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Comments 10301 to 10350:

10301. scaddenp at 10:22 AM on 14 June 2019
       Increasing CO2 has little to no effect
       

       I think there is Jesscars is a little confused about what the science actually states. There is a log relationship between concentration of CO2 and the surface irradation. (not temperature). ie, increase in CO2 since pre-industrial has caused average of 4W/m2 increase in surface radiation. To get another 4W/m2 of irradiation, then you have to double concentration again. (ie go to 800ppm). The relationship is always logarithmic, never linear. As to why, well it falls out of the radiative transfer equations but it is anything but straightforward. More recent work on it here.

       There is no simple relationship between increase in CO2 and surface temperature, because of all the feedbacks that cut in on different timescales. eg water vapour response is near instant; albedo is complex time scale because of dynamics of ice melt; GHG feedback (eg methane from tundra, CO2 from ocean) are on millenial scales. The Equilibrium Climate Sensitivity (ECS) tries to estimate this and best guess is 2.8-3C for doubling of CO2 but with wide bounds.

10302. John Wise at 09:39 AM on 14 June 2019
       State of the climate: Heat across Earth’s surface and oceans mark early 2019
       

       RedBaron: Are you familiar with Oxford University's Food Clmate Research Network study "Grazed and Confused"? It asserts that regenerating degraded soils by converting them to pasture will indeed sequester carbon, but that soils cannot do this indefinitely. The study says that once a soil reaches capacity, the amount of carbon it can then sequester is minimal, and is outweighed by the methane emissions of the grazing cattle. https://www.fcrn.org.uk/sites/default/files/project-files/fcrn_gnc_report.pdf

10303. ebelba at 08:06 AM on 14 June 2019
       Increasing CO2 has little to no effect
       

       Jesscars - just a comment about the log relationship. My intuition is as follows: imagine a completely dense wall of CO2 completely blocking all of the parts of the infrared spectrum that CO2 is known to block. That is the maximum theoretical contribution. As you create gaps by halving that wall, you allow infrared to escape. We are coming at it from below, doubling. It has to be something almost asymptotic to that wall. A log has the right shape - as a practical matter its not really a log, because the total amount of CO2 that could be put in the atmosphere from all stored forms is finite. So a log is a good approximation to the asymptotic relationship as we get to higher levels. At very low starting values close to zero, it could easily be linear (or more).

10304. scaddenp at 07:49 AM on 14 June 2019
       It's the ocean
       

       This article is explicitly refuting William Gray assertion. Your points hardly reference that. In the past, CO2 most certainly came from ocean as it warms and it will again in a few 100 years (currently ocean is undersaturated for atmospheric CO2 levels and absorbing CO2). However, the current increase in CO2 is not from oceanic CO2 ( you cant have ocean as source when CO2 content in ocean is increasing), but from our emissions.

10305. Eclectic at 22:05 PM on 13 June 2019
       Water vapor is the most powerful greenhouse gas
       

       3-d Construct @344 , 

       I apologize for my inexpert comments : but I gather that you are in that state of mind (analogous to writer's block) where useful thoughts may be triggered by re-encountering stuff you've already been acquainted with . . . or even by comments which are vapid & klutzy.

       So :-

       *  Quantification.  Exactly how important is H2O in the stratosphere?  In absolute terms or relative terms.  Lower or upper stratosphere.  Re-visit lapse rates and TOA concepts?

       *  Quantification of "supersaturated" water vapor at high altitude.  Important, or too transient?

       *  There are 350 million square Km of ocean surface interacting with a thin rind [a few dozen Km] of planetary atmosphere.  Is the high-altitude human contribution of water vapor genuinely significant?

       *  In comparison, there were subtle but measurable alterations in regional heat flux for the [ocean-free] expanse of the continental USA during the 3-day "shutdown" of jet flights immediately following the 911 terrorist event.   IIRC, the lack of contrails did have the expected effect : cooler nights, warmer days.   But of course the other 98% of the planet surface has more ocean and/or less air traffic.

       *  I gather Hansen has rather "walked back" his earlier comments about the dangers of runaway warming . . . and, as you say, the paleo evidence points to "moderate stability/resiliency" of global surface temperature.

10306. MA Rodger at 21:15 PM on 13 June 2019
       Climate's changed before
       

       jesscars @739,

       The variation of CO2 levels in very ancient times generally resulted from a balance between the amount of carbon being drawn down into the geology by rock-forming and the amount of carbon being ejected by volcanoes. Periods of mountain-building have an impact on that balance, as do periods of extreme volcanism. The results of modelling of very ancient CO2 levels (using GEOCARB III) have been pretty-much supported by the geological evidence.

       The mechanisms that are at work at a more detailed level can be much more complex. Thus the last de-glaciation saw a rise in CO2 levels but that was the product of many different mechanisms, many of which didn't actually work to increase CO2 levels. Thus warming oceans increase CO2 levels but the significant increase in ocean volume as the ice melts into the oceans decreases it. Peat exposed to clmate change releases CO2 while increased bio-activity buries it. (See Ganopolski & Brovkin (2017) for a study of these mechanisms.)

       You also ask specifically about the ice-age cycles. These have been the major feature of global climate for the last 3 million years and until about 1 million years ago they occurred every 40,000 years but now occur every 100,000 years. It is probably best to see ice-ages as being caused by the unstable nature of the full glacial climate. When triggered by the Milankovitch cycles heating the high northern latitudes, an interglacial will result from northern ice sheets melting out. Thus today, if the melt on Greenland were to become enough to drop the summit significantly (a likely event if AGW reached +1.5ºC for a few centuries), the lowered icy-cold top would warm enough to allow more melting and lower it further. Building it back up with new snowfall is a far slower process, so without the return of an ice-age, once ice sheets like the Greenland one begin to go, they go all the way.

       The reason for the change from 40ky to 100ky ice-age timing is not truly understood. The trigger is the Milancovitch cycle, the 40ky from the tilt in axis & the 100ky from a component of the eccentricity variation. One theory is that dust (which increases the sunlight absorbed by ice) was greater in past 40yr ice-ages but now the soils that created that level of dust have been scoured away leaving un-dusty bedrock.

10307. michael sweet at 21:14 PM on 13 June 2019
       Is Nuclear Energy the Answer?
       

       DPiepgrass,

       you summarize the entire pronuclear argument when you say:

       "Granted I'm not a nuclear expert and I have only found numbers like these on the web and in YouTube presentations; if someone can find a scientific paper that looks at nuclear waste and/or other nuclear issues"

       We have a scientific paper that addresses nuclear issues.  It is Abbott 2011 and Abbott 2012.  Abbott 2011 is more readable for me while Abbott 2012 is in the Bulletin of Atomic Scientists.  Your reply of " I would think", " I thought I heard" and "My God, is that a citation? Great, now I have to go look at it" describe everything I have heard from nuclear supporters.

       It is up to you to provide citations to peer reviewed papers to support your claims.  Saying that you think the paper is incorrect does not mean anything.

       Referring to wild claims you think you read somewhere on the internet does not compare to a peer reviewed paper written by an Engineer who has over 16,900 citations and an h index of 61.

       Undemonstrated wild claims by nuclear designers are also not an appropriate response to a paper. 

       Perhaps this post should be left as an example of the type of post that is worthless.

       Moderator Response:

       [PS] I have added Abbott 2012 to the article. And yes, we need comments that reference publications.

10308. MA Rodger at 20:02 PM on 13 June 2019
       Climate's changed before
       

       TVC15 @740,

       If it is Jim Hansen, we can track down where he stands on this runaway matter. He said in his book 'Storms of My Grandchildren':-

       “After the ice has gone, would the Earth proceed to the Venus syndrome, a runaway greenhouse effect that would destroy all life on the planet, perhaps permanently? While that is difficult to say based on present information, I’ve come to conclude that if we burn all reserves of oil, gas, and coal, there is a substantial chance we will initiate the runaway greenhouse. If we also burn the tar sands and tar shale, I believe the Venus syndrome is a dead certainty”

       This paragraph (I see from Google Books) is a bit of a throw-away at the end of Chapter 10 following a discussion of a boost to AGW from methane hydrates:-

       "If we burn all the fossil fuels, the ice sheets almost surely will melt entirely, ... Methane hydrates are likely to be more extensive and vulnerable now than they were in the early Cenozoic. It is difficult to imagine how the methane hydrates could survive, once the ocean has ahd time to warm. In that event a PTEM-like warming could be added on top of the fossil fuel warming."

       And later, in a Columbia Uni blog page, Hansen explains that he is talking of two things - ☻ The Venus Syndrome runaway (as per the top quote) and ☻ A "mini-runaway" or hyperthermal (as per the lower quote).
       The mini-runaway he decribes as occuring on a millennial scale and which, if we were foolish enough to initiate such an event, could be countered by sequestrating the GHG releases, although there would be a lot to sequester.
       The Venus Syndrome runaway he describes as possibly following on from an un-countered mini-runaway but he ends saying that "Venus-like conditions in the sense of 90 bar surface pressure and surface temperature of several hundred degrees are only plausible on billion-year time scales."
       
       
       So this leads to an answer to the question posed by your denialist trolls - Why would 1,200ppm CO2 (Hansen talks of 1,000ppm to 2,000ppm) lead to the Venus Syndrome when in the past it did not?
       Hansen is saying that the 'early Cenozoic' (so before 20 million yr bp) had less methane hydrate which could potentially boost temperatures enough to overwhelm the tropopause and thus allow the leakage of the planet's hydrogen into space, a road that would lead to a Venus-style climate. But importantly, this is on top of AGW. Back in the PETM (44my bp) the fossil fuels were safely tucked away within the geology greatly limiting the potential warming.
       As for previous CO2 levels, there was periods in the past when the fossil fuels of today were still yet to be buried out of harms way & thus CO2 was far higher than 1,200ppm. But that was a long time ago when the sun was a lot fainter and the combined forcing (see this SkS page) would thus be lower than potentially from a mini-runaway today.
10309. 3-d construct at 20:00 PM on 13 June 2019
       Water vapor is the most powerful greenhouse gas
       

       I am working on a paper that includes depictions of water vapor's role in our current dire situation, I am experiencing research fatigue and would appreciate constructive comments. In the following excerpt I am attempting to provide clear support to well established facts, but I am encountering source variability. Here goes:

       Water vapor is not considered to be a primary forcer in that it does not initiate global thermal loading, even though its presence in the atmosphere has the largest impact.
       This may not seem to fully hold when some details are considered. When any hydrocarbon is burnt, water vapor is always a component of the exhaust. This is particularly significant in regard to commercial air travel. High altitude jet exhaust includes both water vapor and aerosols which are perfect in the formation of cirrus clouds in the cold upper troposphere along contrails. This can be augmented by additional water vapor present in a supersaturated state, which seems to be now more and more the case. Such clouds impart a major greenhouse effect. Also, methane emitted there has an easy way into the stratosphere wherein it is oxidized into twice as many water molecules as that of CO2 by the abundant hydroxyl radicals there present. Water vapor in stratosphere has a greatly amplified greenhouse effect. Otherwise, not much water vapor makes it there.

       
       From the above one could argue that it is a prime forcer. However, apart from the effects of air travel, tropospheric effects are mostly short lived. Since its mean residency period is not much more than a week being largely controlled by condensation at tropospheric dew point encounters, it cannot become well-mixed or be independently sustainable. If forcers suddenly decline, it cannot persist or continue to promote other feedbacks. Furthermore, if other forcers dip below baseline values subsequent declines in water vapor will produce a proportional negative feedback. It is powerful, but passive, sort of like when control levers on earth moving equipment are moved by the operator and the hydraulic system performs monumental tasks.
       Absolute and relative humidity is highly variable from about 0.01 to 3.0 % typically and to about 4.0 % more exceptionally. However, most of the Earth’s surface is wet and able to produce a pronounced feedback. Also, with elevating condensation threshold zones that are now being seen to develop, the residency time will increase as well the total volume. This could increase its temperature response sensitivity. Certainly, in its reliable and large feedback response to all other longer term forcing factors one could consider it to be a co-forcer.

       At current climate sensitivity estimates, a doubling of CO2 will add one degree Celcius to the global mean temperature in itself and water vapors total feedback effect, accounting for all iterations of self-looping, will add another 1.7 degrees. Fortunately, it is apparent that the initial feedback is well below unity and self-limiting at about 0.6. If this sensitivity value reaches 0.7, which is at the threshold of becoming exponential, conceivably, by itself, it could go runaway. We don’t need this as CO2 is already sprinting. Apart from possible PTE or early Venusian extremities, it seems that this has not previously happened. Furthermore, Earth’s persistent resiliency while maintaining abundant free water, logically, precludes it.

       Moderator Response:

       [JH] Put draft paragraphs in block quote for ease of understanding. Please learn how to do this yourself using the edit tools.

10310. DPiepgrass at 17:24 PM on 13 June 2019
       Is Nuclear Energy the Answer?
       

       Oops, forgot to complete the thought. What makes those "geological repositories" somewhat difficult to build is the need to guarantee they won't leak for something like 10,000 years. So if we can make our HL waste have 300-500 years of radioactivity instead (and we can), it should be a lot cheaper and easier to design a structure to last that long.

       But really the issue seems like a nothingburger; everybody says after 500 years the gamma radiation drops off anyway and the only real hazard is ingestion. How hard is it, really, to find an unpopulated area without groundwater where you can put this stuff? Well, we found a spot, Yucca mountain, right? So put the stuff there already. And this is a naive question, but what about all the empty oil wells - the ground was able to store oil for tens of millions of years, so why can't we store a few tons of waste in some empty well 4 kilometers straight down?

       Everybody argues about high-level waste, but what I'd really like to learn about is intermediate-level waste. This type has greater volume and less radioactivity, but I wonder how much volume exactly and whether there are some types of ILW with a very long period of hazardous radioactivity. And then there's low-level waste - do we really need to bury the stuff that was hit by the X-ray scanner in the hospital, and for how long?

10311. Eclectic at 17:02 PM on 13 June 2019
       Antarctica is gaining ice
       

       Jesscars @487 , if you go to the well-known website WUWT [WhatsUpWithThat] you will find that "skeptics" have all sorts of beliefs about climate-change / global-warming.  And these beliefs are mostly mutually contradictory.

       A few hold beliefs that are quite reasonable ~ at least, for the conditions prior to the industrial-revolution / coal-burning.   Others believe that the [observed & well-documented] ice-melt & sea level rise are simply not happening ~ are a hoax (from a two-century conspiracy by corrupt scientists worldwide . . . a conspiracy without even a single whistle-blower ! )    Others believe that "chemtrails" are being sprayed by the Lizard People (disguised as humans) in order to befuddle and subdue the human race . . . leading to a dictatorship by an Anti-Christ or alternatively a Marxist World Government (run by the Illuminati or similar).

       Half are in complete denial CO2 has any physical effect whatsoever (other than nourishing plants).   Others think the atmospheric CO2 effect is low but negligible, and that we can keep merrily burning coal/oil until it's all used up.   Yet others think (despite the evidence) that all global warming/cooling comes from oceanic overturning cycles of 1400 years' duration (or whatever).   Or believe that the the orbits of Jupiter & Saturn are the underlying cause of climate change . . . or that Galactic Cosmic Rays are the sole responsible factor.   In short : ABCD  (Anything But Carbon Dioxide) .

       But what say you, Jesscars ?

       # Probably simpler for you to answer here , rather than on all the other six threads you have posted in over this afternoon.

       # Also, please don't bother to mention Idso & Corbyn ~ since those two gentlemen have failed at basic arithmetic.

10312. DPiepgrass at 17:00 PM on 13 June 2019
       Is Nuclear Energy the Answer?
       

       The mentioned paper Abbott 2011 says nuclear reactors must be placed "away from dense population zones, natural disaster zones, and near to a massive body of coolant water" - I call "citation needed" on all three of those claims, but the third one in particular does not really apply to Molten Salt Reactors which can rely on air cooling or on relatively modest amounts of cooling water. I would think high-temperature reactors, in general, have modest water requirements.

       To be more specific, I thought I heard from one source that an MSR produces 1% of its output after shutdown, but I know I heard a guy from the NRC say that a LWR produces 7% of its output right after shutdown. Given a 2 GW-th MSR plant (about 900 MW-e) I calculate that in the worst case - at 7% output and with secondary coolant water that mysteriously starts out already being at the boiling point - it would boil 62 kg of water per second / or 223 tons per hour. But the radioactivity would drop pretty quickly so that the rate of water loss should be much lower within a few hours, and I assume cooling towers can be designed to recapture much of the water vapor. For comparison an Olympic swimming pool's capacity is 2,500,000 L or 2500 tons.

       Taking into account not just the footprint area of a nuclear power station itself, but also its exclusion zone, associated enrichment plant, ore processing, and supporting infrastructure, work at Stanford University, Stanford, CA [6] has shown that each nuclear power plant surprisingly requires an extended land footprint area of as much as 20.5 km2

       Its exclusion zone, meaning the evacuation area in case of a disaster? First, it is unreasonably pessimistic to say no one should live near a nuclear reactor - sign me up! Every nuclear disaster in history has been an old Generation II plant (AFAIK). Modern reactors are hella safe, that's half the reason they cost so much more than the old ones. Second, you know how it's unreasonable to count wind farms as taking up a huge land area because in reality there can be farms underneath them? The same applies to nuclear. Third, I'd love to hear anyone come up with a theory of how an MSR could produce a hazardous radioactive gas cloud (in all seriousness, e.g. I'm waiting for a chemist to speak up about what would happen if a supersonic jumbo jet mysteriously aims itself direcly at the below-grade reactor, and then let's say it had a water-based cooling system that now pours uncontrollably onto the exposed salt. Given a molten salt filled with dozens of solutes, do some solutes enter the atmosphere when water is added?)

       Thus, if nuclear stations need replacement every 50 years on average, then in the steady state for 15 TW, one nuclear power station needs to be built and another decommissioned somewhere in the world every day. This is questionable, given that nuclear stations are complex as evidenced by the fact they take on the order of 6–12 years to build, and then around 20–50 years to decommission.

       This is an emotional argument, not a scientific one. It's like saying we have a worldwide epidemic of flesh-eating disease, given that 144 human beings die from it every single day. Almost anything looks like a lot when scaled up to the entire population of planet Earth. Anyway, reactors won't take 6-12 years to build if they are built at scale, and the usual debate over nuclear power is not whether we should build 15,000,000 MW of nuclear capacity, but whether we should build any whatsoever.

       In a nuclear power station, entropy is an unavoidable byproduct of the generation of large amounts of energy

       Um, you mean heat? Why wouldn't you just call it heat?

       Maintaining order while subjected to a high entropy condition is a challenging situation, and this leads to a tradeoff between reliability and efficiency. In the same way that any electrical device or machine heats up and eventually fails, the same is inexorably true for a nuclear station.

       Um, humans have built many machines that work at their designed operating temperature for many years without failing, including reactors.

       Together with embrittlement, the metal structure is also subject to corrosion, oxidation, thermal creep, irradiation creep, phase instability, volumetric swelling, void swelling, grain boundary sliding, intergranular degradation, fracture, cavitation, and radiation-induced segregation (RIS) [7]. It is all these aging factors acting together that unavoidably lead to plant shutdown after 50–60 years of operation.

       What businessman won't build something because the profits will stop 50-60 years after construction?

       The situation in proposed Generation IV reactors is worsened where the vessel is 1) exposed to higher temperatures, 2) higher neutron doses, and 3) a greater corrosive environment [7]. There are thus significant challenges to materials selection...

       My God, is that a citation? Great, now I have to go look at it to see if it has merit. I need to go to sleep momentarily... but I have a feeling that experts in GenIV tech are better qualified to comment than this guy.

       After 60 years of nuclear technology, there is still no universally agreed mode of disposal [9] and nuclear waste still raises heated controversy.

       Among laymen, sure. But what do nuclear experts say?

       ...there is not only the problem of spent fuel, but the problem of where to put all the decommissioned reactors. Burial of waste has uncertainty in terms of unforeseen geological movement and radioactive leakage into groundwater.

       The reactors simply aren't large in relation to their stupendous power output (and those giant domes around the reactors aren't radioactive). For reasons that escape me, waste burial is a big concern for some people, but let's consider the length of time for which high-level waste is more radioactive than the natural uranium ore it originally came from. Right now, that length of time is several thousand years, but by building waste-burning reactors, we can burn the long-lived actinide / transuranic waste, leaving us mostly with waste that is significantly radioactive for 300-500 years. (Granted I'm not a nuclear expert and I have only found numbers like these on the web and in YouTube presentations; if someone can find a scientific paper that looks at nuclear waste and/or other nuclear issues in a less biased way than Abbott, I'm eager to read it.)

       Because a nuclear station is a complex system, and where redundant subsystems are necessarily colocated, redundancy can fail and can even have a negative impact.

       A great exercise with any anti-nuke argument is to check if it still makes sense with airplanes: "Because an airplane is a complex system, where redundant subsystems are necessarily colocated, redundancy can fail and can even have a negative impact."

       Or if someone says "There have been nuclear accidents, so we should stop making reactors." No one says "There have been plane crashes, so we should stop making airplanes."

       Now, anyone who wants to make nuclear reactors cheaper must necessarily also make them less complex; good Gen IV designs are simpler than Gen III. But often redundancy is still needed.

       Maybe I'll read the rest of this when I have more time. But Phil, I share your desire for better expert analyses and so far I've been frustrated at the difficulty of finding reasonable, authoritative analysis of nuclear claims on both sides of the issue, based on evidence and facts.

        

10313. jesscars at 16:21 PM on 13 June 2019
       Antarctica is gaining ice
       

       I believe that there are observable changes in the natural environment (such as ice-caps melting and sea-level changes), and that these are due to climate change. But I think denial of such things is probably bad science, and promoted by bad skeptics. It's not fair to characterise all "skeptics" as all having such beliefs.

       The better scientific case against "climate change" is that it's not human causes, but natural causes, that are responsible for the bulk or entirety of these changes. The climate changes naturally and always has. The true question is -what is causing that change-?

       AGW promoters say CO2. "Skeptics" say natural factors such as Milankovitch cycles, solar radiation cycles, and the circumpolar vortex.

       Sherwood Idso, in a 1998 paper, presents a case, based on results from eight natural experiments, that the influence of CO2 on the temperature, through the greenhouse effect is minimal - he derives an upper limit of 0.4 degrees C for a 300 to 600 ppm doubling of atmospheric CO2. Piers Corbyn also believes that the influence of CO2 on climate is minimal/insignificant.

       Moderator Response:

       [PS] Past climate change was most certainly from natural well-understood causes, but that is irrelevant to today because those natural causes should be cooling us. If you are a genuine skeptic try applying that to Sherwood and Corbyn and see if you can spot the errors and downright misleading information yourself.

10314. TVC15 at 15:35 PM on 13 June 2019
       Climate's changed before
       

       Thank you to everyone who responed!

       737@ MA Rodger the man they are talking about is Jim Hansen.

10315. jesscars at 15:10 PM on 13 June 2019
       It's the ocean
       

       I believe this is a misrepresentation of the "skeptics'" argument being made.
       
       "Skeptics" believe that, before the industrial revolution, the correlation betweeon CO2 and temperature (as shown on records such as the Vostok Ice Coe records) was explained by:

       1) Natural factors causing the earth's temperature to change e.g. Milankovitch cycles, solar radiation cycles, and the circum-polar jet-streams.

       2) The ocean beng warmed or cooled due to these natural factors - which takes several hundred years (thus explaining the 800-year lag found on the Vostok Ice Core samples).

       3) The release or absorption of CO2 from the oceans, as the natural solubility or equilibrium level of CO2 in water changes with temperature. (The linear relationship of CO2 to water temperature (below about 23 degrees C.) also explains the linear historic relationship of temperature to CO2 (found at Vostok): which is about 1 degree C. to 10 ppm atm. CO2.)
       
       So yes, the historic source of CO2 was the oceans - and it was the temperature change, caused by natural factors, that caused this change.

       Moderator Response:

       [PS] Please quit spamming multiple threads.

10316. jesscars at 15:00 PM on 13 June 2019
       Models are unreliable
       

       If the models are making predictions of between 1 and 4.5 degrees change per doubling, then they are unreliable. This is a 450% variance. There can only be one answer to how much, if anything, CO2 is contributing to the climate. Why are the models coming up with such different results? Why are they coming up wth multiple answers to the same question?

       Moderator Response:

       [PS] Please dont spam multiple threads. Best to discuss one thing on a thread that you think is important and when satisfied, move to another. (And how do calculate 450% - what is your denominator). Meanwhile, this post from people who do the modelling might be helpful. While models have flaws, they remain the best tool we have for predicting the future - far better than say chicken entrails or assuming tomorrow will be same as today.

10317. jesscars at 14:54 PM on 13 June 2019
       Climate's changed before
       

       If CO2 caused the temperature to change, (and is resposible for the climate historically) what caused the CO2 to change? Volcanoes? Is there any geological evidence to support this theory?
       
       Why do the ice-ages and deglacial period occur cyclically, approximately every 100,000 years? Is there some geological pattern identified on earth that would explain cyclical volcanic activity and CO22 emission?

       N.B. The ice-ages coincide with one of the Milankovitch cycles - the eccentricity of the earth's orbit, which goes through cycles of approx. 100,000 years. If the earth periodically gets further away from or closer to a hot object, this should have some influence on the earth's temperature, correct? 

       Moderator Response:

       [PS] See here for more on milankovich. In the iceage cycle CO2 is a feedback from an initial albedo-driven driver. Water vapour, albedo and the very slow CO2 feedbacks convert a small change at 65N into a global effect.

10318. scaddenp at 14:52 PM on 13 June 2019
       An exponential increase in CO2 will result in a linear increase in temperature
       

       jesscars - Scientists are suckers for 1st law of thermodynamics. If you increase GHG, then you increase the radiation reaching the surface and you can predict exactly the spectrum change associated with it and measure it directly. If you want to invoke some hitherto unnoticed cause, then you have interesting problem of explaining why increased radiation  doesnt increase temperature in violation of known physics. Secondly, if you seriously expect someone to accept a natural cause, then you need to explain where this extra energy is coming from. Not the sun, we measure its output directly; not the ocean - it is getting warmer too; no Milankovich - the 65N forcing has been negative for a long time.

       Furthermore, CO2 increase in past ages as a result of temperature increase are a very slow feedback from bogs and oceans that wont start happening with current temperature rise for 100s of years (we hope anyway). We can tell that all increase in CO2 concentration is from emissions based on O2 decrease; isotopic composition of the carbon; and straight mass-balance from known burning of fossil fuels. Frankly you are clutching at straws rather than examining the science.

10319. jesscars at 14:47 PM on 13 June 2019
       CO2 lags temperature
       

       The Shakun study only covers the last degclaciation, not the entire 400,000 year period (of Vostok Ice Core records indicating a lag), so does not adequately explain this lag.
       
       Whatsmore, the Shakun study offers a highly complex explanation to arrive at the "conclusion" that there was no lag. Is there empirical evidence to support the points made in their explanation or are these just theoretical e.g. ocean circulation, etc.? Do they arrive at the same conclusion "that there was no lag" for the rest of the 400,000 years?

10320. jesscars at 14:42 PM on 13 June 2019
       An exponential increase in CO2 will result in a linear increase in temperature
       

       It doesn't matter how much atmospheric CO2 has risen since the industrial revolution if CO2 does not cause temperature to change. The climate changes naturally and always has.

10321. jesscars at 14:41 PM on 13 June 2019
       An exponential increase in CO2 will result in a linear increase in temperature
       

       This presumes that CO2 is causing the temperature change - and that it's not just a period of (predominantly or entirely) natural warming coinciding with increased emissions since the industrial revolution.

10322. jesscars at 12:55 PM on 13 June 2019
       Increasing CO2 has little to no effect
       

       Please ignore that last point "2)".

10323. jesscars at 12:51 PM on 13 June 2019
       Increasing CO2 has little to no effect
       

       I have a couple of questions re. the historic vs future predicted relationship between CO2 and temperature:

       If you look at the Vostok Ice Core Records, the relationship between CO2 and temperature is linear, and is approximately 1 degree change per 10 ppm change.[1]

       1) Why is this not the expected predicted relationship of CO2 to temperature? Why does it go from 1 degree per 10 ppm to 1 degree per doubling, the first doubling being 300 ppm (then 600, 1200, etc.)? Why does the sensitivity of the earth's temperature to CO2 change so severely to have only 1/30th the sensitivity? What is the reason for this reduction in sensitivity?

       2) Why does the relationship change from linear to logarithmic? There is a steady and consistent linear relationship of 1 degree for 10 ppm - why should this change to a logarithmic relationship of  degree per doubling i.e. instead of 1 degree per 10 ppm, we now have 1 degree per 300 ppm, then per 600 ppm, then per 1200 ppm, and so on. What is the cause of the change of the nature of this relationship?

       It seems to me that the "skeptics'" explanation - which assumes temperature is causal in the observed temperature-CO2 correlation - does not involve such erratic and unexplained behaviour.

       N.B. The linear 1 degree per 10 ppm can be explained by the linear relationship of CO2 solubility in ocean water (at temperatures below 23 degrees, see link [2]).

       As the temperature changes (measured by the atmospheric temperature), this causes the ocean temperature to change. Within the temperature range seen on the graph in link [2] i.e. below about 23 degrees, you would expect a similar amount of CO2 to be released or absorbed, per unit or degree of change, per volume of water, resulting in a linear atmospheric temp-CO2 relationship.

       The Vostok Ice Core records also show an 800-year lag where temperature changes before CO2 does. This indicates that temperature is causing CO2 to change, not vice-versa. (The Shakun study only attempts to provide an explanation for this for the last deglaciation, not the entire duration of the Vostok samples (400,000 years), so really is inadequate.) This can be explained by the fact that the oceans take so long to heat or cool. So it takes hundreds of years for the warming or cooling to have an effect on the CO2 levels, as this has to happen via the oceans.

       2) The causal mechanism to explain the temperature-CO2 correlation is explained by:  natural causes (e.g. Milankovitch cycles, sun radiation cycles, circumpolar jet-streams, etc.)  to be caused by ocean absorption of CO2, is expected 

       [1] http://joannenova.com.au/global-warming-2/ice-core-graph/

       [2] https://i1.wp.com/www.geological-digressions.com/wp-content/uploads/2016/12/CO2-solubility.jpg

       Moderator Response:

       [PS] Just a quick note that icecore data is indeed used as a way to constrain to climate sensitivity. Try for instance Hansen & Sato 2012 which does it properly. Also see here for Co2 lags question

10324. scaddenp at 07:43 AM on 13 June 2019
       Medieval Warm Period was warmer
       

       RBFOLLETT – first I would say, that if you are not interested in having your opinions shaped by data and instead are flaying around trying to rationalize a predetermined position on global warning, then Skepticalscience is not the site for you. Motivated reasoning is all the rage over at WUWT.

       If you are actually interested in the science, then there are some misconceptions to look at.

       Firstly, climate science works with global mean temperature anomaly. This is an important distinction since a global mean temperature is difficult to define and impossible to measure. The discussion and methodology associated with this is in the seminal Hansen and Lebederf 1987. As to actual error bounds on temperature record, try here where there is reference to how uncertainty bounds are determined and where you can find code to play it yourself.

       
       Secondly, you seem to implying that if, for example, you could only measure a person’s height to nearest centimetre, then you believe that the average person’s height could only be expressed to nearest centimetre? This is not true and perhaps you need to refresh yourself about the Law of Large Numbers.

       
       Finally, you should know that proof is some you do in mathematics; science cannot prove anything. What we do have in massive empirical support from many fields supporting the theory of climate.

       You make a massive number of frankly false assertions and unsurprisely provide no evidence to support them (in contravention of this sites comment policy). I suspect you are getting your information from disinformation sites rather than published science.

10325. michael sweet at 07:18 AM on 13 June 2019
       The Scientific Method
       

       To add to Philippe Chantreau's post, in 1850 when the IR spectrum of carbon dioxide was measured the scientists realized that increasing CO2 would cause atmospheric temperature to rise.

         In 1896 Arrhenius published a paper that calculated how much the temperature would increase.  He predicted that the temperature would increase more in winter than summer, more at night than during the day, more over land than over ocean, and more in the Arctic than the tropics.

       These were all predicted 90 years before they coud be measured.  When you predict things in advance and then they happen it shows that you understand why they happened.  As Philippe said, the null hypothesis does not apply to predictions made in advance.

10326. nigelj at 06:07 AM on 13 June 2019
       Climate change: sea level rise could displace millions of people within two generations
       

       higgijh @2, your contention that theres not much we can do about an asteroid threat is not matched by reality. NASA has a substantial programme monitoring asteroids, and NASA has a well advanced programme to deflect an asteroid here.

       
       

10327. Philippe Chantreau at 05:57 AM on 13 June 2019
       The Scientific Method
       

       The argument about the null hypothesis is specious. It is normally applicable to statistical studies used to infer a causative mechanism. In the case of atmospheric CO2, there is a clear and very well studied physical mechanism that is independent of any statistical relationship. Physics predict that increasing CO2 concentration would cause warming, that hypothesis is not derived from correlating the recent observed warming with observed rise in CO2 concentration. Assuming that physics will not work as expected and attempting to find another explanation for the observed warming is going beyond what logical inferrence would call for. Nonetheless, this has been done, and studied ad nauseam, as pretty much all other possible forcings have been explored. I would expect that the attribution litterature in the IPCC contains volumes on that.

10328. Eclectic at 05:55 AM on 13 June 2019
       Medieval Warm Period was warmer
       

       A further reply to comment #250

       The scientific study Kopp et al 2016 [published in the Proceedings of the NAS ] indicates that the fall in MSL was about 10 cm (not 50 cm) during the MWP to LIA transition.   The poster at #250 had wildly exaggerated the sea level fall.

10329. Eclectic at 05:44 AM on 13 June 2019
       The Scientific Method
       

       TVC15 @58 , in view of comments elsewhere . . . it seems your adversarial friends are projecting themselves everywhere, most remarkably.

       1.  They should read the philosopher Popper ~ they have failed to understand the basic concept of Null Hypothesis.  In view of the patently obvious sea level rise & ice melt, it is fair to say Global Warming now is the Null Hypothesis . . . and they themselves need to refute it.

       2.  The various methodologies of temp measurement are a strength, not a weakness.

       3.  It is statistically valid to use a variety of locations.  (And scientist Nick Stokes has demonstrated the validity of using as few as as 61 sites worldwide.)

       4.  Data is often reviewed & adjusted quite openly, in order to reduce errors that are detected.  That's the proper way of conducting science.

       5.  The global mean sea level is rising, and ice is melting, and plants & animals are changing their location as the temperature rises.  All this is physical evidence of ongoing global warming.  No "perception" is required.

       6.  The Little Ice Age and the Medieval Warm Period are both only very minor wiggles in average world temperature (and the 21st Century temperature is still rising and is distinctly above the MWP & the Holocene Maximum).    The LIA and MWP are quite trivial and not in any way "inconvenient".   How could anyone think them inconvenient ?

       Apparently the plants & animals are more intelligent than your denialist "friends" !      ;-)

10330. Daniel Bailey at 05:28 AM on 13 June 2019
       The Scientific Method
       

       As a short answer, demand source citations (to credible sources) for each of those claims.

       They won't furnish any because they don't have any.

       That means no need to rebut each and every claim.  If you feel like it, pick one and demolish it; an example:

       "ignores "inconvenient" data points like the "Little Ice Age" and the "Medieval Warming Period" in data analysis"

       The Little Ice Age and the Medieval Warming Period were not ignored.  The Trump Administration placed them in their appropriate context, back in 2017:

       

        

       Advice:  Don't play their game.  Make them play yours.

10331. TVC15 at 03:36 AM on 13 June 2019
       The Scientific Method
       

       Hi Skeptical Science,

       I'm dealing with some very difficult deniers and I was hoping to gain some insight on how to deal with such deniers.

       This is what a denier I'm dealing with states over and over.

        

       See the cornerstone of the scientific method and legitimate science- refuting the null hypothesis. AGW fails miserably in this regard and is thus not legitimate science.

       AGW;

       1. fails to refute the null hypothesis

       2. compares temp data over time using four different temp measurements

       3. fails to have consistent measuring locations over time

       4. has intentionally altered or "adjusted" data to meet their hypothesis, rather than realizing the data refutes their hypothesis.

       5. uses bogus statistical analysis to create the perception of warming

       6. ignores "inconvenient" data points like the "Little Ice Age" and the "Medieval Warming Period" in data analysis.

       AGW is bogus, junk science.

10332. Daniel Bailey at 00:37 AM on 13 June 2019
       Climate's changed before
       

       Agreed with MA Rodger.

       No Venus-syndrome for the Earth:

       "With the more realistic physics in the Russell model the runaway water vapor feedback that exists with idealized concepts does not occur. However, the high climate sensitivity has implications for the habitability of the planet, should all fossil fuels actually be burned.

       Furthermore, we show that the calculated climate sensitivity is consistent with global temperature and CO2 amounts that are estimated to have existed at earlier times in Earth's history when the planet was ice-free.

       One implication is that if we should "succeed" in digging up and burning all fossil fuels, some parts of the planet would become literally uninhabitable, with some time in the year having wet bulb temperature exceeding 35°C.

       At such temperatures, for reasons of physiology and physics, humans cannot survive, because even under ideal conditions of rest and ventilation, it is physically impossible for the environment to carry away the 100 W of metabolic heat that a human body generates when it is at rest. Thus even a person lying quietly naked in hurricane force winds would be unable to survive.

       Temperatures even several degrees below this extreme limit would be sufficient to make a region practically uninhabitable for living and working.

       The picture that emerges for Earth sometime in the distant future, if we should dig up and burn every fossil fuel, is thus consistent with that depicted in "Storms" — an ice-free Antarctica and a desolate planet without human inhabitants"

       So no runaway. But Hansen notes that it won't take a runaway to basically completely eradicate civilization as we know it.  Supported by this:

       "While dominated by anthropogenic forcing in these recent times, solar variability in prior eras caused much larger relative influences.

       The early Sun was approximately 70% as bright as at the present when it joined the main sequence about 4.6 billion years ago with a current rate of increase in luminosity of 0.009% per million year (Hecht 1994). At this rate, it will take 10 million years for the background solar brightness to increase by the 0.1% typical of a solar-cycle variation, and another 3.5 billion years for heating from the Sun to create Earth-surface conditions similar to those of the present-day Venus; although additional effects, such as feedback from enhanced ocean evaporation, may accelerate this warming and make the Earth uninhabitable (at least to present-day complex lifeforms) in about one-billion years."

10333. Daniel Bailey at 00:23 AM on 13 June 2019
       Climate change: sea level rise could displace millions of people within two generations
       

       "Note the error bars on the graph of reconstructed sea level and how those bars diminish to zero at present day"

       That graphic is from Kopp et al 2016.  From that paper:

       "The 20th century rise was extremely likely faster than during any of the 27 previous centuries"

       Extremely likely = 95%.

       We know that in the early 20th Century, about one-third of the observed warming is from human activities. This corresponds well to the observations from Kopp et al 2016.  However, since 1950, pretty much all  of the observed warming is from human activities.  Thus, the closer we get to the present the greater the human-driven component of the knock-on effects of that warming (like SLR from land-based ice sheet mass losses due to that warming) becomes.

       Per Slangen et al 2016,

       Anthropogenic forcing dominates global mean sea-level rise since 1970

       "the anthropogenic forcing (primarily a balance between a positive sea-level contribution from GHGs and a partially offsetting component from anthropogenic aerosols) explains only 15 ± 55% of the observations before 1950, but increases to become the dominant contribution to sea-level rise after 1970 (69 ± 31%), reaching 72 ± 39% in 2000 (37 ± 38% over the period 1900–2005)"

       Takeaways:

       1. Although natural variations in radiative forcing affect decadal trends, they have little effect over the twentieth century as a whole

       2. In 1900, sea level was not in equilibrium with the twentieth-century climate, and there is a continuing, but diminishing, contribution to sea-level change from this historic variability

       3. The anthropogenic contribution increases during the twentieth century, and becomes the dominant contribution by the end of the century. Our twentieth-century number of 37 ± 38% confirms the anthropogenic lower limit of 45%

       4. This would increase even further if increased ice-sheet dynamics were considered to be a consequence of increased anthropogenic forcing (to 83% in 2000) and if reservoir storage and groundwater extraction were included (to 94% in 2000)

       5. Our results clearly show that the anthropogenic influence is not just present in some of the individual contributors to sea-level change, but actually dominates total sea-level change after 1970

10334. higgijh at 23:56 PM on 12 June 2019
       Climate change: sea level rise could displace millions of people within two generations
       

       This is an interesting post and it's good to know that people in the field are continuing to collect information and re-think climate change and sea level rise in particular.  However, the earth could also be hit by an asteroid large enough to wipe out civilized life - there are still rocks out there that haven't been detected. There are a couple of things about the asteroid problem that are different: (1) there's not much we can do about an asteriod threat and, (2) those predicting possible asteriod threats put some fairly good error bars on their predictions.  Thing is, you can always predict possible disaster ... like maybe a volcano suddenly building under Seattle, but if you can't put error bars on the prediction then the prediction is worthless. Seems like this post suggests high risk with associated extremely high and completely unquantified uncertainty. 

       Note the error bars on the graph of reconstructed sea level and how those bars diminish to zero at present day. That graph does not say that sea level is currently higher than it's been in 2500 years. It says that sea level might be higher than it's been in 2500 years with the uncertainty large in the far past. Peaks in things like sea level and climate temperature will be naturally diminished when tracked, via proxies, far into the past because the measurement methods do a natural averaging. Averaging always diminishes peaks and toughs.

10335. MA Rodger at 21:50 PM on 12 June 2019
       Climate's changed before
       

       TVC15 @735,

       I think I would respond to such a silly comment by asking for the name of this man they are talking about, this because such knowledge may assist in sorting out why they are asking such silly questions.

       But a more direct approach, but more involved could be:-

       There is perhaps a philisophical aspect to the "runaway greenhouse effect." CO2 emissions/CO2 levels that are directly due to man's actions will result in an elevated global temperature and this will result in a further CO2 emissions that are NOT directly due to mankind, this extra CO2 resulting in yet further warming.

       So when would that "further warming" be considered as "runaway"?

       If human emissions totalled 4,000 Gt(C) before we stopped, which is eight-times what we've done so far, that would increase global temperature by perhaps +6ºC which would cause natural emissions of let's say another 4,000Gt(C). These "feedback" natural emissions from a 1,200ppm CO2 world would cause further warming, resulting a total of say +9ºC in a 2,400ppm CO2 world. And then the warming would stop. So is +6ºC with +3ºC of that feedback, is that "runaway"?

       Consider if the physics were such that it didn't stop there, that creating CO2 levels of 1,200ppm would result in say 40,000Gt(C) extra CO2 in the atmosphere - roughly 20,000ppm - which is all the carbon in the oceans & soils (but the rocks would still contain the bulk of the planet's carbon), the temperature would ratchet up to who-knows what temperature and all would see this as runaway warming.

       But at some level it would stop. Any runaway system will eventually stop. Always it will stop somewhere.

       The important thing is whether the runaway effect is so significant that it presents a "wheels-fallen-off" situation. Back in the days of the Hadean or Archean, there may well have been far more than 24,000ppm CO2. Such levels are argued because of the faint young sun paradox. But the Hadean earth was not back-then a "wheels-fallen-off" situation because there was no humans requiring a climate compatable with their needs, while a return to the Hadean climate today would obviously be a "wheels-fallen-off" situation.

       But the physics isn't like that. While a directly-human-caused 1,200ppm CO2 world would result in an additional CO2 boost from warmer oceans & Arctic, any resulting additional temperature rise will be limited so a result like Venus or the Hadean is an impossibility. But that additional CO2 boost will be big enough to make what is an already-very-very-difficult situation for humanity very-very much worse. I would suggest that the increase in suffering from that additional CO2 boost would be enough for some to call it a "runaway" situation.

       But some may disagree. Boosting a warming of +6ºC up to +9ºC perhaps would not constitute "runaway" if human civilisation will have been ajudged to have already suffered that "wheels-fallen-off" situation without the additional natural feedbacks.

       I don't know if that is helpful in the response set out @735.

10336. Eclectic at 16:11 PM on 12 June 2019
       Climate's changed before
       

       TVC @735 , there's no scientific study [to my knowledge] supporting "Runaway" greenhouse effect being possible on Earth.   I think those friends of yours are suffering from a fantasy life of runaway strawman arguments.

       Perhap they misunderstood something they heard somewhere. 

10337. Eclectic at 16:03 PM on 12 June 2019
       Medieval Warm Period was warmer
       

       RBF @250 , your "facts" sound a bit confused.

       You are suggesting that the sealevel fell two feet over several centuries from the Medieval Warm Period until the depths of the Little Ice Age.   Please cite your supporting source for your extraordinary statement !   (And over a total cooling of about half a degree Celsius ~ truly remarkable ! )

10338. TVC15 at 15:20 PM on 12 June 2019
       Climate's changed before
       

       Can you guys help me to understand how to respond to these types of claims?

        

       CO2 levels were 24,000 ppm CO2 for nearly 3 Billion years and there was no runaway greenhouse effect.

       CO2 levels were 8,000 ppm CO2 for several Million years and there was no runaway greenhouse effect.

       CO2 levels were 2,000 ppm CO2 for several Million years and there was no runaway greenhouse effect.

       So, why would 1,200 ppm CO2 over a few centuries cause a runaway greenhouse effect?

       It wouldn't. It's just fear-mongering alarmism by a man who makes his money proffering this nonsense.

        

       Thanks!

       Moderator Response:

       [PS] Just a little bit effort with the search button would find the answers to most of these as would a read of the IPCC WG1.

10339. RBFOLLETT at 14:41 PM on 12 June 2019
       Medieval Warm Period was warmer
       

       Wow, a hundred answers, but I think most of them missed the obvious.  Everyone keeps focusing on the mythic global mean temperature that they say they can measure into the decimals (BS).  They have been talking about sea level rise for the past 30 years almost within every sentence that contains the words global warming.  So take a look at sea levels during the Medievil Warm Period then. Historical sea level charts show sea levels almost a foot higher than today and better yet actual History and living proof confirms historic Sea Ports miles inland from current sea shores.  Actual physical empirical EVIDENCE that establishes sea levels much higher than today in the Medieval Warm Period, no science, no theory, no BS, just ABSOLUTE PROOF.  The same goes for the the Mini Ice Age Cooling, sea level was down almost a foot from what it is today, again no BS, just Absolute Proof.  Surely to God the Scientists are not now disputing the link between warming and sea level rise?  What does it take to accept actual physical empirical evidence over scientific theory?  Why go back tens of thousands of prehistoric years ago to predict what’s going to happen in the next hundred years, when you have historical evidence from the last 2000 years.  Obvious cycles of warming and cooling are there in the sea level charts, a $10 tide gauge proves we have been warming for the last 250 years with another foot to go before we reach the levels of 450 years ago.  Man (and the Polar Bears) have already survived a much warmer Earth, it’s a fact not a theory.

       Moderator Response:

       [DB] "So take a look at sea levels during the Medievil Warm Period then"

       Sea levels are extremely likely (95%) higher know than at any point in the past 2,700 years.

       

       Thank you for taking the time to share with us.  Skeptical Science is a user forum wherein the science of climate change can be discussed from the standpoint of the science itself.  Ideology and politics get checked at the keyboard.  As this venue is based on credible evidence for claims and using the scientific method at all times, the onus is on each participant to be able to cite credible sources for claims made.  Your above claims about past sea levels with respect to those in the modern era are without merit and demonstrably false.

       Please take the time to review the Comments Policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

       Off-topic snipped.

10340. RedBaron at 08:41 AM on 12 June 2019
       State of the climate: Heat across Earth’s surface and oceans mark early 2019
       

       @swampfox, 

        You make an interesting hypothesis. However, your hypothesis lacks any evidence for it, and has quite a bit of evidence against it. So I would suspect you are a very very long way from supporting your assertions.

       More importantly as it applies to agriculture though, those who claim moving their cattle daily is indeed biomimicry are obtaining spectacularly better results than those who fence their cattle near streams and leave them there.

       There are huge improvements to both the animals and the grasses and forbs of the prairie and even a measurable increase in carbon sequestration of the soil when managed holitically with our new understanding of grassland ecology.

       We have fossilized paleosoil evidence:

       Cenozoic Expansion of Grasslands and Climatic Cooling

       We have observational evidence from YellowStone how predators forced herbivores away from lingering near rivers and how that improves ecosystem function.

       How Wolves Change Rivers

       In agriculture using biomimicry we have measurable evidence from modern tallgrass prairies:

       Grazing management impacts on vegetation, soil biota and soil chemical,
       physical and hydrological properties in tall grass prairie

        

       and from drier shortgrass prairie:

       Effect of grazing on soil-water content in semiarid rangelands of southeast Idaho

        

       Notice on the last two that there was even an improvement over the controls without any grazing.

       We even have evidence that many prairie grasses will simply die out if not periodically grazed or burned. This due to the grasses going moribund and choking on old material.

       Fire is a big component to the success of grasslands, large or small. Controlled burns, with a permit, are recommended every 4–8 years (after two growth seasons) to burn away dead plants; prevent certain other plants from encroaching (such as trees) and release nutrients into the ground to encourage new growth. A much more wildlife habitat friendly alternative to burning every 4–8 years is to burn 1/4 to 1/8 of a tract every year. This will leave wildlife a home every year and still accomplish the task of burning. The Native Americans may also have used the burns to control pests such as ticks. If controlled burns are not possible, rotational mowing is recommended as a substitute.

       One of the newer methods available is holistic management, which uses livestock as a substitute for the keystone species such as bison. This allows the rotational mowing to be done by animals which in turn mimics nature more closely. Holistic management also can use fire as a tool, but in a more limited way and in combination with the mowing done by animals.[1]

       So the weight of the evidence leads one away from the understanding you have and towards the new more modern understandings we recently discovered in just the last few decades.

10341. nigelj at 07:40 AM on 12 June 2019
       Climate change: sea level rise could displace millions of people within two generations
       

       Island nations in the Carribean, Pacific and SE Asia are at particular risk from rising seas, and many of these are near the tropics so also at risk from more heatwaves. People from the Caribbean could probably be accommodated in the Americas, but the numbers at risk in places like Indonesia, Malasia and Taiwan is larger and going to cause some real refugee problems, especially for adjacent potential destination countries like Australia, China, Myanmar, Vietnam which are also particulary vulnerable to sea level rise and already have huge population pressures of their own.

       It's not going to be easy to resolve such issues on top of exising refugee problems caused by natural disasters, economic and political problems. Climate change could tip all this so it spirals out of control.

10342. TVC15 at 05:30 AM on 12 June 2019
       Climate's changed before
       

       Much appreciated MA Rodger, Electric and Scaddenp!

        

10343. One Planet Only Forever at 01:51 AM on 12 June 2019
       Lobbying against key US climate regulation ‘cost society $60bn’, study finds
       

       Related to my comment @3, and another exercise in improving my understanding by practising the presentation of it, is the following alternative presentation of the same fundamental abductive reasoned 'explanation of what can be seen to be going on'.

       Competition for status judged by popularity and profitability is likely to develop harmful results because it encourages a narrower more selfish worldview. And narrower more selfish worldviews tend to excuse actions perceived to be personally beneficial but are understandably harmful to Others. Self interest can easily develop harmfulness. And those developed harmful results will resist correction. The more popular and profitable an activity becomes the more powerfully it can and will resist losing developed perceptions of status (resisting correction).

       Divisiveness in societies develops when misleading marketing creates a large enough group of supporters for a harmfully incorrect understanding that increases or prolongs the popularity or profitability of an unsustainable harmful activity. Good helpful people are not on 'both sides of those harmful divides'.

       Regarding the climate science divide, the Good Helpful people include those who try to raise awareness of the extreme but possible levels of harm that could be done to the future of humanity by a lack of rapid correction of the harmful popular and profitable activity that has developed. Evaluations pointing out the harm done to the current day generation by the lack of correction in the past, such as this report, are also helpful. This study points out the future harm done by the lack of correction by people in the past.

       The Other side includes people who try to maintain harmfully developed ultimately unsustainable perceptions of status (even people trying to come up with more gradual reductions of the rate of harm done in attempts to maintain developed perceptions of status and prosperity). It also includes people who try to argue that doing harm to the future generations of humanity can be justified by of any of the following harmful misleading marketing claims:

       • The highest status people being required to give up some of their status to help Others is an unjustified demand. It incorrectly implies that all Winners are 'deserving' and therefore are immune to correction that would reduce their perception of status (Perception of status needs to be corrected to be based solely on helpfulness to improving awareness and understanding to develop sustainable improvements for the future of humanity, with associated sacrifices/loses of incorrectly developed perceptions of status).
       • One person's actions are insignificant, leading to one region's actions being considered insignificant, or leading to the claim that 'someone else has to behave better first' which is a claim that can only be justifiably applied to the ones with the highest status. The highest status should lead by example even if they will lose some developed perceptions of status if they behave better (Failing to behave better because of the excuse that their peers may not behave better is a lousy excuse).
       • The current generation is not being harmed at this moment. Even the evaluation reported is about harm done to a future population (now the current day population) by the lack of correction by a previous generation (then the current generation that was not 'harmed in their moment by the lack of correction').
       • There is uncertainty regarding 'how much harm is being done in the future'. Demanding absolute certainty, to the satisfaction of people who do not want change or correction, before correction is required is the classic harmful activity defence.
       • Monetary evaluations of harm done to the future generations are justified by a monetary comparison that says it is more costly for the current generation to stop harming the future generations than the calculated harm done to the future, with the future harm discounted. Harm to the future generations cannot be justified. (One person, or sub-set of humanity, benefiting by harming another person or sub-set (the future of humanity is the largest 'sub-set'), is not acceptable, no matter what a monetary evaluation says. Contributing to harming the future of humanity is undeniably inexcusable).
10344. swampfoxh at 00:49 AM on 12 June 2019
       State of the climate: Heat across Earth’s surface and oceans mark early 2019
       

       I plan to chat with EliVA about it today

10345. swampfoxh at 00:46 AM on 12 June 2019
       State of the climate: Heat across Earth’s surface and oceans mark early 2019
       

       RedBaron

       But the rest of your observations are demonstratively "right on" and I am pleased to see it in print. Thank you.

10346. swampfoxh at 00:38 AM on 12 June 2019
       State of the climate: Heat across Earth’s surface and oceans mark early 2019
       

       RedBaron

       Don't think grazers have much to do with it. Bison never stomped through sixfoot prairie grass, head down, liable to run into a predator, they stayed along the rivers where there was water. The reason the white man killed off most of them was that the railroads ran close to the river floodplain and hundreds of riflemen could ride in open coaches and shoot the poor hapless creatures. There are thousands of square miles of the "Great American Desert" with hardly a creek, these areas were fostered by rainfall, not creeks. Those vast grasslands never saw a ruminant. Those grasses lived and died in soil delivered by the effects of the last ice age. Had the plow not dug the place up in a frantic attempt at dry land farming, it would still be a grassland and were it not for mining the Ogallala Aquifer, it would still be the Great American Desert...mostly empty of Bison more than a mile or two from the scarce rivers.

10347. One Planet Only Forever at 14:00 PM on 11 June 2019
       Lobbying against key US climate regulation ‘cost society $60bn’, study finds
       

       Detailed analysis like this is an important improvement of awareness and understanding of what is really going on. But, as proven by the climate science case, there are limits to the 'uptake' of improvements of awareness and understanding of what is really going on, especially when that improvement would require corrections of developed perceptions of status or developed perceptions of personal opportunity to enjoy life.

       The problem is not things like 'lobbying' or 'money in politics'. Those are just examples of actions that can be helpful or harmful to the development of a sustainable and improving future for humanity.

       The problem is the success of harmful actions.

       Social systems that rely on popularity or profitability to determine Winners and Losers can be seen to encourage the development of harmful selfishness. A lack of governing based on the importance of improving awareness and understanding to help develop a sustainable better future for all of humanity can be expected to produce the observed harmful, and ultimately unsustainable, results.

       Leadership that understands and honours the importance of developing a sustainable better future for all of humanity would not be influenced by the type of lobbying or money influence that is succeeding in the USA, unless they believe they risk losing their leadership roles if they try to honour that important understanding.

       Leaders compromising what is understandably required in the hope that doing so will improve their chances of 'remaining a leader' is a downward spiral. It resulted in the likes of Donald Trump and Mitch McConnell and the House Freedom Caucus becoming harmfully influential in the USA (and similarly harmful people becoming influential in regions of the USA and in other nations). They become more harmfully powerful the more that the group they lead is compromised by selfish interests such as greed and intolerance.

       Competition for status based on popularity and profitability encourages selfishness and discourages helpfulness. It encourages the pursuit of individual perceptions of success any way that can be gotten away with. Ungoverned by the requirement to not harm Others (especially the future generations), and without the aspiration to help others (including the future generations), competitions can be seen to encourage people to be more myopically focused on immediate personal benefit. And that push for short term gain any way that can be gotten away with will result in people forming collectives that are focused on their collective (tribe/corporation) benefits in the short term.

       A focus on short term benefits for a sub-set of humanity inevitably dismisses consideration of the need to provide benefits into the future. The sustainability of benefits for the sub-set isn't even a serious consideration. The focus is on how to increase or prolong any developed perceptions of status relative to Others without concern for sustainability.

       That lack of consideration for Others and the Future easily extends to a lack of concern for climate impacts, biodiversity loss or other harm being done. The focus on maintaining and increasing perceptions of status relative to Others becomes harmfully all consuming. That harmfully consumptive condition can be seen to have taken over the Political Right in many regions of the planet.

       Lobbying is not the Problem. The success of harmful selfishness is the problem. And the ability to legally get away with misleading political marketing prolongs or increases that incorrect and harmful success.

       Misleading political marketing causes many leaders to incorrectly harmfully dive into the downward spiral of compromising what is understandably required to be done by responsible helpful leaders.

       Populations lose good helpful leadership when misleading political marketing is 'legal'. And the future of humanity loses the most because they do not get to lobby, develop and deliver political messages, vote, protest, or launch lawsuits.

10348. ELIofVA at 11:07 AM on 11 June 2019
       State of the climate: Heat across Earth’s surface and oceans mark early 2019
       

       Our Climate Change Series is sponsored by the Environmental Committee of 50 Ways Rockbridge, a coalition of local political activist that formed after the 2016 federal elections.  Our purpose is to promote self education and activism. The Environmental Committee started out as the Climate Change Committee.  However, seeing existing environmental protections being dismantled, we felt the need to address those issues too, therefore Environmental Committee.  

        

       Moderator Response:

       [PS] edited messages to moderator as per request. Rest of message is informative.

10349. scaddenp at 07:30 AM on 11 June 2019
       Climate's changed before
       

       it should also be noted that D-O and Bond type events are observed when emerging from an ice-age, not during interglacials.

10350. barry17781 at 06:25 AM on 11 June 2019
       Effects of Global Warming
       

       moderato, thanks for the link, I is a long time since i read the paper. 

        

       i hope that this will answer your question

        

       nigel, your figures on the relative abundances of halnium are misleading.

       you have used crustal concentrations by mass, and wikipedia gives typically 2 to 3 times highe amount
       of boron than halfnium.
       however for nuclear absorption use one should use mol, since it is by atom that these materials absorb neutrons

       so this brings the factor of 3 up by 178/11 = 48.

       Coupled with the fact that boron is mainly found in lake deposits not in the crust makes this very irrelevant, on top of this there is avast amount of boron in the ocean some 4.5 -4.8 mg/kg which is readily available
       I suggestquantity is easily extractable and exceeds the born quantity  in the crust so there is a factor of 100 more for the abundance of boron  assuming every drop of halfnium is extracted from the crust

       so Boron is far more abundant than halfnium, and can be readily seperated after use, the unreacted isotope slvaged by distillation and so will become non radioactive.

       as for hafnium in civilian reactors I stand by it that it is currently not used to any significant extent

       The moltex reactor

       "Modest funding now will see Moltex through these approval processes,
       initially in the UK and Canada, and through to the construction of the first reactor.
       Thereafter the market is almost inconceivably large.

       Mr Sweet the reactor has not been built! It is a future projection. please do not insult people.

       As for Abbotts figure of 20.5 km^2 per reactor, Abbot does not explain the calculation of these figures but his citation does

       The originator, Johnson uses US figures, a coutry which has the largest redundant areas for its nuclear facilities nevertherless he states that the
       area occupied by nuclear facity and its supprting infrastructure of enrichment, mining and disposal in the states is between 4.9 and 7.9 km^2.
       Now a facility can have several reactor typically nowerdays say 6 giving a reactor area of 4.9/6 = 0.8166 km^2 a long way from Abbots 20.5 km^3 a factor of 25!

       Abbott inflated his figure to include the us buffer zone which can still be used for agriculture or say a solar farm, which Abbott claims is n either or not both!

        

       Please treat Abbotts figures with great caution . It is as I said and he has communicated to me only a demonstration

       Moderator Response:

       [PS] thank you but no more nuclear energy discussions on this topic. Hopefully we will have a more appropriate place for those interested in the subject in the future.

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