday's slashdot.

 

[BasketCase]

China and India are not going to hop on board Kyoto no matter what.

Start hoping that I'm right on this issue, and that human-generated CO2 isn't causing the planet to warm up, and that the current temperature spike is simply a natural fluke--because if I'm wrong, we're literally toast.....

 

[Dragonlord]

Start hoping that I'm right on this issue, and that human-generated CO2 isn't causing the planet to warm up, and that the current temperature spike is simply a natural fluke--because if I'm wrong, we're literally toast.....

Exactly - I'm surprised you admit it, though.

 

[GEChallenger]

GEChallenger, do you have any idea what the transmission characteristics of the atmosphere are at various wavelengths? Or how the overall energy balance of the earth system is maintained?

Obviously not.

Please, enlighten me, then. I never claimed to know these things-- I pointed out that that, while CO2 leves have increased, they have by what seems to me an incredibly small amount relative to the entire atmosphere. I asked if anyone realizes howe very small this number is. Dodging the question, are we?

I have to say, again, that it amazes my the extent to which environmentalists cling to their beliefs... the only other people who respond as strongly to a challenge to their beliefs are religious folks... (and, I guess, many scientists, although that sort of falls in with environmentalism).

And stonesfan, I couldn't have said it better myself.

EDIT: Hah, I just looked closely at your post. No one knows how the "overall energy balance of the earth system is maintained." Give me a break. When all else fails, respond with fancy but meaningless rhetoric, eh?

 

[betazed]

I have to say, again, that it amazes my the extent to which environmentalists cling to their beliefs... the only other people who respond as strongly to a challenge to their beliefs are religious folks... and, I guess, many scientists... and politicians, for that matter...

well, now we know what the guy cutting down the last tree (metaphorically speaking) on Easter was thinking!

 

[GEChallenger]

well, now we know what the guy cutting down the last tree (metaphorically speaking) on Easter was thinking!

Meaning...?

 

[Akka]

I have to say, again, that it amazes my the extent to which environmentalists cling to their beliefs... the only other people who respond as strongly to a challenge to their beliefs are religious folks... (and, I guess, many scientists, although that sort of falls in with environmentalism).

Funny, because it's precisely the anti-environementalists who are holding firm on their (disproven) beliefs.
Nice attempt to turn tables, sadly crashing into the wall of reality.

But well, it's not like reality was ever something preventing quasi-religious dogma to exist, he...

 

[Gothmog]

GEChallenger...

Feh, though your tone is insulting I understand that it comes from a place of ignorance so I will try to break it down for you in the simplest terms.

The energy in the earth system comes primarily from the sun.

The sun is basically a blackbody operating at roughly 6000 K. This means that most of the suns energy is emitted in the form of visible radiation.

Higher energy radiation is adsorbed in the upper atmosphere creating the ionosphere and stratosphere. The visible radiation mostly is transmitted to the surface (or to cloud tops) where a good portion is reflected. The rest is absorbed by the surface (i.e. the ground).

The earth operates as a blackbody at about 300 K. This means that most of its energy is emitted in the form of infrared radiation.

While N2 and O2 make up the bulk of our atmosphere they do not absorb radiation in either the visible or infrared.

Thus the amount of energy absorbed by our atmosphere is controlled by other, trace, constituents. Both H2O and CO2 absorb infrared radiation, they are the most important greenhouse gasses. Clouds also absorb infrared radiation.

Now the issue gets a bit more complex because only so much of the radiation can be taken out. That is once you are removing 99% of the radiation within a specific wavelength range increasing the absorption there will not change the balance much.

While there is some overlap between the absorption spectra of H2O and CO2, are also regions where CO2 absorbs and H2O does not (and visa vera). The additional amount of energy absorbed by the additional CO2 that has been put into the atmosphere by man can be calculated with great precision and is significant.

Again the problem gets complicated because the atmosphere re-emits some of the energy as infrared radiation, which is then reabsorbed by the earth. At some point an equilibrium is reached. If the earth did not have any atmosphere the global mean surface temperature would be roughly 33 degrees C colder than it is at radiative equilibrium.

This is called the greenhouse effect because it is the same reason a greenhouse gets so warm. Glass and water vapor transmit visible radiation but absorb infrared radiation. Sunlight comes in but the resulting infrared cannot escape as easily.

Please suck on that fancy but meaningless rhetoric, or educate yourself next time.

Edit: I forgot a meaningless but irritating smiley.



ah, now I feel better.

 

[GEChallenger]

GEChallenger...

Feh, though your tone is insulting I understand that it comes from a place of ignorance so I will try to break it down for you in the simplest terms.

Yeah, sorry. I just reread that post and it came across much ruder than I intended.

The energy in the earth system comes primarily from the sun.

The sun is basically a blackbody operating at roughly 6000 K. This means that most of the suns energy is emitted in the form of visible radiation.

Higher energy radiation is adsorbed in the upper atmosphere creating the ionosphere and stratosphere. The visible radiation mostly is transmitted to the surface (or to cloud tops) where a good portion is reflected. The rest is absorbed by the surface (i.e. the ground).

The earth operates as a blackbody at about 300 K. This means that most of its energy is emitted in the form of infrared radiation.

While N2 and O2 make up the bulk of our atmosphere they do not absorb radiation in either the visible or infrared.

Thus the amount of energy absorbed by our atmosphere is controlled by other, trace, constituents. Both H2O and CO2 absorb infrared radiation, they are the most important greenhouse gasses. Clouds also absorb infrared radiation.

Now the issue gets a bit more complex because only so much of the radiation can be taken out. That is once you are removing 99% of the radiation within a specific wavelength range increasing the absorption there will not change the balance much.

While there is some overlap between the absorption spectra of H2O and CO2, are also regions where CO2 absorbs and H2O does not (and visa vera). The additional amount of energy absorbed by the additional CO2 that has been put into the atmosphere by man can be calculated with great precision and is significant.

Again the problem gets complicated because the atmosphere re-emits some of the energy as infrared radiation, which is then reabsorbed by the earth. At some point an equilibrium is reached. If the earth did not have any atmosphere the global mean surface temperature would be roughly 33 degrees C colder than it is at radiative equilibrium.

This is called the greenhouse effect because it is the same reason a greenhouse gets so warm. Glass and water vapor transmit visible radiation but absorb infrared radiation. Sunlight comes in but the resulting infrared cannot escape as easily.

Thanks, makes sense, although it still doesn't explain how very small amounts of CO2 can make a big impact. Maybe I'm just missing something.

Please suck on that fancy but meaningless rhetoric, or educate yourself next time.

Yeah, again, sorry for the rudeness... I think I purposely misinterpreted your whole "energy transfer blah blah" thing, I figured it was one of those meaningless nonsense phrases, rereading it I see it does make sense. Personally, I think your initial post was a little insulting and did avoid the very thing I asked... although I'm not gonna nitpick. I do apologise once again for responding in the very emotional/dogmatic way I accused y'all of.

Edit: I forgot a meaningless but irritating smiley.



ah, now I feel better.

Too true...

@Akka, others:

I still stand by the whole quasi-religious things. Many environmentalists react in a very nasty way to the questioning of their beliefs; I see it here and outside and not just relating to global warming. I don't feel I'm clinging to disproven beliefs-- I have yet to see a convincing argument that global warming is caused exclusively by humans and will have major, catastrophic effects in the future.

 

[Gothmog]

GEChallenger, I guess my original post could have been interpreted as a bit insulting. I just get tired of people assuming that scientists have no idea what they are doing, and that they are missing some trivial point. To even reach the point where you can work on a climate model you need to spend decades studying, to produce one you need to be at the top of the field. These are smart dedicated people. It is too bad that this is not a simpler problem.

How can small amounts of CO2 make an impact? Well starting from what I already explained, I'll try to go a bit further.

CO2 is the major infrared absorber in various regions of the spectra, even the amount currently in the atmosphere saturates in some bands. That means that a given photon emitted from the earth's surface has over a 99% chance of being absorbed before exiting the atmosphere (if we take re-emission into acount it is likely to be absorbed more than once). There are other regions where saturation has not yet occured.

The increase in CO2 just since the Keeling measurements began at Mauna Loa Observatory (about 1960) has been from roughly 315 ppm to 375 ppm. That is an increase of 60 ppm, but more importantly an increase of about 20%. Do you even see equivalent levels on Basket Case's plot? No.

The relationship between column concentration of CO2 and the amount of radiation absorbed is quantified by Beer's law, and so is not a linear relationship. But even this simple analysis shows that the increase in CO2 is significant. We are retaining significantly more energy in the atmosphere.

Other gases such as methane and nitrous oxide are also important, in large part because they absorb in areas where neither H2O nor CO2 absorb (the 10 micron 'window' well known in the space physics community). They are also much more efficient on a per molecule basis, and have a longer lifetime in the atmosphere.

A whole other box of worms involves feedback mechanisms. As an example, the atmosphere warms, that in turn warms the ocean, more water evaporates from the ocean surface, the additional water in the atmosphere causes a furthur greenhouse effect. The additional atmospheric warming warms the ocean even more, etc. etc.

There are a good number of these feedbacks, some positive and some negative. They are the major topic of study in climate models.

Also, as I mentioned in other posts, cloud formation is very important as clouds both reflect incoming visible radiation and absorb outgoing infrared radiation. Cloud formation is sensitive to atmospheric temperature, aerosols, as well as climatic factors such as atmospheric circulation.

So, not a simple problem at all. But we have changed the energy balance of the earth in significant ways. We have also changed the aerosol loading and distribution. We obviously depend on climate for our current mode of living. These are the facts, now do you really think that ignoring the issue is the best way to go?

I think that humans can survive climate change, but my goal is not simple survival. I am interested in improving the human condition. What Basket Case's graph shows is that the climate will eventually change, I feel that we need to understand how and why before we undertake any major alterations to the system. Alterations that we have already begun.

 

[BasketCase]

Exactly - I'm surprised you admit it, though.

Dood, I didn't admit to anything--there was an opening "if" in my post.

 

[Dragonlord]

Dood, I didn't admit to anything--there was an opening "if" in my post.

'Dood'?
Dude, I noticed that, indeed, but you made my point anyway. If you're wrong about manmade emissions causing global warming, we will indeed 'be toast' - or, to put it less drastically, we will 'experience serious negative effects', though I doubt we'll be burnt to toast, exactly.

What I just don't get is your (and others) insistence on absolute, incontrovertible, detailed proof that mankind, and mankind alone, is solely responsible for global warming and that global warming will be so catastrophic it will mean the end of mankind, etc, before agreeing to do anything to counter it.

I've said so before: when you're talking about (at the very least) the possibility of catastrophic changes caused by human behaviour, it's better to err on the side of caution and reduce emissions, than to wait until the effects are already felt.
Among other reasons, there seems to be strong evidence that warming occurs with a significant time lag to emissions, so, even if we reduced emissions right now warming would continue to increase for quite some time. If that is so, we can't afford to wait until we're sure we're in trouble - countermeasures will take time after we're finally all convinced and will take even more time to take effect.

Doesn't this make it much more prudent to take moderate but concerted efforts to reduce emissions now, than to wait until drastic measures are necessary?

 

[Dragonlord]

I think that humans can survive climate change, but my goal is not simple survival.

Good and informative posts, Gothmog, thank you!

I agree that the human race is unlikely to become extinct through global warming (or other pollution), but any kind of drastic climatological changes will surely cause widespread hardship and fatalities.

Do we really want to find out the hard way what will happen to Great Britain or North America if, for instance, the Gulf Stream collapses, or changes direction?
There are many possible scenarios for the effects of global warming, but ANY drastic changes will be for the worse as far as humanity is concerned, because we have adapted to local conditions as they are. It would be just as hard for Tuaregs nomads to adapt to suddenly increased rainfall, for instance, as for Iowa farmers to adapt to a new dust bowl... or Eskimos to warmer weather with less ice.
The most populous regions today are those with the 'best' climate for humans and agriculture. Change those patterns and you'll have mass migrations and war. Sounds like fun, doesn't it?

 

[BasketCase]

What I just don't get is your (and others) insistence on absolute, incontrovertible, detailed proof that mankind, and mankind alone, is solely responsible for global warming and that global warming will be so catastrophic it will mean the end of mankind, etc, before agreeing to do anything to counter it.

Okay, here's a peek at how my brain works. Keep in mind that I don't expect you to "get it". You're not me, you think differently from me, and what makes sense for one of us won't always make sense for the other.

That said, it goes like this:

A lot of people aren't religious. Well, what if there IS a God? Then you're in danger of going to Hell. Play it safe. Get religious.

We're not ABSOLUTELY sure Iraq has WMD. Play it safe and stay the hell out.

We're not sure we can store nuclear waste 100% safely. Play it safe. Don't switch to nuclear power, even though it could be a feasible solution to global warming.

Some people say Social Security is about to go into the red. Play it safe and don't mess with it. If it ain't broke (yet), don't fix it.

News flash! Anthrax scare! Four people dead in a nation of 300 million! Play it safe and get a regimen of antibiotics.​

I'm not religious, I'm glad we kicked Saddam's ass, I think nuclear power is worth the risk, I think Social Security needs repairs now instead of after it goes belly up, and I never bothered to get on antibiotics. In fact, when the anthrax scare happened, a lot of people STARTED antibiotic regimens and then quit halfway through--the regimen is something like sixty days of drugs, which must be taken EVERY day for the whole sixty days in order to actually be effective. But the drugs have some unpleasant side effects, so a lot of people quit.

"Play it safe" is not part of the human mindset--unless it's politically convenient.

Poverty poses dangers of its own: poor water supplies, poor medical care, lack of sufficient preparation for disasters such as tsunamis, breeding grounds for terrorism and the occasional war, etc. So yes--I do need a LOT more evidence (without more holes in it than a screen door) before I'm going to think condemning everybody on the planet to a lower standard of living is a good idea.

 

[FriendlyFire]

That said, it goes like this:

That is So very ironic considering US recent actions of "Pre-emptive" and "Unilateralism"

 

[Gothmog]

BasketCase, you've been a lot of smoke and very little fire in this thread.

Where exactly are all the screen door like holes in the theory of climate change?

Are you disputing that humans have significantly changed the energy balance of the earth system? That we have changed the aerosol loading and distribution? What?

No, we cannot exactly predict what will happen.

Yes, we can say that humans have influenced climate in the last 200-300 years with a very high level of confidence.

I'm not advocating any specific action, and I actually agree with what you said about not lowering the global standard of living. I am 99% sure that humans will burn every bit of oil we can suck out of the ground, I think we will then turn to coal.

But please, more holes than a screen door... what are you talking about?

 

[BasketCase]

I already described what I think those holes are.

If you think the global warming theory is sound and proven, you're obviously going to think the theory is NOT a screen door, and that I'm

I stated my case, you stated yours. Why should I be getting upset that you disagree with me?