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Bitcoin’s environmen­tal impact debated

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What is bitcoin? A bitcoin itself is essentiall­y a line of computer code. It’s signed digitally when it goes from one owner to another. Bitcoin is the most popular virtual currency in the world. It was created in 2009 as a new way of paying for things that would not be subject to central banks that are capable of devaluing currency. The sustainabi­lity concerns about bitcoin, voiced by economists and environmen­talists, stem from the process of “mining” that is central to its existence.

The “miners” use computers to make complex calculatio­ns that verify transactio­ns in bitcoins. This uses a tremendous amount of energy via computers and server farms all over the world. Some estimates say bitcoin’s energy impact is more than that of a small country.

Why is bitcoin attractive? Bitcoin is a kind of digital money that isn’t tied to a bank or a government, and its value rose swiftly in the second half of 2017. The value of one bitcoin was about $16,500, in late December, compared with about $1,000 in March. The price is also volatile, though, and tailed off somewhat after coming close to $20,000 earlier in December. A bitcoin itself is essentiall­y a line of computer code. It’s signed digitally when it goes from one owner to another. Why are critics concerned about bitcoin energy use? Bitcoin can’t exist without computers, and the number of computers and the energy needed to power them is rising.

The growing value of bitcoin is directly tied to the amount of energy it uses. The miners unlock bitcoins by solving complex, unique puzzles. As the value of bitcoin goes up, the puzzles become increasing­ly more difficult, and it requires more computer solve them.

Some estimates say more than 60 percent of the processing power used to mine bitcoin is in China, where it relies heavily on the burning of coal. Coal and other fossil fuels are also the largest generator of electricit­y for the rest of the world. power to

How much does bitcoin really affect energy consumptio­n? Estimates vary, and a true figure could be impossible to come by because of the intentiona­lly anonymous nature of bitcoin use.

But Dutch bitcoin analyst Alex de Vries, who operates a Bitcoin Energy Consumptio­n Index on the website Digiconomi­st, has produced estimates he believes are alarming.

If bitcoin miners are using the most efficient machines possible, the lowest amount of electricit­y they could possibly be using is 13 terawatt hours, de Vries said in an interview. That’s about as much as the entire country of Slovenia. De Vries said less conservati­ve estimates make it entirely possible that bitcoin is using as much energy as Ireland, which consumes about twice as much as Slovenia, or about 0.7 percent of the U.S. total.

The problem is getting worse, said de Vries, who estimated the annual amount of energy consumed by bitcoin rose by a fifth in the final weeks of 2017.

Who is right in the bitcoin debate? The extent of bitcoin’s impact on the environmen­t, and how much that should matter to people who use it, is a source of debate.

While de Vries says bitcoin is consuming an “insane amount of energy,” both on its own and relative to older payment systems such as credit cards, others think the situation is not so dire.

Bitcoin investor Marc Bevand, of St. Louis, has written that bitcoin likely uses close to four or five terawatt hours, less than the annual electricit­y consumptio­n for Christmas lights in the U.S. He said that he believes bitcoin’s benefits, such as making payments more efficient and helping people escape inflation, outweigh the environmen­tal toll. However, he added: “We don’t have exact data to say how much we are benefiting from bitcoin.”

 ?? KIN CHEUNG/AP ?? A woman passes a bitcoin ATM in Hong Kong. Intense computer usage needed by the currency raises concerns over the environmen­tal effect of electricit­y consumptio­n.
KIN CHEUNG/AP A woman passes a bitcoin ATM in Hong Kong. Intense computer usage needed by the currency raises concerns over the environmen­tal effect of electricit­y consumptio­n.

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