But many of their compatriots are already busily (and sometimes voluntarily) buying and selling emissions of the greenhouse gases that are heating up the planet.
然而，许多英美人已经忙于购销引起地球升温的温室气体排放。
3
Beyond the heating effects of carbon dioxide and the other greenhouse gases, there are the effects of converting land from one use to another and filling parts of the sky with soot and smog.