August 16, 2023

expert reaction to study modelling warming-induced glacier retreat

A study published in Nature looks at future emergence of new ecosystems caused by glacial retreat.

Prof Chris Rapley, Professor of Climate Science, University College London (UCL), said:

Does the press release accurately reflect the science?

“Yes, but the emphasis in the first sentence on the high emissions scenario could be seen as alarmist. It is unnecessary to hype the piece, since the paper exposes very interesting and worthwhile insights and results in any case. The appeal to protect newly exposed areas is independent of the scale. The appeal for transformative action, though, is strengthened by the contrast between the area exposed in the low emissions and high emissions cases.”

Is this good quality research? Are the conclusions backed up by solid data?

“It’s a novel and valuable study.”

How does this work fit with the existing evidence?

“They have fitted the model to recent observations.”

Have the authors accounted for confounders?  Are there important limitations to be aware of?

“The ‘wild card’ could be sudden substantial change in the climatic driving forces, as opposed to their assumption of incremental forcing and incremental response.”

What are the implications in the real world?

“A collective response to their appeal is justified. However, see my comments below.”

Is there any overspeculation?

“Not that I noticed.”

Additional comments:

“The exposure of new land areas as glaciers retreat will be an interesting test for humanity. Bosson et al appeal to the nations of the world to ‘urgently enhance the protection of the ecosystems’ which will develop in the newly exposed areas to ‘secure their existence, functioning and values’. The point is that humanity is entwined within a global ecosystem upon which we depend for our life support services and wellbeing. Protecting these areas would demonstrate reverence, responsibility, and recognition of immutable ecological truths, which are indifferent to our fate. Unfortunately, the history of our species is to expand into and exploit newly available territories, usually for the benefit of the few, rather than for the collective good. With the world currently captured by the insidious ‘free market’ ideology, which takes no account of externalities such as ecosystem value, the outlook for these areas, and the array of species which could potentially inhabit them, does not look very promising. It would be welcome to be proved wrong.”

Prof Andrew Shepherd, Head of the Department of Geography and Environment; Director of the NERC Centre for Polar Observation and Modelling, Northumbria University, said:

“This work is important because it reminds us that the initial impacts of global warming on ice melting and sea level rise are not our only concern; the knock-on effects include permanent disruption of water resources and permanent changes to landscapes and ecosystems.  We will have to live with these changes long after the ice is gone, and most new landscapes will be in regions with no environmental protection in place.

Does the press release accurately reflect the science?

“Yes, but the suggestion of “novel ecosystems” means new ecosystems and not new types of ecosystems.  The work is really about landscape evolution and not about the ecosystems which might develop.

Is this good quality research?  Are the conclusions backed up by solid data?

“Yes; the conclusions on landscape evolution are I believe robust.

How does this work fit with the existing evidence?

“It presents a new angle by focussing on the landscape change associated with ice loss, and not the ice loss alone.

Have the authors accounted for confounders?  Are there important limitations to be aware of?

“There is not much in there about the timescale and manner in which the ecosystems will evolve in the newly emerging landscapes; this remains to be determined.

What are the implications in the real world?  Is there any overspeculation?

“The implications are that the story of global warming in mountainous regions doesn’t end at ice loss and hydrological change, it is that start of landscape evolution.”

Prof Jeffrey Kargel, Senior Scientist, Planetary Science Institute, said:

“The work by Jean-Baptiste Bosson and others is a clarion call to conserve glaciers and their underlying land.  The world urgently needs to control climate change and the carbon gas emissions that drive it.  However, the authors point out that a great deal of glacier retreat is baked into the Earth already.  Lacking the needed controls that would minimise glacier losses, glacier retreat will sharply accelerate.

“The authors have competently projected the basic physical Earth habitats that will replace glaciers in these areas of glacier retreat.  Climate change over the past century and impending over the coming century is largely caused by a common inherent reluctance to make changes in how modern economies operate.  This behaviour is driven by economic factors that are rather puny in the large scheme of things, such as the 3-year corporate profit line and 5-year national economic plans.  Decade upon decade, short-term thinking has produced long-term climate consequences. This paper’s authors suggest that long-term thinking could result in conservation of a large land area that will become exposed as glaciers melt.  Ironically, the present deficient ability to make rich near-term economic uses of areas covered by glaciers could and should spur conservation.  It makes sense.

“This work is a blueprint for the lands that currently lack an explicit conservation status but should be conserved for the benefit of future generations of humans and for the wildlife and flora that eventually will occupy deglaciated lands and marine environments.  To defer conservation until the ice is gone carries a serious risk that these areas will never be conserved, or will be conserved at much greater cost than if conservation begins now.  It will require long-term thinking.  Our space agencies plan and build space missions that take decades to complete.  We need comparable long-term thinking that will provide habitat for plants and animals on a planet where natural habitat otherwise is shrinking rapidly.  The deglaciated lands comprise a rare case where the opposite is happening and affordable options exist for conservation.

“One other important matter supports the conservation of these specific areas that are highlighted by the authors.  Glacial hazards, including ice avalanches, glacier surges, debris flows, and glacial lake outburst floods, are exceptionally active in rapidly deglaciating terrain, and these hazards are also changing rapidly in their type, magnitude, specific locality, and frequency of occurrence.  By conserving the glaciers and underlying and nearby adjacent terrain and habitats, human uses of these areas will also be limited at very little cost because of the present low development and habitation pressures.  In so doing, otherwise inevitable glacier-related disasters will be limited.  Avoidance or reduction of exposure to hazards is the most effective and efficient form of hazard and disaster mitigation: just don’t build villages, pipelines, and highways that are going to be destroyed or relocated anyway if they are built.”

‘Future emergence of new ecosystems caused by glacial retreat’ by J. B. Bosson et al. was published in Nature at 16:00 UK time on Wednesday 16 August 2023.

DOI: 10.1038/s41586-023-06302-2

Declared interests

Prof Chris Rapley: “I declare no conflict of interests.”

Prof Andrew Shepherd: “No conflicts of interest.”

Prof Jeffrey Kargel: “I have no conflicts of interest in this newsworthy scientific report.”