Apparel shipment worth $26.78 billion from Bangladesh may be affected due to extreme weather conditions like heat and floods by 2030, according to a study of Cornell University in the US.

The study carried out by the university's Global Labor Institute and Schroders finds extreme heat and flooding are threatening key apparel production hubs globally.

Four countries vital for fashion production are at the risk of losing $65 billion in export earnings and 1 million potential jobs by 2030, it said.

In the case of Bangladesh, the impact will be $26.78 billion while Cambodia will lose $6.75 billion, Pakistan $7.59 billion and Vietnam $24.77 billion, the study said.

The study identifies Karachi, Colombo, Managua, Mauritius, and Dhaka as the most climate-vulnerable manufacturing centres.

"The investors say adaptation measures aren't factored to risk plans because the industry is focused on mitigation."

The report called for climate adaptation finance that redistributes costs and risks away from apparel workers.

The study compared estimates for future temperatures and flooding in 30 apparel manufacturing hubs around the world. It also looked at the impacts for apparel workers in the four countries and how climate change is already affecting them.

The study suggested changes that unions, employers, governments, apparel buyers and investors should make to protect workers and apparel manufacturing from high heat and intense floods.