From EurekAlert!
Public Release: 3-Jan-2019
Melting ice sheets release tons of methane into the atmosphere, study finds
University of Bristol
Melting ice sheet release tons of methane into the atmosphere, study finds
The Greenland Ice Sheet emits tons of methane according to a new study, showing that subglacial biological activity impacts the atmosphere far more than previously thought.
An international team of researchers led by the University of Bristol camped for three months next to the Greenland Ice Sheet, sampling the meltwater that runs off a large catchment (> 600 km2) of the Ice Sheet during the summer months.
As reported in Nature, using novel sensors to measure methane in meltwater runoff in real time, they observed that methane was continuously exported from beneath the ice.
They calculated that at least six tons of methane was transported to their measuring site from this portion of the Ice Sheet alone, roughly the equivalent of the methane released by up to 100 cows.
Professor Jemma Wadham, Director of Bristol’s Cabot Institute for the Environment, who led the investigation, said: “A key finding is that much of the methane produced beneath the ice likely escapes the Greenland Ice Sheet in large, fast flowing rivers before it can be oxidized to CO2, a typical fate for methane gas which normally reduces its greenhouse warming potency.”
Methane gas (CH4) is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide (CO2). Although, present in lower concentrations that CO2, methane is approximately 20-28 times more potent. Therefore smaller quantities have the potential to cause disproportionate impacts on atmospheric temperatures. Most of the Earth’s methane is produced by microorganisms that convert organic matter to CH4 in the absence of oxygen, mostly in wetlands and on agricultural land, for instance in the stomachs of cows and rice paddies. The remainder comes from fossil fuels like natural gas.
While some methane had been detected previously in Greenland ice cores and in an Antarctic Subglacial Lake, this is the first time that meltwaters produced in spring and summer in large ice sheet catchments have been reported to continuously flush out methane from the ice sheet bed to the atmosphere.
Lead author, Guillaume Lamarche-Gagnon, from Bristol’s School of Geographical Sciences, said: “What is also striking is the fact that we’ve found unequivocal evidence of a widespread subglacial microbial system. Whilst we knew that methane-producing microbes likely were important in subglacial environments, how important and widespread they truly were was debatable. Now we clearly see that active microorganisms, living under kilometres of ice, are not only surviving, but likely impacting other parts of the Earth system. This subglacial methane is essentially a biomarker for life in these isolated habitats.”
Most studies on Arctic methane sources focus on permafrost, because these frozen soils tend to hold large reserves of organic carbon that could be converted to methane when they thaw due to climate warming. This latest study shows that ice sheet beds, which hold large reserves of carbon, liquid water, microorganisms and very little oxygen – the ideal conditions for creating methane gas – are also atmospheric methane sources.
Co-researcher Dr Elizabeth Bagshaw from Cardiff University added: “The new sensor technologies that we used give us a window into this previously unseen part of the glacial environment. Continuous measurement of meltwater enables us to improve our understanding of how these fascinating systems work and how they impact the rest of the planet.”
With Antarctica holding the largest ice mass on the planet, researchers say their findings make a case for turning the spotlight to the south. Mr Lamarche-Gagnon added: “Several orders of magnitude more methane has been hypothesized to be capped beneath the Antarctic Ice Sheet than beneath Arctic ice-masses. Like we did in Greenland, it’s time to put more robust numbers on the theory.”
###
This study was a collaboration between Bristol University, Charles University (Czechia), the National Oceanography Centre in Southampton, Newcastle University, the University of Toronto (Canada), the Université Libre de Bruxelles (Belgium), Cardiff University (UK), and Kongsberg Maritime Contros (Germany). It was funded by the Natural Environment Research Council (NERC), with additional funds from the Leverhulme Trust, the Czech Science Foundation, the Natural Sciences and Engineering Research Council of Canada, and the Fond de Recherche Nature et Technologies du Québec (Canada).
Paper: ‘Greenland melt drives continuous export of methane from the ice sheet bed’ by Guillaume Lamarche-Gagnon, Jemma L. Wadham, et al. Nature, Doi: 10.1038/s41586-018-0800-0
“roughly the equivalent of the methane released by up to 100 cows.”
Gee! 100 cows, huh? Doesn’t alarm me. Methane also does not last long in the atmosphere.
Yes, it hardly sounds like a new “tipping point”.
At least they’ve got the memo about W.V. now.
Notice they didn’t give any concentration numbers to help put things in perspective.
That’s because they don’t know. They have essentially just measured some methane in glacial run-off and that is about it. The rest is essentially just make it up and use your imagination to fill in the gaps. Reconstruct a jigsaw puzzle from one or two pieces only. Pretty standard stuff for climate science.
Actually they do, perhaps you should have read the paper before commenting.
Cow tipping point.
I see what you did there.
https://en.wikipedia.org/wiki/Cow_tipping
http://www.todayifoundout.com/index.php/2015/08/possible-tip-cow/
How did that econd link end up there? I meant this one
Oh crap. I feel like an idiot. I didn’t watch that before I posted it. LOL.
I didn’t watch this one either (video playback on youtube doesn’t work on some weekends for some reason), but I bet it’s good
The ‘fix’ is to eat more cheeseburgers.
Do not fear. Norway has started a research program to reduce burping from cows. It’s true! So the planet will be saved, though the cows may not be happy with their new menu.
Yes, Henning. I suspect the cows may have some difficulty adapting.
http://4.bp.blogspot.com/_SkItl_BZ0AA/SDMemZa1sII/AAAAAAAAFrA/9V1B6FJ39I8/s400/vampire+cow.bmp
(From TragicComixBlogspot.com)
Does Norway receive UN Krone-dollar? Must be. U.S. Department of Agriculture sends $$ to UN to spend.
I wish they would start a program to reduce farting in humans. I have one friend who really likes to stink up the joint. I bought him carbon filter shorts, but he won’t wear them. He prefers the look of horror from other people – and the sudden exodus. He loves elevators. To date, the only fix is to have German friends in the group. He can’t fart around them. No idea why.
There is no sarcasm in this post. Cow farts have never bothered me. Human farts have been known to make me gag.
I can see it now: a new scientific unit of measure of emitted methane based on the burping/farting of 100 cows.
A Wadbeef of methane?
… or a Cudswallop?
the Cowfart = 1 joule per liter (at stp)
It’s a cow tipping point !
Head for the hills !
And it’s unlikely they measured the methanotroph concentration – bacteria which eat the methane in the Arctic, oceans and swamps – under either aerobic or anaerobic conditions.
On the contrary:
“We infer the limited methanotrophic signature observed here to reflect the largely anoxic conditions at the sites of methane production (and thus limited aerobic oxidation of methane) and the rapid evacuation of methane from the production site via a fast and efficient drainage system (Supplementary Information 2b).”
I am amazed, just amazed I tell ya! There was that massive multi-month long release of methane gas in California a year or so ago, and no one determined the potential global warming that release has caused. Nothing to see ?
Yeah, how did that story get suppressed?
Myrna wrote, “There was that massive multi-month long release of methane gas in California a year or so ago, and no one determined the potential global warming that release has caused.”
I did. It was less than one-half of one-hundred-thousandth of a degree Celsius.
You’re thinking of the Aliso Canyon natural gas leak, in California, three years ago. (Yeah, time flies!) A Washington Post story about it (one of many) was entitled, “California gas leak was the worst man-made greenhouse-gas disaster in U.S. history” They surely used up most of the apocalyptic terms in their thesaurus: “massive,” “worst,” “historic,” “disaster” and “huge.”
Sounds bad, doesn’t it? Well, that massive, worst, historic, huge disaster was 107,000 tons of methane = 0.000097 metric Gt, which is an immeasurably tiny 0.00179% of the estimated 5.431 Gt (1.85 ppmv) of methane in the Earth’s atmosphere.
(0.000097 Gt) / (2.9356 Gt/ppmv CH4) = 0.000033 ppmv CH4.
Modtran (Tropical Atmosphere, const rel. hum., no clouds) calculates that increasing CH4 by 0.2 ppmv (from 1.85 ppmv to 2.05 ppmv), if held at that level for many years, would increase ground temperature by about 0.03 °C.
(Over the atmospheric lifetime of a methane release, it would be even less.)
0.000033 ppmv is 0.000165 = 0.0165% of that, so we can calculate that the “massive,” “worst,” “historic,” “huge” Aliso Canyon “disaster” presumably caused less than:
(0.000033 ppmv CH4) × (0.03 °C) / (0.2 ppmv CH4) = 0.000005 °C of warming.
But even if enough methane had been released to significantly affect the atmospheric methane level, the impact of a spike in methane levels would be very transient, because even if you don’t burn it, methane in the atmosphere oxidizes with a half-life of only about 6 to 8 years, into minute amounts of CO2 and water:
CH4 + 2·O2 → CO2 + 2·H2O
The WaPo refused to run a correction, or even a Letter to the Editor about it:
My rejected letter to the editor / WaPo
The widespread fear of methane is one of the zaniest aspects of the climate scare. Oh my, “six tons of methane”! We’re all dooooomed!
In this comment (below), I did more careful calculations, using two different radiation codes (rather than just MODTRAN).
I found that the NCAR radiation code estimates the “equilibrium” warming effect or 0.5 ppmv higher CH4 level to be about +0.147°C of warming, and MODTRAN Tropical Atmosphere estimates 0.067 or 0.069°C. The Aliso Canyon “disaster”[sic] caused a transient 0.000033 ppmv CH4 spike. We can calculate that that much CH4 would cause (0.000033/0.5) × (0.067 to 0.147 °C) = 0.0000044 to 0.0000097 °C of “equilibrium” warming, of which perhaps 2/3 could be realized before the spike was gone.
So, both radiation codes calculate less than one one-hundred-thousandth of a degree Celsius of “equilibrium” warming.
That was for the 107,000 tons of methane released at Aliso Canyon.
Six tons of methane would have 6/107000 = 0.000056× that effect, which would be about 2/3 of 2.5e-10 to 5.44e-10 °C, i.e. a fraction of a billionth of a degree.
But it’s still Worse Than We Thought.™ 😀
I just love the “more than we previously thought” always attached to any new findings by the alarmists.
It means we didn’t know what is was before or we had it hopelessly wrong before, therefore we have no idea what this new data actually means.
If we had it wrong before we probably still have it wrong now.
But “worse than we previously thought” is more likely to grab headlines, attention and funding than honesty.
More likely to scare uneducated, easily swayed people. Which is the ultimate goal. No wonder the more you know about science, the less likely you are to believe this AGW line.
“ than previously thought ”
I regard this as ‘lack of thought’.
First is the lack of context. For example, ‘who’ thought what?
What was done and when so that an estimate could be made.
Second issue is the poor wordsmithing. The phrase has become a cliché. It has become a clue to stop reading.
One wonders if a sailing ship passed by a discharging glacier in, say 1876, and 17 of a 40 member crew smelled methane. Because fewer than half noticed this smell, it was thought to be not a lot. Or, . . .
Did a research effort in 1953 measure 33 cows worth of methane on a Tuesday at 4 PM.
This is much adoo about nothing. Coal bed methane production is several orders of magnitude above their production per drill hole per day. Originally coal miners vented the methane to prevent fires as methane is very combustible. This process of organic accumulations exsolving methane is going on totally around the world. The good news is that is is very unstable and quickly oxidizes to plant food.
Now I have ro recalculate the total ice mass loss since the end of the Pleistocene in… cows.
I bet it will be a lot more cows than Manhattan-sized icebergs.
Cows can be the new Bitcoin of the warmist movement, perfectly suited to herd mentality.
Units of BCE – Bovine Carbon Equivalents
Reminds me of the Professor who proposed the utilize Banana Units for radiation measurement (K40 in bananas is radioactive). Works, but didn’t go over very well with the Chiquita crowd.
And what’s the policy proposal to deal with methane from wetlands and termites ? Dry them all and reinstate DDT ?
Implicit plamface.
To paraphrase Shakespeare in Henry the VI,”Let’s kill all the Microbes!!!” 😁
So, you want to gas Termites with insecticide ? That solution would be deemed Antitermitic. I’ve been labeled an Antitermite just for suggesting we round them up and send them to Madagascar.
Tons! Wow, that sounds like a big amount, doesn’t it?
Maybe there will be so much methane released the northern arctic regions will just spontaneously blow up and burn? OH NO, that would release CO!
the fac t theres ex greenery under that mass of ice shows once it wasnt ice…
and theyre having fits over nothing, really
but it pays well
No, they showed that there are methanogenic bacteria under the ice which are generating the methane.
“Although, present in lower concentrations that CO2, methane is approximately 20-28 times more potent. “
We are never told how much that 20-28 times more potent than CO2 translates into global temperature. Do a search on the internet, and you won’t be able to find out. The climate cult doesn’t want you to know how small that number is. Methane is on track to increase by about 0.5 ppm by 2100. An additional 0.5 ppm in CO2 amounts to an increase of about 0.1%. An increase in global temperature due to an increase of 0.1% in CO2 multiplied by 28 isn’t very much.
The Global Warming Potential As described in the various IPCC Assessment reports is pretty much exhibit A when it comes to lying with statistics. One of the most egregious techniques in the Global Warming Potential statistic is the use of CO2 as a reference standard. We are told:
Because CO2 is used as reference, any changes for this gas will affect all metric values via AGWP changes. Figure 8.31 shows how the values of radiative efficiency (RE), integrated impulse response function (IRF) and consequentially AGWP for CO2 have changed from earlier assessments relative to AR5 values.
Source: Page 716 IPCC AR5 Chapter 8 Anthropogenic and Natural Radiative Forcing
That’s right, the standard used for the GWP metric constantly changes. This is comparable to trying to measure Jello with a rubber yard stick. It’s just ridiculous.
If methane goes up 500 ppb by 2100, policy makers need to know how much that will run-up global temperatures and the Global Warming Potential bullshit isn’t providing that answer.
We can get rough estimates of the effect of adding 0.5 ppmv CH4 by running “radiation code” models.
First, let’s roughly estimate the effect by using U. Chicago’s Modtran interface.
Set CO2 to 408 (the current level), and CH4 to 1.85 (the current level). Pick “tropical atmosphere” (that’s the default, and I guess it’s a good one, because the tropics account for a disproportionate share of the Earth’s radiation budget), and choose “constant relative humidity” (to account for water vapor amplification).
Then click [“Submit the Calculation”] .
If you left everything else set to the defaults, then you should see:
Iout, W / m² = 287.373
Ground T, K = 299.70
Write that down.
Now, close the output page, and go back to the input page, and change CH4 from 1.85 to 2.35.
Then click [“Submit the Calculation”] .
You should see:
Iout, W / m² = 287.153
Ground T, K = 299.70
Note that “Iout” has dropped from 287.373 to 287.153, because of the additional methane.
287.373 – 287.153 = 0.22 W/m² forcing, and it is generally estimated that it takes about 3.5 W/m² forcing to warm the planet by 1°C (at equilibrium), so (0.22/3.5) × 1°C = 0.063°C.
However, the low precision of the Modtran web interface means there’s actually a range of “Ground T offset” temperatures which will give that 287.373 W/m² value for Iout for CO2=408 and CH4=1.85. That range turns out to be -0.0084 to 0.0004 °C, the midpoint of which is -0.004 °C. Adding that to the 0.063°C> calculated above yields 0.067°C.
To check that, we can play with Modtran see how much the surface temperature (“Ground T”) must increase to restore Iout to its old value. So close the output page, and on the input page try different “Ground T offset, C” values, until you find it.
However, because of the low precision of the MODTRAN web interface, to get the best estimate of the effect on temperatures you’ll need to find the range of “Ground T offset” values, and report the midpoint. I did that and found that a “Ground T offset” of 0.065°C is the midrange value that restores Iout to its old value, so the estimated “equilibrium” climate response to +0.5 ppmv CH4 is 0.065 + 0.004 = 0.069°C
You can also used the NCAR Radiation Code, in a similar way. U. Chicago has a web interface for that, too.
There are a lot of options; we need to pick some reasonable values. I set “radiation scheme” to “Chou,” insolation to 420, CO2 to 408, CH4 to 1.85, N2O to 0.33, low cloud fraction to 40%, and high cloud fraction to 15%, leaving everything else set to the defaults.
Click “Do it!” It should report: “Equilibrium near-surface air temperature is 7.2 degC (280.3 K)”
Now change CH4 to 2.35, and run it again. It should report: “Equilibrium near-surface air temperature is 7.3 degC (280.5 K)”
So it approximated the effect to 0.1°C. Unfortunately, the NCAR interface reports even fewer significant digits than the MODTRAN interface, but it’s at least in the same ballpark.
If you experiment with the CH4 values you’ll find that for CH4 levels in the range 2.168 to 2.521 ppmv it reports 7.3°C, and for CH4 in the range 1.845 to 2.167 ppmv it reports 7.2°C. Comparing the midpoints of those ranges, we can estimate ((2.168+2.521)/2) – ((1.845+2.167)/2) = 0.3385 ppmv per 0.1°C, or 0.147°C of warming for +0.5 ppmv CO2.
So, NCAR is estimating about twice the “equilibrium” warming effect that Modtran Tropical Atmosphere estimates (0.147°C vs. 0.067 or 0.069°C). But they at least gives us order-of-magnitude estimates.
Thanks Dave, I appreciate all work you did above. I skimmed through it, all the way to the bottom to find (0.147°C vs. 0.067 or 0.069°C) estimates. Thanks
In the world of nearly nothing times 28 is still nearly nothing and never ask a question you don’t already know the answer to, an independent value of about 0.05K can be arrived at by solving for X when the basic climate sensitivity of CO2 without feed backs is known. And it is known, it’s about 1.2K for every doubling in concentration.* It then follows that 500ppb is 0.5ppm and an increase in CO2 from 400ppm to 400.5ppm will result in about a meaningless 0.0015K which can be multiplied by the Global Warming Potential of 28 to get 0.04 which can be sensibly rounded off to 0.05K.
And in the world Dr. Stephen Schneider’s famous scary scenarios quote, I surmise that the tiny figure of about 0.05° of warming due to methane, business as usual, is something the climate cult doesn’t want to admit to. 20-28 times more potent or more often pound for pound 86 times more potent, is what they want the public to hear.
* [T]he climate response to a doubling of atmospheric CO2 … would be around 1.2°C (Hansen et al., 1984; Bony et al., 2006).
(Page 631 IPCC AR4)
https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chapter8-1.pdf
This long comment is in two parts:
1. Q: What’s wrong with “global warming potential” numbers?
2. Q: How we can calculate the approximate relative effects on temperatures of changes in the levels of various GHGs?
1. Q: What’s wrong with “global warming potential” numbers.
tl;dr:
I agree with you, Steve, except that I think the “28” multiplier for CH4 is the wrong number. 40 to 44 is a better number.
Details.
“28” is an estimate by climate activists of what they call the “100-year global warming potential” of CH4 emissions. It does not tell you the relative effects on temperature of +1 ppmv of methane vs. +1 ppmv of CO2.
The purpose of “global warming potential” numbers is so that climate activists can make statements like, “methane is __-times as damaging as carbon dioxide,” for political purposes. (Remember, they passionately want to tax GHG emissions, so they need a basis for setting the tax rates on various GHGs!)
So they start with the estimated warming effects of the two gases, then adjust units from molar fractions / ppmv to mass ratios / ppmm (per Dick Kale, below), and then they adjust the result according to the supposed atmospheric lifetimes of the two gases.
The atmospheric lifetime of CH4 is reasonably well known: it’s about a decade. (Page 11 of this source gives the directly-calculated atmospheric lifetime of CH4 as ~8 years, but identifies a feedback mechanism which (they say) effectively increases the atmospheric lifetime of additional CH4 to ~12 years.) AR5 says 12.4 years. No problem there.
But the “atmospheric lifetime” of CO2 is ill-defined! The lifetime of CO2 added to the atmosphere depends on how you account for it. That means the adjustments used to calculate “global warming potentials” are arbitrary, and the “global warming potential” numbers are junk science.
For most GHGs, the processes which remove them from the atmosphere are pretty well described by half-life or average molecular lifetime (e.g., about a decade for methane). There’s not much argument about that.
But CO2 is very different.
We know from the decay of the Carbon-14 (14C) “bomb spike” that CO2 molecules have an average half-life in the atmosphere of only about 11.5 years, implying a residence time of about 16.6 years. Here’s a graph of the famous 14C “bomb spike:”
http://2.bp.blogspot.com/-G79oXdgIZC4/UnteTCVaGGI/AAAAAAAAAA0/AbSzY3s5ZP0/s1600/logc14.jpg
However, the duration of the effect of CO2 emissions is very different, and it depends on how you account for them.
CO2 in the atmosphere is fungible, meaning that any given CO2 molecule is exchangeable with any other, for most purposes. That means there are multiple ways of “accounting” for the effect of CO2 emissions.
With LIFO accounting, the CO2 “lifetime” is very short. (In fact, AR5 estimates that the biosphere and oceans remove about 55% of anthropogenic CO2 emissions from the atmosphere, each year!)
But with FIFO accounting, which is favored by advocates for limiting CO2 emissions, the duration is much, much longer. If anthropogenic CO2 emissions ceased today, CO2 levels would initially plummet, but it would probably be more than a thousand years before CO2 levels dropped back below 300 ppmv. That’s the basis for claims sometimes heard that CO2 emissions stay in the atmosphere for “hundreds or thousands of years.”
If you’re interested in the effect of current/new emissions, for public policy purposes, then FIFO accounting is simply wrong, and LIFO accounting is better, because what mostly matters with respect to public policy is the effect of today’s emissions.
However, to really understand it, you’d need to understand all the important processes which affect CO2 levels in the atmosphere — and some of those processes are not well understood.
Isotope studies don’t work well for attributing CO2 emission effects, because they get confused by the enormous fluxes of carbon between the atmosphere and other carbon reservoirs. When such fluxes are balanced, so they don’t affect atmospheric CO2 level, but they still can greatly effect the isotope ratios.
Carbon isotopes are fungible for most purposes. The low 14C “fossil” carbon we put into the atmosphere is (nearly) bio-equivalent to high-14C carbon, so the plants take up whichever CO2 molecules they encounter. Likewise, the oceans are happy to dissolve either kind of carbon dioxide. So the atmospheric CO2 is constantly being exchanged with carbon in plants, animals, soil, and oceans.
So, even though our CO2 emissions have elevated atmospheric CO2 levels by about 130 ppmv (over 45%), there’s been only a modest drop in 14C percentage (other than the bomb spike). That’s not because our emissions aren’t responsible for the increase in CO2 level, it’s because most of the low-14C CO2 we put into the atmosphere has been exchanged for other CO2 in the oceans or biosphere.
It’s as if you had $100 in common $1 bills, and I gave you another $50 in Sacagaweas. At that point, 1/3 of your money would be in coins. But then you go play poker all night. You break even, so you still walk out with the same amount of money that you started with, but now you have only a few Sacagaweas, because most of them have been exchanged for other people’s money.
The bottom line is that “global warming potential” numbers are very arbitrary.
2. Q: How we can calculate the approximate relative effects of various GHGs?
We can use “atmospheric radiation codes” to estimate the relative effects of changes in levels of various GHGs. In the following calculations, I used U. Chicago’s web interfaces.
They’re pretty straightforward, and very useful, with one annoying complication: they use and report very few significant digits, which makes it hard to quantify the model-calculated effects of small perturbations in inputs. So, to get better precision, all of the following are “midrange values,” found by exploring the range of inputs which produce the same output. (Tedious!)
(Aside: I might get some criticism about the use of “models” for this. But radiation codes are very different from GCMs. Radiation codes model processes which are reasonably well understood, so they have at least a fighting chance of getting it right. GCMs do not.)
MODTRAN:
First, on the basis of effect on LWIR emission levels (“Iout”):
(Other parameters are the defaults; either hold water vapor pressure or hold rel. hum., it doesn’t matter, since Temperature offset is kept at zero.)
CO2=400 CH4=1.847 Iout=287.467 W/m²
CO2=428.3 CH4=1.847 Iout=287.153 W/m²
CO2=400 CH4=2.518 Iout=287.153 W/m²
In other words, raising CH4 level from 1.847 ppmv to 2.518 ppmv
(428.3-400)/(2.518-1.847) = 42
So, on the basis of their effect on LWIR emissions in the tropics, MODTRAN calculates that changes in CH4 level have about 42 times the effect of changes in CO2 level.
hold rel hum
CO2=428.3 CH4=1.847 Iout=287.153 W/m² (287.467 w/ Toffset=0.0855 to 0.0955, midrange= 0.0905)
CO2=400 CH4=2.518 Iout=287.153 W/m² (287.467 w/ Toffset=0.0906 to 0.0994, midrange=0.0950)
((428.3-400)/(2.518-1.847)) * (0.0950/0.0905) = 44
hold water vapor pressure
CO2=428.3 CH4=1.847 Iout=287.153 W/m² (287.467 w/ Toffset=0.0785 to 0.0875, midrange=0.0830)
CO2=400 CH4=2.518 Iout=287.153 W/m² (287.467 w/ Toffset= 0.0825 to 0.0915, midrange =0.0870)
((428.3-400)/(2.518-1.847)) * (0.0870/0.0830) = 44
So, on the basis of their effect on equilibrium temperatures in the tropics, MODTRAN calculates that changes in CH4 level have about 44 times the effect of changes in CO2 level.
NCAR:
There are a lot of options; we need to pick some reasonable values. Other than CO2 and CH4, I set “radiation scheme” to “Chou,” insolation to 420, N2O to 0.33, low cloud fraction to 40%, and high cloud fraction to 15%, leaving everything else set to the defaults. We find:
CO2 = 400, CH4 = 1.871, Equilibrium near-surface air temperature = 7.1 °C
CO2 = 442.6, CH4 = 1.871, Equilibrium near-surface air temperature = 7.4 °C
CO2 = 400, CH4 = 2.943, Equilibrium near-surface air temperature = 7.4 °C
So, according to the NCAR Radiation Code, (2.943-1.871)= 1.072 ppmv CH4 has the same warming effect as (442.6-400)=42.6 ppmv CO2.
(442.6-400)/(2.943-1.871) = 40
So, on the basis of their effect on equilibrium temperatures in the tropics, NCAR calculates that changes in CH4 level have about 40 times the effect of changes in CO2 level.
That’s pretty close to the MODTRAN values of 42 and 44.
Sorry about the missing </i> tag at the end of the “(Aside:…)”.
[After that whole “Aside” paragraph? .mod]
Yes, thank you for fixing it, Mod!! I’m sorry to have put you to the trouble.
BTW, I’ve noticed that ALL of my comments, these days, initially go to moderation or the spam bucket, regardless of their length or whether they contain links. I don’t know why, and I’m sorry for the work it is causing you, to manually approve everything I write.
(You are innocent, it is about someone else) MOD
Dave, thanks for the reply (-:
This long comment is in two parts:
1. Q: What’s wrong with “global warming potential” numbers?
1. They use a standard: The concentration of Atmospheric CO2 that constantly changes.
2. They are of academic use only aside from the changing standard.
3. They don’t tell the public or policy makers what they need to know i.e., effect on temperature.
You weren’t asking ME to reply to these questions but I thought I’d take a crack at it.
2. Q: How we can calculate the approximate relative effects on temperatures of changes in the levels of various GHGs?
Various? there are only three to consider, and CH4 is the distant third.
I agree with … except that I think the “28” multiplier for CH4 is the wrong number. 40 to 44 is a better number.
You know what Dave? You’re letting the other side define the argument. I don’t care how many angels can dance on the head of a pin or how many climate scientists can dance on the tip of Al Gore’s nose. The Global Warming Potential numbers are what the IPPC says they are. Your argument that follows down below might be right, but it’s the proverbial fart in a hurricane.
The purpose of “global warming potential” numbers is so that climate activists can make statements like, “methane is __-times as damaging as carbon dioxide,” for political purposes.
BINGO! They don’t want Harry and Louise to find out methane’s on track to increase temperatures a measly 0.05°C this century. Harry and Louise need to find that out.
So they start with the estimated warming effects of the two gases, then adjust units from molar fractions / ppmv to mass ratios / ppmm (per Dick Kale, below), and then they adjust the result according to the supposed atmospheric lifetimes of the two gases.
What that does is give them a bigger (scarier) GWP number currently that 85 and 86 with feedbacks.
The bottom line is that “global warming potential” numbers are very arbitrary.
I’d say they’re useless, sort of like pedantically telling someone that a small plane like a Piper Cub will fly 86 times farther on a gallon of gas than a Boeing 747. The proper response to that is, “So what?”
2. Q: How we can calculate the approximate relative effects of various GHGs?
I’m sure it can be done, the answers however need to be in degrees not w/m²
So, on the basis of their effect on equilibrium temperatures in the tropics, NCAR calculates that changes in CH4 level have about 40 times the effect of changes in CO2 level.
That’s pretty close to the MODTRAN values of 42 and 44.
The annual increase in CH4 is about 6.5 ppb and for CO2 it’s about 2100 ppb or 320 times as much. It really is an apples and oranges comparison that means nothing, and that’s what people need to know.
Bottle it. Put a cap over and bottle it. Wait a minute. If I cap it then the ice wont melt and release methane. I know, put a heaters under the cap to melt the ice then bottle it call it “free energy”. Now can I get a government subsidy? LoL
A moderately interesting paper, but unfortunately there is a serious flaw in it. They apparently did not test the methane for radiocarbon.
Since the subglacial river they tested only runs during the melting season the water ultimately is mostly derived from surface melting, though there is probanbly a proportion being carried along that is derived from subglacial melting. Since it is well known that there is extensive bacterial activity on top of the icecap a proportion (or most?) of the methane may be derived from there rather than from subglacial sediments as they argue.
A radiocarbon essay would have clinched the matter since “old” subglacial carbon will be be free from radiocarbon, but unfortunately they didn’t test this.
Actually they did do isotope measurements, they also determined that the supraglacial meltwater was much more dilute in CH4 than the subglacial.
Translation:
Greenland was cool and all, but I’m getting bored. Now I want somebody to pay for me to go to Antarctica. I haven’t been there yet.
There could be 10,000 cows worth of methane down there or, let me re-hypothesize that, there could be billions of cow equivalents (Gce). It’s time to get more robust numbers!
I have some suggestions for the EurekAlert! English major intern who writes this stuff:
Climate Change may be making women flat-chested
Scientist says CC raises concerns about erectile dysfunction
CC makes you fat, raises cholesterol
Beta males who drive Priuses rise up the mating hierarchy
How I shagged a hot chick through more effective virtue signalling
If cows were given or allowed to eat their own chosen diet, they would hardly produce *any* methane.
And no, cows burps and (fictitious) farts are not hysterically funny (for the cows)
Stop Behaving Like Giggling Little Children.
It is Unreasonable – get my drift?
Burps/farts represent chronic belly ache for the cows. and nutrient deficiency.
Just as in humans, eating all that junk fibre (cellulose) sweeps large amounts of water soluble nutrition out of the cows’ digestive system. Not least water itself(##)
…. just as Warmists inflict chronic brain-ache, bank-account ache, tax-ache, regulation ache, face-palm ache, muttering-under-your-breath ache, consensus ache, authority ache and You Can Not Be Serious ache, Big Number ache etc etc etc
## How many brain-dead people try to replace that lost water with soda-pop or beer?
See the problem, taking those options only makes them even more Brain-Dead
PS: Questions for Bristol Uni –
How did the organic ‘stuff’ come to be under the glacier?
How do bacteria operate in frozen water?- does bacterial decomposition happen inside your own home freezer? Might explain a few things if it does ;-D
Are you *really* sure the glacier is not just doing its own Fracking – is it not crunching up Shale Rock to release the gas
Why do you hate People, apart from yourselves obviously.
Finally and slightly OT but maybe not- what’s going on here then…..
https://www.huffingtonpost.co.uk/entry/universities-paying-police-to-protect-students-amid-crime-fears_uk_5c30c3cfe4b0d75a983135c4
– are we *really* sure that it is ‘external’ villains to blame here?
IOW Students of the UK -are you now so dumb you actually need protecting from yourselves?
Anaerobic digestion always produces methane.
The fermentation of sugars in grape juice is anaerobic digestion. It does not produce methane, it produces CO2.
How did the organic ‘stuff’ come to be under the glacier?
How do bacteria operate in frozen water?
Answered in the paper, I suggest you read it.
Now the tipping points must get relocated again some centuries into the future.
There’s already more greenhouse gasses in the air then their climate models dreamed of.
The real, actual functioning global environment thing is so infinitely more complex than any computer model the scientizers can slap together, that the story of the blind fakirs and the elephant comes to mind. Or was that ‘fakers’? They too could honestly say, as they blindly felt along, “It’s worse than I imagined!”
Scary the way so-called scientists can learn something about nature and immediately prance about like Chicken Little screaming the sky is falling. There was a time long, long ago when learning things in science was called “education” and not “scare the daylights out of as many people as possible”. Science—the 21st century fear-mongering method of choice.
Tell us something new.
I thought ice also melted a 100 years ago.
I see it in my drink. So it is very important to empty the glass quickly, because it will overflow when the ice melts. Won’t it?
The source was subglacial? That would, I believe be from under the glacier; the dirt and rock on which it rests. How do they know that? Or perhaps they just mean from a millimeter or so under the surface as it melts and just can’t write very well.
Actually this is good news. Since global warming isnt happening, they have found a source of methane that is naturally produced. When they inevitably blame mankind for releasing too much methane, we can point to this further source of methane that is natural. It also can be used as another metric to prove that the methane production is steady and thus no need to worry.
This is a natural phenomenon so I doubt this deserves much attention other than honing our knowledge base. It just probably goes to show that ancient ice covered the original vegetation there which is now part of the the cause of the methane count as the melt water exits the glacier. In addition to normal micro bacterial interaction on the many surfaces that have been continually buried with each seasonal snowfall. Interesting, but not unexpected. The world is unfolding as it should. CO2 and Carbon are not pollution, and is the reason why the planet can support 7.4 Billion people. If we’re were suddenly transported back to preindustrial times climate and CO2 levels, I doubt the planet could provide enough food for all current humans. Increasing CO2 levels might just give us an edge to survive a temporary 30 year cooling spell, just like the 30+ year temporary warm spell we enjoyed from the late 70’s to the present, albeit we have had little net warming the last 20 years. All within natural variation. What will be telling is what the next 30 years does. My money is on much of the same pause we have seen the last 20 years, if not downright cooling a smidgeon. That should put an end to the ‘carbon madness’.
Not sure if “tons of methane” or 100 cows is something to worry about. Maybe when we get up to megatons.
https://tambonthongchai.com/2018/12/16/beef-and-climate-change/
I was toying with this vegetarian thing but I see it’s my duty to eat more cows to be virtuous. I don’t know about tonnes of them but I’ll do my level best under frying circumstances.
Isn’t it the case that the absorption spectrum of methane overlaps to a large extent with that of water vapour?
If that’s the case then, however “potent” methane may be in isolation, out in the real world it’s effect will be totally trivial.
I am also puzzled about this notion that CH4 is the ‘strongest’ GHG evah…
It has particular cooling properties as well, by deflecting sunlight in the 1-2 um range?
It is not strange at all. ALL greehouse gases are potent in small quantities, when there are only a few molecules arond. CO2 would be much more powerful than itself and very much more powerful than methane if it only occurred in ppb quantities.
However when a GHG occurrs in quantities that have a significant effect on climate saturation sets in and further increases have a minimal effect.
This is very carefully not explained by the MSM.
Excerpted from article:
HA, ….. not even “molecule per molecule” is it 20-28 times more potent.
GHG potency
Carbon dioxide (CO2) – with an SHC of 0.844 kJ/kg K, is only 38% as potent as CH4
Water vapor (H2Ov) – with an SHC of 1.930 kJ/kg K, is only 87% as potent as CH4
Methane (CH4) – with an SHC of 2.220 kJ/kg K is 2.6 x gt CO2 .. & .. is 1.15 x gt H2Ov
Potency of GHGs in atmosphere
Water vapor (H2Ov) @ 20K-40K ppm – 2.0%-4.0% is by far the most potent GHG.
Carbon dioxide (CO2) @ 400 ppm — 0.0400% is pretty much an impotent GHG.
Methane —— (CH4) @ 1.745 ppm – 0.0001745% is pretty much a GHG in name ONLY.
“not even “molecule per molecule” is it 20-28 times more potent”
Yes it is, when there are only a very few CH4 molecules around as there is now but enough CO2 for the absorption bands to be almost completely saturated. Then each additional CH4 molecule will have much more effect than an additional CO2 molecule.
tty – January 6, 2019 at 11:39 am
tty, ….. NO IT ISN’T.
“DUH”, the absorption bands being almost completely saturated has nothing whatsoever to do with the quantity of atmospheric CO2. And the quantity of atmospheric CO2 has nothing whatsoever to do with the different emission frequencies of IR radiation.
tty, ….. to measure the temperature (thermal “heat” energy) of an object (gas molecules, people, heating element) ……. said object absolutely, positively has to be “conducting” or “radiating” thermal (heat) energy to whatever instrument being used to measure said temperature.
And “DUH”, an object doesn’t decide to start “conducting” or “radiating” its thermal (heat) energy just because someone decides to “measure its temperature”.
Apparently you are still a passionate BELIEVER in that “junk science” crapolla that atmospheric CO2 “traps” IR radiation (thermal “heat” energy), …… aren’t ya?
No, CO2 doesn’t “trap heat”, it absorbs IR radiation that is then thermalized. Learn some physics man.
There are only two atmospheric gases which trap heat for significant time intervals – ozone and water vapor – and both have permanent electric and magnetic dipoles.
As far as trapping heat, carbon dioxide is impotent. It can absorb an infrared photon, and electric and magnetic dipoles can be induced, but it’s a premature ejactuler – it emits the photon within nano seconds.
In fact, the excited state of molecular nitrogen can trap infrared photons for long periods of time – it lase.
It’s how a carbon dioxide lases – it’s nitrogen which does the lasing – the carbon dioxide is merely an optical pump.
As far as trapping heat, carbon dioxide is impotent. It can absorb an infrared photon, and electric and magnetic dipoles can be induced, but it’s a premature ejactuler – it emits the photon within nano seconds.
No it takes hundreds of msec.
In fact, the excited state of molecular nitrogen can trap infrared photons for long periods of time – it lase.
Because it is unable to emit a photon.
It’s how a carbon dioxide lases – it’s nitrogen which does the lasing – the carbon dioxide is merely an optical pump.
You have that backwards the nitrogen is electrically excited but is unable to emit a photon, but on collision it transfers the energy to the CO2 which then lases.
Samuel C Cogar wrote, “GHG potency: Carbon dioxide (CO2) – with an SHC of 0.844 kJ/kg K, is only 38% as potent as CH4…”
“SHC” (specific heat capacity) is completely irrelevant. That’s how how GHGs work.
Many folks here have explained this to you. I’ve done so twice. First almost two years ago, here:
https://wattsupwiththat.com/2017/01/17/xkcds-cri-de-coeur/comment-page-1/#comment-2401467
Then about ten months ago, in a series of comments here:
https://wattsupwiththat.com/2018/02/25/a-must-read-the-politically-incorrect-guide-to-climate-change/comment-page-1/#comment-2752419
Samuel C Cogar wrote to tty, “Apparently you are still a passionate BELIEVER in that “junk science” crapolla that atmospheric CO2 “traps” IR radiation (thermal “heat” energy), …… aren’t ya?”
tty is one of the most astute contributors here. Nobody is infallible, but he is not often wrong, about anything, and he certainly is not wrong in this case. You are stubbornly clinging to a complete misunderstanding of how so-called “greenhouse warming” works. He understands it, you do not.
BTW, tty, I’d love to have a reference for this, if you have one.
Global Warming Potential is typically defined as the warming potential over 100 years per unit mass. This is done because emissions are measured by weight. Thus it is not defined by volume. To convert to the ratio by molecule you have to multiply by the atomic weight of CH4 over CO2 or roughly 16/44. 28 x 16/44 is about ten.
Dave Burton – January 6, 2019 at 2:34 pm
Shur nuff, Dave Burton, iffen you say so, ….. but you intentionally FORGOT to inform the Department of Physics at Georgia State University …… that they didn’t know what the hell they were talking about any more than I do ….. and that because of your brilliant CAGW intelligence you can assure them that their explanation of SHC is/was FUBAR from the get-go, ….. to wit:
And Dave Burton, read again the last sentence in the above quote, which states ….. “water plays a very important role in temperature regulation” ….. and then you should understand why H2O vapor is the most potent GHG.
Samuel C Cogar, none of the Hyperphysics material you cited has anything to do with the so-called “greenhouse effect.”
Did you somehow get the impression that I (or tty, or anyone else here) thinks that the so-called greenhouse effect is that only thing which affects temperatures? If so, you’re mistaken. We know perfectly well that many things affect temperatures. That includes GHGs, but not only GHGs.
If you want to understand climate science, and if you want to understand how the (misnamed) greenhouse effect warms the Earth, then:
1. First, BURN your copy of Slaying the Sky Dragons. It is disinformation. The only useful thing you can do with it is to produce life-giving CO2 and warmth from it.
2. Then, peruse the resources here::
https://sealevel.info/learnmore
I suggest that you start with the two “introductions,” then move on to the “amicus brief” and the three “physics” resources.
Dave Burton – January 7, 2019 at 5:33 pm
Shur nuff ….. Dave B, … when you realize your “bluster” far, far, far exceeds your educational expertise, ……… you immediately seek safety in a “roundhouse” because you know that Sam C can’t “corner” you there. ☹ ☹
And now you can “chew” on this, DB, to wit:
Dave Burton – January 6, 2019 at 2:34 pm
Dave Burton, instead of posting CYAs for tty, …. and to prove and/or justify your belief that atmospheric CO2 …. “TRAPS & retains IR thermal radiation”, ….. then please explain to all of us miseducated idiots why you absolutely, positively believe the following statement is FALSE, to wit:
And Dave Burton, …. it won’t surprise if you “run & hide” again, without responding to my request.
Samuel C Cogar, when you ask me to defend or explain a quoted statement, please don’t just make up the material between the quote marks.
When you’re attributing a belief or statement to me, and you put it in quote marks, I expect you to copy/paste it exactly from something that I have actually written, or spoken.
In answer to your question, if you want to understand how atmospheric CO2 helps warm the Earth, then please peruse the resources here::
https://sealevel.info/learnmore
I suggest that you start with the two “introductions,” then move on to the “amicus brief” and the three “physics” resources.
Dave Burton – January 7, 2019 at 5:42 pm
Dave Burton, the “scientific principles” that govern the science of the natural world are still just as relevant today as they were 60 years ago when I attended College and earned my Degree in Physical and Biological Science …. and I have no interest or desire to convert to YOUR political correct (PC) neo-science religious beliefs.
CORRECTION:
I wrote:
““SHC” (specific heat capacity) is completely irrelevant. That’s how how GHGs work”
I intended to write:
““SHC” (specific heat capacity) is completely irrelevant. That’s not how how GHGs work”
Sorry about that!
I hate it when my typos invert my intended meaning! {sigh.}
Okay… about 120 meters of sea level rise occurred as our planet emerged from the last ice age. Presumably with a proportional methane release to what could happen for the last couple of meters-worth of glacial melting. And humans… thrived.
The mere thought of what havoc could be wrought by the last two percent is enough to make me… yawn.
And that’s before considering what someone mentioned above… that the observed melt-water is more likely to have originated near the surface, and its content overstate biological activity in older, deeper ice.
Some perspective is in order. The mean mass of Earth’s atmosphere has been calculated to be 5.15 E+18 kg (ref: Lide, David R. Handbook of Chemistry and Physics. Boca Raton, FL: CRC, 1996: 14–17), or about 5.15 E+15 metric tons.
Now the article only says “. . . team of researchers led by the University of Bristol camped for three months next to the Greenland Ice Sheet, sampling the meltwater that runs off a large catchment (> 600 km2) of the Ice Sheet during the summer months.” Although the size of the Greenland ice sheet is estimated to be presently around 1,710,000 km2, not all of its area will suffer the same degree of melting. Let’s generously assume that 20% of the total ice sheet suffers the same degree of melting as that observed by the researchers and contains the same proportion of methane. That would then represent a 570:1 multiplier on the “at least 6 tons of methane” calculated from the catchment they studied.
So, with these very broad (and unsubstantiated) assumptions, perhaps as much as 3,420 metric tons of methane are released from the total Greenland ice sheet during each summer’s melting. This then would represent an increase of .0007 PARTS PER BILLION by weight of methane when distributed throughout Earth’s atmosphere.
So, accuse me of being off by one, or even two, orders of magnitude in my calculations . . . I still won’t be alarmed.
In other words, why the heck was this study ever deemed worthy of publication?
Well, it has some slight interest for glaciologists, but as you say it is completely irrelevant for climatology, but that is where the big money is, so they try to grab some of it.
If anyone has read the actual paper (I haven’t got access, or at least I don’t think I have) perhaps they could enlighten us to the measurement technology.
“Novel” always triggers warnings in my mind: how does it work; what does it actually measure; how was/is it calibrated; how often must it be calibrated; what is the precision, accuracy, and reliability of the measurement?
How is the meltwater sampled? Presumably something like a diversion of a small part of the flow through the “device”. How many samples on a cross section? What flow regime is assumed to integrate across the cross section?
“In other words, why the heck was this study ever deemed worthy of publication?”
Let me guess. The use of fossil fuels to satisfy our production needs has created a wonderful environment in which we afford the many to dither about doing increasingly marginal tasks of little significance or nothing at all. So much so that said dilettantes and layabouts have no idea what sort of life it would be hoeing the fields or beating the iron on the blacksmith forge with only the horse, ox, cart, windmill and millstream for assistance. Keep it up and they’ll likely foster the Endustrial Evolution followed hopefully by the Second Enlightenment.
I told you already, we need somebody to pay our way to Antarctica so we can look at penguins.
We should question the funding of these people. It never seems to be a measured scientific find, but more to further bend the minds of politicians who seem to be bereft of reality.
We should question the funding of these people. It never seems to be a measured scientific find, but more to further bend the minds of politicians who seem to be bereft of reality.
The three “Daves” plus Allan.
Good on numbers and units of measure.
I recall the unit for measuring feminine beauty.
Helen of Troy was so beautiful that her’s was the “Face that launched a thousand ships”.
From which we get the “milli-Helen”.
Beauty sufficient to launch one ship.
I never heard of the milli-Helen before.
Just so I don’t get into trouble, which direction is Positive?
Have you heard of the unit of measure for genius: the “tary”
Einsten is considered to be equal to one tary.
Subidivided into decitary, centitary and millitary.
“Helen of Troy was so beautiful that her’s was the “Face that launched a thousand ships”.”
No, she was so ugly they launched a thousand ships so they didn’t have to sleep with her !
The premise of this paper is based on quantitative analysis of CH4 gas which is dissolved in glacial melt water by a new sensor. The technologies for measuring CH4 are gas phase. These include GC-FID, IR, LASER and chemical reaction. All of these are gas phase measurements, therefore their first step would be to separate dissolved gases from the meltwater. One could de-gas the water by heat and/or vacuum. In either case, they will get a gas mixture of water vapor and the dissolved gases extracted from the meltwater.
There are basic questions about this extraction process. Did they extract 100% of the dissolved gases from the meltwater? How did they determine the extraction efficiency?
After the extraction, they have gas mixture of mostly H2O. How did they separate the water vapor from the dissolved gases for analysis? How effective was the separation? What percentage of CH4 was lost in the separation?
After these steps, they can analyze the extracted gases for CH4 concentration. Any of the available methods require calibration, both initially and periodically during the project. How did they calibrate and re-calibrate their CH4 analysis instrument?
Most analysis equipment needs to be run at a constant temperature. How did they do this on the glacier?
If the paper does not cover all of these issues, then the accuracy of their CH4 measurements is suspect. If they lacked tight analytical controls, then their paper could very well be another publication based on GIGO.
Did they verify that the sensor didn’t have any temperature sensitivity before sticking it into the ice water?
The paper gives very detailed descriptions of the calibration of the instrument, ( CONTROS HydroC CH4 sensor14 (Kongsberg Maritime Contros, Germany)), by the use of careful in situ sampling. I suggest you read the paper before making such ill-informed comments.
I bet this paper is as brilliant as the press release. It took an untold number of professors from eight different universities to come up with it, so it must be good.
Erm, when the ice refreezes methane is reabsorbed, yes? So that’s all right then
Does it occur to these geniuses that it was all vegetation there in the past and it completely blows their claim it is unprecedented warm today ???
Greenland has a considerable geothermal complex under all that snow and ice…
See http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2689.html and https://www.nature.com/articles/s41598-018-19244-x
http://notrickszone.com/wp-content/uploads/2018/01/Geothermal-Heat-Flux-Melts-Greenland-Ice-2005-2015-Rysgaard-2018.jpg
I wonder if this may modulate the extent of microbial life and the venting of methane.
Seismic activity is known to increase during solar minimums, presumably will also happen in all or parts of Greenland today.
They didn’t produce any evidence that more methane is being released. Only that more water is allegedly being released.
Presumably the rate of biological activity under the ice is pretty constant. A little bit more water trickling in from above isn’t going to increase it. If the biological activity hasn’t increased, then the amount of methane isn’t going to increase either. More water just means the methane in the water is more diffuse.
I guess Loricifera is the only accepted life form on earth,according to greens?
“how they impact the rest of the planet.” Interesting how they characterize a natural occuring process as having an “impact”. This is a part of nature and it interacts with all of nature, but to say it is an impact? Seems kind of extreme and intended to imply something bad.
Having been able to get a glimpse of the paper (actually a letter in Nature Letters) I see the nub to be this paragraph (typed, not copied and pasted!)
LG is the Leverett Glacier. GrIS is the Greenland Ice Sheet.
As far as I have been able to ascertain, the melt water was sampled continuously at a single point in a river downstream from the Leverett Glacier margin. This single point was then extrapolated to calculate the CH4 flux using flow and other dynamics used in another project which reported CO2 emissions from inland rivers.
I didn’t see any mention of the differences between CO2/water and CH4/water systems.
far more than previously thought.
_____________________________________
“far more than previously thought.” ….”far less than previously thought.” ….”Greater than previously thought.”….. “Less than previously thought.”
God help me my head is going to explode.
These expressions casually dissing away all the previous data in the face of “new” evidence when attempting to promote the same old ideology is enough to send a sane man over the edge.
The nutty alarmists must at the very least invent a new terminology when faced with evidence that obsoletes all previous data.
We see these phrases often enough that they deserve to represented with an acronym. FMTPT. FLTHPT and Pthththththttt!