Asking questions, good faith, and the Antarctic geoengineering issue

We’re almost 200 years into the biggest geoscience experiment ever undertaken. Since the industrial revolution, humans have been pumping increasing amounts of greenhouse gases, predominantly carbon dioxide and methane, into the atmosphere. The response is exactly as predicted even before the turn of the 20th century: a rise in global temperatures, whose influence on our experience of climate–via weather–is becoming ever clearer.

In this way, climate change can be considered as large-scale geoengineering–human manipulation of environmental processes which affect the earth's temperature. This begs the question: if we can artificially increase global temperatures, can we similarly reduce global temperatures? What if we could deploy technologies to prevent the most harmful effects of climate change. It’s an appealing idea: save ourselves from climate change without any sacrifice to lifestyles, nor economic, agrarian, or political systems; a few strategically deployed technologies will do all of this for us.

Global heating, resulting from human emissions of greenhouse gases, is, essentially, an accelerated natural process. Organic matter has always decomposed, wildfires have always raged, and rocks have always been weathered.  Each of these are natural sources of greenhouse gases, affecting the climate, albeit on much longer timescales than we’re currently experiencing. Many geoengineering methods, promising climate repair, are similarly inspired by nature. Perhaps the best researched example of such — stratospheric aerosol injection — involves directly introducing aerosols into the atmosphere to reflect incoming sunlight, inspired by volcanic eruptions, which spew huge amounts of the particles into the atmosphere. In the two years following the eruption of Mount Pinatubo in 1991, for example, global temperatures in dropped by approximately 0.4°C (0.7°F).

This drop in temperatures was, however, a temporary blip: as the aerosols dissipated, so too did global temperatures return to their positive trends. The world’s ice sheets — Greenland and Antarctica — continue along a similar trajectory. Over the past 20 years, the Antarctic Ice sheet has lost over 2000 Gigatonnes of ice; that 250 tonnes — about the equivalent of three double-decker buses in volume — for every single person alive today. These estimates are equivalent to about 2cm of sea level rise, which pale in comparison to future projections, suggesting up to a meter by the end of the century. Tempting, then, to wonder whether we can artificially slow down (i.e. geoengineer) the ice sheets to prevent ice loss.

Increasingly over the past five years, a vocal minority of glaciologists (scientists who study glaciers and ice sheets) have pushed the debate on geoengineering of the ice sheets towards the attention of the masses. Despite remaining on the fringes, this movement has gained steam, culminating in workshops at the University of Cambridge, Stanford University, and at the annual general assembly of the European Geophysical Union, Europe’s largest annual gathering of scientists. Prestigious news outlets, including the BBC, Nature, and the New Scientist, have hosted articles discussing the findings.

Articles such as these (and, I would argue, attendance at these workshops) create a false narrative of an open scientific debate. The editorial temptation to present both sides of a debate is understandable, but the reality is that the vast majority of glaciologists do not support geoengineering interventions.

These ideas are being pushed by a small group of scientists, who give the impression of curiosity and cite scientific enquiry (“We absolutely don’t know if [the idea] is going to work or not” they say). To me, motive is irrelevant, and outcomes are all that matter; what the public sees is an ‘open scientific debate’, giving the impression that geoengineering technologies are feasible. This feeds straight into fossil fuel companies’ narratives, which have shifted from denial to more subtle “delay, deflect, downplay” as the evidence and public perception has shifted in recent years. Essentially, by opening the debate, thereby suggesting that geoengineering is a viable solution, urgency is removed from climate action. By hosting workshops on this debate, prestigious institutions are (unwittingly) lending their institutional support to this narrative.

It is hard not to question motives in the face of overwhelming evidence about the infeasibility of these methods. One suggestion is to build underwater curtains, creating a physical barrier that blocks relatively warm water at the bottom of the ocean from reaching the Antarctic Ice Sheet. The quoted cost of this solution is a US$40 billion price tag, for an underwater flood barrier that is 80km long and 600m deep. For context, the Thames flood barrier — which cost around $1.5bn (in today’s money) to build — is 500m long and at sea level, located within a stone’s throw of the major city it serves to protect; it is hard to imagine how a barrier almost 200 times as long, built far below the ocean, in one of the most inaccessible regions on Earth, could be built at such a cost. Other proposals, which mainly involve increasing the friction between the sliding ice and the bed beneath it by either removing water or cooling the area, are similarly infeasible on any number of financial, technological, and logistic grounds.

What I find most interesting about this issue is the broader question of asking questions: asking a question does not exist in a vacuum, it frames the problem and provides implicit support for one viewpoint or another, even indirectly. Broadly, the view of science as a utopia in which any question can be explored honestly simply by being curious, non-judgemental, and having an open mind, with no political or personal prejudice, is exactly that: a dream. The questions we decide to study are informed by — and in turn inform — political and social agendas, and the way we approach them are influenced by our own personas. It is at best naïve, and at worst downright irresponsible, to pretend that asking whether Antarctic geoengineering is feasible can be quite so simple.