The United States Geological Survey (USGS) is warning of the dangers of carbon dioxide emissions from the mining and production of steatites, a mineral with a strong affinity for cement.
The new study by a USGS scientist and researchers at Yale University in New Haven, Connecticut, concludes that the melting of carbonates called steatitic silica, which make up a significant fraction of the American desert, can trigger serious health and environmental impacts.
The scientists, who published their results online in the journal Geology, found that the “extremely low” amount of carbonate in the American sandstone can potentially be enough to raise levels of the greenhouse gas carbon dioxide in the atmosphere by about 50%, enough to trigger the release of methane and other greenhouse gases into the atmosphere.
The carbon dioxide released by the melting process is so low that it does not cause any noticeable warming of the planet, the USGS researchers wrote in the report.
But it is an important milestone in the debate over the long-term health and sustainability of our planet, they added.
“The amount of CO2 released by melting of these silicate rocks is equivalent to about a tenth of the amount released during the combustion of coal and petroleum products,” the researchers wrote.
The findings come as coal mining continues to boom in the US, and as climate change threatens the global economy.
The industry, which produces about 4.5 million tonnes of coal annually, is a significant source of carbon emissions.
Steatite has a much stronger affinity for a cement called phosgene, which is used to make waterproof coatings, sealant, insulators and in some cases, construction materials.
The USGS report noted that the presence of phosgas can be detected in the sediment in the soil, and it has been used as a “tool” in recent decades by the mining industry to determine the health of the land.
“Because phosgenes can be produced in a variety of ways, the health impact from phosgatite and phosgateite mining is likely to be more than the health effect from the combustion process itself,” the report said.
“If these minerals are melted, their melt-to-resilience properties could be a powerful environmental trigger.”
Steatites are extremely rare in the United States, but the industry is rapidly expanding.
The majority of the world’s steatonic deposits lie within California, Utah, Arizona, New Mexico, Arizona and New York.
In California, where the vast majority of America’s mineral extraction occurs, mining companies have set up vast facilities to process and extract the precious stone, known locally as California’s Sandstone.
In 2016, California became the first state to ban fracking, and the state has introduced a number of other measures to control the industry.
However, as the industry has grown, it has also been responsible for significant pollution and waste.
According to a study published in the peer-reviewed journal Nature last year, California’s mining industry has released over 20 million tonnes (tens of t) of methane into the air, a major contributor to global warming.
The report warns that melting of the rock, or “hydrothermal liquefaction”, can also lead to the release or breakdown of other minerals, including silica.
“Our findings are consistent with the idea that melting occurs in the presence and/or in proximity to a highly flammable silicate rock that contains phosgaens,” the USG researchers wrote, adding that they did not expect that melting would have a significant impact on the health and welfare of the environment.
“However, melting of this highly flambable silica rock poses a hazard to groundwater and surface water, particularly the aquifers that are being used to supply drinking water for millions of Californians.”
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