By the way, when you read about the gigatons of carbon emissions that human activities emit each year, it's helpful to have some perspective:
Let's talk gigatons--one billion tons. Every year, human activity emits about 35 gigatons of [carbon dioxide] (the most important greenhouse gas). Of that, 85% comes from fossil fuel burning. To a lot of people, that doesn't mean much -- who goes to the store and buys a gigaton of carrots? For a sense of perspective, a gigaton is about twice the mass of all people on earth, so 35 gigatons is about 70 times the weight of humanity. Every year, humans put that in the atmosphere, and 85% of that is power. Large actions, across whole nations and whole economies, are required to move the needle.
By comparison, our atmosphere is small--99.99997% of our its mass sits below the Karman line, which is often used to define the border between Earth’s atmosphere and outer space. At 62 miles above Earth's surface, it’s about as high as the distance between St. Paul, MN, and Menomonie, WI.
The oceans also absorb some of that carbon dioxide, but not without consequence.
Of course, the great part about being responsible is having capability--if our inventions bring about such transformations in the air and oceans, then couldn't we be inventive enough to reduce their negative impacts?
Aren’t budgets all about money? Don’t they track how many $$$ come in and how many $$$ go out?
That’s right; so what’s a carbon budget? A carbon budget tracks how much carbon, C, goes in and out of a natural area.
Right now, we’re worried about too much C going into our planet’s atmosphere. This excess C is causing global warming, sea level rise, ocean acidification and other environmental problems. These are BIG problems! We can begin to fix these problems if we do a carbon budget and really know how much carbon is where.
Courtesy Sergio Signorini, North American Carbon ProgramAlong with others, scientists at the Center for Microbial Oceanography: Research & Education (C-MORE), based at the University of Hawai`i, have begun to track C in the ocean off the eastern United States. The study area includes a LOT of water! -- all the seawater from high tide out to 500 meters deep, shown by the black line in the map, in the Gulf of Maine (GoM), the Mid-Atlantic Bight (MAB), and the South Atlantic Bight (SAB.)
Imagine your money budget. Let’s say we track your $$$ in and out of 4 categories. Money comes into your pocket from 2 categories, mowing the neighbor’s lawn and babysitting. Money goes out when you pay for movies and snacks.
In the same way, scientists want to track C as it moves between the coastal water “pocket” and 4 nearby areas: the coastal land, the atmosphere above, seafloor below, and the deeper ocean offshore. Where is C leaving the coastal water? Where is it entering?
But wait! Coastal zones are only small slivers of water, compared to the open ocean around the world. Why bother to track carbon in coastal waters?
Ah ha! Coastal waters are very important in C budgeting. Notice the red color in the map above. Red means there's a lot of chlorophyll. Chlorophyll is the green pigment important in photosynthesis, the process that plants use to take in C and fix it as sugar. The red in the map shows that coastal waters are richer in carbon than the open ocean.
Understanding the C budget of coastal waters is one small but important step in solving global warming and other environmental problems.
Courtesy KEIOk, well, there isn’t really such a thing as a nuclear earthquake. “Nuclear Earthquake” just sounds impressive. And I suppose “impressive” is one way to describe what’s happening in Japan right now.
I suppose you’re all aware of the 8.9 (or possibly 9.0) rated earthquake that hit Japan last week (if you aren’t, check out this post), and that the Fukushima nuclear power station there has been severely damaged.
While the country is still trying to put itself together, officials are still trying to get the power plant under control. So what happened, what’s happening, and what’s (probably) going to happen?
Well, a nuclear plant like Fukushima basically operates by using radioactive uranium to boil water. The uranium is always decaying—the number of protons and neutrons it has isn’t stable, so neutrons fly off, causing heat. If the neutrons hit other neutrons in the uranium, they fly off too, causing even more heat. If there’s too much of this neutron-on-neutron action, the uranium will get too hot, melt everything around it, and it’s a disaster. This is what happened at Chernobyl.
To prevent the neutron reaction from getting out of control, and to make sure the uranium produces just the right amount of heat, “control rods” are inserted in with the uranium fuel. The control rods absorb some of the neutrons to keep the reaction under control. When the right amount of heat is being produced, the water around the fuel boils, turns to steam, and spins electric generators. It works out pretty well.
At Fukushima, the control rods were inserted into the uranium as soon as the earthquake started, and they did work—the uranium reaction was shut down. But the decaying uranium had already produced other elements, elements with a lot of heat of their own. So there was a lot of residual heat in the power station.
Normally, water would keep circulating around the hot core, carrying away the residual heat (and turning it into electricity). But between the earthquake and the ensuing tsunami, the power to the water pumps was shut off and the backup generators were disabled. The pumps had backup batteries, but eventually those ran out. That means there was still a lot of heat in the core, but no fresh water to carry it away. The water that was there would continue to heat up until the steam was vented or the vessel containing it simply burst.
Unfortunately, both of those things sort of happened. While purposely venting some of the steam, an explosion happened in the building surrounding one of the cores. According to this site, this is probably because some of the vented water vapor had separated into hydrogen and oxygen, which built up in the building and ignited. This whole situation (the venting and the steam) was radioactive, but not that bad as those things go—the radioactive elements decayed and became stable in a very short time.
The next problem was that with all the venting, the water level around the cores was slowly falling. Without water to take away their heat, the cores could overheat, and eventually melt down. This started to happen, and some more dangerous radioactive products of the uranium started to mix with the remaining water and steam, so officials decided to start pumping seawater into the core. Seawater can get more radioactive than clean water, but it would keep the core cool and under control. And it did.
Today, there was a second explosion at the plant, however. I’m not totally sure what caused this, but it looks like it was again from the accumulation of hydrogen in one of the buildings.
With the uranium reaction under control and the cores under water, the residual heat should eventually dissipate. But the explosions have further damaged the cooling systems, and keeping the multiple cores at the station submerged in seawater has been a challenge. The longer the cores are exposed, the harder it is to control radioactive material already produced by the cores, and the greater the chance of a meltdown occurring at the plant.
Approximately 200,000 people living in the region of the nuclear plant have been evacuated, and it’s still unclear what will happen there. Nothing good certainly, but a meltdown isn’t a sure thing at this point, and even if a meltdown were to occur (again, a meltdown happens when there’s too much heat in the core, and everything around the radioactive fuel melts), the Fukushima plant was built to much higher safety standards than Chernobyl was, and it should contain the damage much more effectively. At Chernobyl, explosions sent radioactive material into the atmosphere and over the surrounding area. At Fukushima, as I understand it, the radioactive products of a meltdown would be contained inside extremely thick, tough containers, which, so far, have not been damaged by the earthquake or the explosions.
There’s more to be said about what will happen, and how this might affect the world’s attitude toward nuclear power, and whether that’s a good thing or not … but that will have to wait for another post.
Update: A Third Explosion at Fukushima
A there's been another explosion at the Fukushima nuclear plant. Now three of the four reactors at Fukushima have experienced an explosion. The previous two explosions were probably caused by a buildup of hydrogen, but it isn't certain whether that was the cause of this explosion as well.
The vents that emergency workers had hoped to use to flood the reactor chamber with seawater were malfunctioning, meaning that the core was dry (and un-cooled) for several hours. The vents finally started working in the early morning, but the chamber wasn't filling with water the way they had hoped, perhaps because of a leak.
A meltdown is still possible, but while radiation levels in the area are considered "elevated," they are low enough that it's very unlikely that the vessels that contain the reactor cores have been breached.
3/15/11 Update: Fire at 4th reactor
Shortly after the explosion at reactor 2 (the third explosion), a fire started at reactor 4. Between the fire and the explosion, radiation levels at the site briefly spiked to about 167 times the average annual dose. Reactor 4 actually wasn't producing power when the tsunami hit, but it did contain a cooling pool for spent fuel assemblies.
Nuclear fuel that has decayed to the point where it's not useful for sustaining a nuclear reaction still produces a lot of heat, and so it's stored in a pool of water for years to deal with the heat and radiation. Reactor 4 at Fukishima has one of these pools, and—just like with the active reactors—it looks like the cooling system was malfunctioning, which allowed the water in the pool to boil away, exposing the spent fuel. The spent fuel likely heated up until it ignited, or caused a fire in the building.
Authorities are now warning people living as far as 20 miles away from the plant to stay inside to avoid any radioactive fallout. As for the emergency workers at Fukushima, CNN's expert says, "Their situation is not great. It's pretty clear that they will be getting very high doses of radiation. There's certainly the potential for lethal doses of radiation. They know it, and I think you have to call these people heroes."
Update: 2 Reactor containment vessels probably cracked
Japanese officials think that the spike of radiation around the Fukushima plant last night might have been associated with a cracked containment vessel in one of the reactors. Today, they think a second container might be cracked as well, and leaking radioactive steam.
This started as a reply to Bryan's comment on the Freaky Frogs post, but it quickly turned into its own blog entry...
Here's Bryan's comment:
I thought the whole BPA freakout was an interesting look at how we think about environmental and personal contaminants like this. People seemed to get all up in arms about BPA in water bottles and bought tons of new plastic or aluminium vessels to replace them. But that switch over raised some questions for me.
Where did all those old bottles go? In the trash?
How much energy does it take to make those aluminium bottles? Is it lots more than the plastic ones?
How many bottles can you own before it'd just be better to use disposable paper?
Courtesy US Government
And my response...
It took some searching, but I did find one article discussing a life cycle analysis from Australia which showed that, in a comparison between aluminum, stainless steel, and plastic, plastic has the smallest carbon emissions footprint, uses the least water, and produces the least manufacturing waste. However, it was unclear whether this comparison included recycled metals in its evaluation. Steel and aluminum are 100% recyclable (vs. plastic, which loses quality every time it's recycled), so over time and on a large scale, their use would lead to less material waste.
Courtesy Matthew Baugh
It's also interesting to note that recycling metals uses significantly less energy vs. what it would take to smelt "new" metal. To paraphrase this reference, recycling steel and aluminum saves 74% and 95%, respectively, of the energy used to make these metals from scratch. As it turns out, we recycle about half the steel we use in a year in the US, and so almost all the steel we use contains recycled content. In contrast, we recycle just 7 percent of the plastic we use.
And then there's glass--we have lots of options, really.
Courtesy Ivy Main
I can't speak to how much material was wasted when people discarded all those bottles (I think I recycled mine?). Personally, I do think that making reusable bottles in general uses less energy than is needed to make all those disposable plastics and recycle them--at least in terms of lifetime footprints. Of course, when it comes to a strict comparison between reusable bottles, switching to a new bottle will always consume more energy than just sticking with your old one.
Unfortunately, it turns out that most plastics, even the ones labeled BPA-free, leach estrogen-mimicking chemicals. So if you're looking for a long term solution, it may be best to just avoid plastics altogether. This does seem to be one of those cases where we have to consider our own health vs. the environment and pick our battles wisely. If people want to switch once to avoid health problems, at least they're still sticking with reusable bottles. Readers, do you agree?
Of course, it would be great if choosing a water bottle were the only drinking water issue we faced. The other day I read about a study by Environmental Working Group, which found that the carcinogen chromium-6 contaminates tap water throughout the US. Are we exposing ourselves to this toxic metal by drinking tap water instead of pre-bottled water? Or is chromium in the bottled water, too? What about other unregulated pollutants in our water?
I guess my point of going into all this is that it's complicated to make these decisions, and we'll probably never be able to avoid every single toxic substance. But does that mean we shouldn't try to make drinking water safer?
For now, I'm gonna stick with the steel and aluminum bottles that I already have and try to get the most out of them. Luckily, I live in the Twin Cities, which don't rate high on EWG's chromium map. Every day, I learn more about my health and the health of our environment, and hopefully by searching, I'll find a direction that hits on a fair compromise.
We've written about freaky frogs on the Buzz Blog before, but some recent news may shed new light on our abnormal amphibians. Until recently, researchers thought that atrazine, an agricultural pesticide, was the sole cause of sexual deformities in frogs. Unfortunately, it's not so simple.
Courtesy Mike Ostrowski
An ecologist at Yale University, David Skelly, sought to test assumptions about atrazine by studying the frequencies of frog deformity in different land types--agricultural, suburban, urban, and forested. Skelly expected to find the highest rates of deformities in agricultural areas, which would be consistent with atrazine being the main cause. Curiously, he found the highest rates of deformity in urban and suburban areas--places we wouldn't expect to find much atrazine. So what's going on?
It turns out that what makes atrazine so dangerous is that it mimics estrogen and binds to estrogen receptors in frog cells. Because estrogen impacts sexual development and function, so too does atrazine. But atrazine isn't the only estrogen-mimicking compound out there--there's a whole class of chemicals that mimic estrogens, including those found in birth control pills and plastics (BPA). And these chemicals are found in droves in cities and surburban areas--they're flushed into the sewage, but aren't filtered out during water treatment.
So why do we care? Besides the fact that frogs are just awesome little creatures and important parts of their food webs, they have something in common with humans--estrogen receptors. The same chemicals that impact frogs can impact us. So how do we humans keep our sexual development and functioning intact?
Skelly had a great idea to filter this stuff out of the water at the treatment plant, so that it won't get into our bodies from drinking water. He also suggested that regulatory changes would help so that when new chemicals are developed, they're scrutinized for unintended side effects. And of course, we can make choices that reduce our exposure, such as by buying BPA-free plastics, or using stainless steel and glass containers. And of course, increased awareness is always a good idea.
Do you take extra steps to avoid things like BPA? What are they?
Courtesy Mark RyanResearchers in Japan are studying the wing structure of dragonflies to help improve how micro wind turbines perform during high winds. Micro turbines are small, affordable energy converters that can be used in both urban and rural settings where giant turbines would be too expensive, too large, and too impractical. Micro turbines can be set up relatively easily in configurations of a single unit or as a bank of several units, and the energy generated can be stored in batteries.
They work on the same principle as the large turbines, but can generate power in wind speeds as low as 4 or 5 miles per hour. One fallback, though, is their generators can get overloaded when hit with high storm winds, producing more energy than the system can handle. Large turbines solve this problem by tilting their propellers - either by computer or otherwise - and adjusting their rotation speed. But that kind of technology just isn’t affordable with micro turbines.
That’s where studying dragonfly wings comes in. Aerospace engineer Akira Obata of Nippon Bunri University in Oita, Japan wondered how dragonflies were able to remain stable in flight at low speeds. He placed a plastic model of a dragonfly wing into a large tank of water laced with aluminum powder and videotaped the flow patterns. He noticed that as the water flow slowed down vortices arose on the wing’s surface that allowed the water to pass over the wing at the same speed, thus keeping it stable. But when water flow sped up the wings aerodynamics performance decreased.
So, Obata developed an inexpensive paper micro turbine with similar “dragonfly wing” bumps on its surface and it did just as he hoped. When air speeds flowing over the turbine wing increased between 15 and 90 mph, rather than speeding up its rotation and overwhelming its battery, the micro turbine curved into a conical shape that stunted rotation and kept power generation low.
Bloom Energy is a CA business that has developed a fuel cell called the Bloom Box. The Bloom Box is a self-contained source of energy. So far its on-site application has been cost prohibitive for the mainstream. To make the Bloom Box more accessible, Bloom Energy is rolling out a system that enables corporations to derive power from the Bloom Box without actually buying it.
The Bloom Electrons Program details
The Bloom Box is something that Bloom Energy got to the clean energy industry. The Bloom Box is an "energy server" that produces electricity with a chemical response and extremely low carbon footprint. Want to understand the price of a Bloom Box? Over $700,000 is the cost. The price has caused the number of Bloom Energy consumers to be pretty low. Corporations consist of B of A, FedEx, eBay and Google. To increase demand for Bloom Boxes, Bloom Energy partnered with Credit Suisse and Silicon Valley Bank to create Bloom Electrons. Bloom Electrons is a financing business that offers 10-year contracts for electricity from on site Bloom Boxes at a fixed rate.
Powering Bloom Electrons with clean power
There are not upfront costs for businesses to use Bloom Box meaning the companies can go off the grid with Bloom Electrons. Companies that have already purchased Bloom Boxes up front expect to recoup the cost of the unit anywhere from three to six years after they're installed. With Bloom Electrons, Bloom Energy said businesses can start saving up to 20 percent immediately on what they're paying in CA. At present, Bloom Electrons only pencils out in California. It's about ten cents per kilowatt-hour within the U.S. for average electricity. About 14 cents per kilowatt-hour is what Bloom boxes do. This is a different price. Bloom Electrons power comes down to about 7 cents per kilowatt-hour with the California subsidies and federal clean power incentives.
The whole world getting Bloom Box soon
Bloom Energy said the Bloom Box will offer businesses a competitive energy advantage without the need for subsidies in three to five years. The first thing the company is worried about is meeting demand for the Bloom Electrons system. The production will need to go up. If you look back 2 years, Bloom Energy was not very fast. About one Bloom Box a month was made. When it comes to shipping Bloom Boxes, the business has gotten faster. It can do one a day now. If Bloom Energy can decrease the production price along with increasing production, it could eventually meet its goal of supplying clean power to the creating world.
If you're a total Buzz nerd like JGordon, you may have noticed a number of posts with the tag "Future Earth" over the last couple of years. They started when the folks here at the Science Museum of Minnesota began researching a new permanent exhibit called Future Earth, opening Fall 2011 at SMM. This exhibit will ask, "How do we survive and thrive on a human-dominated planet?"
This is a different question than we're used to asking, but it's a vital one. Understanding the answer means studying more than just global warming, rising sea levels, and population growth--we also have to think about energy production, agriculture, retreating glaciers, transportation, hunger, poverty, development, and the list goes on. It turns out that because all of these issues are interrelated, we can't study or address any one of them in total isolation.
This new way of understanding is what inspired the Future Earth exhibit. Future Earth will look at environmental issues with a fresh perspective, explore the ways we study and understand our impacts on the environment, and shed light on projects that offer innovative solutions to complex problems, such as this one we hope to implement at Science Museum of Minnesota. The goal is to foster understanding, hope, and action.
Future Earth is part of a larger effort taking place at SMM, the University of Minnesota's Institute on the Environment, and a team of other institutions called the Future Earth Initiative. Funded by the National Science Foundation, FEI aims to raise awareness and offer workable solutions for life in a human-dominated environment. Given adequate time and resources, these solutions could help reduce our negative impacts on the environment while providing us all with the energy we need to live. Think of it as saving two birds with one…thing that you save birds with…
Courtesy Public DomainFor those of you who want to choose the most environmentally friendly shaving solution, Slate's Green Lantern just did a column about the carbon footprints of different shaving options. Disposable or electric? Which is "greener"?
As with everything else in the future (where we live), even this little question is complicated. But the author seems to do a pretty good job unpacking it—you have to consider energy used in the process, whether for hot water or to run a small electric motor, as well as manufacturing costs and each product's useful lifetime.
The long and the short of it, depending on your shaving habits, is that electric razors are ultimately more energy efficient than plastic disposables. But just barely. According to the Green Lantern's calculations, you save about 15 pounds of carbon dioxide by using an electric shaver. And, as the author puts it, you would have to shave with a disposable razor for more than 350 years to equal the amount of greenhouse gases produced by one cow in a single year. (I don't think a cow produces 5200 pounds of greenhouse gas a year by itself. That figure might be taking in to consideration the gases produced by growing feed and processing the animal as well, or it might account for the greater potency of methane—which cows produce—as a greenhouse gas over carbon dioxide.)
In any case, this assumes that you shave your face at all. You might wear a beard, or you might be what I like to call "a female." Or you might take advantage of one of the many other shaving options: some men use old-fashion safety razors and straight razors; Crocodile Dundee finishes his shaves with a bowie knife; I cover my face in high-proof grain alcohol and set it ablaze (it's invigorating, but I can't maintain eyelashes well this way); I have friends who let cats lick away their stubble.
So this isn't the be-all-end-all. But it's like David Schwimmer says.
Courtesy C-MOREThere are microbes…and then there are micro-microbes. Oceanographers on C-MORE’s BiG RAPA oceanographic expedition are finding bacteria the size of one-one-millionth of a meter in the oligotrophic (low nutrient), open-ocean of the Southeast Pacific, far from the productive waters off the coast of Chile. But that’s not all; some scientists are looking for the even smaller marine viruses in gallons of filtered seawater. Meet some of these micro-microbes in these video reports:
Courtesy Dr. Anne Thompson, MIT
Yes indeed, microbial oceanographers are taking home quite a collection from the South Pacific Ocean. In less than a week the good ship RV Melville will arrive at Rapa Nui (Easter Island), and scientists will step onto land for the first time in almost a month. They and their oceanographic samples will return to C-MORE laboratories around the U.S. The oceanographers are also returning with new hypotheses buzzing around in their heads. Now it’s time for them to take the next step in the Scientific Method: data analysis!