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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Suggested supplemental reading:

What Is Kilauea’s Impact on the Climate? by Emily Atkin, The New Republic, May 26, 2018

nigelj at 14:12 PM on 28 May 2018

2018 SkS Weekly Climate Change & Global Warming Digest #21

Volcanoes just don't emit enough CO2 to explain global warming over the last several decades. The magma from volcanoes does have a lot of dissolved gases including CO2, however emissions from fossil fuels are approximately 100 times greater, and emissions from volcanoes have been measured in multiple ways. The keeling curve is also smooth, rather than punctuated by peaks when volcanoes explode.

www.scientificamerican.com/article/earthtalks-volcanoes-or-humans/

Its also a question of what explains the increased atmospheric levels of CO2 in the keeling curve . I was as curious as anyone, so last year I did some digging. Volcanic activity has just not increased over the period when CO2 levels have significantly increased, so volcanoes cannot be the source of the growth of CO2. Look up "list of large volcanic eruptions of the 19th century on wikipedia" and ditto for the 20th century. There are no clear differences between the two centuries overall, although if anything the 19th century had a couple more really large eruptions. I'm not aware of any evidence of significant changes in undersea volcanic activity.

Generally volcanic activity is reasonably regular on these time scales which is not surprising given its a release of pressure from a regular sort of process beneath the crust.

Unfortunately people listen to other people on talk back radio or websites that spread climate denial ignorance, but who sound plausible and confident. I'm a strong freedom of speech advocate, but this ignorance is now on a huge scale.

Moderator Response:

[JH] Also see the SkS rebuttal article, Do volcanoes emit more CO2 than humans?

VictorVenema at 12:49 PM on 28 May 2018

Climate Science websites around the world

For the counterpart article on climate blogs in other languages: In Dutch there is the climate blog of Bart Verheggen: Klimaatverandering.

Evan at 07:05 AM on 27 May 2018

New research, May 7-13, 2018

Military leaders, corporate CEOs, fiancial investors, and decision makers at many other levels also deal with uncertainty when making decisions. It is not unique to science and uncertainty is usually not a good reason for inaction. It is simply being overstated in the context of science as an excuse for doing nothing.

BaerbelW at 16:56 PM on 26 May 2018

Climate Science websites around the world

SirCharles - thanks for the links but I'm actually looking for full-fledged non-English websites for this particular article, not just climate-related content in other languages.

As I'm getting other suggestions for non-English blogs, I'll start a collection of those for a counterpart article about "Climate science blogs around the world".

SirCharles at 07:26 AM on 26 May 2018

Climate Science websites around the world

Two music graphs (CC). Feel free to use them:

Jan 1880 - Dec 2017 Monthly Global Temperature Jazz
https://www.youtube.com/watch?v=amXQMGdWWwo

Global Sea Level Jazz | Jan 1993 - Mar 2018
https://www.youtube.com/watch?v=3se9FR6EoMU

SirCharles at 06:30 AM on 26 May 2018

Climate Science websites around the world

You want sites in English too?

SirCharles at 06:28 AM on 26 May 2018

Climate Science websites around the world

German Alpenverein => https://www.alpenverein.de/Natur/Klimaschutz/

More German sites => https://www.alpenverein.de/natur/klimaschutz/klimawandel-klimaschutz-nachhaltigkeit-weblinks-wo-steht-was_aid_15504.html

rojerfred at 16:53 PM on 25 May 2018

New research, April 16-22, 2018

In a first-of-its-kind study, scientists have combined an array of NASA satellite observations of Earth with data on human activities to map locations where freshwater is changing around the globe and why.

One Planet Only Forever at 04:41 AM on 25 May 2018

Yes, EVs are green and global warming is raising sea levels

My understanding has always been along the lines of the Kevin Anderson quote in Evan's comment @19. And I own a hybrid because where I live it is better than running an all-electric off of the power from the crappy Alberta regional electrical grid that still includes coal burning as a part of the base-load (meaning that even though there are renewable generating options built, the use of coal burning is maximized and the renewables are minimized (even a grid fully powered by burning natural gas produces about 0.6 kg of CO2/kWh which means 1.2 kg of CO2 per 100 km driven based on an electric vehicle efficiency of 20 kWh/100 km. My hybrid annual efficiency is 4.5 l/100 km (closer to 4.0 in the summer and closer to 5.0 in the winter). And burning gasoline is about 3 kg CO2/l when allowance is made for the CO2 associated with extraction, refining and transportation. So in the future my hybrid at 13.5 kg CO2/100 km will only be marginally poorer than an all electric that is powered from Alberta's future grid, after Alberta stops burning coal in 2030, which may not happen if the new United Conservative Party wins the next election).

The only advancements that are true advancements are the ones that reduce consumption of materials or energy to achieve an objective. Kevin states that because of the lack of responsible action in the past to shift to more sustainable ways of getting energy dramatic reduction of energy consumption is now required while the required corrections of energy production are implemented. My understanding has always been that reduction of energy consumption is the proper objective of efforts to develop new things. And I add that 'All of the richest' need to be required to lead the way to sustainable ways of living (not just the richer ones who care to behave better), because the richer ones are the ones who can afford to behave better.

Cheaper quicker flashier 'New'ier ways to do things will always be around and get created. But to sustainably advance humanity any unsustainable or harmful way of doing things ultimately needs to be excluded from competing for popularity and profitability.

Significant effort is undeniably required to overcome the damaging developed popularity and profitability of unsustainable developed ways of doing things. Sustainable ways of doing things cannot compete with the unsustainable alternatives, especially when more people get used to benefiting form the unsustainable or harmful activity. That reality is a Truly Inconvenient Truth.

The best any of us can do is pursue better understanding of what is going on and determining how our actions can best help achieve a sustainable improved future for humanity. That requires constant skeptical investigation of things, with a critical eye always looking for truly sustainable developments and identifying unsustainable things that have developed that need to be corrected or curtailed.

A Good first step is recognising/admitting that self-interest can severely cripple skeptical critical thinking, leading to damaging developments of popular and profitable activity that can develop tremendous resistance to being corrected. A self-interested person will skeptically and critically understand that they have less potential for personal benefit if the accept a true better understanding in pursuit of sustainably improving things for the future of humanity.

Another good step is understanding that the understanding of how to get away with misrepresentations and other misleading marketing is potentially the most destructive thing that humanity has ever developed. And promoting a belief that people should be freer to believe whatever they like and do as they please in pursuit of 'their personal interest' will likely create a massively destructive society, because many people will be tempted to like unjustified damaging and ultimately unsustainable beliefs.

The result of promoting self-interest and people having more freedom to believe and do as they please, will be a society that John Stuart Mill warned about in the following quote from "On Liberty" - “If society lets a considerable number of its members grow up mere children, incapable of being acted on by rational consideration of distant motives, society has itself to blame for the consequences.”

But the damage is done to future generations who can blame their predecessors, but as stated in the following quote from the 1987 UN Report "Our Common Future", the future generations have no ability to actually get even with the ones who caused their problems.

"25. Many present efforts to guard and maintain human progress, to meet human needs, and to realize human ambitions are simply unsustainable - in both the rich and poor nations. They draw too heavily, too quickly, on already overdrawn environmental resource accounts to be affordable far into the future without bankrupting those accounts. They may show profit on the balance sheets of our generation, but our children will inherit the losses. We borrow environmental capital from future generations with no intention or prospect of repaying. They may damn us for our spendthrift ways, but they can never collect on our debt to them. We act as we do because we can get away with it: future generations do not vote; they have no political or financial power; they cannot challenge our decisions.
26. But the results of the present profligacy are rapidly closing the options for future generations. Most of today's decision makers will be dead before the planet feels; the heavier effects of acid precipitation, global warming, ozone depletion, or widespread desertification and species loss. Most of the young voters of today will still be alive. In the Commission's hearings it was the young, those who have the most to lose, who were the harshest critics of the planet's present management."

MA Rodger at 00:22 AM on 24 May 2018

Trenberth can't account for the lack of warming

ab,

With you remaining oblivious to everything said to you and your continued spouting of the same nonsense, I would suggest your time here draws short. Perhaps you should think about returning wence you came. (I note you spent a week fulling up the borehole at RealClimate prior to arriving here at SkS.)

Moderator Response:

[DB] User ab has recused themselves from further participation here.

Eclectic at 23:55 PM on 23 May 2018

Trenberth can't account for the lack of warming

Ab @51 ,

if your proposed 1m x 1m square "black body thermometer" is absorbing 890 watts in total, and is emitting 890 watts upwards . . . then its lower surface (facing the ground) must be emitting no watts at all. In other words, the lower surface must have a temperature of absolute zero.

Do you not find that to be a peculiarly interesting situation?

Could be a source of energy for a perpetual motion machine . . . or a wonderful new way of generating unlimited electric power !

ab at 23:07 PM on 23 May 2018

Trenberth can't account for the lack of warming

MA Rodger @48, Philippe Chantreau @49, Glenn Tamblyn@50,

It seems to one that you are clearly confounding the amount of energy reaching a unit of surface (the fluxes in the IPCC's diagram that we are talking about here) with the amount of energy emitted per unit of surface of the source of the flux itself. Those are totally different concepts.

In the IPCC's diagram, the solar flux coming in is not based on the unit of surface of the sun, it is based on the unit of surface of the Earth, that is, it is based not on the unit of surface of the source, but on the unit of surface of the target: it is directional, as all fluxes are.

Many people have difficulties with fluxes, and from what you are writing, I understand that you are not familiar with them, but in the Earth's Energy Budget, we have to use them, because it is based on them, and we are reasonning with them, as all calculations here are done with fluxes.

A flux in the Earth's Energy Budget is measured as a surface power density in time (W m-² for a given period), so there is no need to look at areas, geometries, and energy, as the surface power density is independent of the surface or geometry that is reached: it radiates some amount of energy per unit of surface in time.

So the unit of surface of a flux is "per se": it is not the unit of surface of the object reached by the flux, it is independent of any particular geometry. Moreover, we are not dealing with the energy exchanged by a particular object per unit of its own surface: we are dealing with "outward", "directional" vectors of energy only here, transmitted by a blackbody.

A blackbody receives input fluxes and emits output fluxes, such as the total input flux is equal to the total output flux by definition. Why ? Because for 1 unit of surface "per se", there has to be the same amount of energy emitted or received for a given period in order that as much energy comes in than goes out of the blackbody. Therefore the total input and total output have the same value.

In other words, there is the same surface power density going in than going out per unit of time, and the total flux value is independent from the blackbody surface, only the number of fluxes, their value and their direction being regulated by the surface, but not their total value, in conformity with the definition of a blackbody radiation.

In other words, each m2 reached by the total input flux will have the same amount of energy than each m2 reached by the total output flux, because a blackbody emits as much as it receives, independently of its own surface or geometry, which is another issue.

So, in fluxes, the total input flux is equal to the total output flux for a blackbody, and it is quite different than the amount of energy emitted per unit of surface of the object itself.

Therefore, coming back to the IPCC's Energy Budget, we add all inputs fluxes together for a blackbody on Earth's surface and we get 890 W m-² coming in.

Because it is a blackbody, there has also to be an output flux of 890 W m-²: it is the same flux going out than going in, only the direction and the quantity and value of individual fluxes are changing, not its total value per m².

Now, if that is clear, at thermal equilibrium, let's apply the Stefan-Boltzmann Law. We get for a blackbody emitting/receiving a flux of 890 W m-² a temperature of 80,8°C.

What would be the input flux for the normal temperature of Earth, 15°C, as experimentally measured on Earth's surface ? Let's apply again Stefan-Boltzmann Law: we get a 390,9 W m-².

Conclusion:

IPCC's radiative model has a 65,8°C difference in temperature, and a 499,1 W m-² difference in radiative fluxes with experimental measures.

IPCC's uncertainties concerning previsional temperatures are just a distraction compared to the huge difference existing between the radiative model and the experimental measures, the radiative model being at the basis of all prevision models.

Loki at 22:31 PM on 23 May 2018

Climate change is already making droughts worse

Anomalous Synergies

Stratosphere = 10-50 km

Troposphere = 0-10 km

Lower stratospheric ozone declines are biggest between 60° South and 60° North. I will refer to this area as mid latitude which includes the tropics. The tropics are 50% of human habitat.

Lower stratospheric ozone is much more abundant than the high stratospheric ozone at the poles, where ozone depletion has somewhat ceased. This abundance makes mid latitude ozone more important to us than high altitude polar ozone.

Mid latitude/lower stratospheric ozone depletion causes more damage to DNA in plants, animals and humans because radiation is more intense in these regions and more people live there. I believe that stronger winds are sending more ozone killing gas into lower stratospheric mid latitude areas.

https://www.sciencedaily.com/releases/2018/02/180206090709.htm

https://www.scientificamerican.com/article/wait-the-ozone-layer-is-still-declining1/

Ground ozone (tropospheric) ozone is a pollutant that is harmful to breathe and toxic to plants. It is also the 3rd most abundant greenhouse gas, not including water vapor I believe. Ground-level ozone pollution is already decreasing global crop yields from 2–6% for maize to 4–15%, and 9–14% for wheat and soybeans. Ground ozone visibly harms foliage and reduces their ability to suck carbon out of the air. North American emissions can affect ozone-induced yield losses in Europe. I believe increased winds are destroying stratospheric ozone. This is complicated by the fact that Asia may be cheating on the Montreal Ozone Protocol.

How is ozone pollution reducing our food supply? - Scary stuff.
https://academic.oup.com/jxb/article/63/2/527/504895

Emissions of banned ozone-destroying chemical on the rise
http://www.digitaljournal.com/news/environment/emissions-of-banned-ozone-destroying-chemical-on-the-rise/article/522644

Oceans currently suck up boatloads of ozone, but as Asia increases nitrous oxide emissions from farms and cars, these ocean ozone sinks will turn into ozone sources.
https://www.newscientist.com/article/dn14211-tropical-ocean-sucks-up-vast-amounts-of-ozone/

Earth's magnetic field has a big hole below the equator that stretches from Chile to Zimbabwe Africa. I imagine chunks of Cratons (huge upside-down mountains) break off and swirl around enough to upset steady magnetic field generation, which may or not be temporary. This area between South America and Africa is the same area affected by ozone depletion. The combination of ozone depletion and a weakening magnetic field will be doubly deleterious to plants and humans in those areas from space radiation because it takes both tropospheric ozone and a strong magnetic field to protect mid latitudes from the sun and space radiation threats.

Water from the tundra and polar ice is moving to the equator, so much so that it lowers polar gravity and slows down earth's crust relative to its core. The rebounding and slowing crust has a double whammy effect on earth quakes and volcanoes. Volcanoes are extremely sensitive to nearby water and ice pressures.

A Mysterious Anomaly Under Africa Is Radically Weakening Earth's Magnetic Field

https://www.sciencealert.com/something-mysterious-under-southern-africa-dramatically-weakening-earth-s-magnetic-field-south-atlantic-anomaly

More volcanoes and quakes are expected this year. When volcanoes go off, they emit sulphur which destroys ozone.

2018 may be the year the earth slows and the world panics
https://www.stuff.co.nz/environment/100345652/2018-may-be-the-year-the-earth-slows-and-the-world-panics

How future volcanic eruptions will impact Earth's ozone layer
https://phys.org/news/2017-08-future-volcanic-eruptions-impact-earth.html

What's important to the ozone are volcanic halogens. Scientists are just starting to figure out how important halogens are to their models. A good burst of volcanic halogens means you can kiss that ozone goodbye. Dire indeed.

The 2 top causes of civil collapse are drought and volcanic ash. We got lots of both this year. Don't say I didn't warn you.

Moderator Response:

[DB] Off-topic snipped. Please comport your comments with the OP of the thread you post them on and the Comments Policy.

Glenn Tamblyn at 17:41 PM on 23 May 2018

Trenberth can't account for the lack of warming

"and the area of the object is of no importance at all".

Um, sorry ab, wrong. Area is absolutely important.

You aren't clearly enough distinguising between flux per unit area, and flux.

In your simple plate example, the plate absorbs 890 watts, from where-ever. It then needs to radiate 890. Since it has a total surface area of 2 m^2 it thus has to radiate 445 per square meter. And the SB equation calculates flux per square meter. So feed 445 into the SB calculator and you get around 14.

The mistake you seem to be making, at least implied, is assuming the SB calculator gives you flux (in watts) when it is actually flux per square meter.

If the plate had a surface area of 10 m^2 and absorbed 890 watts from where ever, it would need to radiate at 89 watts/m^2 to be in balance and the SB calculator would give a much lower temperature than 14 C.

Area matters totally unless you keep all your calculations on a per square meter basis.

Art Vandelay at 16:20 PM on 23 May 2018

Video: The Myth of the Mini Ice Age

There are quite a few solar physicists who no longer subscribe to the Maunder climate theory. Some of the reasons include methodology changes that have altered SSN's since SSN's were observed and documented, and when SSN is homogenised the Maunder minimum doesn't actually exist. And there's little observational evidence that cosmic radiation affects climate as a consquence of cloud feedback changes, as proposed by Svensmark and Christensen. The only metric of value is TSI (irradiance), and as the is spelled out in the video, is a minute modulation.

Philippe Chantreau at 11:01 AM on 23 May 2018

Trenberth can't account for the lack of warming

ab is trying to pull a G&T type of argument. Not interesting. Just trying to play games.

Moderator Response:

[PS] Looks more like skydragon to me.

MA Rodger at 07:57 AM on 23 May 2018

Trenberth can't account for the lack of warming

ab @45,

Reading your comment @45 suggests you have a problem, not with physics, but with the simplest geometry. You write "That is, you have created a flux of 890 W coming in and two fluxes of 445 W going out, one at the bottom and one at the top. Those two output fluxes are generated from one square meter of surface, thus the fluxes that you have created are of 445 W m-²."

But it is not "one square metre of surface."

If I have a flat object measuring 1m x 1m. It has two surfaces, a top surface and a bottom surface. Both top and bottom surfaces have a surface area of 1 sq m. Thus the flat object with its two surfaces has a total surface area of 2 sq m.

nigelj at 07:51 AM on 23 May 2018

Climate change is already making droughts worse

And climate change together with land use changes is causing rivers to dry up, which is causing rapid decomposition of accumulated and exposed leaf litter, and release of CO2 to the atmosphere. The scale of this is significant and not part of current climate modelling, new research here .

nigelj at 07:08 AM on 23 May 2018

Climate change is already making droughts worse

Drought is of course one of the biggest fears of farmers all around the world. The great drought in America's great plains in the 1930s called "the dust bowl" was caused by natural factors but coincided with a warming period which possibly made it worse?

The drought combined with poor farming methods to cause massive soil erosion and dust storms. Despite improved farming systems, millions of acres are still lost to soil erosion each year.

Climate change in New Zealand is expected to increase droughts , stormy weather and so make wind erosion worse. When topsoil is eroded soil carbon is lost to the atmosphere, creating a positive warming feedback.

What do Americas leaders say? "Its all a Chinese hoax". Talk about weapons grade ignorance.

ab at 06:36 AM on 23 May 2018

Trenberth can't account for the lack of warming

michael sweet @ 46,

My calculations have no error and the area of the object is of no importance at all:

Once again, one is not dealing with energy but with fluxes of energy.

Kindly reread my commentary above (@45).

The results are that IPCC's radiative model has a 66°C divergence with observed temperatures.

Unfortunately, here, most posters do not seem to be familiar with physics of fluxes and confound fluxes with energy exchange.

You can not comprehend radiative fluxes with simple energy exchange considerations.

It is like wanting to do quantum mechanics with classical physics.

Moderator Response:

[DB] Inflammatory snipped.

michael sweet at 06:28 AM on 23 May 2018

Trenberth can't account for the lack of warming

Ab,

This is a perfect example of why it is a waste of time for posters to do their own calculations.

As MA Rodger has pointed out, the surface you are discussing has two faces. One is 1 m2 pointing up and the other is 1 m2 pointing down. That means it has a total surface area of 2 m2. This absorbs 890 Watts total and radiates 495 W/m-2 up and 495 W/m-2 down. The area of the object is 2 m2.

Your calculation has a gross math error and you do not understand MA Rodgers explaination. Since you cannot do basic physics calculations without gross math errors, why should I think you can explain the greenhouse effect to me? You think the IPCC has made a mistake but the issue is you cannot do math correctly.

If you are interested in learning how to do the calculation correctly, if you ask nicely there are several people at SkS who are willing to show you how it is done. If you want to lecture us on how smart you are you need to find a venue where they cannot do the math properly.

ab at 05:07 AM on 23 May 2018

Trenberth can't account for the lack of warming

MA Rodger @43,

I can not put it any simpler either and it is very simple physics: of course the blackbody thermometer receives 890 W in the lapse of time that is considered, which is the period between Mars 2000 and May 2004 for the diagram, but here we are talking of fluxes of energy, we are not concerned with the energy itself.

A flux, or flow, represents an emission or a reception of a certain amount of energy per unit of surface in time.

So what is the total flux of energy coming in ? 890 W m-²

And what is the total flux of energy coming out ? also 890 W m-² because it is a blackbody: it emits as much energy as it receives, or in other words, it has the same emission and reception flux.

The only difference between the reception flux and the emission flux being that the blackbody radiates its energy according to its own surface: both 445 W m-² at the top and at the bottom, whereas the reception flux comes in three different fluxes: two at the top and only one at the bottom.

But the energy is conserved, because both incoming and outgoing fluxes are equal: 890 W m-².

Otherwise, if you say that the total flux of energy going out is only 445 W m-² you are violating the law of conservation of energy: there is more energy going into the system than energy going out of the system.

Let's look at it from the energy point of view if you wish: there is 890 W entering into the system, you output 890 W, that is 445 W on the top and 445 W on the bottom.

Now, advance in time, and do the same thing: you receive again 890 W, and you ouput again 445 W on the top and 445 W on the bottom.

That is, you have created a flux of 890 W coming in and two fluxes of 445 W going out, one at the bottom and one at the top.

Those two output fluxes are generated from one square meter of surface, thus the fluxes that you have created are of 445 W m-².

That is simple physics of fluxes.

ClimateChangeIsReal at 04:07 AM on 23 May 2018

Increasing CO2 has little to no effect

I dont actually believe you guys are scientists because "actual scientists" such as nasa have proven that climate change is real and that the sun is not too blame and that co2 is the problem

Moderator Response:

[JH] Your comment seems to be in response to the denier meme statement which the article rebuts. Please read the article.

MA Rodger at 03:47 AM on 23 May 2018

Trenberth can't account for the lack of warming

ab @43,

I don't think I can put it any simpler. This hypotheitcal body does not recieve 890Wm^-2. It recieves 890W. It has a top surface (area 1 sq m) recieving 494Wm^-2=496W. It has a bottom surface (area 1 sq m) recieving 396W^m-2=393W. The body is thus recieving 494W+396W=860W. It has a total surface area (top+bottom) of 2 sq m so will need to radiate 445Wm^-2 to be in equilibrium.

Or perhaps put it this way. If it were a 1m cube it would radiate 445Wm^-2 over its surface area of 6 sq m = 2,670W. If it were just half a metre thick, it would radiate 1,780W over 4 sq m. And a quarter of a metre - 1,335W. And that level of radiation would continue to reduce as the thickness reduces until at 1mm thick it would radiate 892W over 2.004 sq m. So when it is effectively without depth, why would it not be then radiating 890W over 2 sq m = 445Wm^-2? And if that is the radiative intensity, (identical to the cube) what is its temperature?

ab at 02:44 AM on 23 May 2018

Trenberth can't account for the lack of warming

MA Rodger @ 42,

My apologies, I have messed up with numbers because I was looking at two different Trenberth's Energy Budget diagrams from different dates and with updated values.

Let's take the most recent one from Earth's Global Energy Budget:

Absorbed by Surface: 161 W m-²,

Back Radiation: 333 W m-²,

Surface Radiation: 396 W m-²,

Top of the blackbody thermometer: 161+333 = 494 W m-²,

Bottom of the blackbody thermometer: 396 W m-²,

Total received energy: 494 +396 = 890 W m-²,

Total emitted energy at thermal equilibrium: 890 W m-²,

Temperature of the thermometer at thermal equilibrium : 80,8°C (Stefan-Boltzmann Law)

Difference with measured temperature: 80,8 - 15 = 65,8°C

We are reasonning here in terms of fluxes of energy, not in terms of energy.

The thermometer received two fluxes from the top, one flux from the bottom. You combine (add) all those fluxes together in order to get the total flux for the thermometer. That total flux is what is received, and also what is emitted, because the thermometer is a blackbody. Think of the "radiative balance" of the Earth.

After that, how much energy is actually emitted depends on the surface that is considered, that is, in this particular case of a rectangular plane: 445 W m-² at the top and 445 W m-² at the bottom, in equal quantities.

MA Rodger at 02:21 AM on 23 May 2018

Trenberth can't account for the lack of warming

ab @41,

Your sixth paragraph needs correcting. This hypotheitcal body does not recieve 890Wm^-2. It recieves 860W. It has a top surface (area 1 sq m) recieving 494Wm^-2=496W. It has a bottom surface (area 1 sq m) recieving 396W^m-2=393W. The body is thus recieving 494W+396W=860W. It has a total surface area (top+bottom) of 2 sq m so will need to radiate 445Wm^-2 to be in equilibrium. You do manage to present this 445Wm^-2 value in your seventh paragraph but the erroneous 860Wm^-2 rears its head in the ninth paragraph even though there was never a flux of 860Wm^-2, only a total (up + down) flux of 860W acting on a body with a surface area of 2 sqm.

ab at 01:41 AM on 23 May 2018

Trenberth can't account for the lack of warming

MA Rodger @ 40,

Of course, I was implicitely supposing a blackbody of one square meter: a flat rectangular blackbody plane of 1m² as you pointed out.

Let's say a plane that is floating 1 meter above the earth's surface, one face pointing to the sky and the other pointing to the ground, and let's give it a name: "thermometer".

So this blackbody "thermometer" is going to receive from the sky as much as 1m² of earth's surface, as 1meter above the ground is negligible here to make any difference.

And because heat is transmitted within the ground by conduction, this blackbody "thermometer" will also receive as much from the ground than what is indicated into the IPCC diagram, as any difference would be negligible for 1m².

So, the thermometer will receive on its top 161 W m-² from the sun and 333 W m-² from the atmosphere backradiation, and on its bottom 396 W m-² from the ground.

That is, it receives 496W m-² from the top and 396 W m-² from the bottom, that is, in total, it receives 890 W m-².

As it is a blackbody, in thermal equilibrium, it is also going to emit as much as it receives, that is, also 890 W m-², in equal quantity at the top and the bottom: 445 W m-².

Now, the thermal equilibrium of that blackbody thermometer is based on its total energy, right ? It is not based on just the top or the bottom, it is based on the total energy it receives which is also equal to the total energy it emits.

And that total energy is 890 W m-², from which we can infer the temperature of the blackbody thermometer in thermal equilibrium: 80,8°C, according to the according to the Stefan-Boltzmann Law.

That is: a 66°C difference from the model compared to the measured temperature on Earth's surface (15°C), and not just a 10°C difference like you concluded in @40, which is already a considerable difference !

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