POWER plant operators in the US are keen to trade emissions credits with each
another as a way of staying within overall pollution limits. But unless the
trades are carefully monitored, the strategy could make things worse.
Researchers in Texas, where emissions trading is already under way, have
found that the location where pollutants are emitted can be just as important as
the quantity. Get it wrong, and some kinds of pollution worsen.
Nitrogen oxides (NOx), for example, react with volatile organic compounds to
produce smog-forming ozone. If power plants near urban areas buy credits to
belch out NOx, then…
