The Arctic is one of the world's most vulnerable areas to warming temperatures. Over the past 40 years, Arctic sea ice is estimated to have declined by 40%.

According to a new report from the United Nations (UN) Environment Assembly , the Arctic is in even more dire straits than experts thought.

Even if the world met its most ambitious climate change goals, winter temperatures in the Arctic would rise up to 9 degrees Fahrenheit (5 degrees Celsius) by the year 2050.

These rises in temperature would cause worldwide sea-level rise, damaging property, impacting coastal economies , and displacing families.

Over the past few months, news on the climate change front has been dire. The Antarctic ice sheet is melting nearly six times as fast as it did in the 1980s. Greenland's ice is melting four times faster now than it was 16 years ago.

A new report from the UN Environment Assembly delivers another blow to humanity's collective hopes of reining in rising temperatures on a rapidly warming planet. Even if global greenhouse gas emissions were to stop overnight, wintertime temperatures in the Arctic would still go up by 9 degrees Fahrenheit by 2100, the report found.

More realistically, if the world were to cut emissions in line with the Paris Agreement (in order to keep temperature rise less than 2 degrees Celsius above pre-industrial levels), winter temperatures in the Arctic would still rise 9 degrees Fahrenheit by 2050 and up 16 degrees Fahrenheit just thirty years after that.

Such intense warming would cause unprecedented sea-level rise around the globe. Rising waters threaten coastal homes and economies, further endanger species threatened by extinction, and displace families that live by the ocean.

Over the last four decades, Arctic sea ice has declined by 40%. Bob Strong/Reuters

Rising Arctic temperatures would cause devastating sea-level rise

Rising waters not only threaten coastal cities and infrastructure, but also lower coastal property values and hamper economies that abut the ocean.

Over the last four decades, Arctic sea ice has declined by 40%, according to the new report. Climate models predict that, if the current rate of carbon dioxide emissions continues, Arctic summers will be ice-free in just over a decade, according to the new report.

In 2012, Greenland lost more than 400 billion tons of ice — almost quadruple the loss in 2003. Those losses continue to accelerate. The melting of the Greenland ice sheet and Arctic glaciers currently contribute to one-third of global sea-level rise.

Roughly 1.7 million square kilometers (656,000 square miles) in size, the Greenland ice sheet covers an area almost three times the size of Texas. If the entire Greenland ice sheet were to melt — which would take place over centuries — it would mean a 23-foot rise in sea level, on average.

That's enough to submerge the entire southern tip of Florida.

A five-year-old Inuit fisherman's son and his four-year-old cousin run in their home village of Ilimanaq, Greenland. Uriel Sinai/Getty Images

Read More: Greenland is approaching the threshold of an irreversible melt, and the consequences for coastal cities could be dire

Warming Arctic temperatures could kick-start a feedback loop that would derail global climate change efforts

Meanwhile, rising temperatures are rapidly thawing the Arctic permafrost — a layer of soil that remains frozen all year long.

Even if the Paris Agreement emissions levels are met, the Arctic permafrost is still expected to shrink by 45%. This frozen soil traps nearly 2 billion tons of carbon. If it melts, that trapped carbon would enter the atmosphere, contributing to additional warming. More warming will in turn lead to more permafrost thawing, creating a feedback loop that could accelerate global warming enough to make the Paris Agreement’s goal of only a 2-degree-Celsius rise nearly impossible.

“What happens in the Arctic does not stay in the Arctic,” Joyce Msuya, UN Environment’s Acting Executive Director, said in a press release.

“We have the science; now more urgent climate action is needed to steer away from tipping points that could be even worse for our planet than we first thought.”