Dinosaurs May Have Farted Themselves To Death

[The Central Scrutinizer]

http://www.reuters.com/article/2012/...8460PB20120507

It's true!

[GlennB]

I can believe it. Our Labrador has hospitalised us a few times with his "bottom burps".

[rjh01]

A more accurate thread title would have been "dinosaur flatulence may have warmed Earth".

[Dinwar]

Yeah, I was wondering about that. I don't have the numbers in my head, and I'm honestly too lazy to look them up just now (Terraria and rum are calling), but I do know that sauropods were around for a good long time--on a geologic scale--before the dinosaurs had their bottleneck. We know the Cretaceous was pretty hot, if nothing else from the ocean anoxic events. It's interesting that sauropods contributed, though. I wonder how cattle herding would impact our plant.

[Lowpro]

Originally Posted by Dinwar

Yeah, I was wondering about that. I don't have the numbers in my head, and I'm honestly too lazy to look them up just now (Terraria and rum are calling), but I do know that sauropods were around for a good long time--on a geologic scale--before the dinosaurs had their bottleneck. We know the Cretaceous was pretty hot, if nothing else from the ocean anoxic events. It's interesting that sauropods contributed, though. I wonder how cattle herding would impact our plant.

I'm more curious of methane turnover mostly because I'm not aware of what may utilize methane other than local bacteria, other than that aside from conversion to H20 methane seems to be reuptaken in water and soil. Dinwar you'd probably know more but how much terrestrial methane would be reuptaken via oceans and removed from the atmosphere? at least evident on a geological timescale (I'm not sure if eutrophicated lakebeds offer any clues to it either)

[MG1962]

Originally Posted by Dinwar

Yeah, I was wondering about that. I don't have the numbers in my head, and I'm honestly too lazy to look them up just now (Terraria and rum are calling), but I do know that sauropods were around for a good long time--on a geologic scale--before the dinosaurs had their bottleneck. We know the Cretaceous was pretty hot, if nothing else from the ocean anoxic events. It's interesting that sauropods contributed, though. I wonder how cattle herding would impact our plant.

It would all come down to a straight shot at bio mass. Has anyone ever come up with herd sizes for critters like triceratops etc

[MattTheTubaGuy]

Originally Posted by Dinwar

I wonder how cattle herding would impact our plant.

In NZ, farming is the biggest contributor to greenhouse gases, emitting nearly half of the greenhouse gases. energy is close behind, which includes power generation and vehicle emissions.
link to official website
so yes, cattle have a big effect.

[BenBurch]

Originally Posted by Lowpro

I'm more curious of methane turnover mostly because I'm not aware of what may utilize methane other than local bacteria, other than that aside from conversion to H20 methane seems to be reuptaken in water and soil. Dinwar you'd probably know more but how much terrestrial methane would be reuptaken via oceans and removed from the atmosphere? at least evident on a geological timescale (I'm not sure if eutrophicated lakebeds offer any clues to it either)

It simply oxidizes in the air, too.

[paiute]

He who smelt it deathdealt it.

[The Central Scrutinizer]

Originally Posted by rjh01

A more accurate thread title would have been "dinosaur flatulence may have warmed Earth".

But it wouldn't have been as entertaining.

[kajata]

I can't believe farting led to their exstinktion!

[Dinwar]

Originally Posted by Lowpro

Dinwar you'd probably know more but how much terrestrial methane would be reuptaken via oceans and removed from the atmosphere?

I'm not sure. The only thing I've really heard concerning methane and oceans is about clatherates, which are pertty poorly understood. Currently they seem to think they're biogenic, so they're no help at all. I do know (from "Life as we Do Not Know It" and "The Gaia Hypothesis", as well as the references therein) that methane has a pretty short residence time in the atmosphere. It degrades rather quickly--certainly on scales humans would be cognazent of (as opposed to multi-millenial scales).

Originally Posted by MattTheTubaGuy

so yes, cattle have a big effect.

In terms of absolute methane produced, I'll happily agree. However, I'm not sure that's sufficient to answer this question. The real question is, how much has methane production per pound of biomass changed over time? There's a lot more cows out there than there ever were sauropods, but sauropods were so much bigger than cows that I'm not sure how it ballances out.

Originally Posted by MG1962

It would all come down to a straight shot at bio mass. Has anyone ever come up with herd sizes for critters like triceratops etc

Yes, but the results are inconoclusive. It's hard to evaluate this sort of thing. Merely finding bones together doesn't indicate they traveled together--Rancho La Brea is proof of that. And fossil trackways may or may not help--after all, it's entirely plausible that a bunch of individuals were in the same area at the same time (squirrels and rabbits, for example, do this). Sauropods are even worse, because they apparently utilized a number of herd strategies, meaning there's no one answer. And given the rarity of good, solid evidence for ANY herd behavior, that means we may never know the particular behavior of particular species.

[GlennB]

Originally Posted by BenBurch

It simply oxidizes in the air, too.

Does it? At what ignition temperature?

Even then, creating what, exactly, as a by-product ?

x(CH4) + y(O2) -> ????????

[Dinwar]

Quote:

x(CH4) + y(O2) -> ????????

The highlighted part of your equation is wrong. Atmospheric methane racts with the hydroxyl radical to create CO2 and H2O.

Here's a more sophisticated publication.

Here's a somewhat less reputable, but more accessible, link. It's biased against rapid removal of greenhouse gases from the atmospher, so if anything it's on your side.

"Oxidation" does not equal ignition--if it did, rust could only happen at temperatures at which steel burns. It doesn't even have to do with oxygen, necessarily. Oxidation is the loss of electrons during an oxidation/reduction reaction, nothing more. It frequently occurs during combustion--oxygen is a VERY vigorous oxidizer--but to say that all oxidation reactions require high heat is like saying all running must be done at the Olympics.

[GlennB]

Originally Posted by Dinwar

The highlighted part of your equation is wrong. Atmospheric methane racts with the hydroxyl radical to create CO2 and H2O.

Here's a more sophisticated publication.

Here's a somewhat less reputable, but more accessible, link. It's biased against rapid removal of greenhouse gases from the atmospher, so if anything it's on your side.

"Oxidation" does not equal ignition--if it did, rust could only happen at temperatures at which steel burns. It doesn't even have to do with oxygen, necessarily. Oxidation is the loss of electrons during an oxidation/reduction reaction, nothing more. It frequently occurs during combustion--oxygen is a VERY vigorous oxidizer--but to say that all oxidation reactions require high heat is like saying all running must be done at the Olympics.

You're absolutely right, I was talking drivel. Must learn not to post in haste in the early hours.

Mind you, it does have a long life (~10 yrs) up there.

[blobru]

By estimating 44,000 lbs per mid-sized sauropod and "a few dozen"(?) per square mile, the authors come up with a figure of 520 million tons of methane per year, meaning they outfarted modern ruminants - mustering up a measly 50 to 100 million tons per year - by at least FIVE to one!

[Dinwar]

Originally Posted by GlennB

You're absolutely right, I was talking drivel. Must learn not to post in haste in the early hours.

No worries. It was actually interesting to look into, which is why I come here in the first place.

Originally Posted by blobru

By estimating 44,000 lbs per mid-sized sauropod and "a few dozen"(?) per square mile,

Yeah, that's going to be a nightmare....The issue is that I seriously doubt sauropod herds were evenly distributed. I can only imagine that there would be areas of denser sauropod populations, and areas of less-dense populations.

Of course, all of this assumes that the flora is constant. It's not--the Mesozoic flora was wildly different from the Cenozoic flora, to the point where it's hard to imagine what it was like back then. It could be that the increased methane was utilized as a resource by more plants (well, their symbiotes, anyway) than today, making local residence time much, much smaller. It woudl be interesting to see if methane-consuming plant/microbe symbiotes were more prevelant in areas of denser sauropod concentrations.

[Lowpro]

Originally Posted by Dinwar

I'm not sure. The only thing I've really heard concerning methane and oceans is about clatherates, which are pertty poorly understood. Currently they seem to think they're biogenic, so they're no help at all. I do know (from "Life as we Do Not Know It" and "The Gaia Hypothesis", as well as the references therein) that methane has a pretty short residence time in the atmosphere. It degrades rather quickly--certainly on scales humans would be cognazent of (as opposed to multi-millenial scales).

Right but I meant was how much methane wasn't degraded in the atmosphere but reuptaken by other organisms if such a means is possible. We study atmospheric concentrations via lake eutrophication strata (not that it's actually a strata...) in rock; thought that could apply to methane too.

[BravesFan]

Originally Posted by MattTheTubaGuy

In NZ, farming is the biggest contributor to greenhouse gases, emitting nearly half of the greenhouse gases. energy is close behind, which includes power generation and vehicle emissions.
link to official website
so yes, cattle have a big effect.

But wouldn't this be true anywhere? I mean even on a desert Island "something" is the leading cause of greenhouse gasses. That doesn't exactly prove it's a problem.

[Dinwar]

Originally Posted by Lowpro

Right but I meant was how much methane wasn't degraded in the atmosphere but reuptaken by other organisms if such a means is possible.

I know--I just couldnt' find anything to answer your question.

One thing that I DO know is used at times is low delta-C13 values. Methane seems to be overwhelmingly biased towards lighter (I think) carbon atoms. We can tell when methane clatherates, at least, cut loose. I honestly don't know if non-marine methane has a similar bias.

Ice cores may be a good place to look....after that I just don't know, the residence time is so small it's very hard to detect.

Originally Posted by BravesFan

But wouldn't this be true anywhere? I mean even on a desert Island "something" is the leading cause of greenhouse gasses. That doesn't exactly prove it's a problem.

You're right, in that there has to be some maximum contributer (or multiples, in the case of ties). However, that's not the issue of concern here. It's more a question of "How much does this one source contribute?" And the comparison to vehicles and energy is apt, as (at least for us Yankees) we're so used to thinking of energy as The Source for all greenhouse gases.

[jasonpatterson]

I wonder how rigorous the calculations are. There is a pretty wide range in the amount of methane released per pound of modern ruminants (cows produce 5x what wallabies produce, for instance) and it seems not unlikely that there was similar variation in sauropods. I'm also wondering about the few dozen 22 ton sauropods per square mile bit. Per square mile of Earth's surface, on average? Per square mile of optimal habitat? That number just seems high to me. I'm trying to find an estimate of historical elephant populations for comparison, but not having much luck.

[CapelDodger]

Originally Posted by BravesFan

But wouldn't this be true anywhere? I mean even on a desert Island "something" is the leading cause of greenhouse gasses. That doesn't exactly prove it's a problem.

Nor was there any suggestion that it is a problem. It's simply a fact. Ruminants can out-produce the greenhouse gases of four and a half million people living a modern developed lifestyle at low density. It takes a heck of a lot of ruminants, true, but there it is.

That's a problem in the sense that the methane represents wasted food, and efforts are being made to solve that.

[CapelDodger]

Originally Posted by MG1962

It would all come down to a straight shot at bio mass. Has anyone ever come up with herd sizes for critters like triceratops etc

Yes but little of it has been published or digitised; it's mostly still confined to the original bar-mats, napkins, and backs-of-envelopes.

[Dinwar]

Originally Posted by CapelDodger

Yes but little of it has been published or digitised; it's mostly still confined to the original bar-mats, napkins, and backs-of-envelopes.

In my experience that's sadly because once the liquer wears off the calculations look much less rigorous or supportable. Alcohol is great for helping geologists think (I actually once successfully argued in favor of someone taking up drinking because controlled randomness in thought processes is beneficial in certain stages of conceptualization ), but the culling process it necessitates can be a pain in the rear. And the ego. And occasionally, in my experience, the libedo....