Methane production and emissions in trees and forests

Lots and lots of implications for climate models and GHG budgets.

From New Phytologist

Kristofer R. Covey J. Patrick Megonigal

First published: 06 December 2018


Forest ecosystem methane (CH4) research has focused on soils, but trees are also important sources and sinks in forest CH4 budgets. Living and dead trees transport and emit CH4 produced in soils; living trees and dead wood emit CH4 produced inside trees by microorganisms; and trees produce CH4 through an abiotic photochemical process. Here, we review the state of the science on the production, consumption, transport, and emission of CH4 by living and dead trees, and the spatial and temporal dynamics of these processes across hydrologic gradients inclusive of wetland and upland ecosystems. Emerging research demonstrates that tree CH4 emissions can significantly increase the source strength of wetland forests, and modestly decrease the sink strength of upland forests. Scaling from stem or leaf measurements to trees or forests is limited by knowledge of the mechanisms by which trees transport soil‐produced CH4, microbial processes produce and oxidize CH4 inside trees, a lack of mechanistic models, the diffuse nature of forest CH4 fluxes, complex overlap between sources and sinks, and extreme variation across individuals. Understanding the complex processes that regulate CH4 source–sink dynamics in trees and forests requires cross‐disciplinary research and new conceptual models that transcend the traditional binary classification of wetland vs upland forest.


Forests are a dominant feature of the global carbon (C) cycle and play an important role in regulating climate and climate change (Bonan, 2008; Pan et al., 2011). Research on forests in the context of the global C cycle is focused primarily on carbon dioxide (CO2) dynamics, because the fluxes are large and C sequestration in wood and soil organic matter influence century‐scale projections of radiative forcing (Canadell & Raupach, 2008). Less attention is directed toward forests as sources and sinks of other C trace gases such as methane (CH4). Soils are fairly well characterized in forest CH4 budgets, but trees were only recently recognized as sources or sinks of this important greenhouse gas (Carmichael et al., 2014; Saunois et al., 2016). We review evidence that CH4 dynamics in forests are far more complex than previously believed owing to a combination of plant, microbial, and abiotic processes mediated by living and dead trees.

Methane causes 32–45 times more radiative forcing in a century than CO2 on a mass basis (Neubauer & Megonigal, 2015) and contributes c. 20% of radiative forcing (Denman et al., 2007; Myhre et al., 2013; Neubauer & Megonigal, 2015). Because CH4 is more responsive than CO2 to changes in sources or sinks (Hansen et al., 2013), forest CH4 budgets are a meaningful aspect of management directed at slowing the pace of global climate change (UNFCCC, 2016). A more nuanced understanding of forests is needed across fundamental forest–climate interactions to improve Earth system models and manage forests for climate mitigation (Canadell & Raupach, 2008). It is increasingly clear that forest CH4 cycling is one such interaction.

Despite efforts to constrain and refine the strength of the many sources and few sinks of atmospheric CH4, the global CH4 budget remains highly uncertain (Saunois et al., 2016). The total size of the global CH4 pool is well constrained in the range 539–609 Tg CH4 yr−1, but mismatches between bottom‐up models and top‐down estimates leave considerable uncertainty about individual components (Dlugokencky et al., 2011; Allen, 2016; Saunois et al., 2017).

Wetland ecosystems are the largest natural source of CH4 globally, and forested wetlands are c. 60% of total global wetland area (Matthews & Fung, 1987; Prigent et al., 2007), suggesting that forested wetlands are a significant global source of CH4. Reports of a discrepancy between emissions‐based estimates and satellite‐based estimates of CH4 sources in tropical forests (Frankenberg et al., 2008) sparked new interest in tree surfaces as an overlooked source (Terazawa et al., 2007; Gauci et al., 2010). Most of the research effort on wetland CH4 cycling has been in herbaceous wetland systems, but emerging literature on soil‐ and plant‐mediated CH4 emissions in wetland forests indicates that this source alone may account for 5–10% of global CH4 emissions (Pangala et al., 2017).

Upland ecosystems on freely drained soils are recognized as CH4 sinks in global budgets and have been the focus of studies on CH4 consumption by soils (Le Mer & Roger, 2001; Saunois et al., 2016). Transient periods of CH4 emission have been reported in nominally upland forests, but such emissions are cryptic and easily overlooked (Megonigal & Guenther, 2008). It is now clear that all biological surfaces in upland and wetland forests have the potential to emit or consume CH4 (Carmichael et al., 2014).

The emphasis on wetland forests as net atmospheric CH4 sources and upland forests as net sinks masks the complex interplay of aerobic and anaerobic processes that occur to varying degrees in all forest ecosystems (Fig. 1). The outcome of this dynamic can change the radiative balance of forests over temporal scales of minutes to decades and spatial scales of microsites to biomes. It is perhaps because of the focus on forests as either net sources or net sinks that research on the interrelated processes of CH4 production and oxidation has centered exclusively on just one process or the other. This perspective fundamentally limits our ability to fully represent the dynamic nature of forests in budgets and Earth system models. The goal of this review is to emphasize the common processes that exist across all forested ecosystems in order to advance a holistic understanding of C cycling and the radiative balance of forest ecosystems.

Figure 1 The complex variety of methane (CH4) sources and sinks in upland and wetland forests. Red arrows, CH4 sources; blue arrows, sinks. See Carmichael et al. (2014) for a treatment of the role of vegetation in CH4 dynamics across a variety of terrestrial ecosystems


The growing body of literature on CH4 dynamics in forest ecosystems shows that they are far more complex biogeochemical environments than previously believed, and that our previous focus on soil processes alone is insufficient for a rigorous understanding of forests’ greenhouse gas balance and radiative climate forcing. Progress toward this goal will be most effective if we recognize that all CH4‐generating and consuming processes occur in all forest ecosystems regardless of their classification as upland or wetland. Advances in forest ecosystem CH4 dynamics require a new focus on the complex interplay between productive and consumptive processes occurring from the top of the canopy to the subsurface ground water, and their implications for generalized scaling. The subject is ripe for collaborations between people with expertise in plant physiology, soil physics, hydrology, geomorphology and microbial ecology, all of which interact to determine the distribution and activity of microbial communities and abiotic reactions that produce and consume CH4 as a single coupled process (Megonigal et al., 2004; Liu et al., 2015). Of particular importance are collaborations between experts in biogeochemistry, wood anatomy and tree physiology, because they regulate CH4 production and exchange across arboreal surfaces. Indeed, a growing research community with diverse interests in tree CH4 dynamics has developed an agenda for advancing the field (Barba et al., 2018).

Further study is needed to refine ecosystem‐scale estimates, determine the most appropriate scaling metrics, and resolve the distinctions between the arboreal CH4 flux pathways. Whole‐ecosystem studies currently provide the most robust information for global budgeting efforts, but many studies do not distinguish between the three pathways identified here in order to inform mechanistic numerical models. Laboratory studies can isolate specific pathways of CH4 production or consumption, but they often fail to capture the substantial temporal and spatial scales of variation that drive in situ fluxes. In addition to flux measurements, there is a need for thoughtful integration of existing techniques across subdisciplinary boundaries. Until additional integrative empirical studies are conducted, and process‐based models are developed and tested, the contribution of forests to global CH4 dynamics will remain poorly resolved.

Read the full article here.

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Tom Halla
March 26, 2019 8:08 pm

I was aware of VOC emissions from trees, but not methane. Another consideration is emissions from termite digestion of wood, which has to be added in to the environmental impact of trees.

March 26, 2019 8:11 pm

So in addition to killing all the cows, we need to cut down and clear all the wetlands?

But the environmentalists have been rabidly promoting and protecting wetlands these last decades…preventing development on any land that occasionally has a puddle, if they can.

Won’t their heads explode if they realize that instead of saving the earth they have been killing it?

Walter Sobchak
Reply to  kwinterkorn
March 26, 2019 10:48 pm

We used to call ecologically important wetlands: “Malaria Swamps”

Crispin in Waterloo
Reply to  Walter Sobchak
March 27, 2019 3:48 am

Apparently spirochetes are people too and need their “space”. The north shore of Lake Ontario has been declared a methane generation zone to be preserved ad infinitum to ensure the long term survival of swamp mozzies. Without them the snub-nosed minnow (no kidding) might have less to eat. We should check.

On another preservationist note, a friend of mine has a non-functioning rooftop solar array that was sabotaged by a raccoon family. The mother proved to be stronger than the steel roofing and likes the digs. That used to be the reason we kept a box of .22 shorts on hand.

If he pulls the family out and commits them to the ground to become methane for being the invasive pests they are, the fine is twice the value of the whole installation. As he is now losing his 34.5 cents per kWH feed-in tariff perhaps the upside is the savings for the rest of us who pay for this madness.

Now he has to hire a live-capture parcourt artist and an electrician who will have to bring a very tall ladder. I believe he is starting to feel a little green.

Reply to  kwinterkorn
March 27, 2019 9:19 am

Another reason to drain the swamp/wetlands … but after draining them they also need to be filled to such an extent that they don’t revert to wetland again.

If they do revert, you haven’t accomplished anything, spent resources and time, and then you just need to start your process over again.

(both figuratively and literally)

March 26, 2019 8:20 pm

Does this mean that Wetlands which the Greens demand that we have more of them, actually produce lots of Methane. What about the worldwide cultivation of rice, both in the West, but mainly n the Far Eastern countries.

So if the Greens are against the production of Methane, what do they propose to do about rice cultivation ?

All of these natural sources of CO2 and Methane from cows and other animals, including us , must be driving the Greens mad. Perhaps that explains their odd behaviour right now.


Walter Sobchak
Reply to  Michael
March 26, 2019 10:50 pm

“So if the Greens are against the production of Methane, what do they propose to do about rice cultivation?”

Stop it. They are aiming to depopulate Asia anyway.

Reply to  Michael
March 27, 2019 3:45 am

“So if the Greens are against the production of Methane, what do they propose to do about rice cultivation?”
Most Greens are vegetarian. Rice and tofu are a staple diet for them.
Cows??? Well that would go against their ideology. But then again, Greenies fart too, maybe we should just do away with them as well…..Oh well, wishful thinking.

Reply to  Michael
March 27, 2019 4:30 am

“Does this mean that Wetlands which the Greens demand that we have more of them, actually produce lots of Methane.”

Ummm…. well, Michael, you have to remember that you are addressing the ignorance of an entire population group that reacts to words like “methane” with fear and trembling, while not recognizing that it is a necessary byproduct of natural botanical processes, among all the other parts of the biota.

Cow flatulence, insect flatulence, and now plant flatulence – the Greenbeans are living in a world that has a mind of its own and does not care what they want. They have no control over it. Control of everything is their mantra. This news may send them into spasms of panic…. or something equally ridiculous.

March 26, 2019 8:38 pm

“Methane … 20% of radiative forcing”

Technically, all the radiative forcing comes from the Sun. None the less, the total warming effect from GHG’s and clouds that result in the surface emitting more than the 1 W/m^2 per W/m^2 of radiant forcing characteristic of an ideal black body is about 620 milliwatts per W/m^2 of forcing. Most of this is replenished from radiation originating from the water in clouds and of the component attributable to GHG’s, nearly 2/3 is from water vapor, 1/3 is Co2, about 1% is O3 and less than 1% is from Methane.

Methane is proportionally a more powerful GHG agent because it’s effect is so small to begin with.

March 26, 2019 8:41 pm

Chalk up another variable process that wasn’t in the models.

Reflecting on Kip Hansen’s Model-Land article yesterday, I predict some disturbance in the Force models.

In all seriousness, one thing the various climate models have been good for is to turn unknown unknowns into known unknowns as researchers continue to find and point out missing variables and interactions.

March 26, 2019 8:49 pm

Reagan was ridiculed and scorned when he pointed out that trees give off pollution. So, lumber is a great carbon store. Lol

Smart Rock
March 26, 2019 9:13 pm

We review evidence that CH4 dynamics in forests are far more complex than previously believed

A very unusually modest admission in the world of climate science, where “far more complex than previously believed” will probably turn out to be be the understatement of the century.

Reply to  Smart Rock
March 27, 2019 4:15 am

Not modesty; more like self interest. That was just to setup for what followed…

Further study is needed to refine ecosystem‐scale estimates, determine the most appropriate scaling metrics, and resolve the distinctions between the arboreal CH4 flux pathways.

March 26, 2019 9:19 pm

But isn’t the science settled?

bit chilly
Reply to  Retired_Engineer_Jim
March 26, 2019 11:48 pm

I keep being told that as well Jim. This is an interesting paper, now as soon as we know how many trees there we might be able to quantify the effect. Is it 4 billion or 3 trillion trees the science is settled on now 😉

Andrew Burnette
Reply to  Retired_Engineer_Jim
March 27, 2019 6:41 am

Ha ha. “Until additional integrative empirical studies are conducted, and process‐based models are developed and tested, the contribution of forests to global CH4 dynamics will remain poorly resolved.” Translation: “We have no idea. More study! More money!”

Joel O'Bryan
March 26, 2019 9:24 pm

Yes, to the science un-educated Liberal Arts majors, methane is now an evil molecule up there with CO2. The brilliance of a Liberal education in making policy decisions that depend on science.

We know so little though how nature works though. The OCO-2 satellite frequently “sees” CO2 excess over tropical rainforests (which conventional wisdom says they should be bigtime CO2 sinks), some of which may be from dead matter decay, and some of which is from released methane oxidation in UV of sunlight.
(Keep in mind OCO-2 can only see the daytime CO2 concentrations because (relative to an O2 baseline) as it is sunlight absorption that the spectrophotometers are measuring).

The tree-derived methane is both a degradation and reaction product of terpenes and terpenoids and their many terpene-chain built compounds. And terpenoids and terpenes-based molecules play essential roles the plants need for warding off predatory insects, attracting polinators, and inhibiting pathogens.
Aliphatics likes eucalyptus, camphor, citronella, cinnamon and aromatics likes creosote and vanillins are derived from terpene building blocks. We humans have used these tree essential oils and compounds for millenia as medicinals, food and beverages flavors (the taste of whiskey) and fragrant insect repellents. Even the smell of coffee beans and marijuana plants are derived from the unique terpene-based molecules those plants give off. Frequently methane from a growing plant is just methyl groups released in a reaction chain to produce aromatics.

When tree barks and vascular cambium layer are penetrated by insects, the injury releases smells that attract birds and other insects to lure it to come eat the attacker. The woodpecker onto the barker-boring insect, etc. But these smells all have an organic molecule basis that traces back terpenes/terpenoids and their many side methyl groups that are discarded along the production pathways.

So for CO2 and methane around forests, from tropical rain forests to deciduous leaf forests to conifer forests, it is almost certain that “what we we think is we know, it simply ain’t so.”
The sooner we acknowledge that unsettled science the better.

Reply to  Joel O'Bryan
March 27, 2019 9:26 am

just yesterday a woodpecker was 80′ up on a cell tower pecking away on one of the metal boxes for about an hour. may now have an explanation as to why.

Kevin McNeill
Reply to  DonM
March 27, 2019 10:35 am

Was probably a Flicker looking for a mate. They are a terrible nuisance if you have a gas furnace as they love to hammer on the chimney cover creating hell below.

Alastair Brickell
March 26, 2019 10:53 pm

Joel O’Bryan
March 26, 2019 at 9:24 pm

Many thanks for the interesting botany/chemistry lesson! I hadn’t appreciated that woodpeckers are using smells as well as sound in their hunting.

This is the sort of information that makes WUWT so interesting for us all.

bit chilly
Reply to  Alastair Brickell
March 26, 2019 11:54 pm

+1 Alastair, what an informative comment by Joel.

Reply to  Alastair Brickell
March 27, 2019 4:26 am

Woodpeckers would have a hard life if they couldn’t hear/smell where bugs are. There’s some kind of chewing insect that infests pine trees that I cut down and leave on the ground for a while. They are so loud I can hear them up to 40-50 ft away.

Tom Abbott
Reply to  Alastair Brickell
March 27, 2019 4:54 am

” I hadn’t appreciated that woodpeckers are using smells as well as sound in their hunting.”

Nor did I. Those trees are tricky! My thanks, too, for the post, Joel.

Samuel C Cogar
Reply to  Alastair Brickell
March 27, 2019 8:47 am

Alastair Brickell, here is another interesting botany/chemistry lesson which I am sure you will appreciate just as much, or more, than the woodpeckers story, to wit:

Giraffes, acacia trees and tannins, to wit:


Besides tasting awful, tannins inhibit digestion by interfering with protein and digestive enzymes and binding to consumed plant proteins making them more difficult to digest. What’s even more amazing is that acacia trees within 50 yards react to the release of the tannin by their neighbour and jump on the bandwagon by emitting their own. The simultaneous tannin release by all nearby acacias essentially thwarts the greedy giraffe(s), who must now travel upwind to trees that have not yet ‘caught wind’ (irresistible really!) of his insatiable appetite.

Alastair Brickell
Reply to  Samuel C Cogar
March 27, 2019 12:50 pm

Samuel C Cogar
March 27, 2019 at 8:47 am


So maybe if Prince Charles is not talking to his plants and trees perhaps they are talking amongst themselves. Very interesting stuff…thanks.

Patrick MJD
March 26, 2019 11:36 pm

CH4 absorbs LWIR in two specific frequency bands that no other GHG does, so absorbs all of the LWIR. And given it’s “heating” effect, like CO2, is logarithmic, it’s effect is greater. But at 1.8ppm/v (1800ppb/v), I would say this is the least of our problems.

steve case
March 27, 2019 2:54 am

Methane causes 32–45 times more radiative forcing in a century than CO2 … blah … blah … blah … blah … blah … blah

And just exactly how much is methane going to run up global temperatures? That’s what policy makers need to know and no one ever says what it is.

Tom Abbott
Reply to  steve case
March 27, 2019 5:06 am

“And just exactly how much is methane going to run up global temperatures? That’s what policy makers need to know and no one ever says what it is.”

That’s because nobody knows that answer.

Just like they can’t give you a number for how much CO2 warms the atmosphere. They just don’t know. All they have are guesses. Educated guesses admittedly, but still just guesses. And the lowest guesses are low enough that we don’t have anything to worry about anyway, even if they were accurate guesses.

As you say, policy makers need numbers, especially when some fools are proposing to spend TRILLIONS of dollars and ruin the U.S. economy in an effort to manipulate Earth’s climate. These fools want to do this without having any numbers, just guesses. No, we can’t do that. We want the numbers before we take action. The Alarmists should check back with us when they have some solid numbers.

steve case
Reply to  Tom Abbott
March 27, 2019 6:50 am

Tom Abbott … at 5:06 am
That’s because nobody knows that answer.
Just like they can’t give you a number for how much CO2 warms the atmosphere.

Oh, but they do give us answers for that:

IPCC AR4 Working Group1 Chapter 8
Page 630-631; ¶;
What Explains the Current Spread in
Models’Climate Sensitivity Estimates?

In the idealised situation that the climate response to a doubling of atmospheric CO2 consisted of a uniform temperature change only, with no feedbacks operating (but allowing for the enhanced radiative cooling resulting from the temperature increase), the global warming from GCMs would be around 1.2°C (Hansen et al., 1984; Bony et al., 2006).

You can find that 1.2°C figure elsewhere, but you won’t find a similar figure for CH4 anywhere. However the 1.2°C for doubling CO2 along with the definition of the Global Warming Potential for CH4 can be used to solve for the “Climate Sensitivity” of methane and it comes out to be around 0.2°C. Warming due to methane by 2100 business as usual comes to an increase of about 0.05°C which is not measureable and essentially nothing.

Tom Abbott
Reply to  steve case
March 27, 2019 1:18 pm

Another thing about those ECS numbers like 1.2 or 1.5 or 4.5, is they are based on the assumption that 100 percent of today’s warming is from CO2. If some of today’s warming is caused by Mother Nature, then those figures go lower.

Samuel C Cogar
Reply to  Tom Abbott
March 28, 2019 4:07 am

Tom Abbott – March 27, 2019 at 5:06 am

And just exactly how much is methane going to run up global temperatures? That’s what policy makers need to know and no one ever says what it is

“That’s because nobody knows that answer.

And because nobody knows that answer, … it is MLO that not knowing the answer is EXACTLY WHY the experts and/or policy makers are claiming that the “heating” effect of CO2 and CH4 is logarithmic (meaning the more you get the less you have )

They cannot prove their claims of a “warming” effect of CO2, …. therefore they hafta obfuscate matters by claiming a logarithmic “cooling” effect of too much CO2 …….. which can’t be measured either.

Finster Bookinstock
Reply to  Tom Abbott
March 30, 2019 12:47 am

Methane is methane whether it comes from the ground or a tree or a cow or termites, and the gas is not a threat to the climate. Just because a molecule contains carbon and is capable of capturing heat energy in a laboratory does not mean it captures heat energy in the atmosphere. There also has to be energy present in the absorbable radiation bands upon which the molecule works for energy capture to be in the equation. That is where and why ambient methane fails to collect energy. It is competing with a vastly more prevalent gas in its limited sphere of influence.

Before you permit yourself to get all scare-defied over more methane being released into the atmosphere, and even if you buy into recent (since WWII) surface temperature rise being as a result of increased greenhouse gasses, do your research and find that methane is an irrelevant gas in the theoretical causes because of the limited bands of energy from which it can possibly absorb and from those two bands upon which it can act, it must share that potential with one more prevalent, which has already done the job almost completely in those bands leaving nothing much for methane to work upon. Those who promote gloom & doom from impending release of stores of methane wrongly assume the gas would have unlimited stores of energy upon which it could draw to heat the planet should that release occur. Therein lies the failure of this sub-theory even assuming such release is possible and imminent. There is no such pool of energy.

The energy beamed by the sun comes to Earth in the form of short waves, is absorbed by the planet, and some is transmitted back to space in the form of long waves in various bands of energy. Warmists’ Anthropogenic Global Warming Theory holds that greenhouse gasses intercept by absorption and transmit back to Earth a percentage of the long wave radiation energy in natural balance until humans destroy the balance by over supplying unnatural amounts of greenhouse gasses by which such process and added heat causes more of the principle greenhouse gas, water vapor, to be produced accelerating the process in an ever heightening loop of heating Gaia. Methane is a “greenhouse gas.” The misnamed process acts nothing like a greenhouse, BTW, and empirical measurements, the acid test of science, do not reflect water vapor increasing as required in proportion to CO2 increases or even out of proportion. No increase of water vapor at all in fact has been measured among the several failures of the theory to be sustained by empirical measurement.

Methane (CH4) by its physical properties has only two narrow absorption bands at 3.3 microns and 7.5 microns in the overall broad electro-magnetic spectrum from which it can absorb energy. Theoretically, CH4 is 20 times more effective an absorber than CO2 – in those bands in a laboratory. However, CH4 is only 0.00017% (1.7 parts per million) of the atmosphere. Moreover, both of its bands occur at wavelengths where H2O is already absorbing virtually all energy. Because water vapor is much more plentiful in the atmosphere than methane (or any other GHG), H­2O absorbs vastly more energy and is by far the most important greenhouse gas. On any given day, H2O is a percent or two of the atmosphere (1.0-2.0% or 5,882 to 11,764 times as prevalent as methane in the atmosphere, or 5882÷20=294.1 [or 588.4] multiple the absorber as methane); we call that humidity. Hence, any radiation that CH4 might absorb has already been absorbed by H2O in the only radiation bands methane absorbs energy. Once the energy in a band of the spectrum has been sucked dry, no additional absorptive gas can absorb more. Painting a black window another coat will not keep out more light. In other words, the ratio of the percentages of water to methane is such that the effects of CH4 are completely masked by H2O because the absorption of infrared energy in the bands of the spectrum affected by methane has already been saturated by H2O absorption. The amount of CH4 would have to increase 100-fold to make it comparable to H2O and even then it would no longer matter because water vapor has beat it to the punch.

There is not much ambient energy in those two little short, stray bands of the radiation spectrum to start with and most of that has already been worked over by H2O from time immemorial leaving only the scraps to poor CH4, which can never effect climate to any appreciable or worrisome amount. Because it absorbs energy in a laboratory does not mean it works that way in a chaotic atmosphere with other agents and processes present.

Learn more of what the science neophytes should have investigated before fearing methane, which is an irrelevant greenhouse gas (graphs, observed facts & all that tedious math kind of stuff) —

Methane is fine vehicle to instill fear, the politicians greatest ally, on an uninformed populace though. It is the rare person whose knowledge on the substance reaches even the level of understanding the stuff coming from their gas stove is raw methane much less how it works in the atmosphere…easy targets for manipulation.

Samuel C Cogar
Reply to  Finster Bookinstock
March 30, 2019 4:18 am

Methane is fine vehicle to instill fear, the politicians greatest ally,

Greenhouse Gas quantities in earth’s atmosphere

Methane (CH4) ————– 1.79 ppm ——- 0.000179%
Carbon dioxide (CO2) —– 400.00 ppm ——- 0.04%
Water vapor (H2O) –— 20,000.00 ppm ——- 2.00%

The public should ask themselves, ….. of the above three (3) “heat trapping” global warming gases, …. which one (1) has the bejesus scared out of you into believing that any additional increase will surely cause death and destruction of you and yours?

March 27, 2019 2:55 am

“Further study is needed to refine ecosystem‐scale estimates”

Translates into ‘Give us a grant for a lifetime of research’

March 27, 2019 3:33 am

“Methane causes 32–45 times more radiative forcing in a century than CO2 on a mass basis (Neubauer & Megonigal, 2015)”

That critical fact of the weight-for-weight differece between CO2 and Methane in terms of greenhouse effect
reminds me of a post I made on the BBC website some time ago before I was banned, which IIRC caused Naughtie to snort.

It follows that an effective means of reducing ‘Global Warming’ is to convert atmospheric methane into CO2, which would be equivalent to sequestering ~40 times as much CO2 on a weight-fro-weight basis.

This can be achieved by passing air that has been slightly enriched with methane through an internal combustion engine.

A practical example would be a car to tow a trailer containing a natural source of methane, such as a cow, an old tree-trunk infested with termites, or even piles of rotting newspapers. A pipe from the trailer leading to the engine intake would cause the methane to be decomposed to CO2 and then passed out via the exhaust.

The consequence will be a reduction in the Greenhouse Effect on a positive basis, in that the more one drove, the less the effect from methane at 40 times more powerful than CO2.

What more could Greenies want? Drive all you like with your car full of crap, and cool the planet!

March 27, 2019 4:11 am

So many questions, says also James Comey! 🙂 #QANON

Reply to  Pasi
March 27, 2019 4:34 am
Tom Abbott
Reply to  Pasi
March 27, 2019 5:15 am

I think Senator Lindsey Graham, the new Senate Judicial Committee head echoed Comey, saying, yes there were so many questions.

Comey will get to explain himself in front of Graham and the whole world in the near future. Comey and all his co-conspirators.

Brennan, Obama’s CIA Director, is on the record saying Obama was responsible for the Witch Hunt on Trump. It’s TREASON!

This is what Graham needs to investigate, and I have every confidence that is just what he is going to do. We’ve gotten doubly lucky. We have both Trump and Graham putting up one hell of a fight for us. And a lot of other Republicans are doing their part, too. This must happen if we are to save our Republic from these radical, dangerous, Leftists.

March 27, 2019 5:43 am

Thanks to ‘liberal science” we now have some formulas for Mencken’s “hobgoblins”:
To list only two.

michael hart
March 27, 2019 6:35 am

Methane from trees was big news a few years ago.

Bottom line is, they don’t really have much clue about how to quantify methane sources, other than to say they are ubiquitous. Which makes it all the more iniquitous that the vegans, militant vegetarians, and the BBC, get away with stupid arguments about belching cows being a major source. Cows sit near the top of the ecological pyramid, and only graze a tiny fraction of the productive surface. The majority of methane will come from the base. The tail does not wag the dog.

Robert of Texas
March 27, 2019 9:02 am

Whether or not trees and wetlands emit important levels of methane is the wrong question, and can be ignored for now. It is a natural process. One cannot argue that there are more trees now then before man started agriculture.

First we need to answer if there is indeed a link to man-generated (or just released) atmospheric gases and climate change, and if so how much. Until this is understood, all natural processes can be ignored (unless needed to understand man’s impact).

The scientific community has no focus, and all they do is keep piling on more and more data, pseudo-data, and untested conclusions onto an unproven axiom of AGW. If you start with a falsehood, and then try to keep building up off that falsehood, all you end up with is mostly falsehoods with the occasional lucky guess. This is not science.

Who cares if trees emit CH4? It oxidizes to CO2 and H2O fairly quickly. The trees then soak up the CO2 and H2O and the cycle continues. So at best, the CH4 from trees is a temporary state that has little long term effect.

Gordon Lehman
March 27, 2019 9:35 am

“Methane causes 32–45 times more radiative forcing in a century than CO2 on a mass basis (Neubauer & Megonigal, 2015) and contributes c. 20% of radiative forcing (Denman et al., ”

Not according to MODTRAN. From 70 km looking down, MODTRAN gives ~4.5 watts out of ~440 in upward radiance. From 1 meter looking up MODTRAN gives ~5.5 watts out of ~370 downward radiance. These are methane bands only at 1.7ppm.

Much closer to 1% than 20% of radiative forcing.

steve case
Reply to  Gordon Lehman
March 27, 2019 11:56 am

Not according to MODTRAN …blah… …blah… …blah… …blah… …blah… …blah…

Do you think the average policy maker understands that? They understand temperature.

March 27, 2019 4:37 pm

My understanding is that Methane over time changes to CO2. So we should ask the Greenies how can we tell the difference between CO2 from a fossil fuel power station as against CO2 indirectly from say trees ?


Johann Wundersamer
April 1, 2019 12:25 pm

“Transient periods of CH4 emission have been reported in nominally upland forests, but such emissions are cryptic and easily overlooked (Megonigal & Guenther, 2008)”:

Johann Wundersamer
April 1, 2019 12:47 pm

Sure the same mixed feelings around the world:

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