For Bangladeshi garment and textile manufacturer DBL Group, climate change is a growing threat it cannot afford to ignore.

Mohammed Zahidullah, chief sustainability officer for the business, which employs about 35,000 workers at its factories near Dhaka, said a heat wave dented productivity last year, while riverside fabric-dyeing factories face worsening flood risks.

"A large-scale flood like the one recently witnessed in Pakistan could spell havoc for our industry," he warned at DBL's office building in Gulshan district, which maximizes use of daylight including with sensors to save on electricity.