It would allow businesses to buy licenses to emit greenhouse gases from other firms that use less energy.

VOA: standard.2009.05.30

So, if you use a black lamp or something and you excite something up to a higher energy level and then it relaxes back down to its lower energy state, it's going to emit a new wavelength of light, which is going to be visible to you.

如果你用一个紫外灯或别的,东西把某种分子激发到,更高的能级，然后它会掉回,到低能级，它就会释放,一个新的波长的光,这个光是可见的。

麻省理工公开课 - 化学原理课程节选

Each of us individually has an incentive to emit carbons as usual.

通常我们每个人都有排碳的动机

耶鲁公开课 - 博弈论课程节选