Glaciers Are not just a ‘Canary in the Coal Mine’
Related subjects: Africa, Asia / Pacific, Carbon Emissions, China, Climate Change, Economy, Environment & Ecology, Global, Harvest & Food Supply, In the Loop, India, J.E. Robertson, Sustainable Development, U.S. Environment, Water: a Global Crisis Comments (0)
As ongoing global climate destabilization builds momentum, and fundamental climate-linked environmental processes come apart, we are hearing time and again that melting ice, whether in glaciers or in the Arctic Ocean, is “the canary in the coal mine”. The metaphor is very tempting, indeed, as coal is the most carbon-intensive fuel in use and a major contributing factor to global warming and climate destabilization, but the problem with the metaphor lies in the meaning of the canary being nothing more than an alarm signal. Glaciers are very much more important to human civilization than that.
In fact, melting ice is not just a sign of the underlying problem, and something precious to life that can be corrupted and wiped out by ongoing climate change, it is also one of the fundamental engines of climate-linked disaster, as projected in most scientific models looking at the negative impact of warming. As glacial ice melts, it increases the flood-intensity of river systems downstream, during certain periods, but flooding pushes excess water through, leaving more arid conditions behind. Flooding also erodes riverbeds and surrounding terrain, reducing water absorption capacity.
As melt and erosion build into a cycle of degradation, the result is less fresh water available for farming, less stable riverside communities, and reduced protection against forest depletion. Each of these factors enhances the spiral of environmental degradation that depletes the resources which make vital ecosystem services possible. Without those ecosystem services, like forest-cover which absorbs carbon, stabilizes topsoil, takes up water and shifts precipitation patterns inland and upland, the fertility base and stable landscape civilization depends on are not sustainable.
But glacial melt is also part of the process that links rising temperatures to higher sea levels. When sea ice melts, it contributes to the warming process —as ice is more reflective and therefore less heat absorbing than deep-blue ocean water— but it does not contribute to the rise in sea levels, as the floating ice already displaces water to the same volume. But when glacial ice melts, it releases new water into the global ocean, adding volume and pushing sea levels higher.
Rising sea levels are one of the most severe environmental threats to result from global warming. The most obvious result is the erosion of coastal land. Some small island nations are threatened with total disappearance if global sea levels rise just a couple of meters. Whole populations will have to be relocated, raising serious questions of political sovereignty, democratic rights, and the nature of the link between citizenship and geography. Bilateral treaties are already being negotiated to prepare for such evacuations.
In the developed world, such cases seem rare, and highly exotic, and seaboard erosion tends to be equated with beachgoing and little more. But it is very much more serious than that. Nearly half the world’s population lives on land that is close enough to sea level to be under threat with just a couple of meters’ worth of sea-level rise. River systems and watersheds could see tidal flows interrupted and coastal cities could become uninhabitable, without unprecedented water-retention spending and technological development.
But more severe still is the effect such tidal shifts would have on low-lying nations like Bangladesh. With over 162,000,000 people, Bangladesh is the 7th most populous nation in the world, one of the most densely populated, and intensely poor. Enjoying some of the world’s most fertile land, a high percentage of Bangladesh’s arable land lies below sea level, meaning a sea-level rise of just two meters could erase more than 20% of the nation’s land area, most of its best cropland, and displace tens of millions of people.
Already, south Asian countries are dealing with the prospects of catastrophic and unprecedented mass migrations due to climate change. Serious erosion of Bangladesh’s arable land could cause migrations of up to 80 million people, destabilizing border regions and saturating neighboring countries with unmanageable new concentrations of people. Already, the entire Nile River basin is facing such severe chronic water scarcity that migration patterns, food aid requirements and political stability are linked to the water management policies of countries along the river’s length.
Glacial melt is not a canary in the coal mine; it is both a sign of and a driver of human habitat destruction. Without stable climate patterns and resilient ecosystem services, agriculture is not possible and human civilization as we know it cannot be sustained. Where we are seeing accelerated or even severe glacial melt, we are already facing the long-term fallout from climate destabilization linked to carbon emissions and the greenhouse effect. Concerted restorative action is needed to slow or reverse that melting.
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