by Sophie Hughes
According to planetary scientists, ‘hothouse earth’ is an encroaching and deadly concept – even if the reductions in carbon emissions called for in the Paris Agreement are reached, the earth’s climate may keel on to an irreversible pathway of increasing temperatures and rising sea levels in as soon as 50 years (McGrath, 2018; Steffen et al., 2018). It is the notion of a ‘hothouse earth’ I wish to explore in this essay, based upon observations and subsequent research of places I visited whilst on vacation in the West coast of Canada and the US. I travelled down through the Rocky Mountains and ended up in Yellowstone park, an ecosystem not only saturated with geothermal activity but indicative of how nature is coping with changing patterns of anthropogenic activity and climatic variables. The aforementioned landscapes offer an insight into the likelihood of a ‘hothouse earth’ scenario unfolding in the future, which this report seeks to explore.
The above image (Figure 1) is one that I took of the Athabasca glacier, which perhaps does not seem to fulfil expectations of a vast, white, iridescent volume of ice that is typically synonymous with the word ‘glacier’. An information board by the glacier notified tourists that in the past 125 years, the Athabasca glacier has lost half of its volume and receded by more than 1.5km, with about 0.3km of the snout’s retreat occurring in the last 20 years. In addition to these startling figures, a subsequent board highlighted the dangers of straying from the marked path via the story of a 9 year old boy who had been hiking on the toe of the Columbia Icefield in 2001 when a snow bridge which he stepped on gave way, sending him falling into the crevasse below. By the time the rescue crew managed to pull him out 4 hours later, his body had already succumbed to hypothermia. An incident like this tends to happen at least once a year, demonstrating the fragile nature of a glacier that appears to be receding exponentially in an irreversible fashion – thus corroborating the notion of a ‘hothouse earth’.
The next stop on our road-trip, Lake Louise and its proximal glaciers, alluded to similar observations; that glaciers in the Rockies are undoubtedly receding. It appears that this recession is natural, but “augmented by the man-made effects” (Osborn cited in Walton, 2009), leading to such glaciers declining at an increasingly rapid rate. This poses an alarming problem for regions of Western Canada that depend upon glacial water for their homes, businesses and agricultural sector (ibid). Indeed, Bow Glacier, approximately 37km northwest of Lake Louise, is a prime example of glacial retreat, as documented by the Vaux family in black and white photographs over many decades.
Henry Vaux Jr travelled to the Canadian Rockies every August from 1997 to 2013 to replicate images taken by his ancestors a century earlier, providing astounding visual evidence of Bow Glacier’s recession (Derworiz, 2015). Figure 2 was taken by the Vaux family in 1902, picturing Bow Lake and its glacier in the background. Taken exactly 100 years later, Figure 3 shows Bow Lake from the same vantage point, depicting the vast extent to which the glacier has retreated. This is substantiated by the photograph I took this summer (Figure 4), showing that the trend in retreat of Bow Glacier shows no signs of decelerating – perhaps suggesting that a ‘hothouse earth’ scenario is imminent.
The effects of changing environmental variables on Yellowstone National Park, our last stop, were also evident. According to scientists who have been monitoring Yellowstone’s climate for decades, average temperatures are higher than they were 50 years go whilst spring precipitation levels are decreasing, which will likely affect the constitution of plants and animals in the park as well as increasing the frequency and length of fires (Whitlock et al., 2007; Balling et al., 1992). An example of both factors at play regards white bark pine trees and mountain pine beetles. In recent years, a higher incidence of forest fires has diminished the abundance of white bark pines, a foundation species due to its role in enhancing soil formation alongside “providing the major biomass and primary productivity” (Logan et al., 2010 p896) of high mountain and alpine ecosystems. Simultaneously, higher seasonal temperatures have allowed the mountain pine beetle to invade new niche space including white bark pine forests, thus disrupting the wider ecosystem and providing evidence that the effects of climate change work across a range of scales – from global sea level change to regional community composition change.
I would like to conclude by utilising one last example – that of the Morning Glory pool in Yellowstone. Figure 5 is an image of the pool taken in 1940, the tropical blue hues of which seem non-existent amongst the warm yellow/oranges tones in Figure 6, the photo I took during our visit. The change in the colour of the water can, sadly, be solely attributed to visitors throwing pennies, rocks and other objects into Morning Glory. Researchers have discovered that these objects have occluded parts of the heat source and caused the pool’s temperature to lower, enabling microorganisms that thrive in lower temperatures to inhabit the pool (Clark, 2015). Such microorganisms produce pigments that have turned the pool yellow, green and orange over time. Could this example be labelled a micro-scale metaphor for human-induced global warming? It demonstrates how the actions of humans can alter ecological compositions through temperature change and therefore change the appearance of a landform itself. This process, on a macro scale, exemplifies how a ‘hothouse earth’ scenario seems unavoidable on our current trajectory. Beyond the threat of millennials and Gen X having to pay the ‘climate change bill’, a ‘hothouse earth’ sequence of events is becoming more realistic with each day that we fail to address the gravity of the situation, accentuating the need to alter our lifestyles if there is to be any hope of minimising or evading this potentially devastating future.
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Clark, L. (2015). Tourist Trash Has Changed the Color of Yellowstone’s Morning Glory Pool. [online] Smithsonian Magazine. Available at: https://www.smithsonianmag.com/smart-news/touristtrash-has-changed-color-yellowstones-morning-glory-pool-180954239/ [Accessed 26 Aug. 2018].
Derworiz, C. (2015). Decline of glaciers in Western Canada chronicled in family photographs. [online] Calgary Herald. Available at: https://calgaryherald.com/news/local-news/going-back-intime-to-record-retreat-of-glaciers [Accessed 26 Aug. 2018].
Logan, J., Mcfarlane, W. and Willcox, L. (2010). Whitebark pine vulnerability to climate change induced mountain pine beetle disturbance in the Greater Yellowstone Ecosystem. Ecological Applications, [online] 20(4). Available at: https://esajournals.onlinelibrary.wiley.com/doi/ 10.1890/09-0655.1 [Accessed 26 Aug. 2018].
McGrath, M. (2018). Climate change: ‘Hothouse Earth’ risks even if CO2 emissions slashed. [online] BBC. Available at: https://www.bbc.co.uk/news/science-environment-45084144 [Accessed 26 Aug. 2018].
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Walton, D. (2009). The mystery of Lake Louise’s missing water. [online] The Globe and Mail. Available at: https://www.theglobeandmail.com/news/national/the-mystery-of-lake-louises-missingwater/article4216178/ [Accessed 26 Aug. 2018].
Whitlock, C. et al,. (2007). A 2650-year-long record of environmental change from northern Yellowstone National Park based on a comparison of multiple proxy data. University of Nebraska, Lincoln. Available at http://digitalcommons.unl.edu/cgi/viewcontent.cgi? article=1001&context=geosciencefacpub.