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Permalink Reply by Adriana on May 7, 2012 at 4:26pm

PZ Myers weighs in:

The reports of dinosaurs dying of farts are greatly exaggerated

 May 7, 2012 at 12:51 pm  PZ Myers

No, dinosaurs did not fart themselves to death. This is what happens when you get your information from Fox News.

Dinosaurs may have farted themselves to extinction, according to a new study from British scientists.

The researchers calculated that the prehistoric beasts pumped out more than 520 million tons (472 million tonnes) of methane a year — enough to warm the planet and hasten their own eventual demise.

Until now, an asteroid strike and volcanic activity around 65 million years ago had seemed the most likely cause of their extinction.

So I read the paper. The researchers didn’t say that at all. There is nothing about extinction in the paper; it would have been ridiculous and I was prepared to dismiss such a claim without even reading the paper (the Jurassic lasted 55 million years, the Cretaceous 80 million, with dinosaurs farting away throughout). But the paper makes no such claim, instead suggesting that the mass of herbivores during the Mesozoic would have made a substantial, but stable, contribution of greenhouse gases to the atmosphere that may have been partially responsible for the warmer, moister climate of the era and the greater primary production.

Take together, our calculations suggest that sauropod dinosaurs could potentially have played a significant role in influencing climate through their methane emissions. Even if our 520 Tg estimate is overstated by a factor of 2, it suggests that global methane emission from Mesozoic sauropods alone was capable of sustaining an atmospheric methane mixing ratio of 1 to 2 ppm. Equally, our estimate may be understated by a similar factor, (i.e. possibly supporting 4 ppm methane). In the warm wet Mesozoic world, wetlands, forest fires, and leaking gasfields may have added around another 4 ppm methane to the air. Thus, a Mesozoic methane mixing ratio of 6–8 ppm seems very plausible.

The Mesozoic trend to sauropod gigantism led to the evolution of immense microbial vats unequalled in modern land animals. Methane was probably important in Mesozoic greenhouse warming. Our simple proof-of-concept model suggests greenhouse warming by sauropod megaherbivores could have been significant in sustaining warm climates. Although dinosaurs are unique in the large body sizes they achieved, there may have been other occasions in the past where animal-produced methane contributed substantially to global environmental gas composition: for example, it has been speculated that the extinction of megafauna coincident with human colonisation of the Americas may be related to a reduction of atmospheric methane levels.

See? A reasonable conclusion, not Fox News sensationalism.

But here’s the information you really wanted to know: they estimate that a medium-sized sauropod would have farted out 2675 liters of gas a day. Happy now? Impressed?

---

Wilkinson DM, Nisbet EG, Ruxton GD (2012) Could methane produced by sauropod dinosaurs have helped drive Mesozoic climate warmth? Current Biology 22(9):292-293.

Permalink Reply by Davy on May 7, 2012 at 5:06pm

Yeah I read a piece about the flatulence of dinosaurs from Seven news ( Aussie TV station). Their headline read 

 Dinosaur gas 'may have warmed the Earth': UK study

And ended with this sentence.

About 150 years ago, before modern industry took hold, methane emissions were about 200 Tg per year, less than half that of the Mesozoic Era.

Permalink Reply by Doone on May 7, 2012 at 5:14pm

They were giant animals chewing on trees and leaves by the ton per day, of course they made a lot of methane.   

How Could We Affect The Earth?

Category: Environment
Posted on: April 24, 2009 12:18 PM, by Ethan Siegel

As many of you have heard, the Earth has been getting warmer, rapidly, since the industrial revolution. And as many of you have also heard, there is, historically, a link betweengreenhouse gases and temperature here on the Earth.

So, with Earth Day just behind us, I thought of a little analogy for the one question I hear more than any other about global warming:

How could something as small as a human being affect the climate/temperature of the entire Earth?

The analogy is good old-fashioned water torture. What harm can one drop of water do to you? Pretty much nothing, of course. But what if you randomly dripped cold water on the same exact spot for hours or even days on end? The result is that the victim can go insane(as confirmed by mythbusters) from this. It's because a cumulative effect, over a long period of time, can be significant even for a small thing.

But this is Scienceblogs, and I'm a scientist. We don't reason by analogy here except for help in explaining. Instead, if we want to test something, we do the science. So let's take a look at what we've been doing to the Earth. The United States, right now, is responsible for between 20 and 25% of the greenhouse gas emissions in the world, most of which is carbon dioxide. Check out the latest (2007) statistics:

That's a lot of gas, but surely it's insignificant compared with the entire Earth's atmosphere! And, of course, it is. The mass of the entire Earth's atmosphere is somewhere between 5,000 and 5,300 trillion metric tonnes and so this 6 billion metric tonnes that we put out could hardly ruin the planet, right? Well, we're not the only country on Earth, but moreover, 2006/7 wasn't the only time we put large amounts of carbon dioxide into the atmosphere. Take a look at the long-term statistics of carbon dioxide released from fossil fuels.

Well, doing the math on these statistics, from 1800 to 1950, the world's human population released 300 billion tonnes of carbon dioxide into the atmosphere. You'll notice that, because this was such a (relatively) small amount released over a (relatively) long time, the effect on carbon dioxide concentration wasn't very pronounced.

But over the next 30 years, from 1950-1980, we really ramped up out fossil fuel consumption, and over those 30 years we put out 390 billion tonnes -- more than the past 150 years -- in just 3 decades. You'll notice that the rise in carbon dioxide concentration over that time is pretty steep.

And as for the last 29 years, from 1980-2009? We've put out more fossil fuels than ever before: an unprecedented 725 billion tonnes over that timespan. So what does all of this mean for our atmosphere? Could humanity -- a few billion tiny animals -- really affect the entire atmosphere of our planet?

Well, our 5.3 trillion tonne atmosphere is made up of the following:

1. Molecular Nitrogen -- 78.08%
2. Molecular Oxygen -- 20.95%
3. Monatomic Argon -- 0.93%
4. Other -- 0.04%

Nitrogen, oxygen, argon, and a little bit of other stuff. How bad could adding this carbon dioxide to the atmosphere be? (Aside from killing the great barrier reef, of course.)

Well, add those numbers above up, and you'll find that we've added more than 1.4 trillion metric tonnes of carbon dioxide to the atmosphere over the past two centuries. Using the most recently measured figures, how many tonnes of carbon dioxide are in our atmosphere now? Just over 2.0 trillion. The Earth has "processed" (i.e., managed to deal with and remove from the atmosphere) some of this carbon dioxide, but not nearly enough of it, and not nearly quickly enough.

Keeping with the current trends, we will have double the amount of carbon dioxide in our atmosphere by 2040 than we did in 1800, and this carbon dioxide is forcing the temperature increases we're seeing now. Whether you're convinced by this convincing evidence that has convinced climate scientists for decades or not doesn't matter. What matters is that we have hundreds of billions of tonnes of extra carbon dioxide in our atmosphere, with no known way to deal with it.

The least we can do is stop making it worse, which means to stop burning fossil fuels, or -- at the very least -- to burn as little as possible as slowly as possible. And that's my concluding thoughts to you this Earth Week!

Permalink Reply by Adriana on May 7, 2012 at 5:22pm

Yes, and there were no humans living on coastal waters. Plus the Mesozoic climate was different from current climate; vegetation was not the same. 

Permalink Reply by Chris on May 8, 2012 at 7:05am

Reframing the argument is a common technique of the right. They are 'saying' "Climate Change is so stupid that..."

PZ Meyers is doing exactly what's required.

The excerpts below if from Ground Rules and Tips for challenging th... I saw something else that more accurately addresses the changed science article but don't remember where it is on this web site. 

Particularly since the early 1970s, the political Right has successfully reframed a whole series of issues in a way that has moved federal and state governments toward an increasing level of repression; and society toward accepting more social oppression. While successfully establishing their framework the political Right has managed to hide its own role in the process. What this means is that even as the arguments of the political Right have become widely accepted, the way it actually created this situation has been overlooked. Many "average Americans," mainly middle class Whites, now simply accept arguments for repressive measures and oppressive systems as "common sense."

Common tactics of the Right include distorting the truth and manipulating facts and figures in order to deceive the public. The Right often attempts to pass laws that take rights away from groups or individuals. Under the guise of addressing some compelling societal need, they often frame the issue by appealing to prejudice, myth, irrational belief, inaccurate information, pseudo-science, or sometimes even by using outright lies. 

Permalink Reply by Doone on May 9, 2012 at 1:57pm

Farting Didn't Kill The Dinosaurs

Fox News misreads a new study. Daniel Stone corrects the record:

[N]o one ever said anything about extinction—except for the news outlets that picked up the story for its obvious headline potential. Researchers had looked at global climate change, and found that, yes, such a massive amount of methane expulsion "could have been significant in sustaining warm climates." But reports  that the warming was what killed off the animals? Blatant sensationalism, says Paul Myers, a biology professor at the University of Minnesota. 

Glad we cleared that one up.