Just label it
Genetically modified foods are an established part of American agriculture. It began in 1994 with the Flavr Svr tomato, the first genetically modified food licensed for human consumption. [Read more…] about Just label it
Methane—it’s not laughing gas.
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Methane concentrations are rising in Earth’s atmosphere, more than doubling since the beginning of the Industrial Revolution. Like carbon dioxide, methane contributes to global warming. In fact, it is 25 to 35 times more effective at warming our atmosphere than carbon dioxide. Trouble is, we’re not sure what’s causing methane levels to rise. [Read more…] about Methane—it’s not laughing gas.
Toxic mercury is poisoning songbirds
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Each year in the U.S. coal-fired utilities release some 50 tons of mercury into the air. Once emitted, the pollutant is delivered to the landscape, where it takes on its most toxic form – methylmercury – in wet ecosystems such as lakes and streams. [Read more…] about Toxic mercury is poisoning songbirds
What is an ecosystem?
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In their field studies, ecologists are often overwhelmed by the complexity of nature. Many decades ago, the ecosystem concept was developed to help organize scientific studies of the environment. An ecosystem is a subunit of nature, with easily recognized boundaries that allow scientists to measure inputs and outputs of materials from well defined areas of nature. [Read more…] about What is an ecosystem?
Hate starlings? Blame Shakespeare!
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Invasive species get to the Unites States in a variety of ways: zebra mussels arrived in the holds of ships from Europe. Many invasive insects have hitched a ride on wood shipping pallets or plants destined for the horticultural trade. Multiflora roses were brought from Asia as an attractive erosion control measure. [Read more…] about Hate starlings? Blame Shakespeare!
Pollution recognizes no political boundaries—and that includes radiation
Scientists have long recognized that many pollutants travel far from where they originated. Power plant emissions can be carried by winds to distant states, where they contribute to acid rain, ground-level ozone, or mercury in isolated lakes. That’s why some of our national parks, even though they are protected areas, have smog and haze problems.
The challenge for scientists is teasing out the sources of pollution once they have dispersed. Although some elements carry isotopic signatures, others do not; so it’s challenging to trace pollutants like lead or compounds like nitrogen oxides back to their precise source.
The earthquake and tsunami that damaged the Fukushima nuclear power plant in Japan last year provided an inadvertent demonstration of how air currents can transport pollution over long distances. Within a week of the earthquake, radioactive material was found in rainfall on the west coast of North America. It was in such small concentrations that it didn’t pose a health hazard. But the point is that, because there was no other possible source for the radioactive material, it served as a tracer. Meteorologists noted a strong jet stream over Japan in the days after the disaster; it carried the contaminants across the Pacific where they were then deposited in rainfall.
Although this fallout did not prove hazardous to Americans, the story is a sobering reminder that ocean and air currents are powerful mechanisms for moving pollution. We can’t control or regulate them. It is also a reminder that no matter how safe the nuclear power industry portrays itself to be, all of the safeguards in the world could not prevent the disaster that unfolded in Japan.
Web Link
Scientific paper on Fission-Product Isotopes from Fukushima to U.S.
http://pubs.acs.org/doi/abs/10.1021/es203217u
Photo, taken on May 20, 2007 using a Nikon Coolpix L5, courtesy of J. Brew via Flickr.
A-Rod should be worried about invasive species
Most baseball players use bats made from ash wood. It is strong, flexible, and lightweight, a perfect combination for sluggers.
But ash trees are under attack from a tiny insect. The emerald ash borer was first detected in Michigan in 2002. It is believed to have hitchhiked from its native Asia on wooden shipping materials. The iridescent green beetle lays eggs in the bark of ash trees, and when the eggs hatch, the larvae burrow into the tree. They cause damage that prevents the tree from taking up water and nutrient – so the tree usually dies within two years.
Ash borers are now in a number of states, including New York and Pennsylvania, and in Canada. It is believed that they spread within North America when people transported nursery plants or firewood from one place to another. It is now illegal to move ash firewood within or between some states and provinces.
Emerald ash borers have killed between 50 and 100 million ash trees in the North America. If they are not stopped, they could eliminate all the remaining ash trees on the continent.
Scientists are researching biological controls for the emerald ash borer. One approach is to use parasitic wasps; another approach is to use a fungus that contains an ingredient also used in some commercial pesticides. It is too early to know whether these efforts can save our ash trees. That’s why ash seed banks are also being developed.
As for baseball players, maple is also an option for wood bats, but with its shorter grain, it shatters more easily. So if you’re a baseball player or a baseball fan, you have good reason to be a treehugger.
Photo, taken on November 6, 2005, courtesy of Erik Jaeger via Flickr.
