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Messages - Bernard

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Consequences / Re: Chinese coronavirus
« on: February 01, 2020, 06:29:41 PM »

Does this help?


Bearing all of that in mind. We still know far too little to be certain about much. We can be certain that it is a fast spreading lethal disease.

Thanks Sam. Yes, it did help me.

Consequences / Re: Chinese coronavirus
« on: January 31, 2020, 10:37:27 PM »
Looking at the figures published by John Hopkins CSSE at

As I write, 204 out of 213 deaths took place in Hubei province, with 5806 confirmed cases out of 9925.
So, in the province, where the epidemy started the mortality is over 3%.

The second province in number of confirmed cases is Zheijang with 538 cases, but not a single death yet. How do you folks interpret this?

Consequences / Re: World of 2030
« on: January 21, 2020, 10:59:48 PM »
One man's inconvenience is another man's apocalypse.

Indeed. No living thing experiences the death of its species, only its individual death. Either billions of your kind remain after you or you are the last one, you die alone so it's no big deal. And that's maybe the reason why most people will never feel an emergency in saving their species or the planet. If my personal death means the apocalypse, why care for the rest?

The rest / Re: SpaceX
« on: January 10, 2020, 06:27:16 PM »
I am pretty sure that they de-orbit the satellites after 5-7 years but that is if they are responding to commands.  so longer and more random burnup than planned.

Of about 20,000 objects in orbit tracked by the U.S Space Surveillance Network as October 2019 (basically objects over 10 cm in size), 5,000 are operational missions, 15,000 are rocket bodies and other debris. 

That means 3 out of 4 objects in orbit over 10 cm are totally out of control.

From certainly the best source for facts and figures about orbital debris
In Nov.19 issue of their "Quarterly News", page 10.

The rest / Re: SpaceX
« on: January 10, 2020, 06:09:21 PM »
To make my point in a wider perspective. The SpaceX and al. attitude is exactly the same one that put the planet in its current state, and the orbital debris issue is today in the same state global warming was fifty years ago. We know, but so far so good because we're not seeing the actual consequences yet.
We can draw an exact parallel with atmospheric carbon. Mainstream awareness of the problem, and serious works about the solutions, is coming a bit too late, because we've already passed critical density tipping point. The issue with tipping points in slow processes is that you see them too late, when they are passed. Some writers say today that we have already passed the critical density in LEO, and whatever we do, we'll have major collisions in years to come.
I had done some napkin computations years ago I have to unearth from my archives, but they led to a couple major collisions before 2030, and by 2040-2050 a major incident on a yearly basis, a point beyond which the growth of production of debris is faster than their removal by orbital decay.
The Kessler cascade will not happen in a few hours/days like in Gravity. It will take years and decades, but as the melt of Antarctic Ice, once started, no mitigation will be possible.

The rest / Re: SpaceX
« on: January 10, 2020, 05:51:37 PM »
Am I wrong to think that dead satellites and debris in Low Earth Orbit are burned off within a few years due to orbit decay?
Depends what you mean by LEO. Upper limit is altitude 2000 km, the most crowded area being between 300 and 500 km.
This page is rather old but gives a simple introduction to this question with round figures.
The orbit decay is indeed a few years (less than ten) for orbits under 500 km. At 700 km, it's 100 years, at 900 km, 1000 years.
Those are rough figures, an important parameter being m/A, m being the satellite mass, and A its effective cross sectional area. Compact and dense objects (a steel bolt) are less subject to atmospheric drag than plastic bags (like in free fall in low atmosphere, in fact) and operational satellites with solar panels, for example.
Bear in mind that those are simplified figures for circular orbits, many debris are likely to have highly eccentric orbits, with only a part of it in LEO.

[Edited] : Just saw gerontocrat's answer after posting. At least we agree  ;)

The rest / Re: SpaceX
« on: January 09, 2020, 11:21:18 AM »
There is no possible effective way to actively remove the 500,000+ orbital debris in the centimetric range, not to mention the 100 million+ in the millimetric range.

Bear in mind that a 1g chunk (that is sub-centimetric) at relative orbital speed of 10km/s has the same kinetic energy as a 10 kg stone at 360 km/h.

The probability of a random bullet hitting a target is growing in direct proportion of the number of targets. Any hit will generate hundreds or thousands of new bullets. This is just a crazy Russian roulette.


The rest / Re: SpaceX
« on: January 07, 2020, 06:00:13 PM »
Maybe I miss something in this thread, but did anyone assess the (arguable) benefit of those hundreds and soon thousands of satellites, like bringing facebook, snapchat, netflix, streaming porn etc in every corner of the world, vs the huge risk of cluttering the LEO closer and closer, or maybe already beyond, the critical density of objects leading to a Kessler cascade of collisions.

No argument given by SpaceX holds against the bare fact that multiplying the number of objects by n in LEO multiplies by the same factor the number of targets for existing debris impossible to detect and mitigate, typically in the centimeter range.

Consequences / Re: Worst consequence of AGW
« on: November 21, 2019, 12:01:37 PM »
House pets are prisoners. I feel sad to see cats and dogs penned up in houses looking out of windows, allowed out under supervision for small parts of the day. For cats, sometimes never.

Well, not all cats live this way. We have a she-cat, or should I say a she-cat is living in our garden. She lives completely outside, we don't let her inside ever, even in the heart of winter with snow and hard freeze (we live in the mountains). We just feed her, she goes wherever she wants, no barriers whatsoever, but she never ventures much further than the street corner. She's 17 and as healthy as can get a cat of this age.
I've known many stray cats, they mostly live in parasits and scavengers of mankind's food, but many of them could survive in the wild if needed. There would be less of them, but much  more healthy than home/pet cats.

Thanks for your observation Bernard :) (except the last sentence which is somewhat exaggerated)

Strange isn't it? They are not aware they are doing it I think.

The last sentence is not overstating the way I feel about it. There is a name for it : arrogance. And that's exactly the root of what is about to kill us all, along with a lot of our fellow living creatures.


Just in case, the metric system is the superior system and should be adopted internationally, I just don't know how a society would go about doing that in an orderly fashion.

99% of societies in the world did it, most of them back in the 19th century. USA is the only standing exception, and seems proud of it. Of all the explanations I try to imagine, the only plausible ones are akin to what made Trump US President. Just incomprehensible by the rest of the world.

I had not looked at the answers to this thread for months. I must say I am appalled by the level of answers to what seemed to me a quite serious question. The American-centric view of the world is proudly killing the rest of the planet.

Consequences / Re: Hurricane Season 2019
« on: September 01, 2019, 07:26:13 PM »
The latest forecast is closer to Florida coast, and I'm afraid the next one will be yet closer. Models are models, but looking at nullschool the patterns of wind over Atlantic, and the large low deepening in the Gulf, I don't understand how it can make any soon an abrupt shift to the North, against current general circulation.

[edited : just had a conversation with someone-who-knows-best, saying nullschool only shows surface wind, and hurricanes are very sensitive to vertical shift. Sometimes we forget that atmosphere in not in 2-D]

Consequences / Re: Hurricane Season 2019
« on: September 01, 2019, 11:59:17 AM »

Policy and solutions / Re: Greta Thunberg's Atlantic crossing
« on: August 15, 2019, 07:52:34 PM »
Amazing that her voyage is already being covered by media like the BBC and TheGuardian.
She does not paddle through the Atlantic. This is show business.

Policy and solutions / Re: Greta Thunberg's Atlantic crossing
« on: August 15, 2019, 07:49:30 PM »
Malizia II, a high-tech competition boat, of which initial cost of conception/construction is estimated by Wikipedia at 4 millions euros. Maybe carbon-free, but not money-free. (in French).

Science / Re: 2019 Mauna Loa CO2 levels
« on: July 17, 2019, 12:50:42 AM »
Thanks all! Bookmarks updated :)

Science / Re: 2019 Mauna Loa CO2 levels
« on: July 15, 2019, 12:14:49 PM »
Where do you get those July figures? has been stalled since July 1st.

Science / Re: Projecting to 2150
« on: June 04, 2019, 09:16:50 PM »
Here is a rather disturbing report that talks about 2050.
2150 wont matter much to us if this eventuates..... which is likely given we seem unwilling to change.
In such a case, the dates to consider should rather be 2030, 2040 and 2050.
The rest is silence.

Maybe it's Sunday morning and I did not get enough coffee, but I fail to see what the Jevons paradox has to do with all this.  :-\

Science / Re: 2019 Mauna Loa CO2 levels
« on: April 18, 2019, 05:11:46 PM »
Keeling Curve last value is Apr 5
Last tweet at is Apr 12
"A cooling fan in the continuous measurement instrument has failed; it will be replaced soon."

Given the importance of those reference values, strange there is no backup instrument, and that a failed cooling fan put the measures on standstill for two weeks.

Consequences / Re: World of 2030
« on: April 16, 2019, 04:56:04 PM »
In 2030, I will be 77 or dead. That's about the only thing I can bet with some confidence.
For the rest, all the bets are off, but if I had to bet, I would bet on anything but what's expected.

Policy and solutions / Re: Coal
« on: April 06, 2019, 01:40:05 AM »
If you dig into the data, it is hard not to be discouraged.

"World proved coal reserves are currently sufficient to meet 134 years of global production."

Seems a bit much to expect people to convert the numbers in a printed article. 
And to expect thousands of honest readers to figure the conversion themselves, is not it a bit too much? :P

Note that this is a bit off-topic here, so I started a dedicated thread for this units affair.,2610.msg192582/topicseen.html#msg192582

I thought I had already asked, but can't find the subject now. Maybe I only intended to do it?
This is an international scientific forum, which makes two sufficient reasons to forbid local units such as miles, gallons, Fahrenheit etc.
Is it possible to use only units from the International System of Units in all posts in this Forum?

Note that SI will go through a major revision on 20 May 2019  :)

"Estimated Carrying Capacity:     A 1-acre polyculture of maize, beans, and squash with hills spaced 4 feet apart feeds 1 family (4 people) for 1 year = 2.05 pounds of corn meal per person per day + 0.3567 pound (5.7 ounces) of dried beans for each person daily + 4.99 pounds of fresh winter squash per person daily.  This is more than sufficient to support a small family, especially if rations are supplemented by hunting and gathering."

Motion : This is an international scientific forum.
PLEASE use International System of Units  >:(

Policy and solutions / Re: Extinction Rebellion
« on: March 16, 2019, 12:34:05 PM »
According to

"Over 1.4 million young in over 300 cities took part in the March 15 #climatestrike - the biggest day of global climate action ever."

Antarctica / Re: Thwaites Glacier Discussion
« on: February 09, 2019, 11:35:42 PM »
Thanks Stephan for the annotations on the images! Added value, much appreciated  ;)

Antarctica / Re: Thwaites Glacier Discussion
« on: February 09, 2019, 05:09:40 PM »
how to make people aware that understanding what's going on behind those difficult-to-grasp images and data has a critical impact on their future?

You don't. If people don't ask independently they will not listen most likely anyway. So spear your breath i say.

When people ask you, you have already won. In this case, encourage them to stay curious.

Wisdom indeed. But now that Thwaites news are flowing in mainstream media, maybe time has come to be a bit more proactive. ;)

Antarctica / Re: Thwaites Glacier Discussion
« on: February 09, 2019, 12:54:49 PM »
Thanks a lot! Will try to make sense of all this.

Makes me wonder, BTW, how to make people aware that understanding what's going on behind those difficult-to-grasp images and data has a critical impact on their future?

Antarctica / Re: Thwaites Glacier Discussion
« on: February 09, 2019, 12:09:35 PM »
I've been following this thread for a while, but it's often very hard in this complex zone to figure out scale of things, and what is what, default explicit scale and orientation of pictures. Would it be difficult to have some reference map, with scale and orientation, on which background the different pictures posted here could be localized? Or are things so mobile there that the very notion of such a map is impossible?

Having reasoned that out, then you have to come to the conclusion that the "critical last stand" is here, now ...

Well stated, Neil. This is one boat, and we are all on board.

Science / Re: 2019 Mauna Loa CO2 levels
« on: February 01, 2019, 06:01:48 PM »
A hopeful, uplifting paragraph should follow the one above. Something to inspire the vegan cyclists  growing kale in their kitchen window that have voted Green since James Hansen addressed Congress in 1988, but nothing hopeful or inspiring comes to mind. :-\

La lutte elle-même vers les sommets suffit à remplir un coeur d'homme. Il faut imaginer Sisyphe heureux.
Albert Camus, Le Mythe de Sisyphe, 1942

Increasingly warm winters punctuated by extreme cold snaps.

To try and convince those who won't buy this argument and consider this too counter-intuitive, being immune to figures, stats, mean values and so on, in short, those blockheads hermetic to basic science, maybe comparison with violent hailstorms could help. The most stubborn Texan redneck will have to admit that hail, akin to the ice cubes in his jumbo fridge, are produced by storms generated by hellish warmth, and the hotter the summer, the bigger the hailstones will grow. And au passage he will also admit that to make cold his fridge has to warm the outside. Two lessons for the price of one, hopefully.

Walking the walk / Re: Gardening
« on: January 25, 2019, 06:04:31 PM »
Anyone have experience with one of these? I'm trying to start a group at our local library.

A Sharing Economy for Plants: Seed Libraries

Just stumbled on this post. Here in France there are a lot of initiatives in this domain. A major actor here is the RSP, Réseau Semences Paysannes. In french only, I'm afraid.

Consequences / Re: Decline in insect populations
« on: January 22, 2019, 09:47:53 AM »

I find it rather suspect to conclude that the most likely culprit is global warming, especially considering that the temperature in the study area has actually show a slight decline over the time frame mentioned.

I tend to agree. This is just waving over our ignorance. Can't find the reference now, but I read in some article on this topic a scientist saying "there's no obvious smoking gun". If I was researching this subject, I would look closely at the global diffusion of many molecules known as potential endocrine disruptors. Insects behaviour, including mating, relies heavily on chemical signals (e.g., pheromones) acting at very low concentrations, which can be blurred by the presence in the environment of similar molecules. Just an idea.

Science / Re: Underground temperatures trends
« on: January 19, 2019, 11:03:56 PM »
Focus of those papers is rather on assessing the history of ground temperature changes based on the speed of their diffusion in the underground (about 10m/year, or 1km/century).

That would be 1km per 10,000 years if its 10m/year. Diffusion scales with L/T^2. (the further in a change has got, the weaker the gradient driving it gets and the slower it progresses, just like the sea ice grows more slowly as it thickens)

From the above quoted article at

"The depth to which the temperature profile is disturbed in a given time period is governed by Earth’s thermal diffusivity. For typical rocks, a thermal front driven by surface temperature can plunge up to about 15 meters in one year, 160 meters in 100 years and 500 meters in 1,000 years. In other words, the surface ground temperature history of Earth over the last millennium is captured in the uppermost 500 meters of the crust."

Science / Re: Underground temperatures trends
« on: January 17, 2019, 07:32:42 PM »
Default serious papers about it, I tried a napkin computation of the Underground Heat Content growth under the conservative hypothesis of 1K growth in surface temperature over the past century.

According to different papers previously quoted, the diffusion of the mean ground temperature on such a time scale would reach depths around 100 m. So I try below to asses the energy needed to heat up by 1K the first 100 m of bedrock all over continents.

I take mean values for granite or similar rocks :

heat capacity ~ 25 J/mol/K
molar mass ~ 60 g/mol
density ~ 2.5 g/cm3

Continents being about 1.4x108 km² gather to a depth of 100 m a volume of 1.4x107 km3, a mass of 3.5x1022 g, around 6x1020 mol.

To heat this up 1K, you need to transfer 1.5x1022 J, or 15 zettajoules.

This is one order of magnitude (less than 5%) smaller than the ~400 zettajoules added to Ocean Heat Content since 1940, according to

But not small enough to ignore it in any accurate assessment of global warming.

Science / Re: Underground temperatures trends
« on: January 17, 2019, 07:20:03 PM »
Thanks for this Bernard, I'm paticularly interested to see if there's any data about permafrost warming from below, and the activation of microbe specie as the temperature rises.
Maybe you should check the more specific threads about permafrost at,20.0.html

Science / Re: Underground temperatures trends
« on: January 17, 2019, 12:20:33 PM »
A last paper for today, this one is just awesome! The great astronomer Cassini started gathering underground temperatures data in the late 18th century.


Careful temperature measurements performed from 1783 to 1852 in underground galleries, 28 m below the Paris Observatory, are compared with current measurements performed in a limestone quarry, 20 m below ground surface, and with local and European surface temperature records. When averaged using a backward 11-year moving window, the surface temperature time series looks similar and exhibits the already well-known 1 °C temperature increase over the last century. In addition, since about 1987, a steeper increase of about 0.07 °C per year is noticed on all surface records.
Underground temperatures, unaffected by surface fluctuations and averaging procedures, show a 0.9 °C increase and thus confirm the trend indicated by the surface records. The averaged time series of the temperature in Paris and of the Wolf number, an indicator of sunspot activity, were reasonably well correlated till 1987 but deviated significantly from each other after that date. The long-term connection between surface temperature and solar cycles is further supported by a temporal analysis of the frequency content at 11 years and 5.5 years. Visual correlations between temperature and sunspot numbers, unconvincing when using recent records, appear more striking with underground data from 1783 to 1852. This analysis suggests that solar activity played an important role in temperature changes till the last century, but that different processes, possibly related to human-induced changes in the climate system, have been taking place lately with increasing intensity, especially since 1987.

Science / Re: Underground temperatures trends
« on: January 17, 2019, 12:01:29 PM »
Thanks for these, Bernard.

We have learned that over 90% of global warming has actually been warming of oceans. But I have never seen something that quantifies what portion of warming has actually gone into heating the land itself. If anyone has such info, I thank them in advance for sharing... :)

Good question indeed. I've not yet found mention of this aspect of the question in the papers I've unearthed (sorry for the pun) so far. Focus of those papers is rather on assessing the history of ground temperature changes based on the speed of their diffusion in the underground (about 10m/year, or 1km/century).

Science / Re: Underground temperatures trends
« on: January 17, 2019, 11:56:19 AM »
This 2003 publication (free access) indicates state-of-the art studies as far as 1971.
The general method is called underground temperature inversion.


Data are used to demonstrate two effects apparent in ground surface temperature histories coming from inversions of borehole temperatures: apparent climatic warming and apparent climatic stability. Unrecognized local terrain effects, such as spatial or temporal change in land cover, cause warming locally. Where there is seasonally frozen ground, the ground temperature is not coupled to freezing air temperatures due to both latent heat of moisture in the ground and snow cover. Consequently, average ground temperatures can be much warmer than average air temperatures, and changes in average air temperatures result in much smaller changes in average ground temperatures. This produces apparent climatic stability when past air temperatures are inferred from borehole temperatures. However, increases in summer air temperatures, such as those due to deforestation, are well coupled to the ground temperature, causing the average ground surface temperature to increase, even in colder climates.

Science / Re: Underground temperatures trends
« on: January 17, 2019, 12:31:40 AM »
This one is behind a paywall

Evidence of climate warming from underground temperatures in NW Italy


The ground surface temperature (GST) history in NW Italy was reconstructed for the last three centuries by means of temperature–depth data recorded in a borehole in 1982. The results indicate relatively warmer periods in the 18th century and at the end the 1970s. A more recent set of underground temperature data was recorded in 1996. The comparison with the earlier thermal logging shows an evident temperature increase in the uppermost 80 m. Two different inversion techniques yield a subsurface temperature increase of 0.8–1.0 K since the 1980s. The inferred climatic model is consistent with the air temperature variations recorded at the Genoa University meteorological station.

Science / Underground temperatures trends
« on: January 17, 2019, 12:20:44 AM »
I just posted this, a bit off-topic, on another thread about permafrost warming.,2546.msg186586.html#msg186586
But thought it was worth a topic by itself.

The global warming could also be measured anywhere in underground, whether this underground is frozen or not. At depths around 20m, the temperature is mostly stable year-round, and is close to the mean ground temperature. It's a bit of work to borehole at such depths, but not that much, and there are quite a lot of caves worldwide where the temperature could be measured.
Given the stability of underground temperatures year-round, to have interesting series it would not even be necessary to measure it on a daily basis.

Anyone knows science papers on such topics?

Permafrost / Re: Permafrost general science thread
« on: January 16, 2019, 11:35:54 PM »
I just read the quoted article at
One thing I was wondering is if similar studies are conducted in other places than permafrost. We have measures of sea water temperatures at different depths, but the global warming should also be measured in mean temperatures of underground, at depths where the temperature is stable year-round (about 10-20m if what I read is correct), whether this underground is frozen or not.
This is a bit off-topic, please point me to an existing thread if any.

Meanwhile, I created one such topic,2548.0.html

Antarctica / Re: What's new in Antarctica ?
« on: November 17, 2018, 11:18:20 AM »
"Massive Antarctic iceberg spotted on NASA Operation IceBridge flight"
Before and after.
Given the color of ice and melt water on the top image in this article, no wonder why this glacier is called PIG  ;D

Science / Re: 2018 Mauna Loa CO2 levels
« on: November 07, 2018, 10:34:55 AM »
It's the Keeling Curve full record that tells this story best. Continuous acceleration of growth, not a sign of a downturn during the 2008 crash and no visible impact of Paris.
Indeed. And one of the many savvy graph hackers around could/should come out with a very powerful image based on this, placing so-called significant events dates on this curve like Paris or whatever up-and-downs of the global economy, just to show that so far their impact on this curve is just nihil.  I can have a try, although I'm not a very good graph hacker.

I use this direct link for the Arctic Hotel webcam
But it looks like the image has been stuck for some days now.

Policy and solutions / Re: Nuclear Power
« on: May 08, 2018, 11:35:26 AM »
And let's not forget that France has a huge decommissioning problem, that will be very costly, once they figure out how to do it (they still don't know after 30 years).

Indeed! Just to figure, look at the history of the still unfinished decommissioning of Brennilis site.éaire_de_Brennilis 
(the English WP article is very sketchy).
It was a "small" experimental nuclear plant (70 MWe) which was in production from 1967 to 1985. It was the first one to enter a "full decommissionning" process started in 1985, and far from over 33 years later. The process has been facing a endless list of technical and legal issues. That's giving an idea of the time frame and cost of decommissioning of the remaining 60 or so reactors. So far six of them have started the process (including Brennilis).

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