The funeral attendees hiked for two hours up a volcano, where children laid a plaque in honor of the glacier that used to spread for about six square miles. The plaque, unveiled in July, is titled "A letter to the future" and includes text in both Icelandic and English, according to CNN.

"This monument is to acknowledge that we know what is happening and what needs to be done," it concludes. "Only you know if we did it."

The Okjokull glacier has now been stripped of its last two syllables, which mean "glacier" in Icelandic, and is merely called "Ok," according to The Associated Press. In 2014 it was declared dead because it no longer had enough snow and ice to cause it to be moved by its own weight, AFP reported. While it stretched 6.2 square miles in 1890, it only spread 0.7 square kilometers (approximately 0.3 square miles) by 2012.

"We made the decision that this was no longer a living glacier, it was only dead ice, it was not moving," Icelandic Meteorological Office glaciologist Oddur Sigurdsson told AFP.

Icelandic Prime Minister Katrin Jakobsdottir, who attended the funeral Sunday, also wrote an opinion piece in The New York Times calling for climate action.

"On Sunday, we pay tribute to Ok," she wrote. "At the same time, we join hands to prevent future farewells to all the world's glaciers."

Almost half of World Heritage Sites could lose their glaciers by 2100 if greenhouse gas emissions continue unchecked, AFP reported.

Currently, Iceland is aiming to do its part by going carbon neutral by 2040 at the latest. It has already achieved carbon neutral energy production, but the loss of more glaciers, which currently cover around 11 percent of Iceland, could also threaten the country's clean energy.

"A big part of our renewable energy is produced in the glacial rivers," Jakobsdottir said, as AFP reported. "The disappearance of the glaciers will affect our energy system."

Iceland isn't the only country that will be harmed by the disappearance of glaciers. CNN gave a rundown of some of the potential impacts of global ice melt, from Antarctica to the Himalayas.

1. Sea level rise could displace as many as two billion people by 2100.
   
2. Islands like Tuvalu, the Maldives and the Marshall Islands could be entirely swallowed by rising water levels.
   
3. The drinking water of millions of people who depend on glaciers like those in the Andes or Himalayas could be threatened.
   
4. The warmer temperatures and flooding associated with sea level rise could disrupt the global food supply.
   
5. Increased coastal flooding could overflow sewage treatment plants, spreading disease.
   
6. Rising sea levels could harm the economy as they threaten the trading activities and maritime industries of the world's ports.
   
7. Melting ice sheets could exacerbate global warming, since open water tends to absorb the solar radiation that ice reflects.