Guest essay by Eric Worrall
Stephen Hawking thinks President Trump’s decision to pull out of the Paris Agreement and the British Brexit decision might trigger a chain of events which leads to the destruction of the world. My question – where is the evidence?
Hawking says Trump’s climate stance could damage Earth
By Pallab Ghosh
Science correspondent, BBC News
2 July 2017
Stephen Hawking says that US President Donald Trump’s decision to pull out of the Paris climate agreement could lead to irreversible climate change.\
Prof Hawking said the action could put Earth onto a path that turns it into a hothouse planet like Venus.
He also feared aggression was “inbuilt” in humans and that our best hope of survival was to live on other planets.
…
In its Fifth Assessment Report, the IPCC authors wrote: “The precise levels of climate change sufficient to trigger tipping points (thresholds for abrupt and irreversible change) remain uncertain, but the risk associated with crossing multiple tipping points in the Earth system or in interlinked human and natural systems increases with rising temperature.”
…
“We are close to the tipping point where global warming becomes irreversible. Trump’s action could push the Earth over the brink, to become like Venus, with a temperature of two hundred and fifty degrees, and raining sulphuric acid,” he told BBC News.
“Climate change is one of the great dangers we face, and it’s one we can prevent if we act now. By denying the evidence for climate change, and pulling out of the Paris Climate Agreement, Donald Trump will cause avoidable environmental damage to our beautiful planet, endangering the natural world, for us and our children.”
…
And on Brexit, he feared UK research would be irreparably damaged.
“Science is a cooperative effort, so the impact will be wholly bad, and will leave British science isolated and inward looking”.
…
Read more: http://www.bbc.com/news/science-environment-40461726
There is so much wrong with Stephen Hawking’s statement, its difficult to know where to begin.
For starters, the US “commitment” to the Paris Agreement was never going to significantly reduce global CO2 emissions. China, whose emissions already dwarf the USA, demonstrated how they think the Paris Agreement is a joke, when they announced a colossal 20% increase in coal capacity in the next 3 years November last year. Green efforts to cast China as an environmental champion just add to the humour.
In addition to China’s heroic effort to emit plant fertiliser, as WUWT recently reported, 1600 new coal plants are currently under construction around the world..
Hawking’s suggestion that the USA could somehow lead others into economic hardship by destroying the domestic US economy is and always was a liberal fantasy.
As for Hawking’s claim we could end up like Venus, a statement without evidence, even from someone with Stephen Hawking’s reputation or from the IPCC, is no more valid than a prognostication provided by a psychic gazing into a crystal ball.
The Earth has experienced far higher CO2 levels than the present day. CO2 levels in the Cretaceous, the age of the Dinosaurs, were 1700ppm – more than 4x today’s level. The Earth has experienced extreme warming and extreme cooling, but has never experienced a runaway greenhouse effect which made it totally uninhabitable like Venus.
Gigantic CO2 belching volcanic eruptions which lasted for 1000s, maybe millions of years, huge meteor strikes, the advance and retreat of giant ice sheets – for billions of years since life began, nothing in our violent geological history has managed to shift temperatures outside a range where life is possible somewhere on our planet.
Nothing we have done or are likely to do to our planet can come close to what nature has already done – to what our planet has already endured.
In a few centuries fossil fuel resources will likely be exhausted. At most we shall add a few hundred more PPM CO2 to our atmosphere. Suggesting that our mild contribution to global greening is somehow worse than all the awful geological events of our planet’s history is pure and simple fiction.
The destruction of the World, all down to Brexit I am afraid.
Why do we listen to this man whose views are becoming more and more removed from reality/
Mr Hawking is not any longer in control of his ‘talking computer’, it has been ‘hacked’ and then ‘hijacked’ by some mischievous agents, possibly Russians, Chinese, North Koreans or even domestic grown ones.
Poor Mr Hawking has no way of telling us that he is not in control of the weird voice coming out from his wheelchair. ( /sarc, ?)
Me thinks Dr. Hawking is practising the art of satire. His statement obviously is so ludicrous as not to be taken seriously, and this is his way of telling the alarmists what a joke they have going on. He is just outdoing them by a factor of a million…glad to see he still has a sense of humour.
Joe Biden says, “Take a bow Stephen.”
More likely BIden would say, “Stand up and take a bow”
It’s sad when a first rate mind begins to decline and shame on the BBC for exploiting this poor fellow. I’m sure Hawking didn’t wheel down to the BBC to express this spontaneously. Leave the great man alone in his retirement and don’t tarnish his reputation with this soon-to-be-dead Climateering boondoggle. In a real world (not the fake one we’ve been living in for decades) Donald Trump would be a Nobel Prize winner for saving the planet.
Hawking has already gone to the realms of fantasy – in physics too.
If I could see it as B.S. as it is without having science degree, he should have too.
Sad to see.
I can understand the sort of physics he does pretty well.
He ought to have an easy time grasping enough physical geography, Earth history, atmospheric physics, as well as enough biology to know how phony CAGW is.
Orandum est ut sit mens sana in corpore sano.
“One should pray that a healthy mind is in a healthy body.”
I think this proverb applies exactly to Stephen Hawkins, even in his sick body has become an atheist. Envy eats the soul, and so it is not surprising that he is missing a divine or the plan of a higher beeing behind evolution and wants to explain all physical laws with their regularity out of themselves. Why me, God? And if I, then you do not exist.
So at 250 deg C all the oceans will evaporate which will increase the mass of the atmosphere by about 270 times. At standard temp and pressure water vapour is 22 times greater volume than liquid water. So the height of the atmosphere will increase quite a lot, the water vapour will have absorbed all available relevant frequencies so limiting greenhouse feedback. Added to that all the sulphates in the atmosphere will be reflecting lots of insolation.
Hmm, I’m not convinced the Hawking model will work.
I guess Prof Hawkins assumes that all science is as rigorous as his own.
Upon hearing what he said on CNN earlier today (July 3rd), here’s what he “said” in December 2016:
https://wattsupwiththat.com/2016/12/03/stephen-hawking-most-dangerous-time-for-our-planet-because-we-arent-listening-to-our-betters/
Not any better logic then…
And CNN took his word as Gospel…
Another climate change den1er
“I can’t stand this December heat, but it has nothing to do with global warming”
http://www.telegraph.co.uk/content/dam/news/2017/07/04/TELEMMGLPICT000133754121-xlarge_trans_NvBQzQNjv4Bqo6vET2N_4j-nN-njqnCISfZpNBDdM6J_J05gFiKPelo.jpeg
No it’s not POTUS but wannabe British PM.
Boris for PM !
forgot the link
Boris: “It is fantastic news that the world has agreed to cut pollution and help people save money, but I am sure that those global leaders were driven by a primitive fear that the present ambient warm weather is somehow caused by humanity; and that fear – as far as I understand the science – is equally without foundation.”
Whatever Warmunism is about, it most certainly isn’t about cutting pollution or helping people save money, however much they claim it to be. Nor do I believe that global leaders are driven by fear of warm weather caused by humanity. What they fear is the looming downfall of their CAGW ideology and its gravy train.
I love Boris……the thinking man’s idiot.
The Paris Accord is a big fake anyway. It’s non-binding. It is so unserious and so unbacked by data that it is mere political virtue-signaling for credulous media, and for snookered taxpayers who are footing the bill for silly conferences whose attendees aren’t expected to live up to their pronouncements.
If Trump participating in less hypocrisy means the world is doomed, Hawking needs to go back to his lab and recalculate a few equations. More hypocrisy = a better world? I think not.
It is helpful to recall that some people are just steeped in catastrophism while also somehow thinking of themselves as so smart that anything that pops into their heads must be true.
Some tidbits from the intellectual forebears of Hawking’s way of thinking:
1. Harvard biologist George Wald estimated that “civilization will end within 15 or 30 years unless immediate action is taken against problems facing mankind.”
2. “We are in an environmental crisis which threatens the survival of this nation, and of the world as a suitable place of human habitation,” wrote Washington University biologist Barry Commoner in the Earth Day issue of the scholarly journal Environment.
3. The day after the first Earth Day, the New York Times editorial page warned, “Man must stop pollution and conserve his resources, not merely to enhance existence but to save the race from intolerable deterioration and possible extinction.”
4. “Population will inevitably and completely outstrip whatever small increases in food supplies we make,” Paul Ehrlich confidently declared in the April 1970 issue of Mademoiselle. “The death rate will increase until at least 100-200 million people per year will be starving to death during the next ten years.”
5. “Most of the people who are going to die in the greatest cataclysm in the history of man have already been born,” wrote Paul Ehrlich in a 1969 essay titled “Eco-Catastrophe! “By…[1975] some experts feel that food shortages will have escalated the present level of world hunger and starvation into famines of unbelievable proportions. Other experts, more optimistic, think the ultimate food-population collision will not occur until the decade of the 1980s.”
6. Ehrlich sketched out his most alarmist scenario for the 1970 Earth Day issue of The Progressive, assuring readers that between 1980 and 1989, some 4 billion people, including 65 million Americans, would perish in the “Great Die-Off.”
7. “It is already too late to avoid mass starvation,” declared Denis Hayes, the chief organizer for Earth Day, in the Spring 1970 issue of The Living Wilderness.
8. Peter Gunter, a North Texas State University professor, wrote in 1970, “Demographers agree almost unanimously on the following grim timetable: by 1975 widespread famines will begin in India; these will spread by 1990 to include all of India, Pakistan, China and the Near East, Africa. By the year 2000, or conceivably sooner, South and Central America will exist under famine conditions….By the year 2000, thirty years from now, the entire world, with the exception of Western Europe, North America, and Australia, will be in famine.”
9. In January 1970, Life reported, “Scientists have solid experimental and theoretical evidence to support…the following predictions: In a decade, urban dwellers will have to wear gas masks to survive air pollution…by 1985 air pollution will have reduced the amount of sunlight reaching earth by one half….”
10. Ecologist Kenneth Watt told Time that, “At the present rate of nitrogen buildup, it’s only a matter of time before light will be filtered out of the atmosphere and none of our land will be usable.”
11. Barry Commoner predicted that decaying organic pollutants would use up all of the oxygen in America’s rivers, causing freshwater fish to suffocate.
12. Paul Ehrlich chimed in, predicting in 1970 that “air pollution…is certainly going to take hundreds of thousands of lives in the next few years alone.” Ehrlich sketched a scenario in which 200,000 Americans would die in 1973 during “smog disasters” in New York and Los Angeles.
13. Paul Ehrlich warned in the May 1970 issue of Audubon that DDT and other chlorinated hydrocarbons “may have substantially reduced the life expectancy of people born since 1945.” Ehrlich warned that Americans born since 1946…now had a life expectancy of only 49 years, and he predicted that if current patterns continued this expectancy would reach 42 years by 1980, when it might level out. (Note: According to the most recent CDC report, life expectancy in the US is 78.8 years).
14. Ecologist Kenneth Watt declared, “By the year 2000, if present trends continue, we will be using up crude oil at such a rate…that there won’t be any more crude oil. You’ll drive up to the pump and say, `Fill ‘er up, buddy,’ and he’ll say, `I am very sorry, there isn’t any.’”
15. Harrison Brown, a scientist at the National Academy of Sciences, published a chart in Scientific American that looked at metal reserves and estimated the humanity would totally run out of copper shortly after 2000. Lead, zinc, tin, gold, and silver would be gone before 1990.
16. Sen. Gaylord Nelson wrote in Look that, “Dr. S. Dillon Ripley, secretary of the Smithsonian Institute, believes that in 25 years, somewhere between 75 and 80 percent of all the species of living animals will be extinct.”
17. In 1975, Paul Ehrlich predicted that “since more than nine-tenths of the original tropical rainforests will be removed in most areas within the next 30 years or so, it is expected that half of the organisms in these areas will vanish with it.”
18. Kenneth Watt warned about a pending Ice Age in a speech. “The world has been chilling sharply for about twenty years,” he declared. “If present trends continue, the world will be about four degrees colder for the global mean temperature in 1990, but eleven degrees colder in the year 2000. This is about twice what it would take to put us into an ice age.”
Thanks for that litany of stupidity pontificated by our intellectual superiors. They do stupid even better than you or me.
Maybe that is why stoopid government has persisted for so long. Let us welcome a new dawn for “Common Sense” and deride the learned fools who rule us.
It has been going on for a while.
When people finally learned how to talk all those eons ago, the first question was “Honey, can you grab me a cold one while you are up?”
Or words to that effect.
The second sentence was the proclamation that the end was nigh.
It is all right there in the history books…but you have to read between the lines.
Poor Hawkins. He’s become a parody of himself, reduced to idiotic blatherings. Truly, a useful idiot for Leftists, Watermelons, and envirofascists.
As anyone who has perused a book of Einstein quotes with a clear eye knows, even he was given to childish stupidities when venturing outside his area of expertise. Especially where the topic touched on politics.
I believe there is a 97% chance that it is NOT Hawkings making these comments, but his handler…
All this fossil fuel carbon, where did it come from, huh? Answer that coherently, Dr Hawking.
If the globe were to cool 10 cc in 20 years, I will bet you dollars to donuts Dr Hawking would blame global warming for ‘disrupting the climate’.
Honestly Dr H, stick to String Theory, black holes and Big Bangs. There are enough erroneous models in there to keep a physicist busy for life.
Oh, right…
The alarmists are always claiming that things will be very bad, then the date comes and goes and nothing changed, and they keep on doing it again and again, and expect the world to bow down to their knowledge.
Next thing is, Newton – the very, very eminent scientist, will resurrect and tell the world that gold can be made from scrap base metal and as such poverty will soon be abolished
Stephen Hawking – if his conscious brain is still active within his ALS-riddled body, and I have my doubts about that – has become nothing more than a computer-generated “voice” for the leftist global agenda. I honestly believe that he is not aware of what is going on and is trotted out by his handlers to “say” whatever it is they want him to say. It’s almost like the Wizard of Oz. And if he is truly “speaking” as a scientist, he is the worst scientist in history due to his ignorance of evidence.
Perhaps someone has been putting words into his synth speech computer…
I agree w/you — said the same thing below. Hawking is, unfortunately and despicably, being used.
I saw the Hawking quote, and yes, it was ridiculous. But I feel badly about dumping on Steve.
Why? It’s like kicking a guy when he’s down.
A.M.
You must never have been in a real street fight.
Another way to look at it is that the CAGW crowd have been beating the stuffing out of the world economy and the ability of honest scientists to go about their business of elucidating objective reality.
The skeptical community has been a small group standing up to the huge gang doing the rioting, and has been bruised and battered but has remained in the fight.
We now seemed to have staggered onto our feet and the tables are turning…and Hawking steps into the fray and kicks everyone in the teeth.
President Trump’s Paris Agreement Decision Might Cause Hemorrhoids
“… to become like Venus, with a temperature of two hundred and fifty degrees, ”
He should know better than this. The whole concept of a runaway GHG effect is complete BS and is only even a theoretical possibility because Hansen/Schlesinger blew the feedback analysis and assumed that there’s an infinite source of Joules provided by the atmosphere to power the gain (sensitivity and gain are the same thing).
Just look at the claimed sensitivity where 3.7 W/m^2 of equivalent forcing by doubling Co2 is claimed to increase the surface temp by 3C and increase the corresponding surface emissions by more than 16 W/m^2. To emit 16 W/m^2, the surface must be receiving 16 W/m^2, otherwise it will cool. The first 3.7 comes from the ‘forcing’ and the remaining 12.3 Wm^2 are claimed to come from the feedback. The only way for 3.7 W/m^2 to provide ‘feedback’ >3x more powerful than the forcing itself is if Bode’s assumed infinite power supply is present. Otherwise, there’s no place for these Joules to come from.
As another indication, consider that Joules are Joules and each does the same amount of work (work is measured in Joules) and heating the surface takes work. If the next 3.7 W/m^2 is supposed to provide 12.3 W/m^2 of feedback, then all of the preceding 240 W/m^2 of solar forcing must have had a similar effect and if this was the case, the surface temp would be close to the boiling point of water.
co2isnotevil July 4, 2017 at 7:34 am:
I agree that the idea of a terrestrial runaway greenhouse effect is BS but not because there is not an infinite supply of Joules to support it. Joules are units of energy and there is a practically infinite supply of those being provided by the Sun over time.
The reason that I see for its being utter BS is the water-cycle, whose thermodynamics I think Hawking, Hansen, the IPCC etc., have seriously misconstrued. They are assuming that the net water-cycle feedback to surface warming by the greenhouse effect (from CO2 and other greenhouse gases) is strongly positive and this assumption is the foundation of their claim of a potential runaway greenhouse effect on Earth.
But the water-cycle’s feedback is the climate system’s response to surface warming by any cause, not just its response to warming by GHGs. And positive temperature feedbacks cause temperatures to diverge away from their equilibrium values. (Conversely, negative feedbacks cause temperatures to converge on their equilibrium values.) Therefore, if the net feedback from the water-cycle really was positive, any and all occasions of surface warming above the equilibrium temperature by any amount, no matter how minute, would initiate runaway global warming.
However, I think the mere fact that we are here to talk about it means that runaway global warming has never happened at any time in the Earth’s history since the oceans were formed billions of years ago, in spite of the planet apparently having undergone many periods of warming above (and cooling below) the equilibrium temperature at the time since then. This seems very strong empirical evidence to me that the net feedback from the water-cycle must be negative, not positive as alarmists like Hawking are claiming, and that runaway global warming based on the water-cycle’s thermal feedback is fundamentally impossible on Earth.
RP,
” … infinite supply of those being provided by the Sun ”
The Sun is not the infinite supply of Joules that Bode assumes for his analysis. First of all, the Sun is far from being infinite and has an average incident flux of 240 W/m^2 whose equivalent temperature is only 255K.
Most importantly, the input to the Hansen/Schlesinger feedback ‘amplifier’ is forcing which in a technical sense means solar input and nothing but solar input. If the input and power supply for an amplifier are connected to the same thing (in this case solar forcing), the output power can NEVER exceed the input power. In other words, the surface temperature can never exceed 255K independent on the sign or magnitude of any ‘feedback’. I quote ‘feedback’ because in a Bode sense, feedback has no relevance to how the climate system operates.
Keep in mind that when the IPCC claims a 3C rise from doubling CO2, what they are really saying is that doubling CO2 is EQUIVALENT to increasing post reflection solar input by 3.7 W/m^2 and applying the presumed sensitivity of 0.8C per W/m^2 while keeping the system constant, that is, keeping GHG concentrations constant. Calling GHG’s ‘forcing’ is the fundamental error here. Keeping with the Bode terminology, GHG effects are feedback power and not forcing power, where they redirect some of the surface emissions back to the surface. Clouds act in the same way, except that rather than being a narrow band emitter/absorber, the water in clouds is a broadband absorber and emitter of photons. Note that the power emitted by GHG’s and clouds is not new energy being added to the output, but old surface emissions that have been delayed and returned back to the surface. Bode’s analysis assumes that all output power is new power originating from the assumed infinite supply and that the input and feedback are not consumed but only sampled. In contrast, the climate system consumes the input and feedback to produce its output where consumed feedback is no longer available as output until it passes through the gain block once more.
Also note that they assumed unit open loop gain and for the output to be 390 W/m^2 (288K) arising from only 240 W/m^2 of input, net positive feedback is required and the amount of positive feedback required is f = 1 – 240/390 = 0.384 or 38.4% positive feedback. This result arises from Bode’s gain equation which relates the open loop gain, closed loop gain and the feedback fraction as 1/Go = 1/g + f. Note that when the open loop gain Go is 1, this equation becomes g = 1/(1 – f) which you may recognize as the gain equation references by Hansen and Schlesinger and that assumes unit open loop gain. However, if I arbitrarily call the open loop gain 1.6, then the required feedback is zero. If I call the open loop gain 2, then negative feedback is required since the closed loop gain of 1.6 is the ratio between the output power and the input power that resulted in that output (390/240) = 1.6. Note that they obfuscated the requirements of COE by making it ‘incremental’ and claiming that the output of the feedback loop is temperature, when per Bode, the output must be expressed in units that are linearly related to the input. Bode only applies to linear amplifiers in which case, the incremental gain is always the same as the absolute gain.
The reason for all the obfuscation is that 0.8C per W/m^2 sounds plausible as the sensitivity factor until you express it as 4.35 W/m^2 of incremental surface emissions per W/m^2 of forcing (adding 0.8C to the current average temperature increases emissions by 4.35 W/^2). Since all Joules are equivalent, if the next W/m^2 of forcing increases surface emissions by 4.35 W/m^2 then each of the 240 W/m^2 of total forcing that preceded must also contribute 4.35 W/m^2 to the surface emissions which means that the surface would be emitting 1044 W/m^2 and have a corresponding average temperature of 368K. This is 5C less than the boiling point of water and this simple calculation obviously falsifies a sensitivity as high as claimed. In fact, the actual sensitivity factor is about 1.6 W/m^2 of incremental surface emissions per W/m^2 of forcing which converted into a temperature is about 0.3C per W/m^2.
Yes, if a runaway effect was possible, there would be evidence that it has already happened some time in the past. However, the only ‘runaway’ condition ever proposed to have happened in the past is the snowball Earth hypothesis which goes in the wrong direction for the ‘consensus’.
Also, positive feedback only results in a divergence from equilibrium in the runaway case which is when f >= 1/Go. For the climate, whether what people like to call feedback is positive or negative has no bearing on whether the system will converge or diverge to an equilibrium and the unit open loop gain assumption means that the amplifier would be unconditionally stable for any amount of positive feedback < 100%.
co2isnotevil July 5, 2017 at 12:19 pm
You wrote:
“The Sun is not the infinite supply of Joules that Bode assumes for his analysis. First of all, the Sun is far from being infinite and has an average incident flux of 240 W/m^2 whose equivalent temperature is only 255K.”
Yes, I appreciate that the Sun is not truly an infinite supply of Joules. By saying that it was a “practically infinite” supply “over time” I meant that if the Sun was to continue to supply Joules at a finite rate indefinitely, in time it would become as great as required for any practical purpose on Earth.
Since Joules are units of energy, they can accumulate. Watts (as in ‘240 W/m^2’) are units of energy-flux (a.k.a. ‘power’) and correspond with Joules/sec. So ‘an average incident flux of 240 Watts/m^2’ means that, on average, 240 Joules of energy are delivered to each square meter of the surface every second by the Sun. Hence, over a complete day, each square meter of surface receives, on average, a total of 240x60x60x24 = 20,736,000 Joules of energy whilst the power-supply remains constant at 240 Watts throughout the day.
“Most importantly, the input to the Hansen/Schlesinger feedback ‘amplifier’ is forcing which in a technical sense means solar input and nothing but solar input…(etc)”
Can they really have been that stupid? But I suppose they can, in view of their having implicitly misconstrued something as basic and elementary as the sign of the net water-cycle feedback, to which I referred previously.
“If the input and power supply for an amplifier are connected to the same thing (in this case solar forcing), the output power can NEVER exceed the input power. In other words, the surface temperature can never exceed 255K independent on the sign or magnitude of any ‘feedback’.”
It seems true to me that “the output power can NEVER exceed the input power “ so long as you are talking about averages over sufficiently long periods of time, because in reality the input power and the output power to the climate system are fluctuating continuously. However, this rule does not limit the amount of power that may be circulating inside the climate system between the surface and the atmosphere. It is the recycling of surface output power by the atmospheric greenhouse effect that enables the surface to exist at a higher average temperature than the 255K determined by the power input/output balance at the top of the atmosphere (TOA).
“Keep in mind that when the IPCC claims a 3C rise from doubling CO2, what they are really saying is that doubling CO2 is EQUIVALENT to increasing post reflection solar input by 3.7 W/m^2 and applying the presumed sensitivity of 0.8C per W/m^2 while keeping the system constant, that is, keeping GHG concentrations constant. Calling GHG’s ‘forcing’ is the fundamental error here.”
I think the idea that CO2 can double while GHG concentrations remain constant is the fundamental error here. It’s a self-contradiction.
“Keeping with the Bode terminology, GHG effects are feedback power and not forcing power, where they redirect some of the surface emissions back to the surface.”
I think the effect from GHGs is essentially a positive feedback to the surface radiance. However, I think it also becomes a forcing whenever its magnitude changes (perhaps due to a change in GHG concentrations), because that sets a new equilibrium temperature for the surface. When the new equilibrium temperature is reached, the greenhouse effect ceases to be a forcing, although it remains a feedback to the surface radiance.
“Clouds act in the same way, except that rather than being a narrow band emitter/absorber, the water in clouds is a broadband absorber and emitter of photons.”
GHGs and clouds are the same in that they both capture and recycle some of the outgoing longwave radiant energy emitted by the surface back to it. However, whereas GHGs are relatively transparent to incoming shortwave radiation (from the Sun), clouds are relatively reflective of it and act as an effective sunscreen for the surface. Hence, both GHGs and clouds act as positive feedbacks to the surface radiance all over the planet, but clouds also act predominantly as negative feedbacks on the planet’s day-side where they can reflect up to 90% of incident sunlight. I believe this highly reflective property of clouds is what makes them the principal source of the water-cycle’s net negative feedback.
“Bode’s analysis assumes that all output power is new power originating from the assumed infinite supply….”
I’m not sure about that. At equilibrium, the output from the surface is equal to the input to it and that consists of insolation plus the total power being recycled back to the surface by the atmosphere (including that from GHGs, clouds, aerosols, particulates, etc.). We can represent this situation at the surface with the simple equation:
where S is the surface radiance;
I is the insolation;
R is the power being recycled back to the surface by the atmosphere.
In this equation, I and R are independent terms, which means that the value of R is not limited by the value of I. So, in theory at least, R can have any value between 0 and infinity regardless of the value of I. Likewise, S can have any value between I and infinity, depending on the value of R.
The fact that Joules are being received at the surface at a finite rate does not affect the independence of I and R in this equation.
“The reason for all the obfuscation is that 0.8C per W/m^2 sounds plausible as the sensitivity factor until you express it as 4.35 W/m^2 of incremental surface emissions per W/m^2 of forcing (adding 0.8C to the current average temperature increases emissions by 4.35 W/^2). Since all Joules are equivalent, if the next W/m^2 of forcing increases surface emissions by 4.35 W/m^2 then each of the 240 W/m^2 of total forcing that preceded must also contribute 4.35 W/m^2 to the surface emissions which means that the surface would be emitting 1044 W/m^2 and have a corresponding average temperature of 368K.”
ROFLOL! Those figures are obviously crazy and I think they show up the absurdity of the definition of climate sensitivity to CO2 as being a constant amount from a doubling of CO2 concentration regardless of any fixed baseline from which the CO2 doubling should start. However, anything’s possible in the wonderful world of ‘climate seance’, I dare say.
RP,
“By saying that it was a “practically infinite” supply “over time” …”
But the planet is also radiating energy at the same 240 W/m^2 rate so the net power available above and beyond what’s required to sustain the current temperature is 0 w/m^2 and no matter how long you wait, it will remain 0. While Joules can accumulate, the temperature is linearly proportional to accumulated Joules (1 calorie increases 1 gm of water by 1C) while emissions increase at a rate proportional to T^4. The fact that emissions increase at a faster rate then the temperature is something that consensus climate science seems to deny.
“Can they really have been that stupid?”
Yes they can and are. I’ve had discussions with Schlesinger, who along with Hansen developed the feedback model. They made so many silly and obvious errors in the analysis, refuse to acknowledge that they made any mistakes and refuse to defend themselves and explain why the errors I pointed out might not be errors.
“I think the idea that CO2 can double while GHG concentrations remain constant is the fundamental error here. It’s a self-contradiction.”
No. This is a trivial example of EQUIVALENCE, that is two systems whose behavior is indistinguishable from each other. Doubling Co2 keeping post albedo solar input constant is EQUIVALENT to increasing post albedo solar input by 3.7 W/m^2 while keeping Co2 concentrations constant. In other words both will have the same effect on the surface temperature.
“So, in theory at least, R can have any value between 0 and infinity regardless of the value of I”
Not exactly and this is the fault with the consensus model which basically assumes R can be infinite and that this represents the runaway condition (this is what requires the infinite power supply). R in this case is the ‘feedback’ term and the amount of feedback can not exceed the amount of output, which is S, moreover; any amount of output returned as R can not be counted as S because the climate system consumes I and R to produce S, while the feedback model samples I and R to determine how much S to deliver from an infinite power supply. In other words, the unacknowledged and required input impedance of the feedback ‘amplifier’ modelled by Hansen/Schlesinger is 0 while Bode assumes an infinite input impedance.
The other constraint here is that as R increases, which is the energy returned to the surface by the atmosphere, the energy emitted by the atmosphere into space increases by the same amount, thus if all of S is absorbed by the atmosphere, R is then limited to I and S is limited to 2*I. This is what the consensus fails to understand which is that the origin of the energy that leaves the atmosphere is prior surface emissions which can not be counted twice and that the energy absorbed by the atmosphere is returned to the surface and emitted into space in roughly equal amounts. They seem to be flummoxed by Venus by failing to understand that the surface of Venus in direct equilibrium with the Sun (i.e. the emitter of S) is high up in the clouds and not the solid surface below whose temperature is dictated by a lapse rate applied to the distance between the surface in equilibrium with the Sun and the solid surface below.
“… I think it also becomes a forcing”
No. In a strict sense, only the Sun is a forcing influence and changing CO2 represents a change to the system. But as I pointed out, the resulting surface temperature change from a change to the system can be EQUIVALENT to the result from a change in forcing. Note that Bode explicitly defines forcing as the input to the system. So much obfuscation arises as climate science repurposing terms that have a specifically defined meaning (forcing, feedback, sensitivity) to represent something entirely different, yet retain the implications of the original meaning.
co2isnotevil July 7, 2017 at 9:00 am
That only applies to the input and output of the whole system at equilibrium. When we look at the basic components (i.e. surface and atmosphere) we find the following approximate power-flows.
The surface receives about 240 W/m² of insolation plus about 150+ W/m² from the atmosphere, making 390+ W/m² in total. Since the system is in thermal equilibrium, the surface output must balance the surface input, so the surface then radiates its 390+ W/m² straight into the atmosphere towards space.
The atmosphere receives the surface’s 390+ W/m², apprehends some of it on its way through to space and recycles 150+ W/m² of it back to the surface whilst venting the remaining 240 W/m² directly to space. The atmosphere’s ultimate 240 W/m² output is the same as the 240 W/m² primary solar input, so that the overall input/output power-balance is maintained constantly at 0 as you indicated above.
However, there is no requirement for an infinite energy supply to enable the system to sustain itself in this state. A finite one of 240 J/sec/m² (i.e. 240 W/m²) is evidently sufficient.
There is no incompatibility or incongruence between the two formulae as far as I am aware. They simply describe different things and give their results in different units accordingly. The first formula relates to heat content and is expressed in units of Joules; the second formula describes radiance (i.e. the rate of energy-emission by radiation) and is expressed in units of Joules/sec, which are Watts. Taken together they suggest that hotter bodies contain more heat, but they also radiate their heat content away faster than cooler bodies do.
It is truly shameful for people who profess to be scientists to behave in this way. What hypocrites!
OK. Thanks. I see what you mean now.
But what is your objection to this equivalence? I don’t see anything wrong with it in principle (although I might want to take issue with the numbers).
Sorry, but I’m still not ‘getting’ your objection to R having a value between 0 and infinity in theory. Obviously, R could never actually become infinite in the real world, but no-one is suggesting that it could, are they?
Of course, if R could be infinite in reality, that would certainly represent a runaway condition. But I don’t think it is a necessary pre-requisite.
Positive feedback is a system’s response to an action that increases the magnitude of the action. I think runaway conditions can develop under any circumstances where the positive increment added to the action in each cycle is greater than the increment added in the previous cycle, so that the sequence of increments forms a divergent mathematical series, the sum of which always tends towards infinity. If, on the other hand, each cycle’s increment is smaller than the previous one, the sequence forms a convergent arithmetic series whose sum will always tend towards a finite total. In that case, the feedback is intrinsically self-limiting and in no danger of going runaway, even though the nature of the feedback is positive.
So the essential factor which determines whether or not the process will go runaway is not the magnitude of the feedback at some particular time (i.e. R in the climate case we are considering) but the magnitude of the system’s response in each cycle, because that determines the size of each increment in the series.
Therefore, what alarmists like Hawking, Hansen etc. need to support their claim of a potential man-made runaway greenhouse effect, is robust evidence for a positive, mathematically-divergent sequence of climate system-responses to some initial warming induced by man, not just evidence for an initial, human-induced warming that is thought to be big enough to instigate the runaway process.
As far as I can see, the alarmists have absolutely no evidence whatsoever for either of these things and therefore I believe their claim fails on fundamental grounds of objective scientific fact and established physical law.
That’s insane.
A reference link would probably be helpful here.
This is certainly some of the accumulated dung that piles to the rafters of the Augean Stable that presently comprises the House of Climate Science.
RP,
“The atmosphere receives the surface’s 390+ W/m², apprehends some of it on its way through to space and recycles 150+ W/m² of it back to the surface whilst venting the remaining 240 W/m² directly to space.”
Only about 150 of the 240 ‘vented’ to space originates from the atmosphere. The remaining 90 W/m^2 is what passes through the transparent window in the atmosphere. The atmosphere intercepts 300 of the 390 emitted by the surface where half is returned to the surface and half escapes into space. The clear sky alone absorbs more than 150 W/m^2 and when you add clouds, absorption increases to about 300.
It’s dividing the power entering the atmosphere by 2 that sets the limit since no more than 50% of the surface emissions can be returned to the surface. If the surface emitted 1000 W/m^2 and the atmosphere absorbed all of it, returning half the surface, 500 more W/m^2 are required for balance, while only 240 are available, moreover; 500 W/m^2 will be emitted while only 240 is being received. The planet will then cool until it is emitting 240 W/m^2.
You are correct that at this rate, no implicit power supply is required. But, at this rate, the sensitivity is quantifiably deterministic to be about 0.3C per W/m^2. You get there by considering that the atmosphere returns 62% of the 240 W/m^2 of solar input to the surface, or a ‘feedback’ term of about 0.62 W/m^2 per W/m^2 and that when 1.62 W/m^2 is added to 390 W/m^2, the resulting temperature is about 0.3C warmer. The implicit supply is required to support the IPCC sensitivity of 0.8C per W/m^2 which requires 3.4 W/m^2 of feedback per W/m^2 of forcing while only 0.62 can be supplied by the system as it’s energized by the Sun.
You can download Bode’s book here which is the primary feedback related reference in both Hansen’s and Schlesinger’s papers.
https://archive.org/details/NetworkAnalysisFeedbackAmplifierDesign
Here are some page references:
Bode H, Network Analysis and Feedback Amplifier Design
assumption of external power supply and active gain, 31 section 3.2
gain equation, 32 equation 3-3
definitions of feedback fraction and feedback factor, 32-33
real definition of sensitivity, 52-57 (sensitivity of gain to component drift)
effects of consuming input power, 56, section 4.10
impedance assumptions, 66-71, section 5.2 – 5.6
a passive circuit is always stable, 108
Bode plots and stability, 137-168
definition of input (forcing) 31
co2isnotevil July 9, 2017 at 2:57 pm:
This 50:50 division is starkly contradicted by the example of Venus, where the proportion of surface radiance recycled by the atmosphere is over 99% if NASA’s Venus data can be believed!
Thanks for the link you gave to Bode’s tour de force and the page number references. Although he was writing for electrical and electronic engineers, I’m sure many of the concepts he discusses will also have parallel applications in climate science.
RP,
Yes, Venus is a source of confusion. The reason is that the solid surface of Venus is no more a surface in equilibrium with the Sun than is the surface of Earth beneath the deep oceans. What matters is identifying the surface in DIRECT equilibrium with an incoming energy source. On Earth, this isn’t the solid surface of the planet either, but the top surface of the oceans and the bits of land that poke through. The temperature of the solid surface below the deep ocean is about 0C and exhibits absolutely no diurnal or seasonal variability. Similarly, the solid surface of Venus exhibits absolutely no diurnal or seasonal variability, albeit at a much higher temperature. The temperatures of both are dictated by the temperature/density/pressure profile of the matter separating the surface whose temperature we are measuring from the virtual surface above and that’s in DIRECT equilibrium with the Sun.
On Venus, this surface is high up in the cloud layers of its atmosphere. The GHG effect between the emitting surface of the clouds and space affects the temperature of the cloud tops and the temperature of the surface below has an effect on the temperature of the bottom of the cloud layer, but the lapse heading down towards the surface sets the temperature gradient. Keep in mind that the cloud layers of Venus are mostly at a couple of ATM or less, while the surface has a pressure is closer to 90 ATM making the Venusian clouds form much higher in the atmosphere then they do here on Earth (clouds precipitating bismuth not withstanding). Note that about half of the absorbed energy emitted both up and down by the clouds is returned to the clouds, as it is here on Earth. The difference is that Earth clouds are tightly thermodynamically coupled to the surface in equilibrium with the Sun through evaporation/precipitation while on Venus, the clouds are the virtual surface in equilibrium with the Sun and are thermally decoupled from the surface below by a lapse rate.
Bode’s analysis doesn’t map to the climate system at all and this is my point. The whole concept of climate system feedback is dependent on the climate system conforming to a Bode feedback network. This means that the system must also obey Bode’s preconditions which the climate system does not. Add on top of this the mistakes made by Hansen and Schlesinger in their attempts to map the climate to Bode and the whole concept of climate feedback as framed by the IPCC becomes irrelevant.
co2isnotevil July 10, 2017 at 1:23 pm:
Indeed. But the solid surface of Venus doesn’t need to be in equilibrium with just the Sun, does it? It also needs to be in equilibrium with the atmosphere above it at the same time. Hence the equation for the planet’s surface at equilibrium:
I and R are both energy sources to the surface here.
I’m not sure what you’re meaning to say here. That the temperatures of both are caused by the profile, or just that they can be determined by it mathematically? I could agree with the latter, but not the former.
OK, point taken.
I can well believe that Hansen and Schlesinger misapplied Bode’s concepts to the climate system. However, I think they also misconceived both Venus’s and the Earth’s climate systems in important ways to begin with.
On Venus, for example, they have misattributed most or all of the immense positive feedback from the atmosphere to the surface to the Venusian CO2. That is obviously impossible because the Venusian surface is not radiating enough power on CO2 absorption wavelengths to support the amount of power being returned by the feedback.
And on Earth, they have ignored the rather elementary fact known to most schoolchildren that the water vapour feedback to surface warming which is supposed to drive man-made global warming past all the still-unproven tipping points and on to climate catastrophe, will inevitably turn into clouds, whereupon they will induce cooling by the increased reflection of incoming sunlight – a well-known negative feedback called the ‘Iris effect’.
When people make scientific mistakes of such a crude and obvious nature I don’t think we need to examine their climate models in any further depth or detail. It’s self-demonstrated junk at first sight and we can safely bin it.
RP,
They definitely incorrectly attributed the Venus surface temperature to a runaway GHG effect caused by positive feedback. It is more accurately quantified as a runaway cloud effect. If Venus has no clouds, but otherwise had the same 90 ATM of CO2, the surface would be far far cooler than it is now because under these conditions, the GHG effect WOULD influence the surface temperature, whereas now, there’s another more important constraint.
This constraint is the sign and direction of the lapse rate. On Earth, the surface is in equilibrium with the Sun and the temperature profile of the atmosphere is dictated by the atmosphere. The temperature of the atmosphere starts at the surface temperature and decreases with altitude at about 10C per km. The specific heat of CO2 is about 20% lower, so the lapse rate for dry CO2 would be about 12C per km. Adding the other components, the specific heat increases and the lapse rate becomes between about 9C 10C per km which is comparable to the average lapse rate on Earth.
On Venus, the cloud layer starts at about 50km which at 9C per km represents a lapse of between about 450C and 500C which is exactly what we need to separate a surface at 460C from clouds at about 0C. There’s no need to even invoke runaway GHG effect to try and explain the surface temperature.
On Venus, the Sun heats the clouds which heats the atmosphere which heats the surface and the lapse rate puts a constraint on the surface temperature, relative to the temperature of the clouds and the atmosphere heating it. On Earth, the lapse rate puts no such constraints on what the surface temperature must be because the Sun is the source of energy heating the surface and the atmosphere is mostly transparent to solar radiation.
One reason this concept has become too controversial is because some have suggested that the lapse rate determines the temperature of the Earth’s surface, but it does not. Earth and Venus are so different that while the lapse rate has no effect on the Earth’s surface temperature, it’s the primary influence on the temperature of the Venusian surface and many have a hard time wrapping their brains around the implications of the differences.
You should also consider why the atmosphere of Jupiter heats up as you go inward. This is the effect of gravity on a lapse rate which is given as g/cp, where g is the acceleration due to gravity and cp is the specific heat of the atmosphere.
co2isnotevil July 11, 2017 at 1:49 pm
Caused specifically by positive feedback from a combination of CO2 and water vapour, I gather. (See Wikipedia here.)
But since water has an extremely large specific heat capacity AND an extremely large latent heat of vaporisation, it seems extremely unlikely to me that the positive feedback from water vapour to the greenhouse effect of the Venusian CO2 would be powerful enough to initiate a runaway amplification spiral in the first place. And even if it was sufficiently powerful to do that, a restraining negative feedback would also start to develop as soon as the atmospheric water vapour turned into clouds, which would be even more reflective of incoming sunlight than its present ones composed of sulphuric acid, so I think a runaway warming process would be virtually impossible under those circumstances.
However, I’m sure there is a significant cloud effect on Venus as you say. And a significant gravitational lapse effect too, which conspires with the cloud effect to maintain the surface temperature at its remarkable 465°C or thereabouts.
I’m sure the gravitational lapse effect must occur in Jupiter’s atmosphere, probably more than it does in all the other planets’ atmospheres too given Jupiter’s larger and denser atmosphere and its stronger gravitational field. But Jupiter seems something of a scientific anomaly right now, since it is radiating more power than it is receiving from the Sun. I can only speculate about what might be going on in its hidden depths that is causing this apparent TOA input/output disequilibrium.
Yes, water vapor on Venus is irrelevant, but as I pointed out, the greenhouse effect is also irrelevant when it comes to establishing its surface temperature. For one thing, there’s little water vapor in the lower atmosphere since the only way it can get there is to condense and precipitate, but the atmosphere is so hot, it doesn’t get very far into the atmosphere before it evaporates and starts to rise again. CO2 is heavier than O2/N2 so water vapor rises even faster in a CO2 atmosphere than in the Earth atmosphere.
The only logical explanation for this is the precautionary principle. This is based on fear. What if!!
The greatest mathematical brains on earth can be afraid to cross a road, for fear of being hit by a car!
I don’t believe anyone can truly understand/communicate w/Hawking any more, and that his “statements” are actually those of his handlers.