In 1978, pre-eminent geologist John H. Mercer wrote a paper about climate change that was to eventually become one of the most famous documents in the field. More than just a scientific triumph, Mercer’s seminal work would later become a prophecy.
Mercer was, at the time, a member staff at Ohio State University when he cautioned global leaders to heed the “threat of disaster” that was beginning to manifest in various environmental signifiers. It was particularly the probability of vast ice shelves cracking and breaking free from the outer edges of Antarctica that concerned the geologist.
Today, on Wednesday, July 12, that prophecy has been fulfilled in a vindicating event that was predicted by Mercer nearly 40 years ago.
Climate scientists working in Antarctica confirmed that the ice shelf known as Larsen C had finally dislodged from the mainland. In that instant, one of the largest icebergs in recorded history was born.
It is estimated that the behemoth block of ice weighs more than a trillion metric tons, and is roughly the size of Delaware.
In June this year, scientists in the region warned that Larsen C was “hanging by a thread” as the shelf turned towards the ice front – a sign that she was ready to depart from her place of birth, Antarctica.
Over the last few decades, a crack in Larsen C – eventually measuring more than 120 miles across – had been gradually developing. Scientists have studied the fissure with intense scrutiny, hoping that a day like today would never come.
Antarctica’s Larsen C ice shelf has also been the focus of the Copernicus Sentinel-1 satellite mission. The animation below is an educational demonstration – called an “interferogram” – depicting how scientists have been using data collected from space to monitor the progression of the fissure.
The fact that the ice shelf is now floating away from Antarctica towards South America is a bitter pill to swallow for climate scientists. In recent years, experts have significantly intensified John H. Mercer’s warnings of imminent global catastrophe.
Speaking to The New York Times, Adrian Luckman, a researcher working for Project Midas, said that “the remaining shelf will be at its smallest ever known size.” Luckman urges that the loss of Larsen C is not to be taken lightly.
“This is a big change. Maps will need to be redrawn.”
Project Midas consists of a research team representing universities in the United Kingdom who have been monitoring the progress of the crack in Larsen C for about three years.
Their research shows that although Larsen C was not necessarily preventing vast amounts of land ice from plummeting into the ocean, in the wake of the incident, the team fears the loss of ice shelves elsewhere in the Antarctic Peninsula.
If additional ice shelves separate from the peninsula, immense quantities of ice could be jettisoned into the ocean, causing a significant rise in sea-levels.
Climate change is a contentious issue, as scientists and world leaders struggle to reach a consensus as to what degree human behavior is responsible for the spike in global warming. The landmark Paris Climate Agreement, signed last year by 153 countries, was celebrated as a major victory for environmentalists worldwide.
Alas, last month the progressive measure suffered a severe blow when President Donald Trump announced that the United States — one of the world’s largest contributors of CO2 emissions — would be withdrawing from the agreement.
Despite the fact that 97 percent of published climate scientists agree that global warming is the result of human activity, some argue that the Earth is experiencing naturally occurring variables in the planet’s climate cycles.
Climate change skeptics believe that recent geological activities in Antarctica aren’t much different from similar events that have seen ice shelves breaking away from polar regions for millions of years before Larsen C’s departure from the South Pole.
Thomas P. Wagner, head of NASA’s polar studies division, says that the breaking up of polar ice will provide scientists with an opportunity to plot potential sea-level rise scenarios that could be used to avoid future disasters.
“While it might not be caused by global warming, it’s at least a natural laboratory to study how breakups will occur at other ice shelves to improve the theoretical basis for our projections of future sea level rise.”
A common geological feature of the sub-zero polar regions is a constant flow of frozen water into the ocean. Ice shelves tend to form around these glaciers and can result in a blockage that causes a build up of ice as the “frozen rivers” continue to flow out to sea.
If an ice shelf, such as Larsen C, collapses and floats away, the glaciers are once again free to flow, often accelerating in pace due to the release of built up pressure.
Nevertheless, Anna Hogg, an expert at the University of Leeds, claims that Larsen C would not result in a rise in sea-levels.
“It’s like your ice cube in your gin and tonic – it is already floating and if it melts it doesn’t change the volume of water in the glass by very much at all.”
Now that Larsen C is an ocean vessel, the iceberg’s voyage could last for decades. Along the way, she might collide with fellow wandering frozen giants, or she may, sadly, melt away as warmer temperatures threaten her existence.
[Featured Image by Mario Tama/Getty Images]