gold

Bitcoin Mining And The Environment | Earth Wise

November 7, 2022 By EarthWise Leave a Comment

Bitcoin mining, the process by which the prominent cryptocurrency is created, is well-known to be energy intensive, but the environmental impact of it has not been extensively studied. People have described Bitcoin as ‘digital gold.’ A new analysis by researchers at the University of New Mexico has found that Bitcoin mining shouldn’t be compared to gold mining. It is more appropriately compared to the creation of much more energy-intensive products such as beef, natural gas, and crude oil.

Furthermore, the study found that rather than becoming more sustainable over time, Bitcoin mining is becoming dirtier and more damaging to the climate as long as it relies upon fossil-fuel generated electricity. Estimates are that in 2020, Bitcoin mining used 75.4 terawatt hours of electricity, which is more electricity than the entire country of Austria, as well as 150 other nations around the world.

The study looked at the economic cost of the air pollution and carbon emissions associated with Bitcoin mining and found that in many instances, the negative economic impact of creating a single Bitcoin is more than what the resultant coin is worth.

Based on the market value of Bitcoins, the cost of climate damage for that value is a little less that that of electricity produced by natural gas and gasoline produced from crude oil, but actually more than that of beef production.

There are multiple cryptocurrencies. Ether is one that voluntarily switched away from so-called proof-of-work mining. Whether Bitcoin or others will act similarly absent potential regulation remains to be seen. Until such time, Bitcoin mining remains an increasingly dirty and damaging business.

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Technology: UNM researchers find Bitcoin mining is environmentally unsustainable

Photo, posted May 11, 2017, courtesy of Komers Real via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mercury In The Amazon Rainforest | Earth Wise

March 8, 2022 By EarthWise Leave a Comment

Recent research has found that some of the highest levels of mercury pollution ever recorded are in a patch of pristine Amazonian rainforest. The international team of researchers discovered that illegal goldmining in the Peruvian Amazon is the source of the pollution.

Illegal miners separate gold particles from river sediments using mercury. Mercury binds to gold, forming pellets large enough to be caught in a sieve. The pellets are then burned in open fire ovens, releasing the mercury to the atmosphere, leaving the gold behind. The mercury smoke ends up being washed into the soil by rainfall, deposited onto the surface of leaves, or directly absorbed into leaf tissues.

Deforested areas had low levels of mercury, while the areas with the largest, densest old-growth trees captured huge volumes of atmospheric mercury, more than any other ecosystem studied in the entire world. Mercury levels were directly related to leaf area index: the denser the canopy, the more mercury it holds. Birds from this area have up to twelve times more mercury in their systems than birds from less polluted areas. Such high concentrations of mercury could provoke a decline of up to 30% in these birds’ reproductive success.

Small-scale artisanal gold mining is an important livelihood for local communities. Eliminating it outright may not be a viable solution but coming up with ways to continue to provide a sustainable livelihood while protecting communities from poisonous pollution is essential.

In the meantime, the forests are doing an important service by capturing much of the mercury and preventing it from getting into the general atmosphere and endangering more people and animals. Burning or harvesting the mercury-ridden trees would release the mercury back into the atmosphere.

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Modern Day Gold Rush Turns Pristine Rainforests into Heavily Polluted Mercury Sinks

Photo, posted August 24, 2016, courtesy of Anna and Michal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Generating Hydrogen From Poor-Quality Water | Earth Wise

September 8, 2020 By EarthWise Leave a Comment

Hydrogen could be the basis of a complete energy system. It could be stored and transported and could be used to power vehicles and to generate electricity in power plants. Proponents of the so-called hydrogen economy contend that hydrogen is the best solution to the global energy challenge. But among the challenges faced by a hydrogen economy is the development of an efficient and green method to produce hydrogen.

The primary carbon-free method of producing hydrogen is to break down water into its constituent elements – hydrogen and oxygen. This can be done in a number of ways, notably by using electricity in a process called electrolysis. A method that seems particularly attractive is to use sunlight as the energy source that breaks down the water molecule.

While there is an abundance of water on our planet, only some of it is suitable for people to drink and consume in other ways. Much of the accessible water on earth is salty or polluted. So, a technique to obtain hydrogen from water ideally should work with water that is otherwise of little use to people.

Researchers in Russia and the Czech Republic have recently developed a new material that efficiently generates hydrogen molecules by exposing water – even saltwater or polluted water – to sunlight.

The new material is a three-layer structure composed of a thin film of gold, an ultra-thin layer of platinum, and a metal-organic framework or MOF of chromium compounds and organic molecules. The MOF layer acts as a filter that gets rid of impurities.

Experiments have demonstrated that 100 square centimeters of the material can generate half a liter of hydrogen in an hour. The researchers continue to improve the material and increase its efficiency over a broad range of the solar spectrum.

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New Material Can Generate Hydrogen from Salt and Polluted Water

Photo courtesy of Tomsk Polytechnic University.

Earth Wise is a production of WAMC Northeast Public Radio.

What’s On Nature’s Calendar? | Earth Wise

January 29, 2020 By EarthWise 1 Comment

The Inuit Calendar is based on six seasons defined by weather, ice, animal migration, daylight hours and the night sky. All these variables are in flux according to Harvard Narwhal Biologist Dr. Martin Nweeia. Last August in the high Canadian Arctic, at 72 degrees north latitude, temperatures were at an astounding 70 degrees during the day. In 2018, the same region at the same time of year, experienced one of the coldest August months in 15 years.

Disappearing sea ice in Hudson Bay affects migration patterns of ice-dependent species like narwhal and beluga whales and now allows more shipping traffic which produces more marine noise pollution and the risk of an oil spill. As a natural resource, the Arctic has significant deposits of iron ore, gold, diamonds, phosphate, and bauxite, so cargo shipments are increasing yearly.

The disappearance of caribou herds and altered migrations of other animals have also blurred the seasonal changes. Caribou numbers have decreased by more than half in the last two decades. Narwhal populations are remaining steady but are experiencing migration shifts resulting in their appearance at new locations and their absence from traditional areas. Even the timing of the migration has changed, shifting two weeks later from normal late summer – early fall patterns.

The night sky, which has long had identifiable reference points for Inuit observers, is also changing causing speculation about changes in the magnetic field and a polar shift or flipping of the poles. The earth’s magnetic north has been shifting toward Siberia at an alarming 30 miles each year since 2015. Every million years, it is estimated that the poles flip three times. No one knows if or when it will happen again. That’s a calendar with some unexpected dates.

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–Earth Wise acknowledges script contribution from Dr. Martin Nweeia of Harvard University.

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Migratory Tundra Caribou and Wild Reindeer

Earth’s magnetic field is acting up and geologists don’t know why

Photo, posted June 27, 2014, courtesy of the Bureau of Land Management via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Smarter Prospecting

November 18, 2019 By EarthWise Leave a Comment

The global demand for copper and gold continues to grow. Copper is widely used in building materials, plumbing, and electronics. Gold is still highly valued for jewelry and coinage, but nearly a third of the world’s gold is now used in electronics.

Both of these metals are getting increasingly difficult to find as many of the known sources have been exhausted. Companies spend millions of dollars drilling deeper and deeper in search of new deposits.

It costs about $400 to drill one meter into rock and it is not uncommon to drill to depths of one to two kilometers. So, it can cost nearly a million dollars to drill a hole that has no guarantee of success. Given that ore deposits are tiny compared with the totality of the search space, prospecting for these metals is very much like looking for a needle in a haystack.

A researcher at the University of South Australia has developed a suite of geochemical tools to more accurately target valuable mineral deposits and thereby save drilling companies millions of dollars. The goal is to have drilling for valuable minerals be faster, cheaper and more environmentally friendly.

By mapping out where key chemical elements are found in greater concentrations, the new suite of tools greatly increases the chances of finding an ore deposit at a target site and thereby greatly improve the return on investment for exploration companies. The tools have been successfully tested at an iron oxide-copper-gold deposit in the north of South Australia, leading to a four-fold increase in the known footprint of their ore body. Finding economically viable enriched ore sites can generate both revenues and jobs.

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Prospecting for gold just got a lot easier (and cheaper)

Photo, posted April 21, 2005, courtesy of Adam via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recycling And Olympic Medals

March 23, 2017 By EarthWise

Organizers of the Tokyo 2020 Olympic Games announced in February that all the Olympic medals for the games will be made from recycled materials. The strategic roadmap for the games, laid out in the document “Olympic Agenda 2020”, specifically calls for the inclusion of sustainability in every aspect of the games.