Courtesy Public domainImagine you’ve been transported back in time to the Late Jurassic and you’re sitting on a gently sloping hillside watching a large herd of the gigantic sauropod dinosaurs chowing down on tons of vegetation in the valley below. What’s the one thing you might need to worry about? The herd of sauropods suddenly stampeding the hillside? A truck-sized carnivore eyeing you from the shadows? Tiny burrowing mammals gnawing at your ankles? While all these scenarios would have been possible, the most likely worry would probably be (if you’re downwind anyway) getting inundated by a warm blast of dinosaur farts.
That’s right, dinosaur flatulence - tons of it - wafting over you like a huge, stinky old blanket. Ewww.
Researchers from Liverpool John Moore's University, the University of London, and the University of Glasgow have calculated that herds of sauropods, those tiny-headed ,long-necked, long-tailed herbivorous dinosaurs that populated the Jurassic landscape about 150 million years ago, would have been eating a lot of vegetation during their lifetimes and in the process releasing a tremendous amount of methane gas from their guts and into the Earth’s atmosphere. That's a lot of cheese-cutting.
In fact, writing in the journal Current Biology, Dr. David Wilkinson and his colleagues claimed that the amount of emission of methane just from the herbivorous dinosaur gassers would have been about the same amount being emitted from all sources today - 500-520 million tons each year. Methane is a greenhouse gas that can absorb the sun’s infrared energy, and heat up the atmosphere. The producers of methane today range from ruminant species such as cows, goats, and sheep, and from human activities such as natural gas drilling, but the effects on the environment could be similar – a warming of the atmosphere. Back in the Mesozoic, average temperatures were about 18 °F higher than today. Wilkinson and his colleagues suggest the dinosaur backfires could have been a big factor in the warming of the prehistoric environment, but admit it wouldn't have been the only source of the gas back then.
"There were other sources of methane in the Mesozoic so total methane level would probably have been much higher than now," Wilkinson said.
Wilkinson’s research interest lays not so much in the sauropods themselves but in the microscopic bacteria that once lined their guts. It was these microbes that converted the vegetable matter into energy and waste, including methane. Could that vast SBD Mesozoic methane source, as the researchers suggest, have been a big contributor to the warmer temperatures back then? Possibly. Or maybe it's just a lot of hot air.
BBC Nature News
The future is now for some lucky Americans. The rest of us will have to wait and hope that someday soon our recycling trucks might also run on “trash gas.”
“Trash gas” is natural gas that is harvested from landfills where it is produced by the decomposition (breaking down) of organic waste. One future-thinking company, Waste Management Inc, now has over 1,000 trucks fueled by methane (a natural gas) that they collect from one of their very own California landfills.
Courtesy Tom Raftery
Natural gas can be used in vehicles in either a compressed or liquefied state. Waste Management’s trash gas trucks are about 50/50 compressed natural gas (CNG) and liquefied natural gas (LNG). You should check out those links, but to give you the gist of the idea here, imagine a balloon filled with natural gas. CGN is like squeezing that balloon. LGN is like cooling that balloon until the molecules inside condense into liquid like steam on a bathroom wall.
Why is this a BIG idea? CNG and LNG emit less carbon and nitrogen oxides into the atmosphere than diesel (the conventional fuel used by most large trucks). As you’ve probably heard, carbon dioxide is among the greenhouse gases contributing to global climate change. Meanwhile, nitrogen oxides contribute to smog, which is bad for your health besides being unsightly. Less is definitely more when it comes to carbon and nitrogen oxides.
As for more, Waste Management’s single currently operating LGN-generating landfill creates 13,000 gallons of LGN each day, which is enough to fuel 1,000 trucks. According to the primary source of this blog post, Waste Management has another landfill-turned-fuel station up for approval. With an additional 299 landfills and about 21,000 trucks, it might not be that long before a Waste Management “trash gas” truck comes rolling along your street.
Back in November, UC-Berkeley physicist Richard Muller surprised a number of people when he stated at a congressional briefing that “global warming is real.”
Muller had previously been called a climate skeptic for drawing attention to what he called numerous errors in the film “An Inconvenient Truth,” but his own extensive research showed none of his concerns about climate change science to be legitimate.
In fact, according to the Huffington Post, “Muller explained how his team reached the conclusion that in the last half-century the earth's temperature has risen roughly 1 degree Celsius, a number that exceeds the conservative 0.64 degree estimate put forth by the United Nations' Intergovernmental Panel on Climate Change.” His study was partially funded by the Koch brothers, oil-industry billionaires who have, on more than one occasion, funded studies by climate change deniers. The Koch brothers have since questioned Muller’s findings.
In a December Wall Street journal editorial, Bjorn Lomborg, author of the “Skeptical Environmentalist” conceded that global warming is a real threat and will hit developing countries hardest, but states that cutting carbon emissions won’t make much change in temperature over the next 30 years. He claims that rather than continuing to work on getting nations to lower emissions, we should just set up infrastructures to deal with the resulting problems from climate change. Bjorn, whose numbers and conclusions have often been questioned by scientists, seems to be saying we should just throw in the towel and stand back while economics determines our world’s future.
A few days later, the New York Times printed an article on the warming Artic permafrost, which contains twice as much carbon as the entire atmosphere. Scientists believe that both global warming, resulting from human activity, and wildfires may be catalyzing the thawing of permafrost, which releases methane gas into the atmosphere as the ancient plants and animals that make up the frozen tundra decompose. Although it doesn’t stay in the atmosphere as long as carbon dioxide, methane gas is even better at trapping heat and will potentially make earth’s atmosphere warm at an even faster rate, thawing more permafrost, in a vicious cycle.
In the article, the experts said that “if humanity began getting its own emissions under control soon, the greenhouse gases emerging from permafrost could be kept to a much lower level.”
Skeptics are looking at the evidence and becoming believers. Science tells us that climate change is real, and is already well underway, but that we can still slow global warming by reducing carbon emissions. In other words, we shouldn’t throw in the towel.
Here are links to the three articles to which I referred:
Methane deposits occasionally erupt to the surface. A research paper published in the American Journal of Physics explains how large methane bubbles rising from the ocean floor might account for many, if not all, of the mysterious disappearances of ships and aircraft.
Oceanographic surveyors of the sea floor in the area of the Bermuda Triangle have discovered significant quantities of methane hydrates and older eruption sites.
Courtesy kqedquestWe’ve talked about the delights of cow feces before on Science Buzz, but mid-July always puts me in the mind of “brown gold” (coincidentally, the last occasion it came up was exactly four years ago today), and any time there’s talk of turning an animal into a fuel source, I get excited. (Remember that fuel cell that ran on the tears of lab monkeys? Like that.) Why not take another look?
So here you are: another wonderful story of cows trying their best to please us, before they make the ultimate gift of allowing their bodies to be processed into hamburgers and gelatin and cool jackets.
Poop jokes aside (j/k—that’s impossible), it is a pretty interesting story. The smell you detect coming from cattle farms is, of course, largely from the tens of thousands of gallons of poop the cattle produce every day. The decomposing feces release lots of stinky methane. (Or, to be more precise, the methane itself isn’t smelly. The bad smell comes from other chemicals, like methanethiol, produced by poop-eating bacteria along with the methane.)
Aside from being, you know, gross, all of that poop is pretty bad for the environment. The methane is released into the atmosphere, where it traps heat and contributes to global warming (methane is 20 to 50 times more potent than carbon dioxide as a greenhouse gas), and the poop itself is spread onto fields as fertilizer. Re-using the poop as fertilizer is mostly a good idea, but not all of it gets absorbed into the soil, and lots of it ends up getting washed away into rivers, lakes, and streams, where it pollutes the water.
Some farms have managed to address all of these problems, and make money while doing it.
Instead of spreading the manure onto fields right away, the farms funnel all the poop into swimming pool-sized holding tanks, where it is mixed around and just sort of stewed for a few weeks. All of the methane gas produced by bacteria as it breaks down the manure is captured in tanks. What’s left is a fluffy, more or less sterile, solid that can be used as bedding for the animals, or mixed in with soil, and a liquid fertilizer that can be spread onto fields.
The methane can then be used on-site to generate electricity, either by burning it in a generator, or using it in a fuel cell. (The methane is broken apart and combined with oxygen from the air to produce electricity, water, and carbon dioxide.) A large farm will produce enough electricity to power itself and several hundred other houses. (The extra electricity is just put back into the power grid and sold to the power company.)
Whether the methane is burned or used in a fuel cell, the process still creates carbon dioxide. However, CO2 isn’t nearly as bad as methane when it comes to trapping heat, and because the original source of the carbon was from plant-based feed, the process can be considered “carbon-neutral.” (Although one might argue that the fossil fuels involved in other steps of the cattle farming process could offset this. But let’s leave that be for now. It’s complicated.)
The downside is that setting up an operation to capture and process manure, and to generate power by burning it is expensive—it took about 2.2 million dollars to do it at the farm covered in the article, with about a third of that coming from grants. Still, the byproducts (electricity, fertilizer, soil/bedding) are profitable enough that the system could pay for itself over the course of a few years.
It’s amazing, eh? Out of a cow’s butt we get soft, clean bedding, liquid fertilizer, and electricity, all without the bad smell. What a world.
Courtesy Donald Davis (for NASA)
As "mdr" explained recently in, astroid found guilty of killing dinosaurs that a panel of scientists, after reviewing all evidence, blame an asteroid impact for the demise of the dinosaurs.
A paper has just been published saying that dinosaurs choked on ozone.
A new study in the journal Paleogeography, Paleoclimatology, Paleoecology puts forth the idea that the Chicxulub impact, long blamed for the extinction of the dinosaurs at the end of the Cretaceous era 65 million years ago, could have done them in by flinging huge amounts of ozone precursor chemicals -- nitrogen oxides, methane, and other hydrocarbons -- into the air.
Below the article in Discovery News, this comment by 1sang (Doug) explains why mammals and avians survived.
In order to (survive) all you'd have to do is get on steeper slopes and find enough food to live for a couple of years. Mammals and smaller avian dinosaurs could more easily accomplish this than their massive cousins (in fact, many were probably already in this safety zone away from the many large predators roaming the lowlands).
He also notes that methane release leads to an increase in ozone and that today we have the beginnings of lots of methane being released (I wrote about this here: Methane ice).
Courtesy Meredith P.
We've all heard about global warming, the undeniable fact that the Earth's temperatures rose (dramatically / sharply / noticeably – take your pick) from 1980 to 1998. (We've heard considerably less about the equally undeniable fact that from 1999 to present temperatures have held steady or even dropped, but never mind.)
We've all heard that carbon dioxide, released into the atmosphere when we burn coal, gas or other fossil fuels, is the (only / primary / most important) source of the warming. (The Earth also warmed during Roman and Medieval times, when fossil fuel consumption was vanishingly small. But never mind.)
And we've all heard how this warming is going to bring about floods, drought, storms, extinctions and other ecological disasters if we don't reduce out carbon output by (the end of the century / 2020 / tomorrow afternoon).
Those first two points can be tested through observation and experiment. The last one cannot. It's a prediction about the future, and you cannot observe something that hasn't happened yet. But you can always bolster your position by accurately predicting the past.
Now, that may seem like a waste of time – I mean, it's the past. We know what happened. But that's what makes it such a great laboratory. Y'see, scientific predictions are based on models. Scientists take all those observations and experiments, put them in a computer, and see where the trends lead. You can test the model by taking observations from some point in the past, crunching the numbers, and seeing if the results match what we know happened next.
And that's exactly what Richard Zeebe, James Zachos and Gerald Dickens did. In an online article published by the journal Nature Geoscience, these three scientists took the model used by climate researchers to predict future global warming and applied it to an episode of past global warming. Specifically, they looked at a well-studied period 55 million years ago when the Earth's temperature rose dramatically. They plugged the data from that warming into the model used to predict current warming, and they found....
It didn't work. The climate models being used today were unable to duplicate known conditions from the past. They weren't even close – the results were off by about 50%.
Emily Latella, call your office.
Courtesy .robbieY’all got kangaroo knives, right?
What? You don’t have kangaroo knives? Well… I mean… what… How do you cut your kangaroos up, then?! This is madness! Cats and dogs, living together! Ewok Adventure! Sour candy! Madness!
I think there must be some kind of misunderstanding. A kangaroo knife isn’t necessarily like a big Crocodile Dundee knife* (although, that is a really nice kangaroo knife). No, pretty much any sharpish object can be a kangaroo knife. So, yes, a knife can be a kangaroo knife, but what else? A chipped rock? Yes, what else? Sure, a jagged piece of scrap metal would make a nice one. Anything else? A sharpened spoon? Very good, yes, a sharpened spoon could work. A fingernail? Well, I suppose it depends on the finger and the nail, but maybe.
I think you’re getting the idea. But why do we need all of these kangaroo knives in the first place? To be honest, it’s probably only the Australian Buzzketeers out there (maybe?) that would have any use for them, but it doesn’t hurt for the rest of us to be prepared. See, a recent article in the journal Conservation Letters recommends that expanding the kangaroo industry in Australia, and shrinking the cattle and sheep industries, would significantly cut the continent’s greenhouse gas emissions. Specifically, growing the kangaroo population to 175 million by 2020 (and reducing the cattle and sheep populations proportionately) would eliminate 16 megatons of greenhouse gas, or 3 percent of Australia’s total emissions.
It’s not just any old greenhouse gas that would be cut, either—we’re talking about methane, one of the stinkiest, hottest, greenhousiest greenhouse gases of them all. Ruminants—animals that chew cud and have multi-chambered stomachs, like cows and sheep—produce a lot of methane, up to 60 percent of global methane emissions†. A dairy cow can produce about 50 gallons of methane gas a day! Kangaroos, on the other hand, produce only about one third of the methane of a ruminant animal does. And, as a little environmental bonus, kangaroos’ large, padded paws are much easier on the land than the hooves of ruminants, and contribute less to erosion.
But what are we supposed to do with all these millions of kangaroos? Eat them, naturally. (This is where the kangaroo knives come in!) Kangaroo meat is reportedly high in protein, low in fat, and it has high concentrations of conjugated linoleic acid (a chemical that seems to have anti-cancer properties, and tends to reduce body fat in humans). But, you know, it’s kangaroo meat, which some people may have a problem with**.
It’s difficult to say, too, what the other environmental ramifications of increasing one animal’s population dozens of times over might be. Maybe the kangaroos could be trained to eat rabbits, or something.
Assuming y’all had some kangaroo knives, do you think you could deal with eating kangaroo? You know, for nature?
*Doesn’t Paul Hogan look like he’s about to do something just awful to Manhattan there?
†The EPA’s website says that ruminants only account for 28% of global methane emissions. But that’ still a lot.
**The kangaroo meat industry actually held a competition to come up with a new name for the meat that didn’t conjure up images of doe-eyes and fuzzy little faces. The finalists included kangarly, maroo, krou, maleen, kuja, roujoe, rooviande, jurru, ozru, marsu, kangasaurus, marsupan, jumpmeat, and MOM (meat of marsupials), but the winning name ended up being “australus.” Australus was for sure not the best name. The best name was “jumpmeat.”