Climate change threats — from worsening water shortages in Iraq and Pakistan to harsher hurricanes in the Caribbean — are a growing security risk and require concerted action to ensure they don't spark new violence, security experts warned Tuesday.

"Climate change is not about something in the far and distant future. We are discussing imminent threats to national security," said Monika Sie Dhian Ho, general director of the Clingendael Institute, a Dutch think tank.

The drying of Africa's Lake Chad basin, for instance, has helped drive recruitment for Islamist militant group Boko Haram among young people unable to farm or find other work, said Haruna Kuje Ayuba of Nigeria's Nasarawa State University.