Emission Source's emissions, and transactions of allocations, auctions, sales or reduction credits. 27. Carbon leakage means implementation of cap-and-trade scheme may result in relocation of energy-intensive production in less-constrained regions. 28. "Best Available Technology" (BAT) is a commercial technology that provides the greatest reduction in GHG emissions after taking into consideration energy, economic, and environmental impacts. Long-term national GHG emission reduction goal shall be to reduce GHG emissions to no more than 50% of 2005 GHG emission by 2050. The goal pursuant to the foregoing Paragraph shall be timely adjusted by the central competent authority, in consultation with the central industry competent authorities, by taking into consideration the United Nations Framework Convention on Climate Change (UNFCCC), its agreements and or related international conventions decisions, together with domestic circumstances, subject to the Executive Yuan's approval; and in line with the required periodical review.