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Comments 6451 to 6500:
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MA Rodger at 19:34 PM on 25 October 2020Climate's changed before
Eclectic @844,
I'm not sure where you get the metre drop in late Holocene sea levels. There have been dropping sea levels in some locations through the late Holocene but that is due to isostatic rebound caused by the redistribiution of mass - melted ice sheet flowing into tropical seas. The accepted wisdom as I understand it is still as per IPCC AR5 Ch5 5.6:-
"Ocean volume between about 7 ka and 3 ka is likely to have increased by an equivalent sea level rise of 2 to 3 m."
"For the past 5 millennia the most complete sea level record from a single location consists of microatoll evidence from Kiritimati that reveals with medium confidence that amplitudes of any fluctuations in GMSL during this interval did not exceed approximately ±25 cm on time scales of a few hundred years. Proxy data from other localities with quasi-continuous records for parts of this pre-industrial period, likewise, do not identify significant global oscillations on centennial time scales."
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RedBaron at 19:07 PM on 25 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Keithy,
One of the donors lost her farm when the Russians annexed Crimea. As recently as 6 months ago she was struggling to avoid becoming homeless when Corona hit, having her whole family disrupted and nearly "refugee status" around Kiev, an already poor country before the war. And I never asked her for a dime, just showed her the work I am doing to help farmers back when I first designed this, before the corona delay. She told me back then she was almost in tears to think people she never even knew were working so hard to help people they don't even know. So clearly this isn't about being "rich". I was even embarrased that she donated. I wished she would have told me, so I could have stopped her. But you know how farmers are, stubborn to the core.
The whole point of a crowd funding science is to have lots of people donate really small amounts, so that no single person needs to dig deep at all. And then the science is open sourced for all to benefit. In this case there were a few bigger donors and I am eternally grateful and amazed. But that tiny donation from a displaced farmer who lost almost everything she owned so recently, touched me more than I have words to express.
I will bet my bottom dollar Scaddenp was just frustrated, as most of us here are, by the lack of people realizing how important mitigating AGW is.
My friend from Crimea knows first hand how quickly our lives can change through forces out of our control. I am pretty sure that's the sort of motivation the whole world needs to think about, as about 80-90 % of the World's population is in danger zones from unmitigated AGW, whether from coastal flooding, droughts and fires, or war.
There is another group of farmers that know all too well what's in store for us all. Maybe you heard of them?
The Ominous Story of Syria's Climate Refugees
So please don't be too hard on Scaddenp. We are all in this together.
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Keithy at 17:20 PM on 25 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
@ 12: scaddenp, Who are you to be disappointed? The world doesn't owe you anything --> especially when you consider it gave you everything.
How ungrateful are you for being so rich by mistake?
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Eclectic at 13:55 PM on 25 October 2020Climate's changed before
Hal Kantrud @845 , your first paragraph is crossed-up.
As the planet cools 0.7 degreesC during the past 5-ish millennia, more land ice forms, and so the sea-level falls. MA Rodger's graph (above) is a broadbrush illustration of sea-level, yet data fuzziness does not illustrate the small fall (roughly in the region of 1 maybe 2 meters in the past few thousand years).
As far as I have gathered, the broad scientific opinion favors a return to atmospheric CO2 level around 350 ppm. Incorporating carbon into deeper soil is a worth goal, but probably will be too slow (and limited) to achieve a negation of all the recent & continuing fossil fuel usage.
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Hal Kantrud at 12:06 PM on 25 October 2020Climate's changed before
Thanks. To narrow down, the graphs show temperatures dropped during the last 6 millenia, while sea levels rose about 2m. One would think sea levels would rise, so is there a time lag working here?
CO2 increased during this period till the recent spike. There is no data on NH4 and SO2, but I thought this mix tended to prevent reflection of the sun's rays and thus increase temperatures.
I am not convinced that 'cutting trees' in the New World was as important a source of human CO2 emissions as the switch of grasslands from the production of perennial grasses to annual crop plants and domestic animals. Forest soils are notoriously poor in carbon and most is sequestered in the trees themselves, whereas perennial grasslands sequester most carbon deep underground while evolving in cycles of frequent fire and intense herbivory. Soils dominated by grasses have always been the first to be heavily exploited for food production ("the land of milk and honey") and were where our staple foods such as wheat, rice, barley, etc., were domesticated. So to seriously tackle the problem of high CO2 levels, it would be more efficient to seed perennial grasses, whose root systems remain the only viable net CO2 sink. Trouble is those areas are the source of most of our food!
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Eclectic at 10:44 AM on 25 October 2020Climate's changed before
Hal Kantrud , I would like to add a few disparate points which may be of interest to you. (And you may already have come across some of them.) As always, I shall be grateful if MA Rodger (who is extremely well-informed on climate matters) sees fit to make any corrective comment!
1. The term "BP" / bp stands for Before Present, but does not mean "up until right now this year of [2020]". BP is a convention used by the paleo scientists to standardize the reference to past ages - whether centuries, millennia or mega-years [ma]. BP at point zero is taken as year 1950.AD
Some "contrarians" have not been aware of this convention (for instance the slightly-contrarian scientist Loehle has had to go back and correct some of his work, because he was initially unaware of the paleo convention).
Hal, this paleo convention is enormously important, since there has been a huge rise in global surface temperature since 1950. Even today, some Denialist blogsites are publishing graphs which misrepresent reality, and are showing a graph's final temperature as 2000.AD or 2010.AD . . . when the original graph only went up to 1950.AD . . . and worse, the denialists have sometimes doctored or airbrushed-out the most modern temperatures. Sometimes this deliberate deception is outright concealed - and sometimes the deception is camouflaged under the term "Adapted from [a certain scientific paper]" .
Another small point is that some of the ice-core temperatures are recorded up until around 1855.AD , since later/shallower levels of ice are unrepresentative of their ambient conditions.
[You will have noticed how almost all science-deniers are still falsely (and vehemently) asserting that both the Holocene Maximum and the MWP were hotter than 2000.AD and current years.]
2. The Holocene Optimum [sometimes called Holocene Maximum] was roughly 8000 years ago, but as MA Rodger rightly points out, the Maximum was more of a plateau of roughly 5 millennia. Over the succeeding 4 or 5 thousand years, the temperature has dropped roughly 0.7 degreesC as part of the background cooling which would eventually lead into the next glaciation. But AGW has intervened - with global temperature rising like a rocket in the past 100-200 years (dare I say like the end of a Hockey Stick?) Hockey Stick is yet another term which causes Denialists to choke on their cornflakes.
As a consequence of the natural cooling down from the Holocene Maximum, the global sea level has reduced by about 1 or 2 meters . . . and that fall should have continued onwards as we slide into the next glaciation. Except for the modern AGW-caused rise in sea level, a rise which is slow but accelerating.
3. Each glaciation cycle of the past 800,000 has been subtly different, owing to differences in the variations of the Milankovitch cyclings. That makes it difficult to predict when the next glaciation would have occurred in the absence of human influence. One figure I recall seeing, is the next chilly glaciation being due in roughly 16,000 years. So we humans have plenty of time to fine-tune our climatic effects before any threat of severe glaciation! (Some denialists maintain that the "New Ice Age" was due in a few centuries from now . . . and our anthropogenic CO2 has fortuitously been raised only in the nick of time... )
4. I won't comment on your point of interest about the New World grasslands. The changes there would be quite minor in the overall picture.
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nigelj at 07:14 AM on 25 October 20202020 SkS Weekly Climate Change & Global Warming News Roundup #43
"We have the Trillion Trees program. We have so many different programs. I do love the environment (says Trump)”
Trump does not have a one trillion trees programme. America does not have a one trillion trees programme. Its all spin. Trump is just joining something called the "global one trillion trees initiative" which is funded by many countries. in terms of Americas contribution it mostly amounts to planting some extra trees in the USA on conservation land.
Its also "tokenism" because the actual planting plan in the USA is a small part of the solution to climate change. Politicians often have token programmes to try to keep everyone happy, things that sound nice and dont cost too much or ruffle corporate feathers. Some references on the tree planting programme here and here.
We have just had a general election in New Zealand. A centre left leaning Party won, and the centre right party lost in a landslide. The interesting point is the leader of the losing Party was a little bit like Trump in style and personality, although the policies were different except for her very dismissive attitude to climate change and other environmental problems. There is some good evidence that most people are not too impressed with her style (polling and commentary) and perhaps her position on climate change.
Given all this and other evidence, I doubt Trump would get more than 5% support in NZ or Australia. I simply dont understand whats going on in the USA, and how anyone could support a leader who has been so ineffective on really crucial things, and who gets so many facts wrong, regardless of whether the leader leans left or right.
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MA Rodger at 22:21 PM on 24 October 2020Climate's changed before
Hal Kantrud @842,
To address your three requested points of clarification/confirmation.
(1) The only actual continent-sized ice sheet is Antarctica and that remains unaltered in size through an interglacial and through a glacial maimum. The glacial maximum see the growth of ice sheets across the northern half of N America, Greenland and N Europe. The Greenland ice sheet has survived the present interglacial but was melted out in the previous one.
The impact of small wobbles in global temperature is not significant within this process as the temperature change is small and it doesn't last very long. The ice melt is a slow process. Thus, while global temperatures stopped rising 10,000 years ago, the melt continued strongly for a further 2,500 years and less strongly for another 4,000 years, this shown by the sea level record.
(2) Your timings are a little off. After the Holocene peak temperture (best considered as a plateau 10,000y to 6,000y bp), global temperature has been dropping but only to the equivalent of 11,000y bp. 13,000y bp would have you back in the Younger Dryas event when it was very cold.
(3) The CO2 record from ice cores does show previous interglacials with CO2 (& CH4) levels falling quickly from the peak of the interglacial. This is not the case for the present interglacial when CO2 (& CH4) levels are shown to rise not fall. This has led to some interesting work setting out the idea that the activities of mankind are responsible for this early rise, for CO2 perhaps dating back to 8,000y bp (& 5,000y bp for CH4).
While this work remains speculative, the CO2 (& CH4) levels through this interglacial would act to slow the drop back into a glacial maximum.
The unprecedented CO2 levels likely now top the CO2 levels seen 3 million years ago (this was back when N America was joined S America at Panama and initiated the Arctic ice) and are thus uprecedented in 13 million years, thus back to a time when weathering of the newly-formed Himalayas caused reducing CO2 levels.
....
And addressing your main question which concerns the CO2 levels of the last few centuries rather than those of the late stone age because any increase pre-industrial cannot be the result of fossil fuel use.
According to the Global Carbon Project, the anthropogenic CO2 emissions since pre-industrial amount to some 650Gt(C) of which 450Gt(C) results from fossil fuel use and 200 Gt(C) due to Land Use Change, but note this is mainly cutting trees down not "the conversion of New World grasslands".
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Eclectic at 15:50 PM on 24 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Sorry, RedBaron, but I still can't access via Sign In. The pop-up window does not allow me access to email & password fields. Very strange.
I see at the bottom right corner of the [experiment.com] Home page there is a field where I can request the regular newsletter emailed - but I am not wishing to enrol for the newsletter.
RedBaron, you probably can't do anything to raise my IQ to something above moron status. But it may be worth your while to contact the experiment.com Administrator, to see if there is some attention needed to the pop-up window that I mentioned. ( I shall check back in a few days to see if the Home page has altered.)
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Hal Kantrud at 13:23 PM on 24 October 2020Climate's changed before
Thanks. So we are in a period of the current Ice Age where continent-size ice sheets cover land at the poles. While waiting for the next Ice Age, we experience cooling periods, (phases) but these are too small to significantly increase the size of the continental ice sheets. Does this imply that the warming periods or phases will not significantly reduce the size of the ice sheets?
Am I correct in reading the graphs that during the Holocene, Earth reached peak temperatures about 8000 YBP and has since cooled down to temperatures reached about 13,000 YBP, but during the last 200 years has spiked to levels far above those observed during the Holocene peak?
Can I also say that atmospheric CO2 levels followed an opposite pattern, slowly increasing during the last 8000 years, only to spike upwards during the last 200 years to unprecedented highs?
My main question concerns the latter. What portion of the recent spike in CO2 can be attricuted to the conversion of New World grasslands to agriculture and pasturage and what portion can be attriubted to the increased use of hydrocarbons worldwide?
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RedBaron at 04:18 AM on 24 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Eclectic,
I am not exactly sure what you mean, but if you follow the page you will see this at the top right: Discover Start a Project Sign In
Click "Sign in" and it will ask for an email and a password, or you can use facebook if you want.
Fill them in click log in and it will sign you in. Then you can go to my project and click "Back this project".
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One Planet Only Forever at 00:57 AM on 24 October 2020What does the global shift in diets mean for climate change?
RedBaron@28,
Agreed. Pursuing Sustainable Development, which humanity needs to pursue in order to have a lasting improving future, aspires to develop the most sustainable ways of living. That involves doing everything more sustainably, endlessly pursuing better ways of doing things.
The less fortunate seldom have the luxury of choice and have limited ability to learn about their choices. The more fortunate have 'No Good Excuse'.
Differences in the impacts of the ways of growing different foods should be the basis for the choices that more fortunate people make. The more fortunate a person is, the more helpful and less harmful their choices should be required to be (the ball and chain of being more fortunate is the obligation to Be Better).
A related point is that unnecessary over-consumption, like eating more than 100 g of meat in a meal or eating meat in 2 meals a day, needs to be ended. The less fortunate have no role to play in that effort. That one is totally on the more fortunate. And the more fortunate a person is the greater the expectation, or requirement, for them to actually be Better Examples that way (that ball and chain of more responsibility for the more fortunate to be less harmful and more helpful).
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Eclectic at 20:41 PM on 23 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Scaddenp, I wish to donate funds, but am running into an obstacle.
As a computer klutz, I don't recognize what I am doing wrong. There were some earlier problems I had, a couple of weeks back. But now that you have reminded [us] to donate, I find a new problem :-
when I click on the donating field, up pops a window with : "LOG IN"
plus [second line] : "Don't have an account yet? Sign up."
Unfortunately, the LOG IN [etc] announcement almost fully overlaps the first field below it - and I cannot access the first field. ( I can access the email field and the password field which are below that. )
Is there some extremely simple mistake I am making? Do the experiment.com people need to re-jig their layout? (Worse - are other potential donors getting frustrated and abandoning the attempt?)
[ Mine= ancient Apple desktop, but with up-to-date software, I believe. ]
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scaddenp at 07:43 AM on 23 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Hm. I am disappointed with funding so far. This is an interesting experiment that deserves your support. Advertise it on your facebook etc. people.
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RedBaron at 07:19 AM on 23 October 2020What does the global shift in diets mean for climate change?
Like most foods, rice is similar. It's not rice that is the problem, but how we raise the rice that matters.
The System of Rice Intensification (SRI)…
… is climate-smart rice productionIt's not meat that matters, but how we raise that meat. Rice, wheat, meat, timber, you name it. There are right ways to raise it and wrong ways to raise it.
“Yes, agriculture done improperly can definitely be a problem, but agriculture done in a proper way is an important solution to environmental issues including climate change, water issues, and biodiversity.”-Rattan Lal
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One Planet Only Forever at 06:17 AM on 23 October 2020What does the global shift in diets mean for climate change?
nigelj@26,
I agree that lots of people 'rely' on rice for basic food needs.
I would say that the more fortunate people 'choosing' to eat rice may be more helpful regarding climate impacts, and other impacts, if they reduced their rice consumption and replaced it with lower impact alternatives.
With global population still increasing, increased areas for rice cultivation would be a concern from a climate and biodiversity impact perspective (and other impacts). And reducing the extent of areas already under rice cultivaton would, like reducing areas needed for cattle raising, be helpful from a biodiversity perspective.
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RedBaron at 14:32 PM on 22 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
For those considering funding this trial, I thought it might be useful to post a more formal link to the hard science supporting the reprint of now defunct Australian Farm Journal article. Here you can find the methods, scope, and results supporting Dr. Christine Jones claim for a CO2e sequestration rate of 5-20 tonnes CO2e /ha/yr "under appropriate conditions".
The role of grazing management in the functioning of pasture ecosystems
And here is a published paper from the US confirming a similar rate.
I should caution though. While the first one did include both grazing alone and pasture cropping, the second by Teague was only comparing various grazing strategies and did not include any cropping at all, nor was it a long term study either.
Since I am cropping only and only simulating grazing with a mower and compost, I really don't know what the rate of carbon sequestration I will find will be at all. I am as curious as the rest of you. Also the scope of the trial I designed is quite limited. I designed this to be potentially useful for those farmers wishing to help mitigate AGW by changing agricultural methods and become eligible for carbon credit payments. So the audience I am mostly looking at is not PhD's, but just ordinary farmers. So my scope is very modest.
If funded of course all this and more will be added to the lab notes section.
I would think that it would take a much more expensive trial and a formal team of full time research scientists to follow up if the results I find are interesting and/or significant. But the results I find should be useful "in the field" for actual action mitigating CO2 rise in the atmosphere.
We will see?
And the link for those who haven't been there yet.
What is the rate a new regenerative agricultural method sequesters carbon in the soil?
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Eclectic at 12:10 PM on 22 October 2020Climate's changed before
MA Rodger @835,
Thanks. Yes, I had heard that the "frozen Thames" events had occurred even during the Medieval Warm Period (though those are never mentioned by Denialists).
I was interested in the "meme" of Thames freezings being held up as an example of the world-chilling severity of the Little Ice Age. And as I was saying to Hal Kantrud (who seems just starting out on learning about climate science) . . . the main point to remember is that the LIA and the MWP were pretty small beer compared with earlier climate changes.
As you yourself know very well, the LIA is greatly misrepresented by the climate-science Deniers :-
(a) Firstly, they exaggerate its severity ;
(b) Secondly, they falsely claim that our modern rapid warming is (somehow) "just a rebound from the LIA" .
(c) Thirdly - with amusingly unintended irony - they claim that the huge temperature excursions of MWP & LIA make the modern warming look insignificant . . . and yet at the same time they claim that the planet's Climate Sensitivity is so very low that we need not be concerned about the "slight" warming effect of anthropogenic CO2 emissions. Superb!
MA Rodger, you might not have seen it . . . but on one of the Denialist blogs recently, a particular Denier asserted that (by his calculation) Earth's Equilibrium Climate Sensitivity was around 0.4 degreesC. Improving on that, he then (based on the negligibly-small rise in CO2 which he attributed to humans) calculated that, of the modern warming, only 0.02 degreesC was human-caused. To repeat: 0.02 degreesC. Not a misprint. (Ah, who needs to pursue comedy, when so much is freely available on the Denier blogs! )
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Daniel Bailey at 09:20 AM on 22 October 2020Climate's changed before
Hal Kantrud, by definition an ice age is any period with continental-scale ice sheets on land (like now). Within an ice age are warmer periods called interglacials and colder periods, called glacial periods (or glacial phases). The Little Ice Age nor any cool episode in the past 13,000 years do not rise to the standard of a glacial phase.
(bigger image here)
As can be seen below, glacial and interglacial periods are self-evident:
(bigger image here)
When it comes to the modern warming forcing from human activities, it's already comparable to the warming which lifted the world out of the last glacial maximum 24,000 years ago to the height of the Holocene Climate Optimum 8,000 years ago:
"About 2.3W/m2 (from CO2), a few tenths more from CH4 and N2O.Anthropogenic GHG forcing is ~2 W/m2 (CO2) and ~0.5 W/m2 from CH4+N2O+CFCs.
So they are comparable - ice sheets were a bigger term in the deglaciation tho."
(source)
Humans are inducing a phase transition from an interglacial world to a no-glacial world. So we are ending the ice age itself.
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nigelj at 08:30 AM on 22 October 2020What does the global shift in diets mean for climate change?
Wayne @24, I have no dispute with the studies you quote. And yes several things contribute to methane emissions including cattle and other animals, and rice paddies and leaking gas pipelines. The point is reducing red meat consumption is one of the easiest ways to reduce emissions.
Reducing areas in rice cultivation doesnt really make sense and just isnt going to happen. Billions of people are reliant on rice for basic nutrition. Red meat is a much easier target as its not essential in the diet and its such an inefficient use of resources. I think thats pretty much the essence of the issue.
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Hal Kantrud at 08:10 AM on 22 October 2020Climate's changed before
Tom on the 19th. "Within each actual ice age there is a series of glacial periods and interglacial periods" Guess I took that to mean an ice age extends from one peak glaciation to the next. Perhaps you were referring to the 'surges' in glaciers during the peaks.
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scaddenp at 06:55 AM on 22 October 2020Climate's changed before
"I see no dips in atmospheric CO2 following any of the world's worst pandemics"
Others disagree. See Ruddman and Carmichael 2006, vanHoof et al 2006.
Whether such short term effects like pandemics last long enough to affect climate is more debatable (Pongratz et al 2011)
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Tom Dayton at 05:43 AM on 22 October 2020Climate's changed before
Hal Kantrud, you wrote "What threw me off was your statement that LIA's were glacial periods." Who stated that, where?
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Postkey at 04:12 AM on 22 October 2020Is Nuclear Energy the Answer?
“Could Russia Floating Nuclear Plants Change World Economy?
By F. William Engdahl
25 November 2019While the EU and United States have all but abandoned nuclear energy as a future power source, with almost no new reactors being built and existing ones being decommissioned, Russia has quietly emerged as the world’s leading builder of peaceful civilian nuclear power plants. Now the Russian state nuclear company, Rosatom, has completed the first commercial floating nuclear plant and has successfully towed it to its ultimate location in the Russian Far East where access to power is difficult. It could transform the energy demands of much of the developing world, in addition to Russia. An added plus is that nuclear plants emit zero carbon emissions so that political opposition based on CO2 does not apply .“
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Hal Kantrud at 03:54 AM on 22 October 2020Climate's changed before
I didn't say the 'wobbles' caused any LIA's. But the evidence seems to show "wobbles" are assoicated with Ice Ages. What threw me off was your statement that LIA's were glacial periods, hence my question about possible evidence of expanding ice caps during these periods.
It is interesting that the Holocene Macimum occurred about the same time as the dawn of agriculture and pastoralism, concentrated on the carbon- and nutrient-rich grasslands of the Old World. So perhaps the slow atmospheric CO2 buildup shown by the ice core studies could have been caused by such 'mining' of grassland soils, followed by the spike in CO2 during the Industrial Revolution as the grasslands of the New World suffered the same fate, aided by mechanical power rather than the draft animals of old?
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John Hartz at 01:13 AM on 22 October 2020Is Nuclear Energy the Answer?
Recommended supplemental reading:
Regulators have approved designs for 12 small reactors to be built in Idaho, but opponents say the project is dangerous and too late to fight climate change.
Small Nuclear Reactors Would Provide Carbon-Free Energy, but Would They Be Safe? by Jonathan Moens, InsideClimate News, Oct 21, 2020
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MA Rodger at 23:11 PM on 21 October 2020Climate's changed before
Eclectic @834,
Do be aware that London's frozen River Thames was a very rare event and if anything provides evidence against the Little Ice Age being something exceptional with reported freeze-ups occurring even during the Medieval Warm Period. There were perhaps only a half dozen Frost Fairs listed in the records and they stopped appearing, not because of warmer winters but because the old London Bridge was demolished and the river embanked.
Given such reasons for the absence of Frost Fairs since 1813, perhaps a better river to look for evidence of a Little Ice Age (or lack ofevidence) is the Rhine which is recorded freezing 14 times since 1784, the last time in 1963. Of those 14 freezes, most occurred well after any Little Ice Age with seven during the 20th century.
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michael sweet at 20:36 PM on 21 October 2020Is Nuclear Energy the Answer?
Philippe Chantreau,
When I was young I believed the promises of nuclear engineers. After 45 years of following nuclear power I no longer trust their paper designs and promises of safe reactors. If they ever build a pilot plant we will see if their scheme actually works as they claim. Upthread I cite the French Nuclear Regulatory Agency which does not see safety improvements in these new designs and the Union of Concerned Scientists who fear that false claims of inherent safety will lead to removal of expensive safety features in reactors. There are reasons that they have not yet built even a test reactor or pilot plant after 13 years of work.
I note that NuScale is losing customers now that they are actually trying to build their reactors. The cost is too great. It is not clear to me if their reactor price has increased or if renewable energy is now so cheap that they cannot compete. Probably both.
Nuclear power is uneconomic. It takes too long to build. Even if they achieve their goals it will be 2050 before TRW reactors are ready for a large scale buildout. I see no reason to believe that reactors with complicated double cooling systems can control the problems of using liquid sodium in a cost effective manner. They have not addressed the problems of Abbott 2012. I am especially concerned about the extensive use of rare materials.
In a renewable energy world baseload power is very low value. Peak power on windless nights is most valuable. Current baseload plants are dinosaurs.
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michael sweet at 20:03 PM on 21 October 2020All Renewable Energy Plan for Europe
A $20 billion plan (Guardian article) to build a giant solar farm in the Australian outback has been announced. Much of the electricity will be transmitted to Singapore to replace expensive gas generated electricity. I recently saw a description of a scheme to manufacture hydrogen using electricity from a giant solar array in Australia.
The price of solar power is now so much lower than fossil energy that this type of plan can make money. Hopefully more giant farms will replace current fossil generators. The Southwest USA has a large area perfect for this type of farm. Usable deserts exist in many locations worldwide. Existing gas generators can supply backup power at night while storage solutions are developed.
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One Planet Only Forever at 15:03 PM on 21 October 2020What does the global shift in diets mean for climate change?
wayne,
Thankyou for re-presenting the rice example as a part of your thinking regarding this issue.
My comment is that the sustainability of all food production needs to be the objective. From a climate impact perspective the status quo plant and animal growth activity, not its expansion or other impacting things humans do to grow the food, is not an issue in the planet's surface/atmospheric cycle. The issue is human activity that is harmfully changing things like increasing ghg's in the atmosphere.
There have been many study reports regarding the ghg impacts of different types of agriculture. The general, and consistent or common, conclusion of those investigations appears to be as presented in this OP - reduced meat consumption and changes of how the reduced amount of meat is produced or obtained would be beneficial from a climate impact perspective.
My concern is the broader Sustainable Development Goals which include biodiversity loss and other harmful unsustainable impacts of human activity. Expansion of food production that negatively impacts biodiversity is also harmful and needs to be reduced.
It may be that rice and meat consumption need to be reduced, and for more reasons than the climate impacts. Rice has less nutrient value than potato. And over-consumpton of meat has serious health implications.
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wayne19608 at 10:57 AM on 21 October 2020What does the global shift in diets mean for climate change?
Hi Rob @23 that's why I said it was a start :) and was just adressing the impact of rice cultivation. Do we not think that 22% and 11% methane contributions compare unfavourably with those of cattle?
Organisms vary in their efficiency of feed conversion. Ruminants or foregut fermentation is one of the greatest developments in evolution since it's arrival some 50 million years ago. The benefit and efficiency of this system can be seen in their almost complete dominance of the herbivorous meso/megafauna. Virtually all non-ruminants or complete hindgut fermenters have since that time faced extinction. Out of some 450 ungulates today only about 25 non ruminants survive.
See (Demment MW, Van Soest PJ (1985) A nutritional explanation for body-size patterns of ruminant and nonruminant herbivores. Am Nat 125: 641–672) for an explanation on the distribution and relative efficiencies of these different fermentation systems. Notice that non-ruminants are fermenters as well, just that one of the fermentation products ie., methane comes out the back instead of the front.
This does not just apply to different digestive/fermentation systems but the inputs and outputs themselves.
Feeding high nutrient/digestable feed to ruminants may result in lower enteric methane outputs (Boadi, D. A., Wittenberg, K. M., Scott, S. L., Burton, D., Buckley, K., Small, J. A. and Ominski, K. H. 2004. Effect of low and high forage diet on enteric and manure pack greenhouse gas emissions from a feedlot. Can. J. Anim. Sci. 84: 445–453.), but see their qualification and comparison to IPCC estimates
A concern when evaluating animal feeding and management strategies to determine greenhouse gas mitigation potential is that significant emission reduction in one part of the production system may be negated if emissions are increased in another part of the production system. Table 6 demonstrates that inclusion of whole sunflower seed in general resulted in significantly lower (P < 0.05) total daily emissions of CH4 and NO2 expressed as CO2 equivalents. The observed reduction in total emissions is attributed to a significant reduction in enteric CH4, which contributed 95 to 96% of the total non-CO2 emissions from the feedlot. Enteric emissions by feedlot cattle fed a typical barley-based finishing ration were 72% of that estimated by IPCC (Tier 1). Use of whole sunflower seeds in the high forage:grain diet resulted in even lower emissions relative to estimates. Similarly, manure pack emissions in the current study were approximately 50% of that estimated using IPCC (Tier 1) coefficients.
Indeed over 7.5 times more CH4 kg–1 dung (DM basis) was emitted from grain-fed compared to their hay-fed counterparts.
Jarvis, S. C., Lovell, R. D. and Panayides, R. 1995. Patterns of methane emissions from excreta of grazing animals. Soil Biol. Biochem. 27: 1581–1588
Thus the "thermodynamically impossible" comment, but it goes much further than that.
People do realise that sheep and goats are just small ruminants and cattle are just large ruminants. You can even have cattle and sheep that approach each other very closely on a size basis. On the basis of size alone one of the biggest thermodynamic constraints will be the surface area to volume ratio, smaller organism will be energetically less efficient than larger ones, "having to run all day just to stay in one place". This is literally highschool physics and biology.
Monogut organisms like ourselves and for simplicity sake chickens and pigs cannot handle the feed inputs that hindgut and forgut fermenters can, generally requiring higher quality feed from both a nutrient and digestive quality standpoint. But those feed inputs didn't arrive out of the blue, they required huge (relative) inputs and resulting outputs. By focussing on enteric emissions we are missing the forest for the trees.
I can deal with monogut efficiency and energy inputs/outputs of cash crops later as I am running out of time, but these conversations always remind me of how little people understand about their food whether it be wheat, corn, chicken or cows
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Rob Honeycutt at 09:16 AM on 21 October 2020What does the global shift in diets mean for climate change?
Wayne... As far as I can tell, your statement "the math is wrong, that it is thermodynamically impossible" isn't supported by your references at comment #22.
Can you be a little more specific?
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Eclectic at 09:12 AM on 21 October 2020Climate's changed before
Hal Kantrud, the planetary "wobbles" are much too slow to cause any brief effect such as the Little Ice Age [LIA].
Have a look at the PAGES 2K study.
Many people hear the name "Little Ice Age" ~ and combine it in their mind with old illustrations of Dickensian snow and London "Ice Fairs" on the frozen Thames, and suchlike Christmassy freezes.
But in reality, the LIA was very minor. Less than 0.5 degreesC colder than the usual background for the Northern Hemisphere, and more like 0.3 degreesC cooler for the global whole.
Even the Medieval Warm Period [MWP] was only around 0.3 degreesC warmer than the global historic background. Despite some of the trumpet-blowing about the MWP and the LIA, they were both pretty minor events overall. Their names do greatly exaggerate their size. And they are insignificant compared with the level of warmth of the Holocene Maximum (about 8000 years ago) and the even higher temperature levels of recent decades (which are around 0.5 degreesC hotter than the Holocene Maximum).
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wayne19608 at 09:08 AM on 21 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Hi RedBaron
I doubt they would have the time, need,or inclination to do what you are doing as it would be a distraction to their primary endeavour. There is another 20 years of articles going forward and the SFJ has another 20 years going back.
How many acres are you looking at converting to no-till?
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wayne19608 at 09:00 AM on 21 October 2020What does the global shift in diets mean for climate change?
ok moderator let's start with rice cultivation, which literally doesn't pass the smell test. Rice cultivation is responsible for 22% of global agricultural methane emissions and 11% of total anthropogenic methane emissions.
Smith P, Martino D, Cai Z, Gwary D, Janzen H, Kumar P, McCarl B, Ogle S, O’Mara F, Rice C, Scholes B, Sirotenko O. Agriculture. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL, editors. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge: Cambridge University Press; 2007. pp. 498–540.
United States Environmental Protection Agency. Global Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990–2020 [Internet]. 2006. Available from: http://nepis.epa.gov/ Adobe/PDF/2000ZL5G.PDF
Then there's the N2O
https://www.pnas.org/content/115/39/9720
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Tom Dayton at 08:32 AM on 21 October 2020Climate's changed before
Hal Kantrud: The "Little Ice Age" (LIA) was not a glaciation in any sense. It was a brief period within which some particular regions got colder for a little while before getting warmer again, but not all of them at the same time. From the PAGES 2K study:
"Our regional temperature reconstructions also show little evidence for globally synchronized multi-decadal shifts that would mark well-defined worldwide MWP and LIA intervals. Instead, the specific timing of peak warm and cold intervals varies regionally, with multi-decadal variability resulting in regionally specific temperature departures from an underlying global cooling trend."
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Hal Kantrud at 05:42 AM on 21 October 2020Climate's changed before
Thanks. So if the "wobble" that triggered the Pleistocene glaciation, and less extensive glaciations occur during the interglacial, I guess the proper name would be Interglacial Subglaciations. These must be what misinformed laypersons like myself have termed "Little Ice Ages". How many have there been during the last 12,000 years and could they have dampened atmospheric CO2 levels? Did the extent of polar ice increase during these lesser glaciations?
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wayne19608 at 20:57 PM on 20 October 2020What does the global shift in diets mean for climate change?
one planet, no I'm saying that the math is wrong, that it is thermodynamically impossible and using it to justify your life decisions or as a template for behaviour change is probably a mistake
Moderator Response:[DB] "the math is wrong, that it is thermodynamically impossible"
In the same manner that stating that a dog's tail is a 5th leg does not make it so, stating that "the math is wrong, that it is thermodynamically impossible" without citing a credible source or showing your calculated analysis does not make it so.
You'll need to substantiate your position in order to be taken seriously.
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One Planet Only Forever at 15:03 PM on 20 October 2020What does the global shift in diets mean for climate change?
wayne,
I am referring to much more that needs to be corrected than the climate impacts.
But just focusing on the climate impacts, climate impacts need to be ended - all of them. And reduced impacts are reduced impacts - steps in the right direction.
You seem to be arguing that there can be math done that says that some climate impacts are OK because of comparison to other climate impacts. It is not about which ones are OK or better or worse. None of them are OK.
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RedBaron at 11:49 AM on 20 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
@Wayne 8,
Well I did notice this from your link Wayne,
Cultivating Questions: Evolution of a Permanent Bed System
by: Lou Johns
from issue: 27-3
Crops & Soil • Cultivating Questions • Farming Systems & Approaches
Planting Beds
After three or four years we could see that the nature of our farming practices would continue to have detrimental effects on our soils. We were looking for a new approach, a routine that would be sustainable, rather than a rescue treatment for an ongoing problem. We decided to convert our fields to permanent planting beds with grassy strips in between where all tractor, foot and irrigation pipe traffic would be concentrated.It's pretty similar to what I am testing. But I don't see any soil tests, much less a rigorous trial. So it is interesting, and could even be tested to see what rate that sequesters carbon.
Interesting because they saw that they still had the ongoing problem with soil degradation. (requiring amendments to maintain fertility) And decided to make a change. I might encourage them to test it at experiment.com too. If they are legends, it shouldn't be too difficult to raise the expense money by crowdfunding it for a token donation from their followers.
I can assure you though, that isn't a standard biodynamic approach. They even say it themselves.
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wayne19608 at 10:01 AM on 20 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
RedBaron, I'll think you'll find that the Nordell's and a few others have done quite a bit of experimentation with no-till, which is quite amazing as they are farming with horses. We're talking about real working, succesful, profitable farms. I've never met them but know some very impressive people that have, and quite frankly they are legends
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RedBaron at 09:31 AM on 20 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
At Wayne #6,
Yes Wayne, Biodynamic is a way to grow good crops. But it is not no-till and it has quite limited use as a method to increase soil sequestration of carbon. This produces biomass that decomposes in the labile carbon cycle rather than the non-labile carbon cycle. (fixed carbon that decomposes and returns to the atmosphere as CO2, rather than sequestered carbon that forms stabile humic polymers tightly bound to the mineral substrate)
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wayne19608 at 08:36 AM on 20 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Hi RedBaron
I'm not sure how relevant it would be to your work, but for gardening techniques there is probably no better source than Anne and Eric Nordell
https://smallfarmersjournal.com/category/cultivating-questions/
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wayne19608 at 08:29 AM on 20 October 2020What does the global shift in diets mean for climate change?
One planet, I'm afraid I don't undertand what you're saying in this response either
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One Planet Only Forever at 07:18 AM on 20 October 2020What does the global shift in diets mean for climate change?
wayne @ 17,
What you state needs a more detailed presentation. I do not understand how your comment applies to what I presented, not even the part where you appear to agree with what I presented.
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Doug Bostrom at 06:41 AM on 20 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Vertical gardening is a niche method, intended to resuse otherwise wasted space. Within its boundaries, it's a fine idea.
A brief excercise with arithmetic will demostrate how the method is unsuited to making a sufficently substantial contribution to adequately feeding 9-12 billion people for it to be a substitute for more conventional methods.
Meanwhile, hydroponics don't feature carbon capture, which is a key feature here.
We need to sequester carbon and eat. Both things have to happen.
Economics follow reality, in the long term. And "long term" here means "forever." Our systems have to work forever.
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Philippe Chantreau at 05:53 AM on 20 October 2020Is Nuclear Energy the Answer?
I was not under the impression that the 2 designs were similar, perhaps I should have conveyed that better. To my defense I can say that at least I mentioned the 2 different types in 2 different paragraphs... :-)
I had not realized that quite a bit of tension seems to have developed in this thread over time, but had no intention to strike any nerve.
I am quite familiar with Terra Power; the article I linked, however, is of a much more detailed and informative nature than the basic info available through the Terra Power website. Especially interesting is the the radiation induced swelling issue, which does require special alloys, but the paper claims to have a workable solution with the HT9 alloy.
I understand that the classic objections to "new" nuclear designs (there isn't one working, economics have not been demonstrated, time to be online, etc) do apply to this one as well. Nonetheless, the advantages of being able to use spent fuel, leaving depleted uranium as a by-product, and the safety features inherent to the design deserve consideration. Not to mention that a 600 MW plant operating as baseload is nothing to sneeze at. If it can be scaled up, as projected, to 1200 MW, I'm imagining how many coal fired power plants can be replaced by carbon free operations (free beyond, of course, material production, initial construction etc), and I find it very appealing. As far as I know, they do have a buildable prototype design, which was going to be started in China but everything fell by the wayside due to the current US administration policies. I find it shocking that a prototype had not been started in the US before 2016.
This is not something to be discounted only on the basis of traditional objections, ideological opposition, or any other preconceived ideas. It offers tremendous advantages if it works as expected. It can produce, and deserves, a prototype and if it turns out as good as projected, it is, in my opinion, a very good solution.
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reviewron at 21:53 PM on 19 October 2020A Skeptical Science member's path to an experiment on carbon sequestration
Yes, It's good to hear that his experiemnts are trying to do something about the soil and the carbon level of the environment. I wish him al lthe best. But, reducing the soil use should be a goal too. In this era we have alternate way of farming. Like as vertical gardening and using the hydroponic system.
Trying to returning back the carbon back to the soil - I just don't think this will be economically viable. Environmentally - Yes, but think about all the people we have to feed.
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michael sweet at 20:53 PM on 19 October 2020Is Nuclear Energy the Answer?
Philippe:
The TWR reactor you link is a sodium cooled reactor and not an MSR. It is confusing when you discuss MSR's and sodium cooled reactors in the same post. Are you aware that TWR reactors are not MSR's? Sodium cooled reactors have their own, different, set of problems compared to MSR's. Sodium is extremely corrosive and is flammable in both air and water.
The article you link is a progress statement from TerraPower LLC, a company associated with Bill Gates. They claim they are making progress with their design but do not have a buildable design yet. When they have a buildable design we can discuss their future prospects.
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michael sweet at 20:20 PM on 19 October 2020Is Nuclear Energy the Answer?
Philippe Chantreau:
Thank you for providing a peer reviewed study to support your question.
Your reference is a summary of current knowledge of "freeze valves". The first paragraph states:
"Reliable mechanical valves that can withstand the corrosive and high-temperature conditions in Molten Salt Reactors (MSRs) have not yet been demonstrated. In their place, freeze valves (sometimes called freeze plugs) represent a unique nuclear design solution for isolating salt flow during operations." my emphasis.
As I stated above, no alloys to manufacture control valves are known that can withstand the extreme heat, corrosion and radiation fields in an MSR. Reactor designers are looking for other ways to control liquid flow. A freeze plug is a system of a thin pipe where a plug of solid salt is allowed to form. This pipe has to have complicated heating and cooling systems. It takes about 15 minutes to form the plug, during which the molten salt cannot be moving, and about 15 minutes to thaw the plug. Most of the small amount of known data and designs about freeze plugs are from the 1960's. Apparently recently MSR developers have started to investigate freeze plugs again because they have been unsuccessful in finding alloys to build mechanical valves.
Freeze valves are apparently not used in any existing chemical or nuclear processes. Therefore the knowledge of their manufacture, use and failure modes is rudimentary. They are complicated and have many failure modes compared to normal mechanical valves. They open and close very slowly in emergencies. The size of pipes used is restricted. Test valves have suffered catastrophic failure.
The conclusion of the paper you cite says:
"Especially because the technical maturity of all solutions to isolate salt flow is so low, it will be important for MSR stakeholders to advance the state of knowledge surrounding freeze valve systems, and other alternatives under consideration, through a combination of physical tests, computational simulations, and design-related studies." my emphasis
I conclude that it is currently unknown how to control the flow of liquid salt in an MSR. It may be possible to develop a solution but it will take significant research, time and testing. Designers tried to avoid freeze plugs because they have many undesirable properties.
Proponents of MSR's have many significant problems that they need to resolve, including the fact that they do not know how to regulate the flow of liquid through the reactor. It will take many years of research to solve these issues, if they can be solved. Suggestions that a design that can be built exists or will exist in the near future are deliberately false.
Many additional problems exist for MSR's. The designs are complicated and only the nost optimistic proponents envision that they can compete with renewable energy in the foreseeable future. If a reactor is ever designed, there will still not be enough uranium in the world to provide more than a small amount (less than 5%) of energy to the grid.
I think it is a waste of money to attempt to develop a reactor where a pilot plant cannot be designed in less than 10 years. It would take at least 5 years to validate the design and then 10 years to build the first commercial reactor. You are looking at 2050 or later for the first commercial reactor which is too late. The uranium problem has no proposed solutions (thorium has additional problems of its own). The money would do much more good used to build a wind or solar farm.
Your reference is very long and technical. I only read about half of it in detail.
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