乙醇產業蓬勃發展 將造成美國水資源壓力

摘譯自2007年10月10日ENS美國，華盛頓特區報導；吳萃慧編譯；蔡麗伶審校

美國國家科學院國家研究委員會（National Academy of Sciences' National Research Council）10月10日的一份新的報導指出，如果美國的乙醇產量持續增加，將對水質造成影嚴重影響，而水源供給問題也將成浮上檯面。
撰寫報告的委員表示，一些潛在的衝擊持續升高對生長玉米與煉製乙醇區域的地下蓄水層的環境壓力。這些衝擊包括高濃度的氮源將以殺蟲劑及肥料形式滲入地下水，同時生產所釋出的污染也會進入溪流及河川。
以愛荷華大學工程學教授史諾博士（Dr. Jerald Schnoor）為首的6人委員會檢視了幾項政策方案，並在其中發現了可將生質燃料生產對水資源影響降至最低的新型農業技術與科技。
最近的油價上升與補貼政策，使玉米乙醇的生產達到戲劇性的擴展，並且十分可能在未來20年間繼續蓬勃發展。
因為能源自給自足的程度攸關美國重大國家利益，2007年布希總統的國情咨文裡還表示將在2017年之前生產350億加侖（約合1325億公升）的乙醇，這大約是美國運輸用液體燃料需求量的15％。
委員會發現，在農業不發達或特別是在乾旱的區域進行農業轉型生產玉米與生質燃料作物，將會改變現有的灌溉作業方式，並將對美國很多地方造成水資源壓力。
U.S. Water Under Pressure as Ethanol Production Soars
WASHINGTON, DC, October 10, 2007 (ENS)
If U.S. ethanol production continues to rise, the effect on water quality could be considerable and water supply problems could develop, says a new report today from the National Academy of Sciences' National Research Council.
Increased pressure on local aquifers used to grow and refine corn into ethanol, high levels of nitrogen in groundwater from pesticides and fertilizers, and runoff pollution in streams and rivers are a few of the potential impacts, said the committee that wrote the report.
Chaired by Dr. Jerald Schnoor, a professor of engineering at the University of Iowa, the six member committee examined policy options and identified opportunities for new agricultural techniques and technologies to help minimize effects of biofuel production on water resources.
Recent increases in oil prices together with subsidy policies have led to a dramatic expansion in corn ethanol production and high interest in further expansion over the next decade.
Because of strong national interest in greater energy independence, in this year's State of the Union address, President George W. Bush called for the production of 35 billion gallons of ethanol by 2017, which would equal about 15 percent of the U.S. liquid transportation fuels.
The committee found that agricultural shifts to growing corn and expanding biofuel crops into regions with little agriculture, especially dry areas, could change current irrigation practices and greatly increase pressure on water resources in many parts of the United States.