比特幣「環境殺手論」劇增！中本聰早想到：「不用 BTC，才是純粹的浪費」

比特幣「環境殺手論」劇增！中本聰早想到：「不用 BTC，才是純粹的浪費」

對一些人來說，比特幣預示嶄新的未來金融體系；但也有很多人視為環境災害。比特幣愛好者或許會對抨擊方不屑一顧，可若要讓比特幣大規模普及，勢必得逐一排除反對者的質疑。

比特幣今年迎來睽違已久的牛市，眾人對其增加的「碳足跡」也倍感擔憂。一度對比特幣立場轉為中立的微軟聯合創辦人比爾蓋茲（Bill Gates），2 月受訪時就又表示不支持比特幣，主因便在挖礦產生大量碳足跡。

理論來說，比特幣是完全數位化的類貨幣，乍聽之下似乎是有史以來最環保的貨幣。畢竟與紙幣不同，比特幣不需靠砍伐樹木生成，且供應量有限，不會有增發情況發生。

但是，主流媒體對比特幣是否消耗巨大能源的擔憂卻與日俱增。

《衛報》2 月便以《為何比特幣對地球有害》為標題做影片報導；路透社則抨擊特斯拉（Tesla）一方面提倡潔淨能源，另一手又向「能源密集」的比特幣投入 15 億美元；《華盛頓郵報》也指出，以比特幣購買特斯拉車對環境有負面影響。

比特幣可能永遠要消耗大量能源

無論以哪種指標比較，比特幣都確實消耗大量電力。原因就在比特幣採用名為 PoW 的共識機制，讓礦工以競爭方式解決密碼學問題，凡搶得首位，即能領取該區塊的獎勵。

為了保持競爭力，礦工硬體設備也被迫加入軍備競賽；使用更強大的計算機，消耗的能源自然也會增加。加拿大比特幣挖礦公司 Bitfarms 高層就承認，只要依然使用比特幣，就可能永遠要耗費大量能源。

BBC 報導，劍橋大學最近分析報告結果指出，比特幣一年消耗的能源總量，比阿根廷、荷蘭等國家還多，約每年 121.36 太瓦時（TWh）。假如把比特幣視為一國，耗電量將躋身世界前 30 大。

不過進入網路時代後，無論寄電子郵件、使用社群媒體、銀行網路業務，都在增加人類碳排放。在這環境下，比特幣難道真是碳排放的主要貢獻者？認為惡化環境的責任都在它是否誇大？

中本聰早想到了

外界對比特幣的批評，也讓一則比特幣創造者中本聰（Satoshi Nakamoto）2010 年在比特幣論壇 BitcoinTalk 發表的言論被翻出來。之後中本聰便從人們視野消失，至今仍沒有人知道「他」，或「他們」的真實身分。

中本聰寫道：

比特幣讓交易成為可能，效益要遠高於電力成本。因此，沒有比特幣才是純粹的浪費。

比特幣誕生以前，數位貨幣的概念早已出現，也曾付諸實踐，但從沒取得如比特幣的巨大成功。中本聰認為，比特幣「必須」涉及可證明的能源消耗，否則沒有其他方法能以去中心化方式，向全世界公平分配數位單元價值。

中本聰以黃金為例解釋：

（比特幣挖礦）與黃金和開採金礦的情況相同。挖出黃金的邊境成本往往會趨近黃金價格。開採金礦也是資源浪費，但這浪費的後果遠遠低於將黃金當作交換媒介的效益。

和比特幣類似，開採金礦也是能源密集型產業，並有大量資本支出。此外，採礦業是完全自由的市場，礦工往往被剝削，使真正從事辛苦工作的人賺到的反而是最低的薪水。

除此之外，中本聰也已預見未來將有無數開發者在比特幣區塊鏈上建立 Layer2 第二層解決方案，不傷害比特幣交易透明度的前提下，提升能源使用效率和交易速度等。Liquid、Lightning Network 等 Layer2 研究也行之有年。

此外，礦工能源消耗採可再生能源的比例也持續上升。根據劍橋大學替代金融中心（CCAF）去年 9 月發表的《全球加密貨幣指標研究》，高達 76% 礦工使用的電力包含可再生能源，甚至有 39% 礦工「只」使用可再生能源。

不過，可預見的未來，對比特幣造成環境危害的指控想必仍會持續出現。

（本文由 動區動趨 授權轉載；首圖來源：Unsplash）

延伸閱讀：

Bitcoin consolidates above $55,000 as a huge month beckons for crypto - CityAM

Bitcoin’s rollercoaster journey through March is drawing to a close with relative calm as the market-leading cryptocurrency appears to be consolidating.

Following weeks of remarkable highs and mystifying dips, Bitcoin now looks to have settled above the $55,000 line.

A period of sideways movement could be just the tonic that traders have been clamouring for after repeated attempts to climb above $60,000 lost their grip since setting an all-time-high of $61,701 more than two weeks ago.

Despite taking the landmark figure with some conviction, the high didn’t last long as the market became overheated and overstretched, tumbling back to $56,000. A week of volatility chased the peak with further dips and fruitless lifts.

Over the last week, the narrative has been set to backdrop of uncertainty surrounding US bond yields and options closures looking like the teeth of bears which threatened to signal a sizeable correction for Bitcoin.

Some commentators were even suggesting a massive drop was on the horizon, while others had more conservative views that a quiet spell beckoned before the wave of institutional investment carried BTC to new highs.

Of particular interest to many long-term investors is the fact that this has been one of the first spells of weekend trading in months that hasn’t been wildly eventful. On the few occasions where weekend trading has been flat, it has often signalled a robust consolidation or even coiling prior to a significant rise in price.

Too much, too soon

One factor many observers have agreed upon with BTC’s numerous and unsuccessful assaults to hold ground above $60,000 has been the issue of overstretching and the movement being too much, too soon.

Under normal circumstances, a sustained period of relatively horizontal trading heralds the return of confidence to an unsettled market. However, in the case of Bitcoin, it is likely that the bigger investors are anticipating an event.

In mainstream stock markets, a similar pattern to what is shaping up in the cryptocurrency charts often occurs while traders are waiting on certain pieces of information – such as an earnings report. Stock markets will also experience low trading volumes during this kind of sideways movement.

Bitcoin’s trading volume – although often low over weekends – has been showing signs of erosion of late, and seems to be echoing a stock market awaiting news.

Quite what that news might be is something of a mystery. However, it is likely that BTC just needs a rest after a lot of activity and the crescendo of $6bn options expiring on Friday.

There was huge concern that the options expiry might send BTC into a much-anticipated freefall and, as yet, no cracks appear to be showing on the surface.

Instead, the market is looking relatively calm which, as many experienced traders will be aware, is often a signal in itself that something is looming on the horizon.

Past options expirations, albeit none as sizeable as Friday’s, have largely been followed by a pump – something which seems to work against the current narrative of expecting a correction.

Key moment coming up

As always, the volatility of cryptocurrencies mean it is almost impossible to decipher market intentions, but there is a key moment coming up that should be watched very closely.

The close of April will see another significant options expiry and it is shaping up to bigger than Friday’s event. Interestingly, many data collection sites are finding the majority of bets on Bitcoin’s price high in April are centred around $80,000.

Notably, there are also a significant number of traders placing their expectation chips at $120,000 – twice as many, it should be highlighted, as those who are favouring the odds at $60,000.

Considering the fact BTC has ultimately failed to hold above $60k so far, the level of confidence in $80,000 seems almost inconceivable. However, it is desperately hard to ignore the numbers.

用比特幣買特斯拉不僅是貨到付款這麼簡單，美國國稅局：先想想你要繳多少稅

昨天，特斯拉CEO馬斯克（Elon Musk）宣佈，在美國特斯拉官網將正式開始接受用比特幣來買車。過去幾個月來，特斯拉開始接受比特幣的消息，已經成為加密貨幣領域的重大進展，意味著未來加密貨幣將可以像法幣一樣直接購物。

不過，用比特幣購買特斯拉可能不像刷信用卡那麼簡單。除了要支付一筆手續費之外，購買者要付出的費用可能比想像中的還要多。其中，包含了美國國稅局認為，這筆交易還必須要繳納一筆稅金。

在美國國稅局認為，用比特幣直接購物、與直接賣出比特幣獲利是同一件事。而在美國，如果你賣出比特幣，需要繳納一筆稅金。因為美國國稅局將比特幣和其他加密貨幣歸類為資產，因此投資者出售比特幣或將其兌換為實物商品時，必須為增值的部分繳稅。類似於投資者賣出股票。

那麼，假設投資者去年3月以3000美元的價格購買了一枚比特幣，然後現在使用當初買到的比特幣去購買特斯拉，由於當初的三千美元一枚現在已經增值到超過5萬美元，投資者就必須為這筆交易的資本利得4.7萬美元繳稅。

那麼，到底要繳多少稅？取決於當事人持有比特幣的時長。如果持有超過1年，那麼將為盈利支付長期資本利得稅，至於要繳的稅率是多少，則還要看當事人的其他收入與這筆獲利加起來的年收入是多少而定。

對於單身申報來說，如果年收入低於4萬美元，這一稅率為0。如果年收入不超過44.145萬美元，那麼稅率為15%。如果年收入超過44.145萬美元，那麼稅率為20%。如果持有比特幣不到12個月，則支付短期資本利得稅，這與普通所得稅的稅率相同。

因此，除非買車者的年收入低於4萬美元，否則如果使用比特幣購買特斯拉汽車，至少需要繳納15%的稅。