The participants are still hammering out rules for their exchange but are reportedly considering giving utilities in their states the option to purchase allowances from the e . u . emissions trading system and offset credits from clean development projects 参与成员仍在琢磨交易规范，不过据称他们正考虑发给州内公用事业买卖权，向欧盟的排放交易体系购买许可，以及向清洁发展计画买进抵消额度。
