Image by Vojife/Wikimedia Commons (CC BY 3.0)
Scientists throughout the world have observed that the earth’s glaciers are retreating and thinning. Historical photos and satellite imaging offer visual proof of the exact extent of this change in our planet’s ice cover. This is certain to affect the earth in dramatic ways, but the exact results are yet to be understood. Here is some of what scientists know so far.
The extent of glacier melt
How dramatic is the change so far? A page on Nasa’s website, which can be found here, is dedicated to addressing the question and includes a dramatic example focused on Alaska’s Muir Glacier. The page features photos taken at a single spot in 1941 and 2004. During that time, scientists reported that the front of the glacier retreated by seven miles and its thickness decreased by more than 2,625 feet.
Other satellite data that was analyzed at the University of Colorado, Boulder has documented additional ice loss. Their results show that an average of 46 gigatons of ice was lost from Alaskan glaciers each year from 2003 to 2010.
Some of the most obviously expected results of glacier melt has been flooding. One of the biggest contributors to this flooding is meltwater from Greenland. How much will sea levels increase? Generally, sea levels are expected to increase anywhere from between 0.2 to 2 meters by the end of the current century. If the ice sheet was to melt completely, sea levels could rise up to seven meters.
Some coastal cities and other habitable areas are already in fear of the impact of rising sea levels. Juneau, Alaska was deeply concerned about record flooding during the summer of 2018. 50,000 people who are living in the flood path below Peru’s glacial lake Palcacocha are concerned about serious flooding in the next several summers. In New Orleans, Louisiana, residents already talk about how they’re living in an area that is “not quite land, but not quite water either.”
In addition to coastal areas of mainland continents, the United Nations Department of Economic and Social Affairs has identified 52 small island nations at risk of disappearing due to flooding and natural disasters related to climate change. These include The Maldives, Vanuatu, and The Solomon Islands.
Animal habitat loss
There are a large variety of animals that depend on glaciers for their survival. Famously, polar bears depend on glaciers to be able to hunt and feed their young and rest from swimming. Seals also depend on the ice to rest, give birth, and feed. In addition, there are birds who live off of fish that are found in the fresh melting waters of a glacier. When the ice falls away, these species’ ways of life are threatened.
Access to ancient plants and bacterial strains
As glaciers melt, long frozen plant forms, bacterial strains, and viruses are becoming free from ice and exposed to the air. This development is exciting because scientists can learn about this biology first hand. It is almost like rolling back the effects of time on the biology of the planet.
Unfortunately, there’s a dangerous side to this as well. Among the organisms being exposed to the air are organisms that humans haven’t encountered in thousands of years. If they have caused serious, sometimes fatal illness in ancient humans, modern humans would have little if any biologic defense against them.
This hypothetical situation became real in 2016. At that time, a 75-year-old reindeer carcass that had been infected with anthrax died and was frozen under permafrost, thawed. The carcass infected the food and water supply. 2,000 reindeer and 20 humans became infected. A 12-year-old boy died.
Increased information about ancient life
As glacial ice melts, it lays bare ancient living sites that humans haven’t previously been able to access. The ice perfectly preserves artifacts from decay and human disturbance. The results of the ice melt are happening so quickly, that relics are becoming easily visible — often no high tech archeological equipment or mapping technology required.
One of many areas where this is happening is the Lendbreen mountain range in Scandinavia which is typically covered by ice and snow year-round. In the warmer summer of 2006, years of snow melted. While on a hike, a hobby archeologist in the Norwegian part of this range happened upon what he assumed was an old shoe. Upon examination by experts, he was stunned to learn it was a Bronze-age shoe from approximately 3,400 years ago.
Following his find, experts began a more organized archeological rescue program in the area. Scientists believe this needed to happen quickly. As soon as artifacts become thawed and exposed to the air, they’re vulnerable to decay and degradation. If they’re not quickly preserved and identified, they might not last.
Trapped chemicals are released into the atmosphere
Long banned toxic chemicals, including the pesticide DDT, and PCBs which were widely used in insulators for electrical equipment. When they were used in previous decades, they were transported through the air and then trapped in ice on earth’s coldest regions. As this ice thaws, the chemicals are re-released into the atmosphere as well as human food and water supplies. This has first been noted as happening on the Tibetian Plateau and the Swiss Alps.
Ways to mitigate the effects of ice melt
The world is debating, often contentiously, ways to mitigate the causes and results of ice melt. One thing that can be done is for humans to learn more about what is happening through reading the scientific research available. Ideally, once people can understand the issue they can help to improve habitats for all affected on the planet.