Stories tagged Flow of Matter and Energy

Jul
13
2010

…of climate control systems...

Ever notice the plumes of smoke rising from many buildings, factories, and power plants on a cold day? That smoke is actually water vapor, which still contains usable energy, muahahahaha! Our buildings use lots of energy. Electricity, for example, powers everything from lights to computers to copy machines to coffee makers. Electricity eventually degrades into heat—you can feel that heat coming off of electric appliances. Current building energy management systems expel this excess heat energy instead of using it for other purposes, such as building the ultimate tilt-a-whirl of doom. Dave Solberg, an energy miser and consulting engineer-ahem-secret advisor, wants to change all that using the concept of exergy. He envisions a future where energy is used as efficiently as possible, and he has been working with Xcel Energy and organizations in the St. Paul area to re-engineer buildings.

We all know that mad scientists with plans for world domination need money and power. Well, current climate control systems are expensive to build and operate, and they're bad for the environment. But retrofitting old buildings and creating the infrastructure to support Solberg's systems has a higher up-front cost than following the status quo. If Solberg can demonstrate the effectiveness and cost savings of his plan below at SMM, your regional science museum will become a model for climate control systems all over the world--I mean it will take over the world! HAHAHAHAHAHA!

At Science Museum of Minnesota, Solberg wants to make two big changes in the way we use energy:

Solberg's Plan - Phase 1
Like all large buildings, SMM takes in outdoor air, cools it to dehumidify it, then reheats the air and sends it throughout the building to control the climate. Unlike most buildings, which use giant air conditioners and boilers, SMM uses hot and cold water piped in from Saint Paul District Energy to do that job. You can learn more about District Energy in an outdoor exhibit to the left of SMM's main entrance--and you can see the building right next to us!

District Energy burnin' the biomass
District Energy burnin' the biomassCourtesy Andrew Ciscel

The first change Solberg proposes is to re-use the waste heat that SMM generates from cooling down fresh outside air. Currently, SMM's ventilation system cools outside air down to about 50 degrees F with cold water from District Energy, dehumidifies it, and then reheats that air back up to a comfortable indoor temperature with hot water from District Energy.

Solberg would have us cool the air with cold District Energy water, then use that same water (now warmer) to reheat the air back up to 65 degrees F on its way to the ventilation ducts. This change would eliminate the need to use hot water from DE to reheat air, and it would reduce use our demand on DE’s cooling system, because we would send water back to their chilled water plant at a lower temperature than we currently do.

Solberg's Plan - Phase 2
District Energy makes electricity by burning waste wood. DE then uses the heat energy still available after making electricity to produce hot and cold water, making District Energy 50% more efficient than coal-fired power plants. But at the end of the day, DE has 95-degree F water left over. Right now this excess heat is released into the atmosphere from cooling towers on top of the building (see the plume rising from the building in the image?), but that 95-degree water could meet most of SMMs heating needs. Solberg wants us to tap into that wastewater as our primary heating source, replacing the 180-degree water we currently get from DE. This would put an oft-wasted energy source to work, and it would allow the 180-degree water now being used by SMM to be used elsewhere within DE’s hot water distribution system.

This plan is so good it must be evil. In the long run, if the kinds of changes being pursued by SMM were replicated widely, they would amount to lower emissions and lower energy bills everywhere, which is ultimately healthier for our environment (not that mad scientists care about that sort of thing). In fact, we found out that if we had implemented this system when the current building was constructed, we could have saved $1.5 million in infrastructure (which we could have really used for that giant laser in the--end of message truncated--

Jul
13
2010

Brown gold!: This is actually the solid byproduct of a manure-to-methane operation. As you can see, it holds no fear for the owner of this bare hand.
Brown gold!: This is actually the solid byproduct of a manure-to-methane operation. As you can see, it holds no fear for the owner of this bare hand.Courtesy kqedquest
We’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.

Jun
04
2010

Roooaaaarrrr!!!: I have the poison in me!
Roooaaaarrrr!!!: I have the poison in me!Courtesy http://www.flickr.com/photos/kuroha/638778686/
Like all ogres, Shrek is a greedy and covetous beast. He has millions of fine, fine goblets, but should you attempt to drink from any one of them, you risk becoming the target of one of his powerful cancer spells.

“But, Shrek,” you say. “You have so many wonderful cups, brought to us by McDonalds and Shrek 4 Eva. Why can’t I drink from just one of them?”

“Because,” Shrek would surely reply, “they’re all mine. All of them! That’s why I put cadmium in them. Ogres are immune to cadmium, but it is a carcinogen in humans.”

“A carcinogen? In your cups?” you ask.

“Yes, a carcinogen. With long term exposure, carcinogens can increase your chances of developing cancer!” says Shrek.

“Cancer?” you say.

“Yes. Cancer,” says Shrek.

And it’s not only Shrek’s goblets that are cursed; drinking from the cups of Princess Fiona will soften your bones, and sipping from the vessels of Puss in Boots will cast the hex of severe kidney damage upon you. And you should never drink out of something called “Donkey,” no matter what it’s made of.

Fortunately, all of the cups are being recalled to Ronald McDonaldland, to become a part of Ronald’s personal collection. Because clowns feed on poison.

May
11
2010

Assorted rubbish may be pumped into the leaking oil well: To make it more fun.
Assorted rubbish may be pumped into the leaking oil well: To make it more fun.Courtesy obiwanjr
You know, when that oil rig went down and started spilling hundreds of thousands of gallons of crude oil into the Gulf of Mexico, I thought, “What a downer. My reruns of ‘Yes, Dear’ are going to be interrupted with news footage of crying beavers and stuff for months now.”

But then BP came up with that idea for the containment dome, and I thought, “This is so crazy… it just might work. This could be more entertaining than ‘Yes, Dear.’ If such a thing is possible.”

But, no. The dome failed. Petrochemicals and near-freezing ocean water combined to form crystals in the dome, and it didn’t work. And it was super far underwater, so the failure couldn’t even be set to Benny Hill music or anything. Not entertaining.

I was just resigning myself to the fact that such a horrible accident might not actually be funny, when the jokers at BP let slip that they might have another hilarious trick or two up their sleeves. The dome didn’t work? Let’s try a giant “top hat”!

Yes, BP will be sinking a giant top hat onto the leaking oil pipe. It’s not really a top hat, of course; it’s actually a smaller version of Friday’s giant failure. I’m guessing it’s a sort of a bonus joke. But BP claims that the smaller contraption should have better chance of success, except that even if it does work, it won’t work as well as the dome was supposed to. (The dome was supposed to capture something like 85% of the leaking oil. But it captured 0%, so that’s sort of academic. Or, again, a bonus joke.)

And BP even has another plan, a Plan C, if you will, in the works, in case this one flops. Sort of how they filmed the second and third Matrix movies at the same time. According to my sources, the discussion behind plan C went sort of like this:

“So… what does everyone hate?”
“Nazis.”
“Yes, for sure Nazis. What else?”
“Um… oil spills?”
“Correct! Oil spills.”
“Ooh! We should do one of those!”
“No, people hate them. Plus we already have one. So what does everyone like?”
“Top hats.”
“Top hats, obviously. So we should throw one of them in the mix. But, if someone doesn’t like top hats, what do they probably like?”
“Everybody likes… ball pits?”
“Ball pits! Exactly! Let’s do something like that!”
“And tires! Old tires!”
“Yes, old tires too!”

So, in case the top hat doesn’t work, BP is considering injecting the leaking system with golf balls. And old tires. And then they would cap it off with some cement. Oh, right, and there’s this part too:

“What should we call it?
“A ‘junk shot.’ Duh.”
“Oh, my God. Totes perfect.”

And then, I assume, everybody else in the room had to go wash their ears out after hearing the unfortunate term “junk shot.”

Others have warned that such a “junk shot” could have repercussions beyond the phrase appearing in print: damaging the huge valve system at the base of the well could result in oil leaking out even faster—as much as 12 times the current rate.

Performing a junk shot against the flow of oil and the under the pressure at that depth will be extremely challenging, too. According to an expert from Tulane University, such an operation would have to cope with 2,200 pounds per square inch of upward pressure, which would make pumping golf balls and tires down very tricky.

However it turns out, it’s sure to be a barrel of laughs. Or oil. Thousands and thousands of barrels of spilled oil.

(I don’t have any better ideas, by the way. Except not to have a leaking pipeline a mile underwater. But you know what they say about hindsight.)

Apr
16
2010

Is this house a biogeochemical hotspot?
Is this house a biogeochemical hotspot?Courtesy monkeyc.net
To ecologists who study the environment, cities and suburbs are fascinating places. For one thing, they're full of people, and people take-up space, consume materials and energy, and create waste every single day. When people do this together in concentrated areas like cities and suburbs, they create what scientists call "biogeochemical hotspots" - places where chemical and energy reaction rates are much faster than in surrounding areas.

Individual houses are also hotspots. A group of scientists at the University of Minnesota, led by researchers Sarah Hobbie and Kristen Nelson, are trying to understand more about urban ecosystems and how chemicals and energy cycle through different people's homes.

They've begun to study a small group of people whose homes are here in Minnesota - asking them questions about their behavior and taking surveys and samples on their property.

What they've found might surprise a few people. It turns out that not everyone uses energy and chemicals the same way. Small numbers of individuals and families consume and waste much more than others - creating a bigger footprint in their ecosystem.

So who are these disproportionate polluters? There is a lot that scientists still don't know, especially about why people make the choices they do, but one thing seems to be clear - generally speaking, the more money that a family makes, the bigger their ecological footprint.

These bigger impacts come from a few behaviors that wealthier Americans tend to exhibit more than their less-wealthy counterparts. Flying in airplanes, buying a much larger home, having more pets and driving a car more often all contribute to a family's impact on their ecosystem.

While studying the role individuals play in urban ecosystems, another thing these scientists found to be true was that small individual actions - for example, turning down the thermostat in the winter just a few degrees, or using less chemicals on lawns, did have a significant impact on the environment.

You can see a recording of two of the researchers involved this study .

Dec
20
2009

Earn money, save money
Earn money, save moneyCourtesy Achim Hering

Obama's Home Depot speech

We are wasting money when heat is lost from our homes.
What would happen if economic stimulus money was used to improve the energy efficiency of our homes?

Benefits of improving energy efficiency

  • Economic boost ($20 billion cash flow)
  • Money saved on energy bills ($1k - $3k improvement / home X 5 million homes = $3.3 billion saved / yr on energy bills)
  • Jobs creation (600,000 to 850,000 new jobs - contractors, suppliers, and inspectors)

Weatherization legislation pending

Lawmakers recently have begun pushing to offer weatherization incentives immediately as a way to create 600,000 to 850,000 new jobs.

Lane Wesley Burt, manager of building energy policy for the Natural Resources Defense Council, said the program could be set up as a government rebate administered by certified contractors that would shave the money from a homeowner's bill when the work was completed. The contractor then would apply to the government for reimbursement of the incentive, similar to how auto dealers administered cash-for-clunkers rebates.

Learn more about possible weatherization incentives

Source: Los Angeles Times
Obama pushes home improvement to create jobs, save energy

Nov
16
2009

He looks happy, but it's a facade: He's very worried about phthalates, BPAs, and his manliness. (Good thing that's a glass bottle.)
He looks happy, but it's a facade: He's very worried about phthalates, BPAs, and his manliness. (Good thing that's a glass bottle.)Courtesy sirgabe
There’s something I want to get out of the way straight off the bat: the original title for this post was “Monday Nutrition Extravaganza: Chemicals in your food, playing with your manhood!” And while that has a certain whimsical charm, a re-read revealed hidden, disturbing meaning in those words. And I didn’t want to subject you Buzzketeers to that. I just thought you should know.

So, moving on, what’s this stuff playing with our manhood, now?

Chemicalz in our foodz! And stuff.

Earlier today, I came across this study about how there seems to be a correlation between high levels of chemicals call phthalates in pregnant mothers’ urine, and a lowered incidence of “masculine play” in their male children. (“Girls’ play behavior” didn’t seem to be affected.)

Interesting, interesting.

Phthalates are a group of chemicals added to plastics to make them softer and more pliable. We all like soft plastic—no one is arguing that!—but phthalates are all over the place, and increased exposure to them (all sorts of products and packaging use phthalates) is raising concerns about how those chemicals affect us, particularly during childhood development. See, phthalates are antiandrogens, meaning that they mess with the way your body works with hormones like testosterone. Testosterone plays an important role in how we physically develop, and perhaps in how we act. The boys whose mothers had higher levels of a couple kinds of phthalates demonstrated less “male-typical” behavior. The study looked a preferred toy types (trucks versus dolls), activities (“rough-and-tumble play”), and “child characteristics.”

Now, these are slightly sticky things to go judging kids on. Some folks might argue that these characteristics aren’t linked to biology so much as social conditioning. And it feels a little weird quantifying characteristics in children (and, let’s be honest here, characteristics which may not have a solidly identified “norm,” but nonetheless have all sorts of social and sexual baggage that we are uncomfortable with and often deal with in the worst ways). However, there does seem to be some statistical association here, whatever the causal relationship is. One hypothesis is that phthalates alter fetal production of testosterone at an important period of development, affecting “brain sexual differentiation.” It’s not so hard to imagine—a year ago I did a post on how certain common chemicals in pregnant mothers seemed to be causing penis deformities in their male children. The culprit there? Phthalates. The women in that story, however, had had exceptionally high exposure to phthalates (their jobs had them in constant contact with phthalate-containing hairspray), so it’s probably not something to lose sleep over, but it’s worth knowing.

And while phthalates aren’t supposed to be in food packaging, the next article I came across (this is an extravaganza, after all) deals with another plastic additive, BPA, that is found in food packaging, and which may also cause some hormone-related havoc.

BPA has come up on Science Buzz before. It’s in all sorts of packaging and bottles (it’s the reason your over protective mother doesn’t want you to use nalgene bottles) and it may affect tissue development, potentially increasing cancer risks.

We don’t care about that, though, right? Sure, cancer is out there, but in the future, not right now, you know? I know. But BPA’s latest appearance in the news may bring some immediacy to the concern over its use. Concern for some people. For men, I mean.

Chemical BPA in workers related to sex problems, says the Washington Post. “Sex problems”? We don’t want those! Chinese men working in a factory that uses BPA were found to have high rates of sexual problems. (I won’t be defining what “sexual problems” are because whatever you just imagined was probably correct.) Now, these guys have BPA levels about 50 times higher than the average American. But, still, something like 90% of Americans have detectable levels of BPA in their urine. Again, probably nothing to lose a lot of sleep over, but something worth knowing about. This professor is of the opinion that BPAs should be banned, even though most of us will probably never be exposed to dangerous levels of it, because a) it’s not a natural part of our diet; b) it’s not actually necessary in plastics processing; c) it accumulates in the body, and we still don’t know what level at which it begins to become harmful (ask those Chinese guys); and d) it’d be relatively easy to get it out of the food and water supply, unlike some other potentially harmful chemicals.

Accepting that scientific studies are necessarily very focused to eliminate variables, both of these stories still left me wondering what affect phthalates and BPAs have on women and girls. On one hand, one tries to avoid the mindset that average human physiology=male physiology, but on the other hand it’s usually just males that have penises, making their medical problems a little more hilarious.

There are so many… things out there, and they’re all doing… stuff! Interesting to know.

Sep
03
2009

An electromagnetic gun: What's it for shooting? Disks, mostly.
An electromagnetic gun: What's it for shooting? Disks, mostly.Courtesy ScienceApe
Oh, you thought I forgot about the Geoengineering Extravaganza I promised, after just one entry? Did JGordon forget? Or is he just demonstrating a tremendous lack of respect for the Science Buzz audience?

Neither, respected friends, neither. First of all, I’ve never forgotten anything in my life. (This is in case anything I do eventually relates to someone else owing me money.) And I think I’ve demonstrated my respect for y’all over the years.

No, what happened was this: on Tuesday evening, my sock caught on a nail sticking out of my kitchen floor, and I went down like a redwood. Dried or decomposing pieces of food cushioned the fall for most of my body, but I’m afraid my face landed squarely in the mousetrap, which I had just baited with fresh poison. Luckily the trap pinned my lips shut before I ate too much of the poison, but I mix some potent poisons, and it only took a little to put me out.

My poisons are designed to remove a mouse from consciousness for anywhere from a week to several months, long enough for me to shave them, and ensure that they wake up somewhere frighteningly unfamiliar, like Thailand, or inside of someone recovering from major surgery.

At any rate, I was out for almost all of yesterday. It’s good that I woke up when I did, because I was covered with mice, but I’m afraid I just never found the opportunity to do another geoengineering post.

Until now.

So, let us continue with the “forget about the greenhouse gases, and just cool this place off, now!” theories. That is, those theories that could reduce the amount of absorbed heat (from the sun) rather than reduce what’s storing the heat (greenhouse gases). It’s called solar radiation management, and it includes a wide range of potential projects. And I shall now introduce you to several, starting with the most weaksauce of them, and moving on to something with giant space guns.

When I call something “weaksauce,” I don’t mean to imply that it’s a bad idea, only that it doesn’t involve huge guns, or giant sulfur-spewing zepellins. Sort of like how cool roofs are weaksauce. Cool roofs have come up on the Buzz before. The idea is that by simply having lighter-colored roofs, more sunlight and heat is reflected back away from the Earth. And, aside from the planet heating up a little less, your house heats up a little less too, so you don’t have to use as much energy on air conditioning, and the power companies don’t have to burn as much coal, etc. Pretty neat, huh?

Unfortunately, it’d be pretty tricky to get enough people to have reflective roofs for it to make much of a difference to global temperatures—otherwise the cooling would just be local, and who cares about that, right? Plus… no giant guns, or anything.

Not like the plans to build a sunshade in space. They have guns.

Remember that season finale episode of The Simpsons, where Mr. Burns built a giant metal shade to block the Sun from Springfield? I hope you do, because some scientists are actually proposing something like that, but on a larger scale, and in space. Like, massive mirrored satellites. Or there’s the plan mentioned in this Atlantic article (which I’ve linked to before)—A professor at the University of Arizona proposes building 20 giant electromagnetic guns (rail guns?), each more than a mile long, with the purpose of firing Frisbee-sized ceramic disks into space. Each gun would fire 180,000 disks a minute, 24 hours a day, for 10 years. At that point, there should be enough disks suspended “at the gravitational midpoint between the Earth and the Sun,” that sunlight headed toward Earth would be significantly scattered… lowering the planet’s temperature. Unfortunately, the technology for these guns doesn’t exist, it would be really expensive, and it would kind of last forever. Also, one gets the feeling that this professor is just trying to make a point. On the other hand… giant disk guns.

And then there are the middle ground plans, like cloud enhancement. The idea there is to make the clouds puffier and whiter by blasting seawater up into the air with special ships. These nice, white clouds would, again, reflect more sunlight away from the Earth, cooling things down. It shouldn’t last forever, and who doesn’t like puffy white clouds? Unfortunately, it ain’t cheap, and as with all most of the other solar radiation management plans, we don’t know exactly what all the repercussions would be. Clouds are just clouds, right? Yes, but clouds affect how much rain we get, and who gets it, and how much plants photosynthesize, and so forth and so forth. And the plan is slightly less gunny than the space-sunshade thing.

Next time we’ll move on to “carbon-removal projects.” But right now I have to get the taste of mouse blood out of my mouth. (It’s an ingredient in the poison.)

Sep
01
2009

A nice refreshing belch from Pinatubo: Repeat?
A nice refreshing belch from Pinatubo: Repeat?Courtesy D. Harlow
Ever want to change the world?

No, I’m not talking about the awesome drums and bass album you’re working on. And I’m not talking about your new theory of about time and mountains and stuff. And I’m not talking about your award winning bowel movements.

I’m talking about shaking the heavenly spheres until they throw up a little. I’m talking about jamming your boot into the nearest orifice until the planet cries uncle. I’m talking about pinning its arms and slapping its belly until it forgets its own name in frustration. I’m talking about changing the world.

Sure, it’s sort of supervillain territory. And it used to be that you’d need a bad childhood and some sort of superpower, or maybe a giant laser for this sort of thing. But these days… these days you don’t even need to be super-mega-rich to tear the planet a new one; you only need to be super rich. And it could be that the planet needs a new one torn.

We haven’t really talked much about geoengineering here on Buzz, which is weird, because it falls under both “quick fixes” and “things that might look awesome,” categories I very much appreciate. This is why I prefer to deal with hangnails by shooting them off, and why my dog has painted-on zebra stripes. (The “quick fix” there was spray paint being used to make him look less stupid.)

Geoengineering is engineering on the global scale; it’s changing the planet to solve some problem. What if we could, for instance, stop global warming without changing our energy-hungry lifestyles? What if it was as quick and cheap as spray-painting the dog?

The thing is, many geoengineering projects would be quick and easy (relative to, say, transitioning the planet to renewable energy). But, like spray-painting the dog, geoengineering comes with the potential for serious problems. If we’re spray-painting the dog instead of washing him, we have to keep spray-painting him forever, or else one day we’ll have an obviously incredibly unwashed dog on our hands. And what sort of health problems might a spray-painted dog unexpectedly develop? And can we get used to living with a dog that is spray-painted?

(Bryan Kennedy posted a link to an article about these issues this summer. Check it out.)

Consider these problems with me as we turn away from painted dogs, toward the wide world of geoengineering. In the coming days, if I remember to, and if I’m not feeling too lazy, we will meet some possible geoengineering scenarios. And, remember, these aren’t totally sci-fi—they’re very possible (for the most part). The question is, do we really want to do them?

And so, geoengineering day 1: A fart like you wouldn’t believe.

Y’all know what killed the last dinosaurs, right? Yes: loneliness. But how did they get so lonely? It was that, ah, meteorite thing, right? A big space rock smashed into the Earth, boom, no more dinosaurs. But it’s not like all the dinosaurs got smashed by that falling rock. Most of the trouble came after the impact. Vast quantities of dust were thrown way up into the atmosphere when the space rock hit the planet… and it stayed up there for a while. The affect all that dust had on climate is pretty complicated, but, if we boil it way down, it basically blocked sunlight, and made the world a shadier, colder place for a while. Lots of plants couldn’t live in colder, darker conditions, so they died. And the dinosaurs couldn’t live without those plants, and so they died. (Again, it’s more complicated than that, but…)

And now… now we have a situation where, in the coming decades, the world may be getting much hotter than a lot of organisms can survive for very long. We aren’t hoping for an asteroid or meteorite to smash into us, of course, but is there another way to fill the sky with sun-blocking particles?

Yes. In 1991, Mount Pinatubo in the Philippines exploded, blasting millions of tons of sulfur into the sky. All that sulfur, and other tiny particles from the eruption (called aerosols), reflected lots of energy from the Sun back into space. Because it’s solar energy that provides the heat for global warming (greenhouse gases like carbon dioxide just trap the heat here), the Pinatubo eruption is thought to be responsible for temporarily lowering global temperatures by about 0.5 degrees Celsius (0.9 degrees Fahrenheit). That might seem like only a small drop, but a few fractions of a degree change in temperature worldwide can have a big affect on climate, and when we think about how it was caused by just one eruption… We could do it too! We could change the world!

One of the major ideas in geoengineering is to essentially recreate the Pinatubo eruption. Over and over again. Factories on the ground could pump tons of sulfur dioxide into the atmosphere, where it would bond with water vapor and condense around floating dust, blocking solar radiation from heating the planet. (This article envisions zeppelins hovering 12 miles up, tethered to factories by SO2-carrying hoses.)

The project might cost only tens of billion dollars (small potatoes when talking about changing global climate), and it might actually work… but then what? What happens once the dog has been spray-painted?

Some scientists are concerned that all that SO2 in the atmosphere could damage the ozone layer, which protects us from UV radiation from the Sun. (After Pinatubo erupted, the ozone layer suffered temporary but significant depletion.) Others point out that the project would do nothing to remove greenhouse gases, so that once the sulfur settled back down to Earth, we’d face very sudden temperature rises again; we’d have to continue to block out the Sun until we could decrease our production of greenhouse gases. The main thing that could happen is, well, we don’t totally know what would happen. It’s unlikely that a solution like this would only lower global temperatures, but exactly how it would affect other aspects of the climate and life on the planet is unclear…

Is it worth it? Should we pump the skies full of sulfur gas, even if we don’t understand everything that could happen because of it? What if it was the only way to hold off a “tipping point”? (Many climate scientists are concerned that gradual global warming will lead to a “tipping point,” after which warming accelerates rapidly. Thawing frozen tundra, for instance, might release vast amounts of trapped methane, which is a much more potent greenhouse gas than CO2.) Or do you think geoengineering would distract us from addressing the basic causes of climate change?

Any thooouuughts?

Aug
10
2009

Typical T. rex?: Image modified slightly by JGordon.
Typical T. rex?: Image modified slightly by JGordon.Courtesy ArthurWeasley
Oh, paleontologists… with your grabby little claws… always grabbing for the juiciest headlines… late to the table of the hard sciences, where your neighbors long ago grew fat and respected.

JK, of course. You’re a spunky young science, paleontology, and I love you for it. And who doesn’t want headlines? Why do you think I keep lighting fireworks off on my roof? If you’ve got something as loved, feared, and debated as the mighty Tyrannosaurus rex as your specialty, why not be a little provocative?

And so it went with a couple of paleontologists based out of Beijing and Munich. They’re all, “Ahem. Ahem. Is this thing on? Hello? We think, ah, that the Tyrannosaurus rex probably ate a lot of baby dinosaurs, and not so many fearsome adult dinosaurs. And, um, we…”

And then the press is all, “Say what?! Are you trying to say that the T. rex was just a big, dumb baby-eater? You are?”

Scientists: “Sort of, but not exactly.”

Press: “Print it!”

And so we have a new contender in the “Fearsome Hunter vs. Giant Scavenger” ring: Fearsome Baby-Hunter!

The idea, say the scientists, is that it’d be a lot easier to go around eating weak little babies than to go around fighting big triceratops and stuff, so that’s probably what T. rex did. (T. rex and other large, two-legged meat eaters.)

That part makes sense. Even if you’re as big and strong as the T. rex certainly was, eating something that can’t hurt you or run away from you pays off a lot more than eating something that can hurt seriously damage you, and takes a lot of energy to get. If you were a dinosaur, babies would probably be your favorite food. They’d be like the equivalent of individual serving yogurts. (Fun, delicious, and easy to eat.) That doesn’t mean that there were no epic dino-battles… they would have just been rare, I guess.

The paleontologists go on to say that T. rex-like dinosaurs specialized in baby eating so much, that it could explain the lack of immature dinosaurs in the fossil record. Juveniles would have been eaten whole, or at least in large chunks, their predators digesting the bones and everything. This would also explain, the claim, the low occurrence of bite marks on fossilized adult dinosaur bones—they just weren’t getting bitten much, if they made it to adulthood.

That’s where some of the theory falls apart for me. Why would an organism expend so much energy growing and maintaining a body the size of T. rex’s if its main prey was small and weak? Also, did dinosaurs just leave their young lying around for any old predator to eat? Unless a predator were small and sneaky (and whatever else T. rex was, it wasn’t small and sneaky), and could grab baby dinos on the sly, one would think that it would run into some protective parent dinosaurs pretty often. And then they’d have to fight, which defeats the purpose of going after little dinosaurs in the first place.

The lack of scarred adult bones seems to be incidental too. If a dinosaur died from whatever scarred its bones, I’d assume that it would be totally eaten (either by its killer, or later, by scavengers) before it fossilized. And maybe the type of wound that would leave scars on a bone would likely kill the attacked animal. And if the creature didn’t die, if it healed totally, it still might get eaten later on. And most animals don’t fossilize anyway.

And do we need a reason why there aren’t more baby dinosaur skeletons? They survive to adulthood, no baby skeletons. They get eaten, no skeleton. (Babies were bound to have been eaten, even without large dinosaurs specializing in eating them.) Even if they died of other causes, I wonder if their parents would eat the body themselves, or at least push it out of a nest, or leave it behind (where it would get eaten).

I wonder, too, if the ratio of baby dinosaurs to adults is similar in periods and areas without large theropods. (Theropods are the group of two-legged meat eaters T. rex belonged to.) If it’s the same, then the reason for so few specimens would have to be low fossilization rates, or a sampling problem, or just that everything was eating baby dinosaurs, not just theropods (which is a much less interesting claim to make).

Anyone care enough to offer an opinion?