A report prepared jointly by the U.N. and Interpol has pegged the earnings of criminal gangs from illegal mining, poaching and logging in the range of $91 to 258 billion in 2015. This marks an increase of 26 percent from the 2014 figure of $70 to 213 billion. 

The United Nations Environment Programme (UNEP)-Interpol report was released on Saturday, on the eve of the World Environment Day.

Highlighting the scale of environmental crime, the Interpol said in a statement it is far bigger than illegal trade in small arms and the world's fourth-largest criminal enterprise after drug smuggling, counterfeiting and human trafficking.

What is environmental crime?

It includes illegal trade in wildlife, corporate crime in the forestry sector, exploitation and sale of gold and other minerals, illegal fisheries, trafficking of hazardous waste and carbon credit fraud, according to the joint report. 

The money generated from such crimes sustains criminal gangs and said it's high time to act.

"The rise of environmental crime across the world is deeply troubling. The vast sums of money generated from these despicable crimes are fuelling insecurity and keeping highly sophisticated international criminal gangs in business. It is essential the world acts now to combat this growing menace before it is too late," the Interpol update quoted UNEP Executive Director Achim Steiner as saying.

The trade knows no borders and actually thrives on criminal gangs teaming up with each other.

"Environmental crime is growing at an alarming pace. The complexity of this type of criminality requires a multi-sector response underpinned by collaboration across borders," Interpol Secretary General Jürgen Stock said.

Elephant poaching

More than 25 percent of the world's elephant population has been killed in the past 10 years. Some of the world's most vulnerable wildlife, including rhinos and elephants, are being killed at an alarming rate. In the last 10 years, poachers have killed an average of 3,000 elephants per year in Tanzania, the UDEP-Interpol report said.

In India, the tiger population faced more threat this year, with more tigers killed till April than those killed in the whole of 2015, AFP reported. Citing data by Wildlife Protection Society of India, the agency said 28 tigers were killed till April 26 this year, as against 25 in 2015.  

Tiger poaching is attributed to demand in neighbouring China where tiger meat and bones fetch high prices for their presumed medicinal value, the agency said.