There are over five million cubic miles of ice on our planet. That volume includes the Arctic, the Antarctic and a swath of ice sheets and glaciers crusted around the Earth’s northern and southern boundaries. If all of it were to melt, global sea levels would rise at least 216 feet.
Alex Kuzoian has produced a rather chilling video of what that would look like. Martin Vargic, an amateur graphic designer, has created a slightly less chilling but no less alarming map that does the same.
Now, as Douglas Adams once said, “Don’t Panic.” Even with global warming, scientists estimate that it would take several thousand years for all this ice to melt. But imagining this sea level rise (SLR) is a valuable thought experiment, and reveals how vulnerable humanity is to the elements.
And this is not to say that SLR isn’t already impacting civilization.
What SLR Looks Like Now
In the United States, the state of Florida is seeing the worst of it. Miami Beach, Key Biscayne and Virginia Key are all suffering regular flood events that are worse than they were a century ago. According to Harold Wanless, Chairman of the Geological Sciences Department at the University of Miami, Florida can expect between four and six feet of SLR by 2100. About $1.5 billion is currently being invested in city-wide flood control for Miami.
Unfortunately, Florida officials aren’t exactly allowed to discuss global warming or climate change, thanks to an unofficial decree from Governor Rick Scott, an avowed climate change skeptic.
“You have to wake up to the reality of what’s coming,” Wanless told The New York Times in 2013.
The tide has already risen 10 inches since the 19th century.
Last year, an analysis conducted by the National Oceanic and Atmospheric Administration found that approximately 1,536 square miles of wetlands have disappeared from American coastlines due not only to sea level rise but also land subsidence, erosion, storm surges and man-made development. This is a major loss to the surrounding communities, as these wetlands provide a buffer against the ocean in times of flooding and hurricanes.
Some 2,000 square miles of Louisiana is now underwater, largely due to overdevelopment, and Hurricane Katrina proved how devastating that loss can be. Louisiana’s government has estimated it will take 50 years and $50 billion to replace some of that land, though it has yet to raise even a tenth of that money.
According to the Union of Concerned Scientists (UCS), U.S. coastal communities are on course to experience more severe and frequent flooding in as little as 15 years. A UCS report released in October 2014 analyzed 52 of these communities between Freeport, Texas and Portland, Maine and estimated that more than half of them will experience 24 tidal floods per year by the year 2030.
The severity of these floods will vary by location, but will largely be determined by how far the ocean has already encroached on the land. Boston, like Florida, has seen about 10 inches of SLR since 1921. New York City, meanwhile, has recorded almost 18 inches of SLR since 1856. Annapaolis, Maryland and Washington, D.C. will experience the greatest amount of flooding, at about 150 tidal floods per year.
By 2050, UCS estimates that all 52 of the communities surveyed will experience at least 12 inches of sea level rise. Five mid-Atlantic communities could be flooded 10 percent of the year.
The economic damage of this sea level rise, combined with other climate change factors, will be immense. Researchers from several organizations, including Industrial Economics, the University of New Hampshire and the Climate Change Division of the Environmental Protection Agency, have calculated that the joint effects of storm surge and SLR on U.S. coasts could total up to $1.1 trillion by the end of this century.
The World Resources Institute has estimated that SLR and extreme weather events caused by climate change will impact 54 million global citizens by the year 2030. Over the next 15 years, the WRI projects the cost of flood-related damages will increase from its current £65 billion to around £340 billion.
How Bad Could It Get?
It could get very bad. Roughly 10 percent of the planet’s population (634 million people) lives less than 30 feet above sea level. In the United States, over half of the population lives near the coast.
National Geographic has produced an excellent (and terrifying) interactive map that shows how 216 feet of sea level rise would impact each continent.
In North America, the entire Atlantic seaboard would sink into the sea. Florida would be completely gone, as would most of the Gulf coast. California’s Central Valley, which provides nearly half of all U.S.-grown fruits, nuts and vegetables, would become a giant bay.
In South America, Buenos Aires, coastal Uruguay and most of Paraguay would disappear.
In Europe, London, Venice, the Netherlands and most of Denmark would become bathtubs.
In Asia, all of Bangladesh would be flooded and an area of China inhabited by 600 million people would be inundated.
Africa would actually fare the best of all continents, but NatGeo estimates that global warming would render most of it uninhabitable.
“If we continue adding carbon to the atmosphere, we’ll very likely create an ice-free planet,” the website warns, “with an average temperature of perhaps 80 degrees Fahrenheit instead of the current 58.”
So What Do We Do?
Already, satellite data has revealed that the massive Antarctic and Greenland ice sheets are melting at an “unprecedented rate.” A report on the phenomena was published in the European Geosciences Union journal The Cryosphere in August of last year. Since 2009, according to one of its authors, volume loss in Greenland has increased by a factor of about two. In West Antarctica, by a factor of three.
Some months later, scientists discovered that Antarctica lost so much ice between 2009 and 2012 that the shift in mass had slightly altered the Earth’s gravity.
The best thing humanity can do is attempt to keep global warming below two degrees Celsius by the end of this century. The best way to do that is to limit the emission of greenhouse gases like methane and carbon dioxide, though world governments’ attempts, to date, have been half-hearted at best.
Perhaps it is unfortunate that hundreds of feet of sea level rise is slated for so far into humanity’s future, because that makes it so easy to ignore. Yet according to climatologists like Planet Expert Michael Mann, global warming may soon get a boost from an alternating weather pattern known as the Pacific Decadal Oscillation.
If SLR also increases past scientists’ projections, it may finally motivate governments and corporate emitters to take the issue seriously. It is already long past the hour.