Here is an illegal industry growing three times as fast as the global economy: environmental crime.
A new report from the United Nations and INTERPOL says activities revolving around exploiting natural resources and pollution are becoming big business, and lining the pockets of international criminal organizations and terrorist groups.
Illicit hunting and trading of wildlife, illegal mining, logging, and even waste disposal, have become the fourth largest criminal business around the world, after drugs, arms, and human trafficking.
Together these illegal industries have risen by 26 percent since a previous estimate was made in 2014, and growth is continuing at an annual rate of 5-7 percent, according to a paper released this week, jointly produced by the United Nations Environmental Program and INTERPOL.
Valuing illegal activity is tough, but the latest estimate places it somewhere between $91 billion and $258 billion, annually.
These are not isolated crimes occurring on a small scale in individual countries, said the study's editor, Christian Nellemann, in an interview with CNBC.
Nellemann, who is the head of UNEP's Rapid Response Unit, said that as commerce has become global, criminal networks have globalized along with it.