The UN refugee agency warned on Friday that nearly 90 million forcibly displaced people live in countries highly exposed to climate hazards, ahead of next week's COP31 summit in Turkey.

Three-quarters of the world's displaced people live in nations facing severe exposure to climate hazards, the agency said. Countries such as Afghanistan and Bangladesh are among those highly exposed. It cited droughts, floods and extreme heat that are making lasting solutions harder to find.

"Refugees face a double injustice," said Anton Leis Garcia, UNHCR's assistant high commissioner for operations. "Forced to flee conflicts they did not cause, they are now on the frontlines of a climate crisis they have contributed least to."

More than two-thirds of refugees who returned home during the first half of this year went back to countries highly vulnerable to climate hazards, UNHCR said. In Syria, where nearly four million displaced people have recently returned, declining groundwater and climate shocks were threatening recovery. Flooding along the Euphrates River last May damaged homes and displaced thousands once again.

Extreme heat was also a growing threat, the agency said. By 2050, one in three refugee settlements across sub-Saharan Africa could face 100 or more days of dangerous heat each year. Weather-related disasters have caused more than 255 million internal displacements worldwide over the past decade, or 70,000 each day, UNHCR said.

This year's exceptionally strong El Nino was expected to cause even more displacement. In East Africa, forecasts indicate that severe flooding could displace up to three million people across Somalia, Kenya and Uganda by the end of 2026, with South Sudan also affected.

UNHCR said only 10 percent of global climate finance goes to fragile and conflict-affected countries hosting large populations of climate-exposed displaced people. During COP31, the agency will call on governments to include refugees in national climate plans and financing mechanisms.

"We cannot allow those who have already lost so much to be left behind in global climate action," Garcia said.