Two Caribbean island nations and one South Asian country have topped the newest Climate Risk Index as worst-affected by extreme weather in 2017.

Puerto Rico, Sri Lanka and Dominica ranked one to three in the index, followed by Nepal, Peru and Vietnam, based on their level of exposure and vulnerability to destructive weather events.

According to the report by Germanwatch, 2017 was the world's most devastating year for extreme weather on record.

Poorer nations suffer

Researchers point out that the countries least equipped to deal with such disasters, and which have typically contributed the least to human-induced climate change, are bearing the brunt of its consequences.

"Of the 10 countries most affected in the last 20 years, eight were developing countries with low or low-middle incomes," David Eckstein, lead author of the report, said in a statement.

Sri Lanka endured its worst flooding in more than a decade in 2017

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"They have the fewest resources to protect themselves from the consequences of climate change or to compensate for their losses and therefore need particularly strong support."

Denis McClean from the United Nations Office for Disaster Risk Reduction (UNISDR) told DW it was a "cruel irony" that countries that have contributed least to greenhouse gas emissions suffer the most.

He added that people there often die in greater numbers from extreme weather events and suffer more significant economic losses as a percentage of income than people in higher-income countries.

More than 11,500 people died and around $375 billion (€329 billion) worth of damages were incurred last year as a direct result of extreme weather incidents, researchers calculated.

'Exceptional catastrophes' on the rise

Hurricane Maria, dubbed "catastrophe of the century," by Eckstein, wreaked havoc in both Puerto Rico and Dominica when it hit in September 2017.

Puerto Rico was pushed to the top of both indexes after the devastation of Hurricane Maria

The category 5 hurricane decimated Puerto Rico's infrastructure, killing nearly 3,000 people.

In Dominica, thousands were rendered homeless and 90 percent of the country's roofs were destroyed. The tiny Caribbean island nation suffered around $1.2 billion of damages — losses double that of the country's GDP.

That extreme event pushed the former country to the top slot in both the Climate Risk Index for 2017, as well as the long-term index that covered the last two decades (1998-2017). After Puerto Rico, Honduras is ranked second on the long-term index, followed by Myanmar, Haiti and the Philippines.

Sri Lanka, number two on the 2017 index, suffered heavy landslides and flooding in May 2017 after enduring the worst monsoon rains in more than a decade. More than 200 people were killed and at least 600,000 people displaced from their homes.

Climate change fueling extremes

As highlighted by the IPCC's 1.5 degree Celsius report, the risks associated with extreme weather events will continue to increase as the average global temperature rises.

Although the authors acknowledge it is not easy to assess the impact of climate change on a single weather event, evidence from the past several years has linked global warming and extreme weather.

The IPCC report shows, for example, that in many places around the world, the likelihood of droughts and heavy rain is higher under climate change of 2 degrees Celsius.

"There has been a doubling of extreme weather events over the last 40 years, and much of the increase is in line with the reality of climate change and predictions of climate change scientists," McClean pointed out.

"We are seeing more powerful storms, more variable weather, extensive flooding, wildfires, drought and heat waves on a scale not previously seen."

Read more: Extreme weather threatens African society and economy

In addition to extreme weather events, authors of the new report also highlight "slow-onset events," such as sea-level rise or salinization of soils, which can have devastating impacts. "Here, too, climate change is increasing damage and losses, especially for the poorest and most vulnerable states," Eckstein told DW.

European nations are expected to feature more prominently in next year's index after 2018's extreme drought

Wealthy nations not immune

But not just low-income countries suffer under increasing extremes. As Eckstein points out, the last few years in particular have also shown that also industrialized nations are increasingly suffering due to climate change.

Read more: Can Germany's supposedly crumbling infrastructure hold up against extreme heat?

In 2017 in Germany, 27 people died due as a result of extreme weather events, and $360 billion worth of damage was incurred — mainly due to storms and flooding. The industrialized nation ranked 40th on the Climate Risk Index for 2017 — two slots higher than in the previous year — and 25th on the index for the past 20 years.

It is likely, Eckstein says, that due to record drought and extreme heat this year, the next index will feature even more European countries. France, for example, is already one of the 20 most affected countries in the long-term index.

As 190 states gather from around the world at the UN's COP24 conference in Poland this week and next, the index's authors are hopeful that the frightening potential for future climate-related loss and damage highlighted by their work will be high on the agenda.

"In the long term, there needs to be much greater ambition accompanied by action to reduce greenhouse gas emissions," McClean concluded.