Stories tagged air pollution

It is estimated that two-thirds of sulfur dioxide (SO2) air pollution in North America comes from coal power plants. In a recent scientific article published in Geophysical Research Letters, a team of scientists have confirmed that SO2 levels in the vicinity of U.S. coal power plants have fallen by nearly 50% since 2005. .Mean SO2 values for 2005-2007
Mean SO2 values for 2005-2007Courtesy NASA
This finding, using satellite observations, confirms ground-based measurements of declining SO2 levels. In many parts of the world, ground-based monitoring does not exist or is not extensive; therefore, the Ozone Monitoring Instrument (OMI) on the Aura satellite could potentially measure levels of harmful emissions in regions of the world where reliable ground monitoring is unavailable..Mean SO2 values for 2008-2010
Mean SO2 values for 2008-2010Courtesy NASA
Key: Yellow to violet colors correspond to statistically significant enhancements in SO2 pollution in the vicinity of the largest SO2 emitting coal-burning power plants indicated by the black dots.
Key: Yellow to violet colors correspond to statistically significant enhancements in SO2 pollution in the vicinity of the largest SO2 emitting coal-burning power plants indicated by the black dots.Courtesy NASA

Previously, space-based SO2 monitoring was limited to plumes from volcanic eruptions and detecting anthropogenic emissions from large source regions as in China. A new spatial filtration technique allows the detection of individual pollution sources in Canada and the U.S.

"What we’re seeing in these satellite observations represents a major environmental accomplishment," said Bryan Bloomer, an Environmental Protection Agency scientist familiar with the new satellite observations. "This is a huge success story for the EPA and the Clean Air Interstate Rule," he said.

Article: NASA Satellite Confirms Sharp Decline In Pollution From US Coal Power Plants

May
19
2010

Kudzu: A kudzu infestation of a wooded area near Port Gibson, Mississippi. Note that the kudzu has completely overgrown several of the trees in this picture.
Kudzu: A kudzu infestation of a wooded area near Port Gibson, Mississippi. Note that the kudzu has completely overgrown several of the trees in this picture.Courtesy Gsmith
Chances are good that if you're reading this post from North of Kentucky or West of Louisiana, you've never heard of kudzu. Down here in Charlotte and the rest of the Southeast, we're very, very familiar with this plant.

Kudzu is an invasive species of vine indigenous to Japan and parts of China. As with many invasive species, kudzu was brought to America as a problem solver. Kudzu grows exceptionally fast, does a great job preventing erosion, and can be used as a feed for animals like goats and sheep. Humans can even eat kudzu flowers in the form of jelly.

Unfortunately, the growth of Kudzu soon spun out of control. With no natural consumer or pest to keep population in check, the fast growing plant began to spread, strangling trees and entire fields of low lying plants in its way. Today, the entire Southeast United States is effected, with no real solution available.

Well, a recent study by scientists from The Earth Institute at Columbia University just added another entry to the list of reasons to pull out the industrial sized weed-whacker: air pollution.

Another reason kudzu was so sought after is its ability to take nitrogen from the air and introduce or "fix" it into the soil. There, microbes turn the nitrogen into fertilizer for other plants. Huge mats of kudzu are so good at fixing nitrogen that they're upsetting the chemical balance of the ecosystem, which in turn results in increased levels of hazardous ozone gas.

Using the data they collected near areas of dense kudzu growth, the team of scientists were able to predict that in an extreme scenario, kudzu growth could contribute heavily to ozone warning days in the vicinity.

For lots more information about kudzu infestation and control, check here.

Apr
23
2009

An environmentalist's dream: The rat-filled cans are too small to see in this picture.
An environmentalist's dream: The rat-filled cans are too small to see in this picture.Courtesy steven.buss
Here at Science Buzz, we sometimes have what might seem like a Through the Looking Glass attitude towards Earth Day and environmentalism. I, for one, litter filthy old cans all over my yard, comfortable in the knowledge that these cans will provide wonderful little shelters for the population of rats in my neighborhood. Sort of counter-intuitive, huh? Well check this out: after I get rats living in those cans, I’m going to use highly toxic chemicals to poison the little suckers in their homes. I will then plant sunflower seeds in my dead rat filled cans. So litter + poison + patience = a beautiful garden + delicious sunflower seeds.

Sophisticated environmentalism can be complicated like that.

It feels good though, doesn’t it? A little weird, but good.

Here’s another one (and this one comes from scientists who published in the journal Nature, not just from, you know, me):
Air pollution is fighting global warming!

Say what? We thought global warming was caused by air pollution.

Yes, but… think back to flowers growing from cans of dead rats. It’s like that, kind of.

See, yes, air pollution in the form of carbon dioxide (and other gases, but we’re dealing with CO2 here) is warming the planet. But CO2 isn’t the only junk we’re burping up into the atmosphere. Think about the grey brown haze you see over some big cities. Co2 is invisible, so what’s that stuff? Some of the chemicals we put into the atmosphere have the effect of absorbing sunlight, or reflecting it back into space. Some particles form the nucleus of water droplets in clouds, and cause the same amount of water in a cloud to be spread out among a much larger number of droplets, and more droplets cause light to be reflected and scattered more. It’s all part a phenomenon sometimes referred to as “global dimming”.

Some scientists believe that “global dimming” has had the effect of partially masking global warming; we aren’t as warm as we might otherwise be for the amount of greenhouse gasses in the atmosphere because a significant amount of solar energy has been prevented from reaching the Earth by other pollutants. So there’s that.

The Nature article, however, focuses on something else entirely. While many people might assume that plants have a harder time growing in our pollution-dimmed world, it turns out that they actually seem to grow better under a hazy blanket of pollution. The light-scattering effect of many air pollutants actually causes light to reach more plant leaves. So more photosynthesis is taking place under this diffused light than under direct sunlight. That means that plants are growing more, and growing plants suck up more carbon dioxide.

The scientists behind the study estimate that global dimming could be responsible for as much as a one quarter increase in plant productivity from 1960 to 1999, causing a 10% increase in the amount of carbon stored by the land.

This also means that as we have stricter air pollution controls, the rate of global warming probably won’t decrease as much as we’d have thought—there’d be less CO2 in the air, but because other pollutants would be reduced as well plants would be less productive, and suck up less of the CO2 that is released.

Well, shucks.