[championoftruth (OP)]

We're told 97 percent of scientists agree the world is made hotter by humans burning fossil fuels. Less well-known is the fact that number was conjured into being by having a team read the abstracts, which is to see just the front pages of nearly 12,000 scientific papers dealing with climate change. 3,896 were judged as blaming humans for the changes, 7,930 didn't endorse a position, 78 exonerated humans altogether, and the final 40 were unsure. This meant 32.6% of the scientists held humans to blame. Only when the decision was taken to discard, simply to chuck in the bin, the nearly 8,000 papers with no position whatsoever was 32.6% magically transformed into 97%. What a scam.

Oh, brace yourselves, for we are once again graced with the all-mighty "97 percent of scientists agree" chant! Cue the dramatic music! But guess what, folks? This magical number didn't just fall from the sky, oh no! It was summoned into existence by the wise ones who decided to play a little abstract peek-a-boo with 12,000 climate change papers. I mean, who needs to read the whole thing when the abstracts hold all the secrets, right?

Oh, those precious 3,896 papers had the nerve to point fingers at us mere mortals for making the world hotter. How dare they! But hold your applause, 'cause a staggering 7,930 papers were too cool to take a stand. They were probably sipping pi?a coladas on some tropical beach while the planet heated up!

Wait, wait, here comes the highlight! 78 papers, yes, just 78, played hero and cleared us of all guilt. Hallelujah! We are absolved! But wait, there's a cherry on top: 40 papers were caught sitting on the fence, forever undecided. Must be tough being so indecisive in the world of climate science!

Now, get ready for the real magic trick. Poof Those undecided papers vanish into thin air! Abracadabra! And voil?! Suddenly, 97 percent consensus is born, like a phoenix rising from the ashes! It's a miracle, folks!

So, let's give a round of applause to the masterminds behind this statistical circus. They've managed to turn a bunch of indecision and uncertainty into an awe-inspiring 97 percent! Bravo! But, hey, who needs accurate data and genuine consensus when you can have a grand spectacle like this, right? Climate change might be serious, but let's not forget to enjoy the show!

[Bored chemist]

It has been challenged and, if  you didn't notice, then that says a lot about you.
It has been regularly questioned.
I think what you mean is "why hasn't it been challenged successfully?", and the simple answer is that it's true- or at least, "near enough".

https://www.forbes.com/sites/uhenergy/2016/12/14/fact-checking-the-97-consensus-on-anthropogenic-climate-change/?sh=7b904cd61157

[alancalverd]

There is a clear correlation between global mean temperature (however measured or defined) and atmospheric CO2 concentration, but a number of mysteries remain, which throw doubt on causation.

1. There is a historic cycle of about 100,000 years with the temperature rising rapidly to somewhere near its present level, then declining asymptotically towards an extended ice age  at about 12 degrees below present level. We have evidence of at least 4 such cycles and whatever the mechanism, we are now living at a time when we should be reaching another peak.

2. The CO2 level has always followed the same cycle but historically some 500 years behind the temperature curve, so clearly CO2 cannot be the primary driver of temperature

3. There is no suggestion of where the CO2 came from or went to in the geological record. The CO2 curve is not synchronised with volcanic ash

4. It seems most probable to me that the cycle is driven by water, not CO2, which is completely out of human control

5. My hypothesis is that the concentration of CO2 in the atmosphere is governed by the ratio of animal (CO2 emitting) activity to plant (CO2 absorbing) activity. The expansion of agriculture in the last 10,000 years  has indeed altered that ratio.

Problem is that there is no money in saying "nothing can be done" and a lot of problems associated with blaming human aspiration for animal respiration, so it is hardly surprising that 97% of any group prefer to cleave to the anthropogenic hypothesis, either because it is profitable, or because of some predilection for Original Sin and Guilt, or sheer vanity in thinking that we can do anything about it, or some idea that you can get money from rich people by claiming it is their fault that you can't feed your family on the desert that you and your ten siblings inherited from your two parents.

Fact is that the world is going to become very uncomfortable for humans for the next 500 years  unless we reduce the population to a sustainable level of about one tenth of the present number.

[Bored chemist]

1 the historic cycles did not have as steep a rise of either temperature or CO2- so, whatever caused them, it's probably not what's happening now.
2 Ditto.
3 Ditto
4 The thing about water is that, if "more than usual" gets into the atmosphere , it falls out as rain.

5 We can "radiocarbon date" the excess carbon in the air. It's "ancient" which says it must have come from some old source, not current biology. Also, the additional CO2 is in good agreement with the tax revenues on fossil fuels.

Whether or not "nothing can be done" depends very strongly on what's happening.
If (and you personally might think it's a big if) it's down to CO2, then we can do something.

[alancalverd]

1. Depends on the finesse of your analysis.

2. You can't determine phase lag until one or other variable begins to decrease

3. "Ditto" misses the point. If previous cycles were not caused by anthropic or volcanic emissions of CO2, what else could have caused the change in CO2 levels? The only obvious cause is temperature.

4. Not true. If the temperature rises, so does the dewpoint for any given concentration of H2O - the feedback is positive. Whilst cumulus (water droplet) clouds form at around 2000  ft in the UK, the base of the same type of cloud over Texas can be 10,000 ft. More interestingly, warm wet air often rises until it forms cirrus (ice) clouds at 20 - 40,000 ft altitude. These have a profound effect on surface heating and don't precipitate. I surmise that the rather consistent maximum surface temperature of the globe is determined by cloud cover, particularly cirrus, increasing to the point that reflection and absorption eventually reduce insolation.

5. There is a significant "carbon deficit" of about 30% that is not accounted for by direct combustion of fossil fuels. Obviously the figures are debatable as we are talking about the difference between crude estimates of the excess above an unknown baseline, but the concept of animal/vegetable balance does at least consist with the seasonal fluctuations of the CO2 level at Mauna Loa, which are out of phase with anthropogenic emissions.

My concern is that people concentrate on an improbable but psychologically satisfying scapegoat, spend vast amounts of time, money and emotion on comforting "solutions" like electric cars (which in the short term actually increase global carbon emissions) and fail to prepare for the wholly avoidable disaster of an overpopulated and underwatered planet.


 

[paul cotter]

Alancalverd has a strong argument that the current rise in temperature is a natural phenomenon. Most of the climate scientists argue that anthropogenic co2 is the culprit. Me, I don't know, not being competent to analyse such a complex problem. But I do know one thing for certain and that is the future for mankind is utterly bleak. In the situation where climate change is natural there is virtually nothing we can do about it and all the prophesies of doom will arrive in the next~50 years. In the case of man made climate change, correcting the problem would required global concerted action. All one has to do is a brief look at history to understand that global concerted action has never happened and will never happen. The very nature of the human creature rules out any possibility of such action.

[Bored chemist]

If the temperature rises, so does the dewpoint for any given concentration of H2O

No
Air with a  concentration of 17.3 grams of water per cubic metre has a dewpoint of 20C.

As the earth warms up, more water will evaporate and more of it will stay in the air before it rains out.
And, yes, that's a positive feedback mechanism- (unless it isn't because clouds cause cooling- but that's a separate issue.).

But water can't spontaneously cause the heating.

And you still have to recognise that CO2 is a greenhouse gas.
More of it will result in more warming.

And we have produced more of it.

1. Depends on the finesse of your analysis.

No.
It's just the observation of reality.
" Measurements from older ice cores (discussed below) confirm that both the magnitude and rate of the recent increase are almost certainly unprecedented over the last 800,000 years (Fig. 2). The fastest natural increase measured in older ice cores is around 15ppm (parts per million) over about 200 years. For comparison, atmospheric CO2 is now rising 15ppm every 6 years. "
from
https://www.bas.ac.uk/data/our-data/publication/ice-cores-and-climate-change/


So, do you see why I don't really care much about what happened ages ago.
I'm wondering what is causing this roughly order of magnitude faster change.

So, all the stuff about the cause of what happened before (i.e. your points 1,2 and 3) is largely irrelevant.

[Bored chemist]

Alancalverd has a strong argument that the current rise in temperature is a natural phenomenon.

Not really.
The current rate of rise is much faster than any historic natural rise.

I keep pointing this out to him.

As I already pointed out to you, the current rise is about 100 times faster than the previous ones.

https://www.thenakedscientists.com/forum/index.php?topic=83465.msg661680#msg661680

[alancalverd]

Compared with the average (1 degree every 800 - 1000 years), yes, but within that average we have some very sharp spikes, particularly near the maximum. Perspective, my friend!

[alancalverd]

So, do you see why I don't really care much about what happened ages ago.

Pity, that. Scientific evidence is usually the results of experiments previously conducted.

[alancalverd]

But water can't spontaneously cause the heating.

Nobody said it does, but IPCC has stated that it is the most important greenhouse gas, and I'm sure you wouldn't disagree with such an ex cathedra statement.

[alancalverd]

Air with a  concentration of 17.3 grams of water per cubic metre has a dewpoint of 20C.

And if you heat your sample to 30 C, does the RH increase, decrease or stay the same? 

[Bored chemist]

So, do you see why I don't really care much about what happened ages ago.

Pity, that. Scientific evidence is usually the results of experiments previously conducted.

Was mankind dumping CO2 into the air back then?
Or was it a completely different experiment?

[Bored chemist]

Air with a  concentration of 17.3 grams of water per cubic metre has a dewpoint of 20C.

And if you heat your sample to 30 C, does the RH increase, decrease or stay the same? 

Did you not read what I said, or did you not read what you said?

Compared with the average (1 degree every 800 - 1000 years), yes, but within that average we have some very sharp spikes, particularly near the maximum. Perspective, my friend!

The rate of change of CO2 is unprecedented.
But that's only what the data says.

[Bored chemist]

Nobody said it does

Somebody seems to have said it's driven by water.

4. It seems most probable to me that the cycle is driven by water, not CO2, which is completely out of human control

but IPCC has stated that it is the most important greenhouse gas, and I'm sure you wouldn't disagree with such an ex cathedra statement.

If you look really really carefully, you will see that nobody said otherwise.

[alancalverd]

Was mankind dumping CO2 into the air back then?
Or was it a completely different experiment?

The experiment shows only that CO2 followed temperature, which is entirely to be expected in the earth's ecosphere.

Since the CO2 IR absorption lines are all saturated  at about 200ppm, and "pressure broadening" depends not on the partial pressure of  CO2 but on the total atmospheric pressure, adding more won't have any effect. Apologies for quoting a more recent experiment but the numbers are from a NASA-funded PhD study in the 1970s - I'll see if I can find it again!

40 minutes later - just found it! "The effect of several infrared transparent broadening gases on the absorption of infrared radiation in the 15μm band of  carbon dioxide" HG Reichler Jr, University of Michigan May 1969 under NASA contract NASr-54(03). IIRC NASA was interested  at the time in the use of CO2 lasers to "punch holes in the atmosphere" to provide temporary line-of-sight waveguides. 

[alancalverd]

Did you not read what I said, or did you not read what you said?

You won't get nucleation and precipitation until the RH reaches ~100%. So the hotter the atmosphere gets, the more water it can hold before it rains, and (thanks to the greenhouse effect) the hotter it gets, until something (ice cloud cover? there's nothing else) reduces the heat input.

[Bored chemist]

Did you not read what I said, or did you not read what you said?

You won't get nucleation and precipitation until the RH reaches ~100%. So the hotter the atmosphere gets, the more water it can hold before it rains, and (thanks to the greenhouse effect) the hotter it gets, until something (ice cloud cover? there's nothing else) reduces the heat input.

Yes.
But what you said was still wrong, wasn't it.
You said this

If the temperature rises, so does the dewpoint for any given concentration of H2O

And, as I pointed out, reality is this

Air with a  concentration of 17.3 grams of water per cubic metre has a dewpoint of 20C.

Since the CO2 IR absorption lines are all saturated 

That's still meaningless.
Why do you keep saying it?

[paul cotter]

For the record, it was Alan's point about the absorption being saturated that got my attention and not the historical record. I do accept that there has been an unprecedented rise in co2 due to use of fossil fuels.

[alancalverd]

But what you said was still wrong, wasn't it.
You said this
Quote from: alancalverd on Today at 11:10:33
If the temperature rises, so does the dewpoint for any given concentration of H2O

And, as I pointed out, reality is this

Quote from: Bored chemist on Today at 11:36:22
Air with a  concentration of 17.3 grams of water per cubic metre has a dewpoint of 20C.

I stand corrected. Brain temporarily in neutral! What I meant was that hotter air can hold more water before it condenses into liquid drops, which is pretty obvious.