Carbon markets work in Europe, not in New Zealand, and sometimes in Korea

A new study looked at how well carbon trading systems actually cut emissions in three different places. It turns out the European Union's system worked, New Zealand's did not, and Korea's had mixed results. This means that just having a carbon market is not enough; the details of its design and what it covers really matter.

Governments around the world are trying to figure out how to cut carbon emissions without crippling their economies. Carbon trading systems are a popular idea, but this paper shows they are not a magic bullet. If a country wants to use one, it needs to make sure the system covers the biggest polluters and has strong enough rules to actually drive change. Otherwise, it is just a lot of paperwork.