Unprecedented flooding unleashed by Hurricane Harvey in the United States underscores the need for even wealthy countries to boost their disaster plans to keep vulnerable people safe and help them deal with the knock-out blows that climate change could bring, experts say.

Yet few expect the devastation wrought by Harvey to convince U.S. President Donald Trump to boost government funding for disasters or reinstate regulations that would limit heat-trapping emissions and protect infrastructure from extreme weather — let alone reconsider his decision to quit the Paris Agreement on climate change.

"What Hurricane Harvey is demonstrating to those few hold-out climate change skeptics is that this is our new reality. And it's only going to get worse," said Heather Coleman, associate director for climate change and energy policy at Oxfam America. "As we've seen in other disasters here and around the world, it's the poorest who are the most vulnerable."