Geoengineering – an option to slow down sea level rise?
A new report from the University of Chicago presents various measures that could slow down the melting of glaciers in the Arctic and Antarctic in the future and discusses the feasibility, financing and environmental and social impact of so-called geoengineering, among other things.
Like a band-aid on a wound, light-colored sheets covering glaciers in the Alps (e.g. on the Rhône Glacier in Switzerland and the Schneeferner on the Zugspitze in Germany) have been in place for years to prevent the glaciers from melting even faster during summer.
Could similar geoengineering measures – a collective term for large-scale technical interventions by humans in the Earth’s geochemical or biogeochemical cycles, for example to mitigate the effects of climate change – also be used effectively in the Arctic or Antarctic?
A number of international glaciologists discussed this question at two scientific workshops last fall. The resulting white paper, with a call to explore what interventions could and should be used to slow glacier melt in the coming decades, was published by the University of Chicago on July 11.
One option for protecting the glaciers from melting is to use “underwater curtains” to prevent warm ocean water from reaching the underside of ice shelves and glacier fronts and melting the ice from below.
“Everyone who is a scientist hopes that we don’t have to do this research,” Douglas MacAyeal, professor of geophysical sciences at the University of Chicago and co-author of the white paper, said in a university press release. “But we also know that if we don’t think about it, we could be missing an opportunity to help the world in the future.”
The persistently high carbon emissions worldwide and the associated expected rise in sea levels due to the rapid melting of glaciers and ice sheets gave rise to such considerations in the first place. However, the report explicitly points out that the most important thing is to drastically reduce carbon emissions into the atmosphere. “We can never say often enough that that is the first priority,” emphasized John Moore, professor at the Arctic Center at the University of Lapland and co-author of the report.
The implementation of such measures is the subject of controversial debate and critics not only argue that artificial curtains or similar measures would be far too expensive and logistically almost impossible to implement, but also question their effectiveness.
Tipping points already passed?
The Arctic and Antarctic are home to the largest ice masses on our planet. Proponents are therefore speculating as to whether, for example, the installation of a kind of underwater curtain along the large and particularly endangered glacier fronts could slow down the melting.
The authors of the White Paper are aware of the potential consequences, ranging from high costs for little impact to significant disruption to polar ecosystems and social impacts on Arctic indigenous communities. They emphasize that there are many questions to be answered before such efforts can be undertaken.
“It will take 15 to 30 years for us to understand enough to recommend or rule out any of these interventions,” said Professor Moore, and Professor MacAyeal added: “Our argument is that we should start funding this research now, so that we aren’t making panicked decisions down the road when the water is already lapping at our ankles.”
At present, no one can say whether the ice sheets have not already passed their tipping point, if there is one, and whether any interventions would come too late anyway.
“Humans have already released so much carbon dioxide that we are seeing profound changes in every glacier system around the world,” said Professor MacAyeal. “Many of these are likely to have a tipping point where even if we were to stop emitting all carbon worldwide tomorrow, the system would still collapse. And we are not in a position now to say that we haven’t already crossed those points.”
Not without international cooperation
Should such geoengineering ever occur, the report’s authors call for “robust participation of sociologists, humanists, ecologists, community leaders, scientific and engineering governing bodies, international treaty organizations, and other relevant stakeholders in guiding the research”.
The Arctic would be the best place to test these approaches, as it is much easier to reach than the Antarctic, although there is another important aspect to consider here: thousands of people live in the Arctic who depend on it for their livelihoods, especially indigenous peoples. “It is imperative that any of these interventions be done in concert with these voices,” emphasizes Professor Moore.
No matter how great the precautionary measures will be, we can only hope that we can do without these “band-aids” in the future and instead prevent further “injuries” to the earth.
Julia Hager, Polar Journal AG
Link to the White Paper: https://climateengineering.uchicago.edu/wp-content/uploads/2024/05/Glacial-Climate-Intervention_A-Research-Vision.pdf
More about this topic:
