譯/莊蕙嘉
煤電式微 天然氣成氣候議題新戰場
America's coal-burning power plants are shutting down at a rapid pace, forcing electric utilities to face the next big climate question: Embrace natural gas, or shift aggressively to renewable energy?
美國的燃煤發電廠正快速關閉，迫使電力公司面對下一個氣候大哉問：擁抱天然氣，或積極轉向再生能源？
Some large utilities, including Xcel Energy in the Upper Midwest, are now planning to sharply cut their coal and gas use in favor of clean and abundant wind and solar power, which have steadily fallen in cost. But in the Southeast and other regions, natural gas continues to dominate, because of its reliability and low prices driven by the fracking boom. Nationwide, energy companies plan to add at least 150 new gas plants and thousands of miles of pipelines in the years ahead.
一些大型公用事業公司，包括中西部北部地帶的卓越能源公司在內，正計畫大砍煤和天然氣的使用量，改用成本不斷下降，潔淨且豐富的風力與太陽能。但在東南部和其他地區，卻仍然是天然氣掛帥，因為裂解技術興起，造就它的可靠及低價。在美國全境，能源公司計畫在未來幾年至少增加150座新天然氣電廠以及數千英里的輸氣管。
A rush to build gas-fired plants, even though they emit only half as much carbon pollution as coal, has the potential to lock in decades of new fossil-fuel use right as scientists say emissions need to fall drastically by midcentury to avert the worst impacts of global warming.
雖然燃氣的碳汙染只有燃煤之半，爭建燃氣電廠熱潮湧現，卻可能就此鎖定未來數十年使用新化石燃料的態勢，而此際科學家正呼籲世人在本世紀中之前大幅降低碳排放，以避免全球暖化的最嚴重影響。
"Gas infrastructure that's built today is going to be with us for 30 years," said Daniel Cohan, an associate professor of civil and environmental engineering at Rice University.
"But if you look at scenarios that take climate change seriously, that say we need to get to net zero emissions by 2050," he said, "that's not going to be compatible with gas plants that don't capture their carbon."
「今日建造的天然氣基礎設施將與我們為伴30年。」萊斯大學木土及環境工程副教授丹尼爾．柯恩說。他說：「檢視正視氣候變遷問題而推演出的未來可能景況，會知道我們需要在2050年之前達到淨零排放，這個目標與我們使用無法捕集碳的天然氣電廠，是彼此扞格的。」
In some states, policymakers are now pushing to leave gas behind to meet ambitious climate goals. Last month, New York lawmakers passed a sweeping energy bill that calls for the state to switch to entirely carbon-free electricity sources by 2040, following states like California and New Mexico that have passed similar laws.
在一些州，政策制定者正加快捨棄天然氣的腳步，以達到遠大的氣候目標。紐約州議會上個月通過重大能源法案，要求州政府在2040年之前完全改用碳零排放的電力能源，跟隨已通過類似法律的加州及新墨西哥州。
Since 2005, most power companies have lowered their carbon dioxide emissions significantly, in large part by shifting from coal to gas. Coal plants have become uncompetitive with other kinds of energy generation in much of the country, despite the Trump administration's efforts to save them by rolling back federal pollution regulations.
自2005年以來，多數電力公司已顯著降低二氧化碳排放，頗大部分是靠從燃煤改為燃氣。儘管川普政府放寬聯邦汙染管制法規欲以拯救燃煤電廠，在國內很多地方，燃煤電廠已無力與其他發電方式競爭。
But in a recent analysis, David Pomerantz, the executive director of the Energy and Policy Institute, a pro-renewables group, looked at the long-term plans of the 22 biggest investor-owned utilities. Some in the Midwest are planning to speed up the rate at which they cut emissions between now and 2030.
大衛．波莫藍茲是支持再生能源的組織「能源和政策研究所」的執行長，他最近做了一項分析，檢視22家最大民營電力公司之長期計畫。中西部有些公司計畫從現在到2030年加速削減排碳。
But other large utilities, like Duke Energy and American Electric Power, expect to reduce their carbon emissions at a slower pace over the next decade than they had over the previous decade.
但是另有些大公司，如杜克能源公司和美國電力公司，卻預期未來10年減排的速度會比過去10年慢。
"I really think gas is at the crux of it," Pomerantz said. "You've got some utilities looking at gas and saying, 'No thanks, we think there's a cleaner and cheaper path.' But then you've got others going all-in on gas."
「我真的認為天然氣是關鍵所在。」波莫藍茲說。「你已見到一些電力公司看著天然氣說『不了，謝謝，我們認為還有更潔淨也更便宜的方法。』但是緊接著你又看到另一些公司全面採用天然氣。」
