The joke of “carbon credits” defined:

In an odd twist on market economics, Europe’s ex-communist states are starting to exploit a new market. Thanks to the Kyoto climate-change agreement, they can, in effect, now make money off the pollution their onetime central planners were willing to tolerate as the price for rapid industrialization and universal employment. Ukraine, Hungary, the Czech Republic and other countries of the region not exactly renowned for clean air have made or are close to signing deals to sell the rights to emit greenhouse gases, and their main customer is environmentally friendly Japan. This carbon windfall dropped into Central and East Europe’s lap because the Kyoto Protocol sets 1990 as the reference year for future reductions in greenhouse gas emissions. The socialist states at that time were producing gargantuan amounts of CO2 and other gases implicated in global warming from unfiltered coal-fired power plants and factories; when those unprofitable industries withered, countless thousands of workers went on the dole — but the air got cleaner. In the coming years, in line with European Union mandates, would-be members gradually adopted better environmental policies. It’s the difference between the often unspeakably bad air of 1990 and the comparatively clean air of today that allows them to sell “carbon credits” potentially worth billions of euros.