How the Greenland Ice Sheet is Impacting Global Sea Level Rise

Sea level rise is a major component of climate change and global warming. It has the potential to impact millions across the world. Now, predictions of sea level rise could become a bit more accurate. Scientists have gained new insight into how glacier movement is affected by melting ice in the summer.

Sea level rise has become a huge worry for climate scientists. It could destroy island ecological diversity as low-lying areas flood. In addition, it could affect island nations. Already, Hawaii is being influenced by this phenomenon. That's why it's more important than ever to study the factors that influence this particular rise.

In order to examine how summer conditions can impact ice, the scientists looked at the Greenland ice sheet and studied its flow. Ice flows slowly from the center of this ice sheet toward its margins, where it eventually melts or calves into the ocean as icebergs. Knowing exactly how fast this movement occurs is essentially for predicting the contribution of the ice to sea level rise.

In 2012, an exceptionally warm summer actually caused the Greenland Ice Sheet to undergo unprecedented rates of melting. After examining this occurrence, though, the researchers found that fast summer ice flow caused by significant melting is cancelled out by slower motion the following winter. Large drainage channels, formed beneath the meltwater, helped to lower the water pressure and ultimately reduced the sliding speed.

So what does this mean for future melting? It suggests that the movement in the parts of the ice sheet that terminate on land are insensitive to surface melt rates. This in particular can help scientists improve their understanding of melt rate of glaciers. That's not to say that this means that sea level rise from glaciers still isn't an issue, though.

"Although the summer melt did not intensify future ice motion, warmer summers will still lead to more rapid melting of the ice sheet," said Peter Nienow, one of the researchers, in a news release. "Furthermore, it is important that we continue to investigate how glaciers that end in the ocean are responding to climate change."

The findings are published in the journal Proceedings of the National Academy of Sciences.