Terror group Al Shabab doesn't smuggle ivory for cash. It sells charcoal.

Every year, hundreds of boats leave Somali ports bound for the Gulf states, packed full of contraband goods whose profits line the coffers of the Somalia-based extremist group Al Shabab.

But the boats aren’t carrying illegal drugs or dangerous weapons. They’re filled with charcoal.

Every year Al Shabab earns as much as $56 million from an illegal charcoal trade, making it the group’s primary source of income, according to a report released by the United Nations at its Environmental Assembly in Nairobi this week. 

While a number of African insurgencies and militias -- like Joseph Kony's Lord's Resistance Army -- finance themselves largely through poaching and ivory smuggling, Al Shabab does not, according to the report. 

The charcoal lucre is used to help carry out Al Shabab's campaign of terror that last fall included the high-profile siege of Nairobi’s Westgate Mall and last week saw a series of deadly attacks claimed (twice) by Al Shabab in the coastal Kenyan town of Mpeketoni that killed more than 60 people. (Kenyan President Uhuru Kenyatta subsequently and surprisingly denied the massacre came from Al Shabab).

“These are not small amounts of money,” said Achim Steiner, executive director of the UN Environmental Program. “When you add it up, you’re talking about a lot of money for a lot of weapons. And it’s also a major onslaught on Africa’s natural resources.”

Despite a 2012 ban on Somali charcoal exports by the UN Security Council, more than $350 million of the product is still leaving the country each year, most of it bound for Yemen, Saudi Arabia, Kuwait, Egypt, and the UAE, the report states. 

Al Shabab serves as a gatekeeper for this trade, illicitly taxing market-bound charcoal at roadside checkpoints and in ports it controls in Kismaayo and Baraawe in southern Somalia.

The money Al Shabab earns from its participation in the charcoal trade dwarves the annual estimated $4 million to $12 million that is banked by African militias involved in poaching. It’s also more than the value of the drug trade in Africa, according to Christian Nellemann, the lead author of the UN’s report.

“The scale of this trade has been totally underestimated,” he says.

Al Shabab is not the only African militia group that lines its pockets with profits from illegal charcoal sales. Militias in the eastern Democratic Republic of Congo make at least $14 million annually from their participation in the trade.

Official charcoal production in Africa is worth between $9 and $24.5 million annually, and charcoal and wood fuel account for 90 percent of wood consumed on the continent. The UN estimates that African countries lose about $1.9 billion in potential revenues each year to the unregulated charcoal trade.

Charcoal production is also a growing source of deforestation in Africa, with demand expected to triple in coming years due to consumer demand.