Climate-vulnerable countries said disasters and weather patterns driven by global warming have wiped out around a fifth of their economic growth, in a report published Wednesday amid growing calls for funding to help nations hammered by weather extremes.

The research, released by a consortium of 55 developing nations across Africa, Asia, the Americas and the Pacific, comes as UN climate negotiators meeting in Germany wrangle over "loss and damage" the costs of climate change impacts that are already unfolding.

According to the report, heat, changes in rainfall patterns and other weather extremes are already putting a severe dent in developing economies.

Ghana's Finance Minister Kenneth Nana Yaw Ofori-Atta, who wrote the preface to the report, said the finding should "sound alarm bells for the world economy", calling for global action to support nations most exposed.

The research, carried out on behalf of finance ministers, compared observed losses to modeling that estimates how the economies might have grown without the impacts of climate change.

It finds that rising temperature and modified rainfall patterns have already reduced wealth in these countries by 20 percent, or $525 billion, over the last two decades.

"We are bearing this alarmingly high economic cost, despite having contributed the least to causing climate change, while also being least equipped to respond to its costly consequences," the report said.

"Losses and damage go well beyond what can be quantified in dollars and cents in the form of lost and destroyed lives, livelihoods, land, even threats to our culture."

Funding from rich polluters to help vulnerable developing nations adapt to a warming world has already fallen short, with a promise of $100 billion a year from 2020 still not met.

Vulnerable countries say wealthy nations' failure to curb emissions coupled with a lack of adequate adaptation funding  is leading to ever-greater losses and damages as temperatures rise.

A landmark report by UN climate science experts this year on the impacts of global warming said extreme weather had caused direct economic damage, which can sometimes weigh on growth for a decade or more.

Africa was particularly affected, it said, adding that one estimate suggests gross domestic product per capita was around 13 percent lower for African countries in 2010 than it would have been without the previous two decades of global warming.