Zombie Ice And Momentum In The Climate System
Will a charismatic name catalyze action?
An earlier essay documented the inertia and momentum now embedded in the climate system by the dynamics of oceans and ice. One aspect of this momentum is captured in the popularized term “Zombie Ice.” Sadly, the concept does not seem to have captured the public imagination or spurred a sudden increase in action to reduce greenhouse gas emissions!
Charismatic Names Can Help Focus Attention on Major Environmental Issues
The second time I saw the film "Night of the Living Dead" I had nightmares for a week. There is something terrifying about zombies - their apparent immortality (or undeadness) and unyielding destructiveness - even in fiction.
That same imagery has now been adapted to a real and perhaps similarly immortal, inevitable, and deadly environmental issue in the term “Zombie Ice.” It is tempting to run with gallows humor on this - like Night of the Living Ice Cap, or posting this essay around Halloween (!) - but maybe the topic is too serious to be presented that way.
And perhaps there is some real value in the expression. Catchy phrases have long played a role in riveting popular attention on environmental issues. From acid rain to the ozone hole to the polar vortex to El Niño, the ability to capture an issue in two words has been important in focusing national and international attention. You can find editorial or humorous cartoons on all four of those issues, a sure sign of general awareness.
Zombie Ice is too new a term to have appeared yet in the cartoon medium, but don't be surprised if we see it there soon (note from 2024 - sadly, that hasn’t happened!).
The acid rain and ozone hole issues have been at least partially resolved through international cooperation driven by solid science. Maybe catchy names helped a bit by conveying something of both the cause and the danger of those issues to the general public.
Understandably, current climate change reporting tends to focus on today's environmental disasters - major storms, floods, droughts, and fires. On average, the increase in these disasters is being driven by climate change, but any one story about any one event tends to be couched in wording suggesting that it might be related to climate change, or might not.
Compared with the immediacy of disaster reporting, an additional 2-5 inch increase in sea level by 2050 does not sound very frightening, and does not seem to have conveyed the kind of immediate threat that would lead to immediate action.
So maybe "Zombie Ice" will be the phrase that brings immediacy to what is most likely to prove, in the long run, the most important climate change outcome: the inevitable rise of sea level. Maybe Zombie Ice is just what we need - as a media term anyway.
So what is Zombie Ice and what does it mean for our environmental future?
Water in Zombie Ice Is Currently "Dead" to the Global Water Cycle But Is Coming Back to Life
“Zombie Ice” apparently first appeared as a term on August 29 [2022] in an article by Seth Borenstein of the Associated Press. It then circulated rapidly through media news outlets and by August 31 had even reached our local newspaper here in the seacoast of New Hampshire, where the full story captured all of the space above the fold on page 7.
Zombie Ice is ice that is already unsustainable under current climate conditions - ice that will melt yielding liquid water to the oceans and causing sea level rise - no matter what we do to mitigate global warming.
We can think of the massive, truly massive, amounts of water captured or stored in the ice caps of Greenland and Antarctica as being currently "dead" to the global water cycle, but that massive catastrophe-in-waiting is also, inevitably, slowly, rising again, zombie-fashion.
There Is Solid Research Behind the Charismatic Name
It is fascinating to watch how the kind of dry, precise, totally factual presentation of scientific results in professional papers, purposely devoid of inflammatory adjectives, gets turned into the grist of popular media presentations. Needless to say, the authors of the scientific paper cited below did not coin the term Zombie Ice. The actual article on which the media reports were based is a carefully documented study of rates of ice loss and replenishment on the Greenland ice sheet.
In that original paper, the authors note that modeling the dynamics of ice flow, iceberg calving and meltwater runoff from the massive glaciers that ride atop Greenland is a complex and still evolving area of science, making accurate and precise predictions of water loss to the oceans difficult.
In response, they offer an alternative analysis using a mass-balance approach based on measured gains and losses of water, the current volume of ice, and its exposure to the atmosphere. Using remote sensing images, the authors mapped the area of the ice cap covered in snow in summer, where ice is accumulating, and the area exposed to the atmosphere, where ice is being lost through melting, water runoff, evaporation, and iceberg calving (all of the processes of ice loss are combined in the term "ablation").
A direct correlation between net change in total water mass and this ratio of exposed versus snow-covered ice allows a calculation of how much of the exposed ice would have to melt to bring gains and losses into balance. This is the Zombie Ice - already committed to the oceans.
Zombie Ice Will Cause Sea Levels to Rise 10 Inches
Using average numbers for the period 2000-2019, the calculated difference between the amount of water held in the ice now in Greenland, and that equilibrium amount (the Zombie Ice), is enough to raise sea level by 27.4 centimeters, or more than 10 inches. So Zombie Ice tells us that, even without any further warming, an additional 10 inch rise in sea level is already inevitable.
The researchers made some conservative assumptions along the way. For example, they applied the method to 473 subregions across the island. A single calculation for the entire ice cap would have yielded a 20% higher estimate of the total amount of Zombie Ice.
The use of average water loss values for the years 2000-2019 is also very conservative. Rates of ice loss from Greenland over that 20 year period have been trending upward, and global average temperatures, important in determining snow cover and melting, are going to increase across the century no matter what steps we take now.
If the average conditions across the 21st century are more like the extreme ice melt year of 2012 described in the paper, then the total amount of Zombie Ice is enough to raise sea level by 78.2 cm or more than 32 inches.
When Will All That Zombie Ice Melt?
Where the uncertainty lies in this analysis is in the timing. This is an equilibrium calculation, not a dynamic one. Current thoughts are that it might not be until 2100 or even 2150 before all of this Zombie Ice actually melts. I take no comfort in that. Someone will be here then, maybe even my grandchildren (in 2100), and they will have to deal with this. But, unlike the dynamic models of ice flow, this one does not have a predicted timeline.
The next essay in this series will put this kind of equilibrium thinking into the context of previous geologic eras with global temperatures similar to those predicted for our near future. That steady-state approach suggests that the last time the Earth was 2 degrees Celsius warmer than now (a conservative estimate of warming by the end of the century), sea levels were 15 meters, or nearly 50 feet, higher!
This is the direction we are headed; timing is the question. All that ice in Greenland and Antarctica is melting slowly as only a fraction of it is exposed to the warming atmosphere, and this delays sea level rise. Conversely, that same ice, committed to melting eventually, represents irresistible momentum toward those higher levels. This makes the Zombie Ice calculation seem conservative in the extreme, and also perhaps makes a better understanding of the timing of ice loss from those two massive ice sheets one of the most pressing climate change research issues.
And the article cited here deals only with Zombie Ice on Greenland - how big are the zombies waiting for us in Antarctica?
Will Zombie Ice Cause Us to Rethink Climate Change and Sea Level Rise?
Charismatic names have perhaps helped raise awareness and lead to solutions for acid rain and the ozone hole, issues that have been addressed successfully through the kind of science-based international cooperation and action that we have failed to achieve so far on the climate issue.
Maybe the specter of Zombie Ice can achieve what 30 years of careful IPCC study and synthesis, and recurring international gatherings, has failed to do - motivate increased acknowledgement of the inevitability of climate change and sea level rise, and motivate coherent action in response.
Acknowledgement: Thanks to Caitlin Aber for bringing Zombie Ice to my attention!
Sources
The original scientific article that has led to the term Zombie Ice is here:
https://www.nature.com/articles/s41558-022-01441-2#code-availability
Media stories using the Zombie Ice name include:
https://abcnews.go.com/Politics/wireStory/zombie-ice-greenland-raise-sea-level-10-inches-89003077
https://www.cbc.ca/news/science/zombie-ice-greenland-1.6566437
https://news.yahoo.com/zombie-ice-greenland-raise-sea-145917647.html
The image of the Greenland ice cap is from:
https://earthobservatory.nasa.gov/images/147728/shrinking-margins-of-greenland
The image used adjacent to the ablation discussion is from:
https://climate.nasa.gov/news/3206/nasa-studies-find-previously-unknown-loss-of-antarctic-ice/
The Image depicting re-establishment of equilibrium between ice formation and melting in Greenland is from the Geological Survey of Denmark and Greenland and can be found here: