Melting alpine glaciers in a global system
The Rocky Mountains of Western Alberta are a short drive from my home in Calgary, and a favourite weekend getaway. Amidst their beauty it would be easy to overlook the reality that they face a serious environmental issue: the rapid melting of alpine glaciers.
With the heat waves that hit Western Canada in the summer of 2021, between June 25th to July 4th it was reported that melt from the glaciers was 3x greater in this 10 day window than in the last 12 years. This rapid melting causes masses of meltwater to rush down the Bow River, impacting areas along its course, including the city of Calgary, and increasing the risk of flooding. Receding glaciers also impact our water supply. 60 percent of the Calgary’s water comes from the Bow River, which is fed by an alpine glacier originating at Lake Louise.
But it’s not just the local area that is impacted by these freshwater systems. The Bow River courses through Saskatchewan and Manitoba, eventually feeding into Hudson bay, impacting industries and farmers along the way. According to Canada’s Changing Climate Report, a change in the rate and timing of streamflow has consequences for both the quality and temperature of the river, impacting not only our water supply and ability to generate hydro-electricity, but also having grave consequences for the many aquatic species that rely on that habitat and are part of a larger food chain. As you can see, this issue may seem local at first, but it is in fact much bigger than that.
What are the large-scale drivers causing this?
Glaciers all around the world are shrinking and receding as a direct result of global warming. According to the IPCC 2018, human activity on earth has caused an increase of around 1 degree Celsius above pre-industrial levels, and this number could get as high as 1.5 or more in the next few decades. This warming tends to be higher over land compared to the ocean, and higher at northern latitudes than south, meaning Canada is likely to see continued warming in coming years - in fact, our average temperature is projected to increase at twice the rate of the global average. The greenhouse gases causing this warming are the result of human activity, including land conversion that leads to the loss of carbon sinks and emissions from the burning of fossil fuels.
Proximate drivers are defined as the immediate human activities that drive a particular environmental change. It’s easy to declare GHG emissions the root of the problem. But underlying drivers are those related to the fundamental needs of humans, and are important to consider here.
What are the interactions of this issue in terms of socio-ecological systems?
In the province of Alberta, the oil and gas industry is a major part of not only the economy, but the social culture. For many whose livelihood is linked to the industry, the concept of phasing out fossil fuels is undesirable and scary. Whilst from an ecological perspective it may seem obvious that we need to replace this industry with renewables in an attempt to curb our emissions, its important to consider the social and economic imperatives here, because they present barriers to this reality.
Ironically, many people in Alberta enjoy outdoor activities, whether it is skiing in the winter or hiking in the summer, and don’t seem to see that our industries may limit our ability to enjoy these recreational activities in the future, if our landscape and local climate changes as a result of untethered warming.
How is this local issue interconnected with global issues?
Well for starters, we are one of many places experiencing the same issue. According to the IPCC 2012, both the Greenland and Antarctic icesheets are losing significant mass, arctic sea ice is shrinking, and spring snow cover across the northern hemisphere is decreasing. The report claims that since the 1970s, 75% of the rise in sea levels that scientists have observed could be attributed to ocean thermal expansion and the loss of glaciers.
According to Canada’s Changing Climate Report, glaciers in the Canadian Rocky Mountains shrunk roughly 40% between 1919-2006, and are projected to lose upwards of 90% of the volume that remains by 2100. Between this and the projected loss of alpine snow cover, regional water resources will be undeniably impacted.
Secondly, GHG emissions may be released in one place, but the effects of it will be felt in another. On top of that, impacts of human activity on the earth are not linear, and can often cause delayed or cascading effects. For example, every Calgarian remembers the flood of 2013. Well, according to Canada’s Changing Climate Report, while we can’t be sure that human activity caused the flood itself, recent studies that have analyzed the event did detect human influence for the mass amount of rainfall that caused it.
A flood of that scale may be the result of many factors and difficult to attribute to any single one. However we know that increased GHG emissions, primarily due to human activities, result in increased temperatures, which then lead to increased precipitation, and ultimately more extreme rainfall events. The 2013 flood might be one of many examples of a cascade caused by a changing climate.
The melting of ice can cause large influxes of freshwater to our oceans, which is a global concern. If larger glaciers like those in the Canadian Arctic continue to melt as rapidly as they currently are, a threshold may be reached where the ocean currents become impacted and altered, and this could have impacts on countries across the world.
So what?
As the Executive Summary points out, global changes like this are not a result of simple, linear cause-and effect mechanisms, but rather many interacting factors that may trigger cascading effects throughout the system, or even become feedback loops that amplify certain effects. For example, as climate change leads to melting ice, this leads to a torrent of effects that lead to further climate change.
The Executive Summary claims that we as humans have altered the hydrological cycle on earth, and at this point climate change will impact freshwater availability noticeably by the year 2025.
So, what are we waiting for?
References
City of Calgary. (n.d.) Calgary’s water supply. https://www.calgary.ca/uep/water/water-and-wastewater-systems/water-treatment/water-supply.html
Elliot, J.K. (2019, September 18). When does an ‘I love Canadian oil and gas’ shirt become political? Global News. https://globalnews.ca/news/5913362/i-love-canadian-oil-and-gas-shirt-political/
Environment and Climate Change Canada. (2019). Canada’s Changing Climate Report. Canada in a Changing Climate. https://changingclimate.ca/site/assets/uploads/sites/2/2020/06/CCCR_FULLREPORT-EN-FINAL.pdf
IPCC (2013). Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
IPCC (2018). Summary for Policymakers : In:Global warming of 1.5 C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [V. Masson-Delmotte, P. Zhai, H. O. Pörtner, D. Roberts, J. Skea, P. R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J. B. R. Matthews, Y. Chen, X. Zhou, M. I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, T. Waterfield (eds.)]. World Meteorological Organization, Geneva, Switzerland, 32 pp.
Moore, S. (2021, July 6). Alberta glacial melt about 3 times higher than average during heat wave, glaciologist estimates. CBC News. https://www.cbc.ca/news/canada/calgary/jeffrey-kavanaugh-glacier-melt-retreat-rockies-heat-wave-1.6091949
Steffen, W., Sanderson, A., Tyson, P.D., Jäger, J., Matson, P.A., Moore III,B., & Wasson, R.J. (2004). Executive summary of “Global change and the earth system: A planet under pressure”. Berlin: Springer-Verlag.