From retreating glaciers to dangerously high sea levels, the recent developments are calling future generations to take climate action now. Deep crevasses have developed in the rapidly flowing ice at Store Glacier, one of the outlet glaciers of the West Greenland Ice Sheet. This phenomenon points to a larger, more troubling question. Since the 1990s, the average mass of ice lost from ice sheets has quadrupled, reaching some 370 billion metric tons annually. Scientists warn that if current trends continue, the 1.5°C target set by the Paris Climate Agreement may be too high for the stability of these critical ice formations.
The East Antarctic Ice Sheet has not been spared, too—recent reports show massive, skyscraper-sized icebergs calving from its fringes. These profound changes should sound loud alarms about what’s to come with future sea level rise. The Greenland and Antarctic ice sheets combined contain enough ice to raise global sea level by almost 65 meters. Scientists warn that once enough ice is gone, recovery won’t happen until the Earth is plunged back into a new ice age.
The Role of Scientific Observations
Noting the use of recent satellite-based observations, Professor Jonathan Bamber, an expert in measuring changes in ice sheets, warned that this paints a worrying picture. These revelations are what has spurred scientists and policymakers into action.
“Recent satellite-based observations of ice sheet mass loss have been a huge wake-up call for the whole scientific and policy community working on sea level rise and its impacts. The models have just not shown the kind of responses that we have witnessed in the observations over the last three decades.” – Professor Jonathan Bamber
Everything that you would expect to see if the ice loss were accelerating – it is. Otherwise, this trend may become entrenched for generations to come. UMass Amherst Climate Change Professor Rob DeConto expressed concern over how permanent these changes could be.
“It is important to stress that these accelerating changes in the ice sheets and their contributions to sea level should be considered permanent on multi-generational timescales.” – Professor Rob DeConto
The need to act on climate is more and more apparent as the science speaks louder with each passing day. Professor Chris Stokes remarked on the implications of exceeding 1.5°C:
“There is a growing body of evidence that 1.5 °C is too high for the ice sheets in Greenland and Antarctica. We’ve known for a long time that some sea level rise is inevitable over the next few decades to centuries, but recent observations of ice sheet loss are alarming, even under current climate conditions.” – Professor Chris Stokes
The Consequences of Warming
This figure demonstrates the existential consequences of global warming on polar ice sheets. Evidence from past warm periods suggests that several meters of sea level rise can be expected when global temperatures reach 1.5°C or higher. The longer these extreme temperatures are maintained, the more damage done to ice melt and thus the rising sea level.
“Evidence recovered from past warm periods suggests that several meters of sea level rise—or more—can be expected when global mean temperature reaches 1.5 °C or higher. Furthermore, this evidence also suggests that the longer those warm temperatures are sustained, the greater the impact on ice melt and resulting sea-level rise.” – Professor Andrea Dutton
Recent findings indicate that even a modest increase to 1.5°C could result in significant sea level rises over the coming centuries, driven primarily by melting Greenland and Antarctic ice sheets.
A Call for Action
Climate experts warn that the world must stick to ambitious targets in order to avoid the worst climate-induced disasters. Ambassador Fuller stressed the importance of limiting temperature increases:
“Findings such as these only sharpen the need to remain within the 1.5°C Paris Agreement limit, or as close as possible, so we can return to lower temperatures and protect our coastal cities.” – Ambassador Fuller
Other climate experts argue that 1.5°C isn’t a lost cause after all. They understand that even one hundredth of a degree matters, especially for the eventual collapse of ice sheets.
“We are not necessarily saying that all is lost at 1.5°C, but we are saying that every fraction of a degree really matters for the ice sheets—and the sooner we can halt the warming the better, because this makes it far easier to return to safer levels further down the line.” – Professor Stokes
Meeting the 1.5°C target is important, but it likely won’t be sufficient to prevent accelerated sea level rise. Future projections show us getting rates like this or even approaching one centimeter per year relatively soon.