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Scientists Call For Geoengineering Research | Earth Wise

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A group of more than 60 climate researchers has published an open letter calling for accelerated research into what is called solar radiation management.  This means changing the amount of solar energy reaching the surface of the earth by adding various substances into the stratosphere or into the clouds in order to help cool down the planet.

This form of geoengineering is controversial to say the least.  While such approaches would most likely be successful in cooling things down, such climate manipulation could have dangerous and unexpected consequences.

For their part, the scientists explicitly state that they do not support the use of solar radiation management or SRM.  Their position is that our current level of knowledge is not sufficient to accurately assess potential risks and consequences.  What they are advocating is for scientific research to be conducted to support the assessment of the potential effectiveness of various SRM techniques, to determine how these techniques would affect climate change under various greenhouse gas scenarios, and to determine the capabilities for detecting and attributing possible impacts of SRM interventions.

The letter was a response to a larger group of scientists and academics who called for a strict ban on geoengineering, saying that it could divert attention and resources from much-needed greenhouse gas reductions.  The new letter claims that gaining additional knowledge about SRM is a critical part of making effective and ethical decisions about its implementation.  They state that we have no right to ban the ability to search for a solution to the mess we created.

Opponents of such research are concerned that even pursuing it normalizes in the public eye what could potentially be a catastrophically dangerous activity.

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60 Scientists Call for Accelerated Research Into ‘Solar Radiation Management’ That Could Temporarily Mask Global Warming

Photo, posted February 11, 2006, courtesy of Janice Waltzer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Getting Rid Of Hydrogen Sulfide | Earth Wise

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Hydrogen sulfide gas produces the characteristic smell of rotten eggs, sewers, stockyards, and landfills.  The petroleum industry produces thousands of tons of the stuff each year as a byproduct of the processes that remove sulfur from petroleum, natural gas, coal, and other products.  The industry faces substantial fines for emitting hydrogen sulfide, but remediation is expensive.

Researchers at Rice University have developed a method for turning hydrogen sulfide into hydrogen gas and sulfur in a single step.  Called plasmonic photocatalysis, it not only gets rid of an undesirable substance, it does so by producing valuable byproducts.

The established way of getting rid of hydrogen sulfide is called the Claus process.  It requires multiple steps, including some that require combustion chambers heated to 1,500 degrees Fahrenheit.  The end product is sulfur and water.

The Rice University process gets all of its energy from light.  A surface of grains of silicon dioxide is dotted with tiny gold nanoparticles.  These particles interact strongly with a specific wavelength of visible light and cause plasmonic reactions that create short-lived, high-energy electrons that drive the catalysis of hydrogen sulfide.  Given that the process requires only visible light and no external heating, it should be relatively straightforward to scale up using solar energy or very efficient LED lamps.

The new hydrogen sulfide remediation technology has been licensed by a Houston-based startup company with more than 60 employees whose founders include some of the Rice researchers.  The process may end up being efficient enough and cheap enough for cleaning up non-industrial sources of hydrogen sulfide such as sewers and animal waste.

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New catalyst can turn smelly hydrogen sulfide into a cash cow

Photo, posted July 8, 2021, courtesy of Doug Letterman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mosquito Magnets | Earth Wise

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We’ve all probably had the experience of being in the great outdoors with other people and having some of them being nearly devoured by mosquitoes while others didn’t get bitten at all.  It seemed like some people are mosquito magnets while others just aren’t the insects’ cup of tea, so to speak.

There have been various theories proposed over the years including such things as it being a question of blood type, or it having to do with how close one’s blood vessels are to their skin surface.

A new study by the Howard Hughes Medical Institute and the Rockefeller University has uncovered what appears to be the real explanation.  According to the paper published in the journal Cell, certain body odors are the deciding factor.  Every person has a unique scent profile associated with different chemicals present on their skin.  The researchers found that people whose skin produces high levels of carboxylic acids are the most attractive to mosquitos.

The researchers collected scent samples from participants by having them wear silk stockings on their arms for six hours.  The nylons were then cut into pieces and the pieces exposed to mosquitos.  After several months of head-to-head battles between various nylon samples, the study clearly demonstrated that the samples from subjects with higher levels of carboxylic acids in the skin were far more attractive to mosquitos.

Humans produce the substance at much higher levels than other animals.  There is little one can do about their own levels.  Changing one’s diet or what soap they use doesn’t seem to make a difference. 

Perhaps researchers can come up with some method of breaking down carboxylic acids in the skin in the future.  Until such time, there are really people who are mosquito magnets.

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Some People Really Are Mosquito Magnets, and They’re Stuck That Way

Photo, posted September 4, 2014, courtesy of James Gathany / Centers for Disease Control via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Heat And Plastic Bottles

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In the middle of July, Americans along the East Coast and in the Midwest suffered through a massive heat wave that saw actual temperatures soaring and so-called feels-like temperatures go much higher.  The punishing heat had many of us reaching for those plastic water bottles all day long as we tried to keep hydrated.

Studies have shown that those single-use plastic bottles do not handle the heat very well.  Most plastic items release tiny amounts of chemicals into the beverages or food that they contain.   But the hotter it gets, the more the substances in plastic can move into food or drinking water.  As temperature and time increase, the chemical bonds in plastics increasingly break down and chemicals are more likely to leach.

A study at Arizona State University in 2008 looked at how heat sped up the release of the element antimony in bottles made of the common plastic PET.  Antimony is used to manufacture the plastic and can be toxic in high doses.  At mild temperatures, very little antimony is released.  But PET and other plastics can leach a variety of chemicals when exposed to higher temperatures.

According to the FDA, the amounts of chemicals released by plastics are too miniscule to cause health problems.  However, scientists are still looking at the long-term effects of using so much plastic.  The question is whether all those small doses can eventually add up to something not so harmless.  Given that we don’t really know the cumulative effect of being surrounded by plastics in the goods we buy as well as the presence of microplastics in our water, it seems like a good idea to try to limit our exposure when alternatives are available.

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Exposed to extreme heat, plastic bottles may ultimately become unsafe

Photo, posted June 7, 2013, courtesy of Tim Stahmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)