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The thing is... change would be happening regardless. Mini-ice age that caused mass migration just a couple hundred years ago ring a bell? One a couple kilo years before that that pushed mankind aroun

The only problem is that Co2 levels in the jurrasic period would have been over 5 times greater than modern "skyrocketing" Co2 levels. If you look at the reconstructed georecord from ice coring we are

For the last four or five decades, atmospheric carbon dioxide has increased (gasp!) at a rate of approximately 1.3 parts per MILLION volume (ppmv). Today, that concentration is slightly over 400 ppmv.

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The thing is... change would be happening regardless. Mini-ice age that caused mass migration just a couple hundred years ago ring a bell? One a couple kilo years before that that pushed mankind around the world and over the arctic landbridge? The current trend towards another mega-ice-age that is only being staved off by mankind's rekless release of energy into the system?

 

Just from the tone of your posts, I recommend you look into a book, because some decisions are worsened by the absence of logic.

Rapid change, dimwit. 

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Rapid change, dimwit. 

Ooh, and you kiss your mother with that mouth.

 

The change isn't rapid when you compare it to other events. The amounts we're  talking about  arn't large when compared to other amounts. and the only thing you've got is "dimwit." Very salient, Enlightened even. A feast of words from the boy who laughs at 'ya'. C'mon, be better than that, even if you're playing with a hokey-stick-graph.

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Ooh, and you kiss your mother with that mouth.

 

The change isn't rapid when you compare it to other events. The amounts we're  talking about  arn't large when compared to other amounts. and the only thing you've got is "dimwit." Very salient, Enlightened even. A feast of words from the boy who laughs at 'ya'. C'mon, be better than that, even if you're playing with a hokey-stick-graph.

Yes, I did kiss my mother with that mouth, just before she died.

 

And yes, the change is rapid compared to other global scale temperature changes. See for example the so-called mini ice age compared to what we are seeing now, here: https://en.wikipedia.org/wiki/Little_Ice_Age#/media/File:2000_Year_Temperature_Comparison.png

 

Will that do "ya"?  

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Climate change deniers say that.  All the time.  Those four positions are common positions of climate change deniers, not you.  Indeed, I have only seen three of the four positions from any poster on this board so far.

So your argument is 'others who share this particular conclusion of yours are guilty of this, therefore by association the credibility of anyone who shares that conclusion is affected despite not being guilty of it themselves? It's a very cheap debating tactic to attack the rhetoric of extremists of the position you're arguing against and it gets us nowhere.

 

Nope.  I am using the 1990 IPCC predictions.  Chapter 6, page 190.  Look at graph B.  That's their median sensitivity plot.  Now note the BaU (business-as-usual) trace.  It predicts we will hit 1.6 degrees F warming by 2020.  We hit it in 2016.  If you want to argue and say "that's not the AVERAGE, it was a one time peak" then the average will hit that around 2020 if the current trend keeps up.  Pretty good for a 28 year old prediction.

You're cherry picking your predictions (I'm doing the same). The predictions of around five years ago had us at a higher average global temperature by now.

 

Clouds during the day reduce temperature by reflecting light energy.  Clouds during the night increase temperature by retaining heat.  (Note the title of this thread.) Which one will dominate?  We don't know yet.  It's one of the less well understood feedback mechanisms.  So far they have roughly balanced out, based on weather observations.

No they don't balance out. The cooling effect of cloud cover had been greatly underestimated. Look at the most recent studies.

 

1) Carbon dioxide is a greenhouse gas.  (Provable by a high school level experiment.)

2) If you add more greenhouse gases to the atmosphere without changing anything else more heat will be retained.  (Basic thermodynamics.)

3) We have significantly increased the concentration of CO2 by burning fossil fuels.  (Easy to calculate since the tonnage of coal, oil and gas burned every year is well known - and it's easy to measure the increasing concentration.)

3) Temperatures have been increasing since we started adding CO2 into the atmosphere.  (Proof - instrumental temperature record)

1) It sure is.

2) It sure will. But raising the CO2 does change other factors, most of which produce a negative feedback.

3) We sure have. But nothing in comparison to what the Earth at times releases naturally, and it's always recovered.

4) They sure have. But correlation doesn't necessarily mean causation. The fact that CO2 increase and global temperature increase correlated so closely before the industrial revolution and diverged so rapidly after shows that CO2 is not the main cause of warming, instead both CO2 increase and global average temperature increase have a common cause.

 

Those are four very strong pieces of evidence - and are the basis for the carbon dioxide component of AGW.  Those four pieces of evidence, combined with subsequent modeling and observation (and contributions from other anthropogenic changes) is why 97% of the scientific community accepts the science behind climate change.

I think 97% of the scientific community accept the false and misleading conclusions of climate change science because of a combination of their own political bias, a recognition that messing around with things we don't fully understand is dumb and that polluting our planet is horrible, peer pressure and wanting to get paid.

 

Unfortunately for that hypothesis, the warming we are seeing is quite rapid in terms of climate history.  And so far the most likely tipping points result in rapid increases, not decreases, in temperature.  These include:

I don't think the warming we're seeing qualifies as rapid considering how long it's been going on and how rapidly the Earth appears to have cooled in the past.

 

And so far the most likely tipping points result in rapid increases, not decreases, in temperature.  These include:

 

1) Loss of polar ice.  Open water absorbs more solar radiation than ice.

This is my absolute favourite false claim ("Some of these are being seen already (loss of polar ice, melting of tundra.)") in this subject. Most of the ice sheet is increasing both its surface area and depth. In the places where it isn't we've found sub-surface volcanoes that have recently become active.

 

2) Melting of tundra and clathrates.  These release methane, which is an even stronger greenhouse gas than CO2.

This one might be true.

 

3) Increased evaporation.  Water is the strongest greenhouse gas there is.  The more evaporation, the more water in the atmosphere - and the more warming we see.

No, water vapour is far more of a heat reflector than it is a trapper. Again, take a look at recent studies.

 

?? OK.  I said nothing about "a change in orbital distance."  Were you perhaps answering someone else?

I misread your post for some reason, not sure how. You said solar output, not distance would need to change. Well solar output does change.

 

Whatever effect we're having is negligible compared to long term natural climate changes. You can add that one to your list of climate change denier's arguments. 5) Even if the temperature continues to increase and if we are at least partially responsible for it and if all or the vast majority of the changes will be detrimental, the natural climate cycle of this planet isn't going to care and will greatly overpower these relatively minor changes.

 

Are you kidding?  We have a president and a congress here in the US who have made climate change denial the politically correct opinion.  It gets you jobs and promotions within the government and within the massive fossil fuel industry.  Some researchers are willing to buck political correctness, but it comes at a heavy cost (being fired, getting death threats etc.)

I don't live in the US. I'd be very surprised though if the politically correct opinion within the academic community has changed. If it has because of Trump then they're doing the right thing for the wrong reasons. Or if they're using it as an excuse to increase pollution, the wrong thing based on the right conclusions but for the wrong reasons.

 

 

The Beaufort Gyre is well overdue to release lots of cold water. The length of time since the last release means it will likely have a much larger cooling effect than before. This isn't part of the overall climate cycle but it could potentially be what pushes into the next cooling phase. Of course if the cooling phase is actually triggered by warming then this could delay it.

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BTW it is the CO2 of Venus's atmosphere that traps all that heat.

We know four things:

 

1) Carbon dioxide is a greenhouse gas.  (Provable by a high school level experiment.)

2) If you add more greenhouse gases to the atmosphere without changing anything else more heat will be retained.  (Basic thermodynamics.)

3) We have significantly increased the concentration of CO2 by burning fossil fuels.  (Easy to calculate since the tonnage of coal, oil and gas burned every year is well known - and it's easy to measure the increasing concentration.)

3) Temperatures have been increasing since we started adding CO2 into the atmosphere.  (Proof - instrumental temperature record)

 

Those are four very strong pieces of evidence - and are the basis for the carbon dioxide component of AGW.  Those four pieces of evidence, combined with subsequent modeling and observation (and contributions from other anthropogenic changes) is why 97% of the scientific community accepts the science behind climate change.

 

 

NO, your "basic thermodynamics" is not correct.

Once a saturation level has been reached, no more radiant energy can be absorbed.

100% is 100%. 

 

1.3 ppmv ANNUAL INCREASE in atmospheric CO2 is trivial since:

A.  It includes natural sources, which constitute 96% of all CO2 added, and

B.  Water vapor constitutes 15,000 ppmv of the atmosphere, making it by far the dominant greenhouse gas.

 

NO, 97% of the scientific community does NOT accept your premise.  That was the claim of one graduate student based on her cherry picked data.

Absurd, really.

 

CO2 follows temperature increases, it does not lead them.  The primary source of CO2 is decomposition of organic matter.  Human sources are trivial.

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NO, your "basic thermodynamics" is not correct.

Once a saturation level has been reached, no more radiant energy can be absorbed.

100% is 100%. 

 

1.3 ppmv ANNUAL INCREASE in atmospheric CO2 is trivial since:

A.  It includes natural sources, which constitute 96% of all CO2 added, and

B.  Water vapor constitutes 15,000 ppmv of the atmosphere, making it by far the dominant greenhouse gas.

 

NO, 97% of the scientific community does NOT accept your premise.  That was the claim of one graduate student based on her cherry picked data.

Absurd, really.

 

CO2 follows temperature increases, it does not lead them.  The primary source of CO2 is decomposition of organic matter.  Human sources are trivial.

There is no "saturation level" in the Earth's heat balance.

 

If you do not have greenhouse gases in the atmosphere, the hot ground can radiate directly into space without heating the atmosphere, leading to a thermal equilibrium. If greenhouse gases are present, a proportion of that radiation is absorbed and re-radiated randomly within the atmosphere, before it escapes into space, heating the atmosphere up. Once the atmosphere is heated, it too becomes an IR emitter and it and the ground between them will eventually radiate enough IR into space to balance solar input. So again equilibrium is restored, but at a higher atmospheric temperature. 

 

If you increase the concentration of greenhouse gases, and increase the range of IR wavelengths at which they absorb, you diminish the ground radiation and thereby require more heating of the atmosphere before thermodynamic equilibrium is restored.  

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NO, your "basic thermodynamics" is not correct.

Once a saturation level has been reached, no more radiant energy can be absorbed.

100% is 100%. 

Yes, it is.

 

The CO2 absorption bands, however, are not saturated 100% across the spectrum.  They are close to being saturated, but are not saturated.  (This is why increasing CO2 concentration by 50% increases retained heat by only a fraction of a percent, rather than 50%.)

 

From a University of Michigan paper:

============================

 There is a huge change in the outgoing energy flux between the runs with 0 ppm and 10 ppm because you go from having no absorption to having a quite noticeable peak by adding a relatively small amount of CO2, just 10 ppm. Then, as you go up to 100 and 1,000 ppm, the change in energy balance for each new molecule of CO2, or each new ppm of CO2 , gets weaker.

 

The energy balance never becomes totally insensitive to further additions of CO2, however.  More CO2 will always make it warmer, even up to the 70 atm of CO2 in the atmosphere of Venus. In part, this is because as the CO2 concentration increases, the absorption peak in Figure 4-5 gets fatter, even if it cannot get much deeper. The middle of the absorption band is saturated, but the edges are unsaturated.

============================

http://forecast.uchicago.edu/chapter4.pdf

 

1.3 ppmv ANNUAL INCREASE in atmospheric CO2 is trivial since:

A.  It includes natural sources, which constitute 96% of all CO2 added, and

B.  Water vapor constitutes 15,000 ppmv of the atmosphere, making it by far the dominant greenhouse gas.

 

 

 

Correct.  Which is why we are seeing warming of a few degrees rather than dozens of degrees.  With all the AGW gases we have added, we have increased forcing by only about 2 watts per square meter - which accounts for the (small) warming we are seeing.  As we increase the concentration of those gases, warming will continue to increase.  Basic logic.

 

NO, 97% of the scientific community does NOT accept your premise.  That was the claim of one graduate student based on her cherry picked data.

 

97% of the CLIMATE science community accepts the premise.  It has been confirmed by at least four metastudies. (Doran, Anderegg,Cook, Carlton)  Also interesting is the fact that the closer you get to someone who is researching climate, the closer that number gets to 100%.  If you go to economic geologists, for example, the number is under 50%. 

 

For all publishing scientists (i.e. petrochemists, biologists, physicists)  the number goes as low as 84% (Bray.)  For all nonpublishing scientists (i.e. anyone who claims to be a scientist, no matter what his/her credentials) then it drops to as low as 53% (von Storch.)   Which also makes sense; climate change denial is both profitable and popular.

 

CO2 follows temperature increases, it does not lead them.  The primary source of CO2 is decomposition of organic matter.  Human sources are trivial.

 

Do you deny that the increase in CO2 from 280 to 400ppm has been driven primarily by human releases of CO2?

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Note the width of the absorption band.  If you make it wider, you absorb more energy.  Basic math.

My understanding of this is that there is another twist to it as well. For IR radiation in the highly absorbed regions of the spectrum, the radiation eventually reaches space after a series of scattering processes causes by repeated absorption and re-emission. The more absorbing molecules there are in the atmosphere, the longer it takes for the radiation to get to an altitude from which it can then be radiated into space. There is thus  more heat trapped, ricocheting around, on its way out at any given moment and thus the heating effect is increased.      

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Note the width of the absorption band.  If you make it wider, you absorb more energy.  Basic math.

 

 

You pretend that you can change the IR spectrum of compounds?

You're pretty far off there.  Basic science.

 

Moreover, the Keeling Curve, which is really the Scary Graph, as it is intended to frighten and mislead, shows ONLY 1.3 ppmv per YEAR for decades.

Divide 1.3 by 15,400 ppmv, which is the total of just water vapor plus carbon dioxide and tell everyone what that infinitesimal fraction is.

 

 

carbon-dioxide-and-water1.jpg?w=640

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You pretend that you can change the IR spectrum of compounds?

You're pretty far off there.  Basic science.

 

Moreover, the Keeling Curve, which is really the Scary Graph, as it is intended to frighten and mislead, shows ONLY 1.3 ppmv per YEAR for decades.

Divide 1.3 by 15,400 ppmv, which is the total of just water vapor plus carbon dioxide and tell everyone what that infinitesimal fraction is.

 

 

carbon-dioxide-and-water1.jpg?w=640

Oh dear, so we are reduced to recycling already refuted arguments, apparently. It has already been explained in this thread, at some length, why it is wrong simply to add up water vapour and CO2 contributions.

 

But then, taking refuge in ignorance and firmly resisting any opportunity to learn is a hallmark of climate change deniers and creationists, so it was only to be expected.  

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The Beaufort Gyre, an immense 60-mile-diameter pool of cold freshwater and sea ice, is “stuck” in a clockwise rotation that should have ended years ago. Its eventual reversal could send massive amounts of chilly water straight toward western Europe, plunging it into brutal winters and disrupting fisheries.

The gyre spins in the Beaufort Sea, north of Alaska and Canada and south of the North Pole. When this ocean current spins clockwise, it traps Arctic ice and freshwater melt. When it spins the other way, it ejects that ice and freshwater out past Greenland into the North Atlantic, making weather in Northern Europe cooler. It is a natural phenomenon, but something has gone awry with the way it operates, as its periodic reversal is way overdue.

Typically, cyclonic storms occur every five to seven years in the North Atlantic and move into the Arctic, causing the gyre to weaken and reverse direction, explains journalist Ed Struzik, a fellow with the Institute for Energy and Environmental Policy at Queen's University and author of “Future Arctic: Field Notes from a World on the Edge.” In recent years, however, the Arctic has been warming faster than the rest of the planet, and scientists speculate this has caused the gyre to stay in a clockwise direction for more than a dozen years.

“Nobody really understands what's going on,” Struzik says, “but it's probably a combination of climate change and massive runoff of freshwater coming off the Greenland glacier that is preventing those big cyclones from forming over the North Atlantic and moving into the Arctic.”

So the gyre just keeps getting bigger, spinning faster and collecting more water, Struzik says. “Imagine all of the water that we have in the Great Lakes — that’s the amount of freshwater trapped in the Arctic just waiting to get out.”

Scientists are waiting with bated breath, he says. They see signals that the gyre could reverse sooner rather than later, but they thought this was the case in 2013 and it turned out not to be. When it does happen, Struzik says, we won’t see a "The Day After Tomorrow" scenario, in which the world goes into a deep freeze, but it's definitely going to “create some problems" for the European countries near the North Atlantic. The last time this happened, in the 1960s and 1970s, western Europe endured eight of its most severe winters and the surge of ice and freshwater disrupted the North Atlantic food chain; this, in turn, caused a collapse of the lucrative herring fishery.

Hypothetically, a quickly warming Arctic and its effect on the gyre could impact weather across North America, as well. Warming Arctic waters appear to be disrupting the flow of the jet stream, creating a kind of “loopiness” in its shape that tends to hold weather patterns in place, Struzik explains. This can bring Arctic air further south than usual and create unusual extreme weather events, like what recently occurred in Corpus Christi, Texas, which received several inches of snow a few weeks ago.

“I think that's likely what's happening and we're going to see more of that in the future,” Struzik says. “But then again, we really don't know, because this is sort of an emerging science that everybody's trying to study and everybody's figuring out.”

This article is based on an interview that aired on PRI’s Living on Earth with Steve Curwood.

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