While there are many indicators to hint that climate change is real, one of the biggest ones is the melting of the ice shelves in Antarctica and the Arctic. In this article, Xeraya discusses these natural features, their role in the environment, and why it is crucial that we save the ice from completely melting off the face of this earth.
Defining Ice Shelves
According to the National Snow and Ice Data Centre, ice shelves are essentially extensions of thick land ice that flow out over a cold coastal ocean. Ranging in thickness from 50 to 600 metres, ice shelves can extend tens to hundreds of miles from the coast, which is where they first go afloat. Some of these massive natural features have been formed over thousands of years.
There are three types of ice shelves, ones fed by glaciers, ones created by sea ice and local snowfall, and ones that are composite, made of both glacier-fed ice and fast ice which is thickened by snowfall. In fact, the accumulation of snow plays a significant part in the creation of all ice shelves.
Where Ice Shelves are Located and the Role They Play in the Environment
Most the world’s ice shelves are found on the Antarctic coast. In fact, these shelves fringe three-quarters of the Antarctic coastline; in total, the continent has 15 large ice shelf areas and several smaller ones. The largest shelves can be as big as the US state of Texas or the country of France.
As per the European Geosciences Union, ice shelves act as a natural barrier to the ice sheet, stabilising the flow of grounded ice and its contribution to sea levels. Simply put, ice shelves help to restrain the flow of ice on land, thus controlling how much ice flows into the ocean; when ice shelves shrink or disappear, this balance is disturbed as more ice enters the water and increases global sea levels.
The Current Situation
Scientists and researchers have been observing the ice shelves of the Arctic and the Antarctic for the better part of 50 years according to the Environmental Protection Agency (EPA), watching them collapse, thin, and retreat. The reason of this observation is that the activities of ice shelves serve as good indicators of climate change – as the seas warm, the rate of an ice shelf shrinking increases.
Most recently, a report from The Guardian this past October has put environmentalists on high alert: scientists at the University of Leeds in the UK have discovered that between 1997 and 2021, 40% of Antarctica’s ice shelves have shrunk and almost half of these shelves are not regrowing themselves – a natural process that contributes directly to stabilising sea levels. This lack of regrowth is alarming (usually, the ice will rapidly shrink and then regenerate at a much slower pace) and is being attributed by glaciologists to climate change.
In terms of actual numbers, 67 tonnes of ice on the western coast of Antarctica have entered the ocean over the past 25 years, thus impacting the transport of heat and nutrients in the world’s waterways. Conversely, on the eastern coast, 59 tonnes of ice have been added to the shelves present. This means that there has been a net loss of 7.5 tonnes of ice in Antarctica during this period. This seemingly odd phenomena can be attributed to the ocean currents surrounding the continent; warm water on the western side has melted the ice, while a band of cold water on the eastern side has been protecting the shelves there from rapid erosion.
The Catalysts
Rising earth temperatures which have been sped up by climate change in the last few decades are essentially why ice shelves are shrinking and not regrowing; the biggest culprit are CO2 emissions from human activities, including manufacturing of various goods, the burning of fossil fuels, and deforestation. Additionally, the oceans, which absorb 90% of the warmth generated by the earth, are steadily growing warmer, thus adding to the warm currents flowing around the west coast of Antarctica.
Why the Ice Shelves Melting are a Cause for Concern
The melting of ice shelves on both axes of the planet has severe repercussions for the environment, with the three biggest problems being:
- The rising sea levels will lead (and have already led) to flooding, natural disasters and the destruction of wildlife habitats.
- The ice shelves can reflect the Sun’s energy better than land or water; without any ice, the planet will absorb the full amount of energy from the Sun and will warm up faster.
- There are whole ecosystems of animals that rely on icy habitats that will be endangered should all the world’s ice disappear.
What is Being Done to Stop the Ice Shelves Melting
French scientists have found that Antarctica is warming at almost twice the rate of the rest of the world; however, most glaciologists believe that there is still time to save the ice. The first and most important step is to of course have the world reduce its C02 emissions by 45% over the next decade and achieving a target of net zero emissions by 2050. However, there are also other answers to this conundrum, including a few that are being proposed by glaciologist John Moore at the Arctic Centre, which is a part of the University of Lapland in Finland.
Moore proposes exploring the concept of glacial geoengineering, which means building artificial braces through polar megaprojects and installing other structures that would nudge nature to restore existing ice shelves. In 2018, he and several partners floated the idea of shipping in or dredging up large amounts of material that would be used to build artificial islands around or beneath key glaciers; these structures would then support the glaciers and ice shelves by blocking warm dense layers of water at the bottom of the ocean. Subsequently, Moore and researchers from the University of British Columbia in Canada suggested the creation of seabed anchored curtains which would be made of geotextile material that is buoyant and flexible; these curtains would hold back and redirect warm water around glaciers and ice shelves. They envisioned that the curtains would be able to stand up to iceberg collisions, and that they would be easily removed if they caused any negative side effects.
Other solutions have also been brought forward by the world’s researchers, including placing reflective and insulating material over portions of the glaciers, building fencing to retain snow that would otherwise blow into the ocean, and drying up the ocean bed beneath the glaciers which would eliminate water as a lubricant and thus slow the glaciers’ movements.
Time is Running Out for the Ice Shelves
There is certainly incentive for Moore and other glaciologists and researchers to continue finding ways to save the ice. As it stands, the West Antarctic Ice Sheet will continue to increase its rate of melting for the rest of the 21st century, regardless of how much fossil fuel use is reduced. The fact of the matter is, an acceleration in ice melting cannot be avoided, which means that the freshwater from Antarctica’s melting ice shelves will increasingly contribute to rising sea levels over the next few decades.
As such, now more than ever, humans must reduce their dependency on fossil fuels; while the impending situation can’t be stopped, governments and society can eventually adapt to it, if the rate of sea level rise is slowed down.
Sources:
- National Snow and Ice Data Centre: Ice Shelves
- European Geosciences Union: Change in Antarctic ice shelf area from 2009 to 2019
- EPA: Climate Change Indicators – Ice Sheets
- The Guardian: Antarctica has lost 7.5 tonnes of ice since 1997, scientists find
- Iberdrola: Glaciers, the great guardians of stability of the planet’s climate
- Exploratorium: Global Climate Change Explorer – Ice
- MIT Technology Review: The radical intervention that might save the “doomsday” glacier
- British Antarctic Survey: Increased West Antarctic Ice Sheet melting “unavoidable”
