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Posts Tagged ‘chlorofluorocarbons

“In every grain of sand there is the story of the earth”*…

 

Green sand

 

A pair of palm-tree-fringed coves form two narrow notches, about a quarter of a mile apart, along the shoreline of an undisclosed island somewhere in the Caribbean.

After a site visit in early March, researchers with the San Francisco nonprofit Project Vesta determined that the twin inlets provided an ideal location to study an obscure method of capturing the carbon dioxide driving climate change.

Later this year, Project Vesta plans to spread a green volcanic mineral known as olivine, ground down to the size of sand particles, across one of the beaches. The waves will further break down the highly reactive material, accelerating a series of chemical reactions that pull the greenhouse gas out of the air and lock it up in the shells and skeletons of mollusks and corals.

This process, along with other forms of what’s known as enhanced mineral weathering, could potentially store hundreds of trillions of tons of carbon dioxide, according to a National Academies report last year. That’s far more carbon dioxide than humans have pumped out since the start of the Industrial Revolution. Unlike methods of carbon removal that rely on soil, plants, and trees, it would be effectively permanent. And Project Vesta at least believes it could be cheap, on the order of $10 per ton of stored carbon dioxide once it’s done on a large scale.

But there are huge questions around this concept as well…

Scientists are taking a harder look at using carbon-capturing rocks to counteract climate change, but lots of uncertainties remain: “How green sand could capture billions of tons of carbon dioxide.”

* Rachel Carson

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As we contemplate carbon, we might send airy birthday greetings to F. Sherwood Rowland; he was born on this date in 1927.  A chemist whose research focused on atmospheric chemistry and chemical kinetics, he is best-remembered for his discovery that chlorofluorocarbons contribute to ozone depletion– for which he shared the 1995 Nobel Prize for Chemistry.

F._Sherwood_Rowland source

 

“Civilization is a race between disaster and education”*…

 

pre-human

 

One of the creepier conclusions drawn by scientists studying the Anthropocene—the proposed epoch of Earth’s geologic history in which humankind’s activities dominate the globe—is how closely today’s industrially induced climate change resembles conditions seen in past periods of rapid temperature rise.

“These ‘hyperthermals,’ the thermal-maximum events of prehistory, are the genesis of this research,” says Gavin Schmidt, climate modeler and director of the NASA Goddard Institute for Space Studies. “Whether the warming was caused by humans or by natural forces, the fingerprints—the chemical signals and tracers that give evidence of what happened then—look very similar.”

The canonical example of a hyperthermal is the Paleocene–Eocene Thermal Maximum (PETM), a 200,000-year period that occurred some 55.5 million years ago when global average temperatures rose by 5 to 8 degrees Celsius (about 9 to 14 degrees Fahrenheit). Schmidt has pondered the PETM for his entire career, and it was on his mind one day in his office last year when the University of Rochester astrophysicist Adam Frank paid him a visit.

Frank was there to discuss the idea of studying global warming from an “astrobiological perspective”—that is, investigating whether the rise of an alien industrial civilization on an exoplanet might necessarily trigger climate changes similar to those we see during Earth’s own Anthropocene. But almost before Frank could describe how one might search for the climatic effects of industrial “exocivilizations” on newly discovered planets, Schmidt caught him up short with a surprising question: “How do you know we’re the only time there’s been a civilization on our own planet?”

Frank considered a moment before responding with a question of his own: “Could we even tell if there had been an industrial civilization [long before this one]?”

Their subsequent attempt to address both questions has yielded a provocative paper on the possibility Earth might have spawned more than one technological society during its 4.5-billion-year history. And if indeed some such culture arose on Earth in the murky depths of geologic time, how might scientists today discern signs of that incredible development? Or, as the paper put it: “If an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today?”…

The entire fascinating piece at “Could an Industrial Prehuman Civilization Have Existed on Earth before Ours?

* H. G. Wells

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As we ponder predecessors, we might recall hat it was on this date in 1974 that Nature published a paper by F. Sherwood Rowland documenting his discovery that chlorofluorocarbons (like freon in aerosols and refrigeration units) contribute to ozone depletion.

MINOLTA DIGITAL CAMERA source

 

Written by LW

September 25, 2019 at 1:01 am

“Summer will end soon enough”*…

 

As temperatures across the globe continue to rise, one might look to areas accustomed to extreme heat for tips on how to cope…

More helpful hints at “Genius/bizarre/insane methods of beating the summer sun- Vietnam style.”

[Vietnamnet.vn, via Dangerous Minds]

* George R.R. Martin, A Game of Thrones

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As we search for shade, we might recall that it was on his date in 1934 that Thomas Midgley and a team of scientists working for Charles Kettering at GM’s Dayton Research subsidiary filed for a set of patents covering the use of chlorofluorocarbons (CFCs)– specifically, Freon– in refrigeration (and ultimately, air conditioning and aerosols).  Midgley had earlier developed the tetraethyllead (TEL) additive to gasoline– that is, leaded gas– an effort from which he contracted lead poisoning.

While both of these inventions have been effectively banned for their contributions to climate change, they were celebrated in their time.  Indeed, in 1941 Midgley was awarded the Priestley Medal (the American Chemical Society’s highest honor).

 source

 

Written by LW

July 31, 2015 at 1:01 am

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