a system for controlling carbon emissions and other forms of pollution by setting a limit on the amount any business or organization may produce while allowing them to buy extra capacity from other organizations which have not used their full limit Some environmentalists oppose the whole idea of cap and trade. 一些环保主义者反对上限和交易的整个想法。 The centrepiece of his energy plan was a cap-and-trade system. 他的能源计划的核心是总量控制与交易系统。