Watch A Mile Of 3,000-Foot-High Ice Fall Into The Ocean

It's hard to truly appreciate the effects of climate change. We hear of a two degree jump over the course of decades, of dwindling animal populations, and of sea levels rising inches. These effects don't sound all that stunning.

But when we see something like an island-sized chunk of ice fall into the ocean, that's when we really start to understand the drastic impacts that climate change is happening - already. Even now. Even back in 2008.

It was in May 2008, when a team of documentarians in western Greenland caught one of the most stunning examples of climate change in action. They were there to see what's happening to the world's glaciers first hand.

What they recorded is both awe-inspiring and terrifying.

They visited the Ilulissat Glacier, also known as the Jakobshavn Glacier or Sermeq Kujalleq. It has an area of more than 42,000 square miles and is believed to be the same glacier that produced the iceberg that sank the Titanic.

It's one of the most active glaciers in the world - earlier this year, scientists found that the glacier is shedding ice into the ocean at a rate of more than 150 feet per day. That's a lot of ice.

As the film-makers looked on, they watched not just the normal ice loss, but an extreme example of shedding as a massive chunk of the glacier broke away, or "calved," retreating a full mile before coming to rest.

Calving is the natural process through which glaciers lose mass. The calving process begins when a rift opens in the edge of a glacier, caused by wind or water erosion, melting ice, or other events that cause the glacier to become unstable.

This crack in the ice ultimately causes a block to break away from the land and form an iceberg, which falls into the ocean. More ice from the land flows in behind it and breaks off next.

In this case, the section of ice, which was about as large as the lower tip of Manhattan, was approximately 3,000 feet tall, most of it under water. Since ice floats, the entire freshly shorn berg jumps up and bobs up and down.

This calving event lasted 75 minutes, and the filmmakers describe it as the "largest witnessed calving event ever caught on tape."

This process makes these icebergs created by glacier calving distinct from sea ice, which is just frozen ocean water. Both glaciers and the icebergs they create originate on land. It's these chunks of ice that raise sea level - since they used to be on the land, and are now melting and breaking off into the ocean.

Calving is a natural part of a glacier's life cycle to a certain extent, but the extreme rate at which these glaciers are calving is what's incredible and worrying: between 2000 and 2010, this glacier retreated nine miles - further than it had retreated in the previous 100 years combined. Scientists say its current flow rate, the rate at which the glacier drops ice into the ocean, is three times what it was in the 1990s.

The culprit is global climate change, which causes polar ice to weaken and melt, making glacial calving more frequent and more dramatic. And it's not just land ice that is suffering: sea ice is melting too as a result of rising global temperatures.

The footage shown above was later incorporated into a feature-length documentary called Chasing Ice, which premiered in 2012. The film follows photographer James Balog as he journeys across the Arctic, documenting the effects of climate change on the world's glaciers in an expedition dubbed the "Extreme Ice Survey." The documentary can be viewed through Netflix, Amazon, or iTunes.

The breaking of the Ilulissat Glacier is just one example of climate change's already apparent effects in the Arctic and Antarctic regions. Melting polar ice, the result of rising global temperatures, is a major concern among climate scientists, causing the destruction of polar habitats and contributing to sea level rise.

View the complete clip of their incredible footage below: