Not long before that, the Kyoto Protocol had assigned industrialized countries responsibility for carbon reductions, causing the European Union to encourage its members to use more clean energy sources, which drove demand in the market sharply upward.
而京都議定書 (1997) 制訂了工業國二氧化碳減量責任，促使歐盟鼓勵各國使用潔淨能源，市場需求量日益爬升。