Courtesy US Department of EnergyA couple of months ago, I noticed something happening on the roof of the RiverCentre, the big building across the street from the Science Museum. After noticing, however, I didn’t give it any more thought. This was for two reasons: because a couple of months ago it was approximately one billion degrees below zero here, and I didn’t want to stand outside looking at roofs any longer than I had to; and because I’m a firm believer that you shouldn’t stare too long at anything you aren’t certain about. Don’t believe me? Examples: the sun (it’ll burn your eyes), chimpanzees (they will literally tear you to pieces), and roadkill (it’s gross).
At any rate, it turned out that the goings-on on the RiverCentre roof would have been largely harmless to watch, and that they were a part of a big, interesting project that I hadn’t heard about—they were installing a large array of solar thermal panels.
Solar thermal panels, just as a reminder, aren’t exactly like the photovoltaic solar panels you might be thinking of. Unlike panels that use sunlight to produce electricity, solar thermal panels absorb the heat in sunlight (or solar radiation, if the distinction bugs you), and uses it to heat water.
So … the new solar array on the RiverCentre is a joint project between the RiverCentre itself, and St. Paul District Energy, another neighbor of the Science Museum, which supplies hot and cold water to buildings downtown for efficient heating and cooling. The array has 144 solar panels, altogether taking up about the area of half a football field, and they should be able to produce about 1 megawatt of power.
Now, compared to a 1,000-megawatt coal or nuclear power station, 1 measly megawatt probably doesn’t seem like much, but it’s nothing to sneeze at. A single megawatt is still approximately enough to power 1,000 homes. Sort of.
It depends on the average consumption of the homes in the area, which varies from region to region, but 1 megawatt is usually touted as the power consumed by 1000 homes. And, in any case, this is a little different, because it’s not feeding an electrical power grid, but a grid of heat energy for downtown—any extra heat that’s not used by the RiverCentre facilities will be fed back to District Energy, which will redistribute it around the city.
The new array is the largest of its kind in the Midwest, and, in addition to creating a local energy source (as opposed to buy coal or natural gas from somewhere else), it should reduce St. Paul’s carbon dioxide emissions by about 900,000 pounds annually—more or less the amount created by 90 vehicles in a year.
Again, 90 cars’ worth of CO2 may not seem like much, but it’s a start, and it’s kind of cool that that’s just from the panels on one building. And, with the help of a million and a half dollar stimulus from the Minnesota Office of Energy Security, a mix of solar thermal and photovoltaic solar panels are going to be installed on 10 more buildings along the Central Corridor. In addition to the new light rail line from St. Paul to Minneapolis, the Central Corridor is meant to be a showcase for a bunch of energy innovation projects. (Click that last link for a list of projects—there are a whole bunch.)
Pretty slick. (More info and links here.)
Courtesy NASALife scientists study…well, life. They want to know everything about living things on planet Earth. One of the first things biologists want to know is who’s here. What kinds of plants and animals live in a forest? --or in a field? –or in the ocean?
If you’re an oceanographer who studies marine mammals, perhaps you’d go to sea on a ship with a good pair of binoculars and hunt for whales. As you focused your binoculars you’d be able to see different kinds of whale species. As you looked closer, for example at Humpback Whales, you'd see that each individual whale has a different black-white pattern on its tail. You might even take a biopsy, a small sample of whale flesh, and do a more detailed study of genetic differences among individual Humpbacks.
But what if you’re a microbial oceanographer? You sure can't use binocs to hunt for microbes! How can you study individual differences among tiny creatures that are only one-one-hundredth the width of a human hair? How do you hunt and capture single-celled bacteria, like Prochlorococcus, the most common bacterial species in the world’s ocean?
Courtesy C-MOREYoung scientists, Sebastien Rodrigue and Rex Malmstrom, at the Center for Microbial Oceanography: Research and Education (C-MORE) were doing research in Dr. Sallie Chisholm’s C-MORE lab at the Massachusetts Institute of Technology when they adapted a “laser-based micro-fluidic system” used commonly by medical researchers, for the study of marine bacteria. With this method they could put each individual tiny Prochlorococcus cell into its own little pool of seawater.
And then the excitement began.
Courtesy Dr. Anne Thompson, MITEven in scanning microscope photographs, each Prochlorococcus looks like just another teeny, tiny balloon; we can't see any individual differences. However, Sebastien and Rex used fast and inexpensive genetic methods and discovered an extraordinary variety of individual differences among Prochlorococcus. Of course the variety among these microbes doesn't have to do with tail patterns, like whales. Prochlorococcus vary in their method of getting nutrients, like iron, out of seawater.
So what? Why do we care?
We care A LOT because microbes like Prochlorococcus are operating at the nitty gritty level of cycling not only iron, but also other elements in the ocean. Like carbon. That's right, as in carbon dioxide accumulating in our atmosphere -- and ocean -- causing climate change and associated problems. The more we understand about individual differences among oceanic microbes, the more we'll understand how they influence and respond to changes in Earth's climate.
Take a break and listen to the sounds around you. What do you notice? Is there anything surprising that you've been tuning out? How do the sounds change over time, and do they improve or degrade your well-being?
Courtesy David Benbennick
It's easy to think of sound as a side-effect of important behaviors like communication, transportation, building stuff, etc. But could sound be important all on its own, worthy of our attention? We all live within environments of sound, and so do animals. In fact, there's a emerging field called soundscape ecology, which aims to study sound and its relationship with ecosystem health.
Traditionally, studies focus on the sound of one animal to understand its communication. For example, one scientist recently decoded prairie dog-ese.
But soundscape ecologists don't look at individual animal sounds so much as the bigger picture--they want to know which animals are loud or quiet, which ones have higher or lower pitches, which animals follow the sounds of other animals, and then they try to put it all together to understand the soundscape as a system that shows how animals interact with each other through sound. They also want to understand how human sounds impact these soundscapes.
Researchers compared bird life around noisy equipment that compresses natural gas with similar — but quiet — habitat. In Alberta, they found that birds had fewer offspring at the noisy sites. Similar results came from the Southwestern U.S.
Species that use echolocation, such as bats and (potentially extinct) Yangtze river dolphins, have trouble locating prey and moving safely through their habitat when unexpected sounds disrupt their echos.
Musician David Teie has even shown that he can create music that impacts the moods of tamarins.
And then there are the impacts of human sound on humans. Garret Keizer writes in his book, The Unwanted Sound of Everything We Want, that he "chose to write a book about noise because it is so easily dismissed as a small issue. And because in that dismissal I believe we can find a key for understanding many of the big issues."
Courtesy John PozniakKeizer distinguishes between sound and noise, which is unwanted sound. He discusses how soundscapes are divided up according to wealth and sociopolitical power--that there are people who make noise and people who listen. Airports or loud factories might be built near less affluent neighborhoods, for example. Keizer asks us to recognize that the sounds we make can have impacts beyond us:
A person who says “My noise is my right” basically means “Your ear is my hole.”
So sound can be an indicator of larger social issues or ecological disruptions. As you read this, do you notice anything about the sounds around you that make you think of a bigger issue or problem?
In the public media, the impacts of global warming have been less important than questioning its causes. And at any rate, reports on the impacts have alternately a catastrophic immediacy or an ambiguous, amorphous quality--the latter likely born out of caution due to the former's inaccuracy and tendency to undermine action. But there's room for a third approach--one of reasonability and inquiry.
And in fact, scientists' explorations go beyond the intangible models of earth covered in gradations of 5 colors, which represent average temperature change over the last century. Their work tests changes in the real world with real organisms. This field work generates data that can be used to test and improve the accuracy of the earth systems models we use to predict future change.
One such project is literally heating up wheat fields and spraying CO2 over them. The researchers want to find out how global warming and increasing concentrations of CO2 will impact crops. It turns out that plants will react to these changes differently in different latitudes and climes.
For example, plants in warmer climates might grow better earlier in the year only to take a dive once summer temperatures pass a certain range. Plants in cooler climates might thrive with warmer temperatures and increased CO2, whereas tropical plants might suffer from too much heat.
"There is a narrow latitudinal band that could make rising heat beneficial to growers, Kimball concluded. But farther south, especially in Mexico, the implications of the warming mean serious reductions in crop yields."
Courtesy Robert A. Rohde
The information gleaned in these plant studies is helping validate and improve existing models of vegetation so that the tools we need to make decisions about climate change are more accurate. One of the researchers in the article implies that we need a lot more of this validation than we do predictions right now. Even so, changes in reporting on climate change's impacts are often due less to increased uncertainty and more to increased information.
So it seems that rather than the impacts of climate change being universally good or bad, they're a little of both in different parts of the world. What can we do to improve communication in the media on this front?
And to take this a step further, given the varying environmental responses to global warming, it is ethical for one country to make decisions about climate change without consulting other countries?
Researchers at the University of South Florida recently found that the fungicide chlorothalonil, in the same family as DDT, killed almost 90% of the frogs exposed to it. They tested several species of frogs, and all had the same reaction. They are now testing the chemical's mortality rate for other organisms, including bees.
Courtesy Miguel Tremblay
We've all been there. You're driving along, bobbing your head along to the music, when suddenly you hit a pothole and it feels like your suspension is coming apart. It's especially bad here in Minnesota, because our extreme winters take their toll on worn asphalt. What's a gal to do?
One possible solution is a better way to fix potholes. In Duluth, MN, MNDOT workers are experimenting with new ways to hot patch asphalt with recycled materials and microwaves. In wintertime, crews usually have to patch potholes temporarily until summer comes along and they can use hot asphalt to make a more permanent patch. By using a special microwave, they can make hot patches even in bitter cold temperatures, and the recycled materials make for less waste and pollution. The new fix is also faster and cheaper than current methods.
My friend Wendie pointed out some billboards that went up recently in the metro area to promote concrete as a pothole-free alternative. (Wendie also passed along a handful of the articles in this post--thanks, Wendie!)
On the Think Concrete website, there's loads of info about how concrete lasts longer and saves money. But the question on my mind is, "Which is better for the environment?"
A life cycle assessment comparing the environmental impacts of asphalt and steel-reinforced concrete was completed in 1998. It showed that while producing asphalt required more energy input, concrete required more ore and fertilizer inputs, and gave off more toxic emissions. On the other hand, asphalt was associated with higher levels of hazardous waste generation and management needs. The authors concluded that over the life of each material, the environmental impacts were roughly equal, but they also mentioned that asphalt was recycled more often than concrete, potentially turning the sustainability tide in its favor.
However, two separate studies have shown that concrete provides a better driving surface, decreasing the fuel needed to move a car down the road and thereby its emissions. (Both of the studies were completed in cooperation with cement associations, so throw some grains of salt in there). But there are other examples of concrete's environmental benefits.
And that's not all--there are some great innovations afoot with concrete. Some researchers are working to make cement with carbon absorbing properties, while others have found ways to make flexible concrete that heals itself, reducing the need for new materials and increasing safety.
Of course, there's also the pie-in-the-sky option: solar highways.
Courtesy US Fish and WildlifeWord on the street is that Xcel Energy has canceled its $400 million, 150-megawatt wind farm project in North Dakota. (North Dakota, if I remember my geography right, is the Dakota directly … above South Dakota. I think.)
The reason Xcel is giving for the cancellation is the same one I give for never going out in the yard without a rake: birds.
The wind turbines, it seems, could pose a potential hazard to two endangered birds: the whooping crane (known to be a silent, thoughtful bird), and the piping plover (known for perching on bathroom windowsills to watch people bathe). The whooping crane is the tallest bird in North America (save that for humiliating your fiancé on trivia night), and its population has been reduced to only about 400 birds, largely due to habitat loss. The piping plover, also a victim of habitat loss, is a shore bird with a global population of just over 6,000 individuals.
Faced with a federal mandate to mitigate the threat to the birds, Xcel, like an unenthusiastic kid who just found out he’d have to bike to a lame birthday party, decided that that the wind farm scene just wasn’t worth the hassle.
It’s too bad, really. Shana explored this issue a couple weeks ago, but the long and the short of it is that it’s a doozy. On one hand, no one wants to see a five-foot-tall crane run into a windmill (if you laugh, you go to Denny’s when you die), but on the other, you have to balance that threat against the chronic environmental effects of fossil fuel use. If both species are vulnerable to habitat loss, climate change probably isn’t going to be a great thing for them. And at least in the case of the cranes, fossil fuel has an even more direct effect on them—the cranes’ only winter habitat, Aransas, Texas, is a regular spot for oil and gas drilling operations. So … they’re able to work that out, but not the North Dakota wind farm?
It kind of feels like that kid was really looking for an excuse not to go to the birthday party. But I suppose we can’t really blame it all on the kid—we should have made sure it was a better party. And, yeah, I can see how having a bunch of birds around would make for a creepy party, but if it was done right it could also be an awesome party with all those birds!
Oh, god, I don’t know what’s metaphor and what’s reality anymore.
Anyway, no more big wind turbine field in North Dakota. What do y’all think about that?
We often hear about gravity being different on other planets--the Moon is an oft-cited example of how weaker gravity makes you weigh less. But did you know that gravity actually varies on our own planet?
There's this thing called a geoid. It sounds like something out of a sci-fi story, but it's quite real. The geoid is a map of the Earth's gravitational field. And since gravity impacts things like sea level and currents, it's important to understand how it varies.
Luckily, those crafty Europeans came up with the GOCE (Gravity field and steady-state Ocean Circulation Explorer) satellite, which has painted the clearest picture yet of the geoid. With its variations exaggerated, it makes the Earth look like a giant potato. The variations come from unevenness in earth's mass and shape. Its wobbly surface represents what shape the oceans would take without current, wind, or tide to move them. The satellite also studies ocean circulation and the movement of ice.
This information is particularly important to understanding sea level rise. Scientists predict that, on average, sea level will rise 3 feet overall by 2100. But those three feet will be distributed differently throughout the world, and studying that distribution is pretty complicated. There's the impact of the geoid and of gravity from large ice sheets, but winds and water circulation, water temperature, salinity, meltwater from ice sheets, rainwater runoff, and land changes all leave their marks.
Some of these changes redistribute water (ex. geoid), others add to the volume of seawater (ex. temperature increases), and still others modify the land's height relative to the water (ex. land changes, such as sedimentation and oil extraction). Some changes leave a lasting impact (ex. meltwater from glaciers), while others can vary by the hour or the season (winds).
By developing this most-accurate-to-date geoid and ocean circulation model, researchers have created a picture of sea level at its natural state and modeled some of the processes that alter that state, so that we have a reference point for understanding many of the less-defined factors in sea level rise. And that, my friends, will help us better anticipate and plan for the changes ahead.
Plus it's just kinda cool to see how the Earth is really shaped, huh?
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?
It's a world leader in clean energy investment and clean coal research and development. Last year, it manufactured a third of the world's solar panels and wind turbines, and it's luring companies from all over the world to build factories there. It has recently made huge investments in clean energy education. But it's not America.
Courtesy Jude Freeman
The country I'm describing is China. That's right--the world's newly-dubbed largest net emitter of greenhouse gasses. It isn't bound by reduction requirements under the Kyoto protocol, and its use of fossil fuels is powering a growing and booming economy. And yet, the Chinese are courting US companies with financial incentives to build clean tech factories and research centers in China. They're working to corner clean tech markets in California and South Africa. In fact, over the last three years, China has gone from controlling 2% of California's solar market to a whopping 46%--ousting its American competitors. And that's not all--the country has become a proving ground for clean coal with the guidance of US companies and researchers.
These companies hope to learn from their experiences testing clean coal tech in China, and bring that knowledge back to the US to transform our own polluting coal plants into next-generation powerhouses. So what's in it for the Chinese? They're quickly gaining lead on the cutting edge in green technology, making room for growth in the energy sector without increasing pollution or relying on foreign imports, and reaping economic benefits--and they foresee substantial economic benefits in the future, when they could be the major supplier of green technology and research to the world.
Given the US's slowing progress on clean technologies, what do you think this will mean for our future? Should we be trying to get on top of green tech research and development? Or is it best left to others? Or are those even the right questions--will we have the best success when we pool resources with other countries?