One source of nitrogen dioxide is the tailpipe of your car (Source: Jensbn at Wikimedia Commons)
The Environmental Protection Agency wants to make
the limit on nitrogen dioxide tighter. It’s a
pollutant that’s emitted by power plants, and we
all spew it from our cars’ tailpipes. Rebecca Williams
has more:
Transcript
The Environmental Protection Agency wants to make
the limit on nitrogen dioxide tighter. It’s a
pollutant that’s emitted by power plants, and we
all spew it from our cars’ tailpipes. Rebecca Williams
has more:
Nitrogen dioxide is bad stuff. It’s part of smog and it can trigger asthma attacks and other serious lung problems.
Bonnie Holmes-Gen is with the American Lung Association.
“People can have effects from exposure to nitrogen dioxide for even 30 minutes to an hour. This exposure is particularly harmful to anyone with asthma or other lung illnesses.”
There’s already a national standard for long-term exposure to nitrogen dioxide.
EPA wants to set a national standard for short-term exposure. And the American Lung Association thinks that’s great, but they want the long-term standard to be even tighter.
A tighter standard will mean cutting back on smokestack emissions and tailpipe pollution… and that’s always a tough sell.
The coal industry hopes the federal government will help them find a way to catch and store the carbon coming from smokestacks.
The coal industry got hit with expensive
pollution restrictions almost two decades ago. Now, the government’s considering putting a price on carbon dioxide emissions that cause global warming. Coal companies think they have a technological solution in a test project called FutureGen. In the
second part of our series on the future of coal, Shawn Allee looks at why they
have such high hopes for it:
Transcript
The coal industry got hit with expensive
pollution restrictions almost two decades ago. Now, the government’s considering putting a price on carbon dioxide emissions that cause global warming. Coal companies think they have a technological solution in a test project called FutureGen. In the
second part of our series on the future of coal, Shawn Allee looks at why they
have such high hopes for it:
The last time the federal government put a price on coal pollution was in 1990.
Power plants had to start paying for sulphur dioxide that came out of smoke stacks and caused acid rain.
To clean up, many burned cleaner coal.
That was bad news for Illinois miner Chris Nielsen.
He happened to mine some of the dirtiest coal.
“A good portion of the economy around here was built on coal industry. And coal mining jobs not only paid a good wage, they had terrific benefits. And as the industry went soft, people lost the best jobs they ever had.”
Cleanup technology improved, but it took nearly two decades to make burning the highest-sulpher coal economical again.
Nielsen says today, coal executives worry they’ll lose profits if the government prices carbon dioxide.
And coal miners worry they’ll lose jobs again.
The industry wants new plants that do two things: first, they capture carbon dioxide while burning coal, and then bury, or sequester this carbon dioxide – so it stays out of the atmosphere.
Nielsen says there’s a plant like that in the works, it’s called FutureGen.
“We can burn the coal in a clean, environmentally friendly manner. The FutureGen project where they were going to sequester the carbon dioxide was a terrific opportunity to show that.”
Well, Nielsen’s jumping the gun.
FutureGen hasn’t proved anything; it’s not even built.
The coal industry and the government were supposed to design and fund FutureGen, then build it in Central Illinois.
The government and coal companies fought over how much the plant would cost but now, it’s likely to move forward.
Even with a sketchy history though, the industry’s got almost no choice but to be hopeful for FutureGen.
The industry wants carbon dioxide capture and sequestration to work – otherwise, it’s gonna pay big for carbon pollution.
Not everyone’s so confident in the technology.
“We can not depend on carbon capture and sequestration to achieve greenhouse gas emissions reductions because we don’t know whether it’s going to work.”
That’s Ron Burke, with the Union of Concerned Scientists.
He says FutureGen is worth testing but it shouldn’t distract us from technology we know is low-carbon.
“There are ways to meet the greenhouse gas reductions targets that we need to meet without carbon capture and sequestration. We can do it, it’s primarily through in investing in renewable energy and energy efficiency in the near term.”
There’re energy researchers who aren’t so sure enough renewable energy like wind and solar will be available soon enough.
One is of them is Ernest Moniz at MIT.
“We have a ways to go for let’s say, solar, to scale up. Right now, it’s less than point 1% of our electricity.”
Coal generates nearly half our electricity.
Moniz says it won’t be easy to replace, but it might be possible to improve it.
He says its likely carbon dioxide capture and sequestration can work technically.
But he says we need to build FutureGen to answer whether it works efficiently and economically.
“Well, if we are going to establish a new technology, like sequestration, and be able to have it not only demonstrated but then deployed and implemented, that means we would need to start, preferably yesterday, but at worst, today.”
For Moniz, FutureGen could be clean coal’s first major test – not just of whether it works – but whether it’s too expensive.
Engineering Professor Rich Axelbaum studies his "oxy-coal combustor," a device he hopes could someday trap CO2 in coal-fired power plants. (Photo by Matt Sepic)
The device has not yet been adapted to an industrial scale, and researchers are not whether the CO2 it would capture could be stored underground indefinitely. (Photo by Matt Sepic)
The combustor burns the coal with pure oxygen, rather than in the air. (Photo by Matt Sepic)
Coal has a reputation as a sooty, dirty fuel. More recently, environmentalists and the coal industry alike have become just as worried about the carbon dioxide released when coal is burned. In the third part of our series on the future of coal, Matt Sepic has this look at the science behind so-called “clean coal”:
Transcript
Coal has a reputation as a sooty, dirty fuel. More recently, environmentalists and the coal industry alike have become just as worried about the carbon dioxide released when coal is burned. In the third part of our series on the future of coal, Matt Sepic has this look at the science behind so-called “clean coal”:
As far as most leaders of the coal industry are concerned, the debate about global warming is over. It exists, carbon dioxide contributes to it, and it’s a crisis. But as they’re quick to point out, nearly half the nation’s electricity comes from coal. It’s domestic. It’s relatively cheap. And there’s a lot of it.
Steve Leer is the CEO of Arch Coal. Leer says unless Americans want that power to get really expensive, coal will have to remain part of the equation. But he says something has to be done about all that carbon dioxide.
If we don’t solve that CO2 question, the backlash of high cost electricity becomes an issue for all of us.
Arch Coal is the nation’s second largest coal producer. It’s paying for research into carbon capture and storage. The idea is to divert CO2 from smokestacks, compress it, and then pump it underground.
Engineering professor Rich Axelbaum is studying this with money from Steve Leer’s company. In his lab at Washington University in St. Louis, Axelbaum and two students are tweaking a device they call an oxy-coal combustor.
RA: “It’s a relatively small scale, quite a small scale for industrial, but it’s a relatively large scale for a university.”
MS: “It looks like a few beer kegs stacked end to end and welded together.”
RA: “Right, right.”
Axelbaum can burn coal inside this furnace along with a variety of combustion gases. He’s trying to figure out exactly how much oxygen to inject to yield pure carbon dioxide.
“We can capture the CO2 from a combustion process, by instead of the burning the coal in air, you’re burning it in oxygen, so the stream coming out of the exhaust is CO2.
Axelbaum says there’s no sense in filling valuable underground storage space with CO2 mixed with other gases if a power plant is built that can grab nearly pure carbon dioxide and store it.
He says energy companies already pump CO2 underground to extract crude oil, so some of the technology already exists. But environmentalists say the next step – which is crucial for any so-called clean coal power plant to work– is far from proven.
“No one knows in the industry whether in fact they can sequester carbon permanently.”
David Orr teaches Environmental Science at Oberlin College in Ohio. He says storing CO2 underground is easier said than done. And nobody knows if rock formations in different parts of the country can hold the huge amounts of carbon dioxide America’s power plants produce without it eventually leaking out.
Orr says because the goal is to reduce global warming, politicians would be better off funding research into other energy alternatives.
The metric here is how much carbon do we eliminate per dollar spent on research and deployment of technology?
Orr says the 3.4 billion dollars set aside for clean coal research in the federal stimulus bill would be better spent studying wind and solar power, modernizing the nation’s electrical grid, and finding ways to improve energy efficiency.
But the United States still has more than a century’s worth of coal reserves. And with plenty of money going into both research and advertising, talk of carbon capture and storage is certain to continue, even if it remains just that.
Artist's concept of the Orbiting Carbon Observatory. The satellite crashed into the ocean on Tuesday, February 24th, 2009.
(Photo courtesy NASA Jet Propulsion Library)
(NOTE: THE SATELLITE FEATURED IN THIS STORY CRASHED INTO THE OCEAN ON TUESDAY, FEB. 24TH)
Drive your car. Mow your lawn. Heat your house. It all puts climate changing carbon dioxide in the atmosphere. But not all of the carbon dioxide stays up there. Vincent Duffy reports scientists at NASA hope a new satellite will help them solve the mystery of where some of that CO2 goes:
Transcript
(NOTE: THE CARBON SATELLITE CRASHED INTO THE OCEAN ON TUESDAY, FEB. 24TH)
Drive your car. Mow your lawn. Heat your house. It all puts climate changing carbon dioxide in the atmosphere. But not all of the carbon dioxide stays up there. Vincent Duffy reports scientists at NASA hope a new satellite will help them solve the mystery of where some of that CO2 goes:
People worried about climate change pay a lot of attention to carbon dioxide.
It’s one of the chief causes of climate change. And people put a lot of carbon
dioxide in the atmosphere, almost 8 billion tons a year.
That has former Vice President Al Gore worried. Here he is testifying before
Congress last month –
“Our home, earth, is in danger. What is at risk of being destroyed is not the
planet itself of course, but the conditions that have made it hospitable for
human beings.”
If we are in danger, then scientists need a good handle on what happens to
all that carbon dioxide.
About half of the CO2 created by humans is absorbed back into the earth by
what scientists call ‘carbon sinks.’ Scientists know half of the absorbed
carbon dioxide goes into the oceans, and the other half is sucked up by
plants. But scientists don’t know which plants are absorbing the most carbon
dioxide, and how the CO2 travels there.
The scientists at NASA hope a new satellite, called the Orbiting Carbon
Observatory, will help them answer those questions.
David Crisp heads up the project. He says measuring carbon dioxide levels
from the ground doesn’t provide enough information to know where the
CO2 actually ends up.
“But from space we can actually make much more detailed measurements,
make a snapshot of the carbon dioxide distribution in the atmosphere. That
will give us much more information about where the carbon dioxide is and
from that we can infer where the sources are and where the sinks are.”
Right now it’s a bit of a blur. Anna Michalak is a professor at the University
of Michigan and part of the NASA team. She says to track what’s going on
with all the CO2 on the earth is like trying to figure out how cream went into
a cup of coffee.
“If I give you a cup of coffee, and I pour cream into the cup of coffee, and I
ask you what’s going to happen when I start stirring, it’s pretty easy to
predict that you’ll have a creamy cup of coffee. But what we do instead is
someone hands us a creamy cup of coffee and asks us, ‘Did we pour the
cream in on the left side or the right side, and did we pour the cream in five
minutes ago or ten minutes ago?’ And you can imagine that’s a much more
difficult question.”
Michalak says the satellite observatory will help answer that difficult
question, and help us understand how plants may react to carbon dioxide in
the future, as the earth’s climate changes. She says right now plants seem to
be absorbing more CO2 than ever before.
“And we have no guarantee that this is going to continue in the future. And
so you can imagine that something that has such a high value, there is an
interest in us knowing how predictable and how reliable this service is to us.
Because the cost for us to replicate anything resembling that is just
astronomical.”
The satellite will also answer other questions about climate change. Things
like which countries emit the most CO2.
Jiaguo Qi studies climate change at Michigan State University. He says the
satellite may show that people concerned about the cost of reducing green
house gasses may unfairly blame the United States and other developed
nations.
“Media report that North America is primarily responsible for global
warming. But we don’t know how much carbon dioxide other countries are
emitting, because we donít have good measure. This one will tell us who is
emitting and how much they are emitting instead of just blaming us.”
And the data from the Orbiting Carbon Observatory might show that it’s not
just the forests and jungles that help keep climate change at bay. It might
also be forests and farmland in the United States, and your lawn, and even
golf courses.
Corn-processing giant Archer Daniels Midland creates excess carbon dioxide while brewing ethanol and other alcohols from corn. The company is donating carbon dioxide from a plant in Decatur, Illinois. Scientists will bury the CO2 deep underground and test whether the local rock can hold it there indefinitely. If it can, the government may encourage coal-fired power plants and other carbon sources to sequester their carbon underground. (Photo by Shawn Allee)
One of the cheapest, easiest ways to make
electricity in America is to burn coal, but there’s
this little problem of global warming. The coal power
industry is a major offender because burning coal
gives off carbon dioxide, the main greenhouse gas.
It’s enough to make you think – should we burn coal at all?
Shawn Allee reports some scientists hope to prove
we can put coal emissions out of sight, out of mind:
Transcript
One of the cheapest, easiest ways to make electricity in America is to burn coal. But there’s this little problem of global warming. The coal power industry is a major offender… because burning coal gives off carbon dioxide – the main greenhouse gas. It’s enough to make you think – should we burn coal at all? Shawn Allee reports some scientists hope to prove we can put coal emissions out of sight, out of mind:
A big part of our global warming problem starts right in coal country. Recently, I recorded this coal train leaving a coal mine, destined for some power plants.
(sound of coal train)
It was a long train … and across the country, hundreds like it run constantly. The coal power industry generates half our electricity. And that’s responsible for nearly forty percent of the carbon dioxide, or CO2, we chuck into the atmosphere.
Well, wouldn’t it be great if we could reverse some of this? So, when we pull coal out of the Earth and then burn it … we could just send some of the carbon dioxide gas underground?
That’s getting tested by scientists.
I found one.
ALLEE: “What’s your name, sir?”
FINLEY: “Robert Finley. I’m the director for the center for energy and earth resources at Illinois State Geologic Survey.”
Finley wants to take carbon dioxide and bury it deep under the town of Decatur, Illinois.
He says the rock has to be just right.
One layer needs to absorb the carbon dioxide, while other rock has to keep it put.
“In order for the CO2 to remain in the subsurface, to not leak back in the atmosphere, we have to have an excellent seal.”
Finley calls this geological carbon sequestration, and he says it’s worked … in small tests. His experiment and six others across the country are much larger. Finley says the technology is promising, but needs testing.
“Decatur involves two years of characterizing the site and drilling wells before we even inject CO2. Three years of CO2 injection, then two more years of study of the site. So, that in total is a seven year effort.”
Again, he’s gotta make sure the carbon dioxide stays underground … and that it won’t hurt water or other underground resources. But while Finley experiments, coal plants continue to dump CO2 into the atmosphere. That’s got some environmental groups a little impatient.
“The best way to avoid emissions from burning coal is to not burn it in the first place.”
This is Ron Burke, the Midwest Director for The Union of Concerned Scientists.
“We can meet most of our energy needs by substantially increasing the use of energy efficiency and renewable energy.”
Allee: “But when you listen to Mr. Obama and Mr. McCain, it seems that both of these candidates seem to want to make it work, when Mr. Finley and others doing work on the ground say I won’t even have my data until 2014.”
Burke: “It’s clear that a lot of elected officials share this aspirational goal to commercially develop so-called clean-coal technology. But right now we can’t depend on it. We shouldn’t be developing plans to mitigate greenhouse gases assuming that technology’s going to be available.”
Geologist Robert Finley says we cannot rely on carbon sequestration exclusively.
Even if CO2 can stay underground forever, there’s no guarantee we can afford to send it there.
“One could argue we should have been doing this five years ago or earlier, but we can’t go forward and simply drill a well next year and move forward without these kinds of studies, because that would be reckless in my view.”
Finley doesn’t apologize for the pace of science.
He says he’s confident it can answer questions about carbon sequestration…. he just hopes it’s in time to make a difference for the global warming problem.
Memorials to miners and past mining disasters dot the public spaces in rural
parts of southern Illinois. This granite obelisk is in honor of mining near
West Frankfort, which is in the heart of Illinois coal country, and close to
several operating mines. In 1980, Illinois had 18,000 coal miners - now, the
workforce is less than 4,000. Mining experts say new digging permits, new hires
and new investment in Illinois coal signals a comeback, though it's unclear
mining employment will reach former heights. (Photo by Shawn Allee)
John Mead directs the Center for Clean Coal Research at Southern Illinois
University. Mead says the probable comeback of Illinois' coal industry
hasn't fully materialized yet, but he agrees with industry experts who say
cleaner-burning coal-fired power plants are creating a new market for the
state's high-energy resource. By the way, the coal nugget in his palm is the
only coal he could find in his office. (Photo by Shawn Allee)
The exit at an operating mine near Galatia, Illinois. (Photo by Shawn Allee)
This coal fired power plant sits at the corner of the SIU campus in Carbondale,
Illinois. It's built sulfur scrubbers and other technology that allow it to use Illinois coal. (Photo by Shawn Allee)
America has a love-hate relationship
with coal. We burn coal to make half our
electricity, but we’re always fighting coal’s
air pollution. Some regulations decimated
the coal industry in one key state. Shawn
Allee reports miners there are caught
between a slow comeback and another round of
regulation:
Transcript
America has a love-hate relationship
with coal. We burn coal to make half our
electricity, but we’re always fighting coal’s
air pollution. Some regulations decimated
the coal industry in one key state. Shawn
Allee reports miners there are caught
between a slow comeback and another round of
regulation:
Coal was once king of the Southern Illinois economy, but no longer.
Nathan Threewitt lives in the area. He explains mining jobs evaporated.
Nathan Threewitt: “Eighteen years ago, give or take a couple, people went from
making a nice, upper-class living to nothing at all. Couldn’t find work, everybody
had to move.”
Shawn Allee: “Did you have that happen in your own family?”
Threewitt: “Yep. My dad’s got ten brothers and sisters. They went from, everybody
had clothes for school, everybody had food to eat, to, we don’t know how the hell it
was gonna happen.”
Even though Threewitt has a tough history with coal – he’s actually trying to get into the
industry.
In fact, I find him while he’s taking a break from a coal mining training class at Rend
Lake College.
I know at one time, classes like these had been canceled.
I track down instructor David Colombo to see what’s changed.
David Colombo: “This room is where I train miners for the most part.”
Shawn Allee: “What’s this?”
Colombo: “Ugh. This is a high voltage cable.”
Allee: “This is almost as thick as your arm.”
Colombo: “This isn’t the biggest of the bigs, either.”
Right now, only about four thousand Illinois miners need to be familiar with equipment
like this.
But Colombo gets calls from mining companies in the area who need trained workers.
So, his school’s growing to keep up.
Shawn Allee: “Why have faith that you’re going to need space for miners to be
trained?”
David Colombo: “With the mining permitting that’s going on, is the highest it’s been
in thirty years.”
Colombo: “Gentlemen in this afternoon’s class will start sinking a mine within the
next week or two. Right now it just employs ten people, but in a year from now, that
same mine’s probably going to employ a hundred and ten people.”
People use words like rebound and comeback when they describe the Illinois coal
industry.
To understand what happened, you have to dial back a little.
“It was really the effect of Clean Air Act amendments of 1990.”
This is John Mead. He heads coal research at Southern Illinois University.
He says Illinois coal is blessed with high energy, but it’s cursed with sulfur that caused
acid rain and lung disease. The amendments aimed to cut that.
“Most utilities were able to switch to lower-sulfur coal, and that’s just what they
did.”
In fact, utilities opened new mines out West where the coal has less sulfur.
As for an Illinois coal turn-around?
“Today, sulfur and other materials in the coal can be controlled pretty effectively
with technology.”
So, now Illinois coal can better compete with lower-sulpher coal.
But here’s the thing. There could be another pollution clamp-down in the works.
You know about global-warming, right? Well, carbon dioxide’s a big cause, and coal
produces carbon dioxide in spades.
Scientists say cutting coal emissions would be a quick way to cut carbon.
So, miners in Southern Illinois get mixed messages – the country wants their coal again,
but maybe not for long.
Miner-to-be Nathan Threewitt says he’s thought this through.
Nathan Threewitt: “Well, if anybody looked at the economics of it, it’s gonna go
back. Coal used to be fifteen dollars a ton, it’s now 65 dollars a ton. You’re gonna
have these coal companies with coal left in the ground, it used to not be worth it to
get the money out, now it’s worth it.”
Shawn Allee: “You like those odds.”
Threewitt: “Yeah, I do. I’m rolling the dice on it.”
Threewitt figures, he’s got time to build a career from coal, while America makes up its
mind just how clean it wants its coal-fired electricity.
The EPA is looking into storing CO2 emissions underground (Photo by Lester Graham)
The US Environmental Protection
Agency is looking at ways to make sure
carbon dioxide can be stored underground.
The agency is proposing rules that would
keep CO2 from seeping out of the ground or
cause problems for ground water. Chuck
Quirmbach reports:
Transcript
The US Environmental Protection
Agency is looking at ways to make sure
carbon dioxide can be stored underground.
The agency is proposing rules that would
keep CO2 from seeping out of the ground or
cause problems for ground water. Chuck
Quirmbach reports:
Some coal-fired power plants are looking into storing their carbon dioxide emissions
underground.
If the system works, it’d be a way to slow down climate change.
But EPA water administrator Ben Grumbles says injecting large volumes of CO2
to underground storage wells is a concern. So, he says the proposed rule calls for
extensive testing and monitoring.
“So that the CO2 doesn’t migrate. If it did, it could also push other fluids, like
salts, into that underground source of drinking water.”
Grumbles says if there was contamination, companies could be ordered to stop
injecting the gas. He says the rule also aims to make sure the CO2 doesn’t seep
from the ground into the air.
The EPA will take comments on its proposed rule until mid-November.
Researchers have found that the Pacific Ocean is becoming increasingly acidic as a result of CO2 emissions (Photo by A. Kalvaitis, courtesy of NOAA)
The Pacific Ocean is becoming more acidic.
The corrosive water could start dissolving shells
and coral. The problem is largely caused by carbon
dioxide emitted by cars and power plants. As Ann
Dornfeld reports, researchers say the problem is
happening faster than they expected:
Transcript
The Pacific Ocean is becoming more acidic.
The corrosive water could start dissolving shells
and coral. The problem is largely caused by carbon
dioxide emitted by cars and power plants. As Ann
Dornfeld reports, researchers say the problem is
happening faster than they expected:
Scientists have known for a long time that the world’s oceans are becoming corrosive
from so much man-made CO2. Carbon dioxide dissolves into the ocean, and forms
carbonic acid.
The corrosive water is concentrated in deep, cold parts of the ocean. Scientists had
predicted it would approach the vulnerable coastal zones in about a century. So they
were alarmed to find the acidity just a few miles off the California coast.
Burke Hales is a chemical oceanographer. He says this corrosive water could break
down the calcium carbonate in coral and shells.
“So we’re talking about things like barnacles and oysters and mussels and
clams. And some planktonic organisms form calcium carbonate shells, as well.”
Researchers say the acidification approaching the coasts is from CO2 that was emitted
50 years ago. That means we’re just at the start of increasingly acidic oceans.
The Great Lakes region is home to major power producers. But along with the electricity they make comes some amount of air pollution. When coal-fired power plants in Illinois and Ohio emit sulfur dioxides, prevailing winds blow them to the Northeast, where they can fall as acid rain. Several northeast states are suing those power plants to clean up their emissions. Earlier this summer, a professor at Clarkson University in northern New York coordinated a unique study to learn more about the life cycle of air pollution, from where it’s produced to where it lands. The Great Lakes Radio Consortium’s David Sommerstein has the story:
Transcript
The Great Lakes region is home to major power producers. But along with the electricity they make comes some amount of air pollution. When coal-fired power plants in Illinois and Ohio emit sulfur dioxides, prevailing winds blow them to the Northeast, where they can fall as acid rain. Several northeast states are suing those power plants to clean up their emissions.
Earlier this summer, a professor at Clarkson University in northern New York coordinated a unique study to learn more about the life cycle of air pollution, from where it’s produced to where it lands. The Great Lakes Radio Consortium’s David Sommerstein has the story.
Chemical engineering professor Phil Hopke will take any opportunity to get out of his office and over to his field lab. It consists of a concrete slab amongst the weeds in a corner of the local airport. Installed on the concrete are monitors he uses to find out exactly what’s in the air we breathe.
(sound of opening lock)
Hopke unlocks a gate in a chainlink fence. You can already hear a strange hum in the distance. It gets louder as Hopke strides up to one of three white machines the size of dishwashers.
“Come out and change the filters once a day. This one’s for organic constituents in the air.”
He pulls out what looks like an air filter for your furnace. These machines suck in air. They leave a unique footprint of chemicals on the filter that represents what was in the air in this place on this day — chemicals like sulfur dioxide and mercury. Hopke will send these filters to specialty labs around the world to be analyzed.
There are hundreds of stations like this in North America. Groups of researchers study daily air quality for every region of the country. They examine how things like traffic and smokestacks might affect the air we breathe.
But Hopke says they mostly focus on their own areas. They don’t often coordinate studies to see how the chemicals they find move from region to region.
“It struck me a couple of years ago, particularly in the Northeast, that we have these groups talking to one another.”
Working with the U.S. Environmental Protection Agency, Hopke convinced 26 sites in the East, from Texas to Toronto, to measure the same stuff on the same days. They chose the whole month of July.
It’s perhaps the largest simultaneous air sampling effort ever conducted in this country. When the data’s complete, the study will track the lifespan of pollution, from when it leaves a smokestack or a car’s tailpipe to when it is taken up by a tree or your lungs.
But scientists can’t just follow one molecule of pollution from a car in St. Louis to a lake in Michigan. They have to make models of how the chemicals move, like how meteorologists make weather maps to trace storm systems. As if that’s not complicated enough, says Hopke, naturally occurring chemicals make the job even tougher.
“You have to keep in mind that the Blue Ridge Mountains in Virginia are blue because of natural photochemical smog, particles being formed because of the pine materials that come off. Those materials that you smell are chemically reactive and will undergo the same type of smog reactions as human emitted materials.”
So researchers use techniques to separate out the “man-made” pollutants from the “natural” pollutants. Next they look for high concentrations of, say, sulfur dioxide in Chicago on July 15th. Then they follow those high levels east with prevailing winds. They look for high sulfur dioxide levels in Ohio or New York a few days later. After doing this many times in July for many types of chemicals, the researchers hope patterns will begin to emerge.
Hopke sits on a scientific advisory committee that helps the EPA develop pollution standards. He says this coordinated study will bring stronger science to the EPA’s sometimes controversial decisions.
“Suppose I require all power plants to reduce their sulfur dioxide emissions by twenty percent. What does that do for me for particle concentrations in New York City? What will that do? Will that get us where we want in terms of clean air?”
With a study this large in scope, the answers to those questions won’t come quickly. The massive amount of data gathered in the study will take a few years to interpret.
In the meantime, Hopke and the EPA are planning another cooperative sampling effort for wintertime, when temperatures and people’s habits are different from summer.
For the Great Lakes Radio Consortium, I’m David Sommerstein.
Emissions from power plants in the Midwest are still causing acid
rain in the eastern United States. The Great Lakes Radio Consortium’s
Lester Graham reports:
One source of nitrogen dioxide is the tailpipe of your car (Source: Jensbn at Wikimedia Commons)
