What Happens If The Antarctic Ice Sheet Collapses?
In recent years, more and more people have started sharing concerns about the future of the world as we know it. These worries range from natural disasters to political protests, but today I’d like to focus on another reason why people are worried: the possibility of the Antarctic Ice Sheet collapsing. It’s easy to see why so many people are concerned about this.
Antarctic Sea Ice Is Melting Faster Than Scientists Thought
The world’s largest mass of ice, the Antarctic Ice sheet has the potential to raise global sea levels by hundreds of feet if it ever fully collapsed.
Scientists have long known that the ice sheet is vulnerable to warming ocean temperatures. Yet research recently published found that it may be more sensitive to temperature changes than previously thought.
The new study suggests that Antarctica’s ice is sensitive to climate changes at temperatures similar to what the planet is already experiencing today. This means that parts of the ice sheet will likely collapse sooner than expected.
The ice sheet has been melting for decades. However, the new findings suggest that temperatures of today’s climate are warm enough for the process to continue unabated and possibly even speed up.
It’s No Secret That Global Warming Is Causing Glaciers Across The World To Melt
When we think of global warming and its effects on the climate, we often think of increased temperatures. But those rising temperatures are only part of the story—as greenhouse gases trap heat in our atmosphere, they also drive the ocean surface to warm at a faster rate. As that water warms, it expands and raises sea levels around the world by about 1/8th of an inch per year.
In Antarctica, however, things are going much more quickly than that—even before factoring in the potential for rapid ice sheet collapse. Over time, warmer temperatures cause glaciers to retreat and melt faster than they usually would; as a result, ice shelves break off into icebergs or melt into the ocean altogether.
In some areas of Antarctica such as Pine Island Bay, this is causing glaciers to flow out at almost quadruple their previous speed! Oceans around Antarctica are also absorbing carbon dioxide from our atmosphere at a faster-than-normal rate; when combined with melting glaciers, this could lead to significant changes in ocean temperature and salinity that disrupt delicate ecosystems like coral reefs.
What Happens If They All Melt? That’s A Good Question And An Important One
Figuring out the answer involves a process called mass balance, which is pretty much what it sounds like: tallying up the gains and losses in the system. If there is more ice entering the system than leaving it, then it grows; if there is more ice leaving than entering, then it shrinks.
You may have heard that the ice sheets hold enough water to raise sea levels by 60 meters—over 200 feet. That’s true, but it would take thousands of years for all that ice to melt.
The most widespread loss occurs when glaciers flow into the ocean and break off, or calve, into icebergs. Another way glaciers lose mass is through melting as they flow downhill; warmer air temperatures can cause more of this kind of melting at lower elevations or latitudes.
When glaciers flow onto land instead of into water, they can also heat up in summertime due to the absorption of sunlight by rock debris such as gravel and sand that cover parts of their surface. Glaciers also gain mass through snowfall adding to their upper surfaces (accumulation), especially during winter months at high altitudes or latitudes where precipitation tends to come as snow rather than rain.
- Global warming has caused glaciers across the world to melt
- Many glacial lakes are likely to burst in the near future
- Mountain glaciers keep water streams flowing and cool cities in the summer
- Global warming is caused by humans and there are ways to reduce our impact
Well, It Depends On What Glaciers You’re Talking About
There are two distinct regions in the Antarctic: The East Antarctic Ice Sheet (EAIS) and West Antarctic Ice Sheet (WAIS). The EAIS is the larger of the two and is a thick, stable ice sheet that’s not going anywhere anytime soon. If you’ve ever seen an iceberg come off Antarctica and then sink into the ocean—as happened to a very large chunk of Larsen C last year—it likely came from this eastern sector.
The WAIS, on other hand, is much smaller than its counterpart but potentially more dangerous. It sits on top of bedrock that dips downward as it stretches out beneath the sea. If you had to pick one part of West Antarctica to look at for signs of significant collapse, it would be Thwaites Glacier.
If All The Mountain Glaciers And Icecaps Melted, The Oceans Of The World Would Rise 0.5 Meters (1.64 Feet)
When it comes to the sea level, there are two key sources of frozen water: glaciers and ice sheets. Glaciers make up what’s known as the cryosphere—the region of Earth where temperatures are so cold that water remains in a solid-state.
As we’ve already learned, mountain glaciers account for roughly one-quarter of the world’s glacial volume. But this isn’t all those scientists include when they think about glacier volume; they also include ice caps and ice sheets. These are much larger bodies of frozen water, vast expanses with a thickness of at least several hundred meters (think more than 980 feet). The latter is particularly important—ice caps cover huge swathes of land in places like Antarctica and Greenland, with many hundreds of kilometres extending from coast to coast, and thousands of meters deep.
If you added up all these regional contributions across Antarctica (0.5 meters), North America (3 meters), South America (0.1 meters), Europe (1 meter) and Asia (2 meters), the total would be 6.6 meters, or 21 feet 8 inches—enough to submerge London under 30 feet or so of seawater!
If The Greenland Ice Sheet Melted
The Greenland ice sheet holds the world’s largest reservoir of ice. It covers roughly the same surface as Antarctica, but it is not so thick around Greenland and has a smaller volume.
This sheet is in the northern part of Greenland, where it meets a mountain range on the southern coast. It spreads over an area of 1.7 million square kilometres, though it is slowly melting away due to climate change.
If the Greenland ice sheet melted completely, you would see a global sea-level rise of between 7 and 8 meters (23 – 26 feet). That alone would be enough to submerge several major cities in the United States and much of Florida’s coastal communities. It would put over 100 million people at risk of flooding from rising seas.
Greenland is far smaller than Antarctica, but it would still be the largest contributor to sea-level rise if it melted completely.
- If the Greenland ice sheet melted, we’d be in big trouble
- Around half of the freshwater in the world is held in this ice sheet
- This entire body of ice is likely to shrink and disappear if temperatures continue to rise
- Weather would become extremely severe everywhere
And Finally, If The Antarctic Ice Sheet Melted
If the entire Antarctic ice sheet melted, it would raise the sea-level by 164 feet. The hardest-hit cities would include New York, Edinburgh, St. Petersburg, Shanghai, and Mumbai.
In fact, global warming is affecting Antarctica more than any other place on Earth. And for the continent to melt entirely, global temperatures would have to rise by about 3 degrees Celsius (about 5 degrees Fahrenheit) from their current levels.
The good news is that we can still avoid this scenario if we act soon to reduce greenhouse gas emissions and slow down warming across the planet—but it won’t be easy!
And there it is, friends: the full scoop on one of the most devastating but plausible threats facing our planet. Is global warming truly a problem? You bet it is.
The magnitude of the threat, and the speed at which it’s unfolding, are both soberingly large. Fortunately, there are plenty of things that you can do to help slow the progress of climate change and ensure that this disaster never comes to pass…