????到目前為止，日本國家石油天然氣和金屬公司( Japan Oil, Gas and Metals National Corporation )一直肩負鉆探甲烷水合物之責，但這家公司表示，一旦試鉆于2016年至2018年之間某個時候完成，私人公司將接管鉆探業務。

????日本鉆探隊表示，他們向海浪下1公里處發送了一臺被官員稱為“挖掘機”的機器，從而破解了技術難關。在海下，這臺機器把固化的甲烷水合物分解為水和天然氣，然后將天然氣傳送至海平面。

????日本國家石油天然氣和金屬公司甲烷水合物研究團隊的項目總監山本浩二解釋：“我們給甲烷水合物鉆了一些孔，生成水，以減少壓力，從而使甲烷從冰狀物質中分離，向上流動至井口?！?/p>

????雖然一些人歡迎一種全新能源供應的潛在好處，但其他人指出，鉆探冷凍氣體構成的不穩定床體有一定的危險性，會給大氣增添更多的二氧化碳。

????“從海床下釋放大量甲烷的想法嚇壞了許多環保人士，”魯德哈特能源咨詢公司(Roodhart Energy Consultancy)主管利奧?魯德哈特表示（甲烷是一種溫室氣體，其強度比二氧化碳大20倍）。

????“雖然相比于煤或石油，甲烷是一種更加清潔的化石燃料，但尚未利用的甲烷水合物其實是‘被捕獲的’溫室氣體，一些人認為它們應該繼續被鎖定在海下。開采甲烷冰也可能對海洋生態系統造成嚴重破壞?！?/p>

????山本浩二并不認為存在這種井噴或重大環境破壞的危險，盡管一個小規模的甲烷水合物井噴與此前英國石油公司(BP)的墨西哥灣漏油事件有關?？v觀歷史，從包合物床體大規模釋放甲烷——這種活動被稱為“包合物槍”——一直是造成大規模滅絕事件的原因之一。

????研究人員并不認同與出于商業能源使用的甲烷水合物勘探相關的風險。海洋學家，萊斯大學(Rice University )教授杰拉爾德?狄更斯同意日本研究團隊的觀點。他認為，人類活動幾乎不可能造成如此大的災難。

????“與鉆探有關的唯一一個潛在問題是，在天然氣水合物的正下方是否存在承受過大壓力的氣體，”狄更斯說。“然而，越來越多的理由促使我們相信，這種事情其實不可能發生。所以，就鉆探而言，應該是沒有問題的。”

????甲烷水合物領域的頂級專家、美國地質調查局(United States Geological Survey)的蒂姆?科利特認為，自然和人類引發的改變有可能導致水合物失去穩定性，造成災難性滑坡。

????2004年，他在出席美國國會聽證會時聲稱：“在美國大西洋沿岸和北歐沿岸已經發現了一些涉及天然氣水合物引發海底滑坡的證據。這些活動可能給地球的海洋和大氣釋放出大量甲烷?！保ㄘ敻恢形木W）

????譯者：任文科???

????The state-owned Japan Oil, Gas and Metals National Corporation (JOGMEC) is behind the successful methane hydrate drillings so far, but it says private companies will take over once test drilling finishes sometime between 2016 and 2018.

????The Japanese team say they have cracked technical difficulties by sending down what officials describe as "an excavator" one kilometer below the waves. There the machine separates solidified methane hydrate into water and natural gas, and funnels the gas up to the surface.

????"Holes are drilled into the methane deposits to produce water to decrease the pressure, allowing the methane to separate out from the ice-like material and flow up the wellhead," explains Koji Yamamoto, project director of JOGMEC's Methane Hydrate Research Team.

????While some welcome the potential benefits a new supply of energy, others point to the dangers of tampering with unstable beds of frozen gas and adding more CO2 to the atmosphere.

????"Environmentalists are horrified by the idea of releasing huge quantities of methane from under the seabeds," says Leo Roodhart, director of the Roodhart Energy Consultancy. (Methane gas is a greenhouse gas that's 20 times more potent than carbon dioxide.)

????"Although methane is a cleaner-burning fossil fuel than coal or oil, the as-yet untapped methane hydrates represent 'captured' greenhouse gasses that some believe should remain locked under the sea. The mining of methane ice could also wreak havoc on marine ecosystems."

????Yamamoto disagrees that there is any danger of such blowouts or major environmental damage -- although a small methane hydrate blowout was linked to the BP (BP) spill in the Gulf. Larger releases of methane from clathrate beds throughout history, known as the actions of a "Clathrate gun," have been responsible for mass extinction events.

????Researchers do not agree on the risks associated with methane hydrate exploration for commercial energy use. Oceanographer and Rice University professor Gerald Dickens agrees with the Japanese research team, arguing that there is little danger of such catastrophes coming from human action.

????"The only potential issue in regards to drilling would be if there is greatly over-pressured gas immediately beneath the gas hydrate," Dickens says. "However, there is growing belief and rationale to suggest that this cannot occur in nature. So, as far as drilling is concerned, there should be no issue."

????Tim Collett of the United States Geological Survey, a leading expert on methane hydrate, believes it is possible that both natural and human induced changes can lead to hydrate destabilization, triggering catastrophic landslides.

????"Evidence implicating gas hydrates in triggering seafloor landslides has been found along the Atlantic Ocean margin of the United States and off northern Europe," he told the U.S. Congress in 2004. "These processes may release large volumes of methane to the Earth's oceans and atmosphere."??