Graduation year: 2022
Semester/year area of interest proposed: Spring 2020
Major status: ENVS single major
Other major (if applicable):
Minor(s) (if applicable):
I believe that climate change is the most pervasive threat that we face in our modern world. Global temperature increase will permanently alter the characteristics of the biophysical systems in which we live. The constant warming trend we are experiencing is particularly dire for the stability of our alpine regions. Mountainous regions covered in glaciers and snowpack do not warm linearly as global temperature increases. Alpine regions experience compounded warming which magnifies the slower global warming trend. As snowpack and glaciers melt the albedo effect in the region decreases. Rock and dirt exposed by melting absorbs solar radiation where it was once reflected by glaciers/snowpack, causing significant temperature increase and even faster rates of melt (D. Viviroli et al., 2011), therefore, even the slightest overall temperature increase is compounded. However, there is some research which suggests that glaciers and snowpack in alpine regions can be protected from compounded temperature increase. A study situated in the Himalayan region concluded that glaciers covered in debris retreat much slower than uncovered glaciers, or are sometimes even stagnant (Scherler et al., 2011). The debris insulates the covered glaciers from the exponential temperature increase. This phenomena is important to consider while examining the changes in our alpine regions, however, it is certainly not significant enough to counteract the temperature increase.
Compounded warming trends in alpine regions will severely impact the effectiveness of glaciers and snowpack as water reservoirs. To understand how access to water will be impacted by melting alpine regions I have examined research conducted in the Himalayan region and the Tropical Andes. The glaciers and snowpack in these regions play an integral role during the dry seasons, annual melt replenishes rivers and other reservoirs as precipitation tapers off. In India, during the dry season, 70% of the water in the Ganges, Indus, Tarim, and Kabul Rivers is sourced from snowpack/glacial melt (Xu et al., 2009). In Western China, 25% of dry season discharge is sourced from melt in alpine regions (Xu et al., 2009). In South America the situation is very similar. The Rio Santa provides the perfect example; ~ 40% of the dry season discharge of this river, which supports a significant portion of rural Peru, is sourced from annual melt (Bradley et al, 2006). Highly populated areas of the world rely heavily on regular annual melt in order to survive. As warming trends continue in alpine regions the timing and characteristics of annual melt will drastically change. A study which modeled glacier and snowpack melt in the greater Himalayan region predicts an initial increase in annual melt, however, flow rates will decrease significantly sometime between 2045 and 2065, at current warming rates (Immerzeel et al, 2010). At this point in time snowpack and glaciers will have been depleted creating massive water shortages. Of course, populations will feel the impact of warming trends in alpine regions long before 2045. As temperature increases, the timing of the annual melt will shift dramatically. Peak melt will occur earlier and earlier each spring, moving away from peak growing seasons (Barnett et al, 2005). This will reduce the productivity of agriculture significantly. Models predict that the Brahmaputra basin will be able to feed 34.5 million less individuals, the Indus basin will be able to feed 26.3 million less individuals, and the Yangtze basin will be able to feed 7.1 million less individuals (Immerzeel et al, 2010). We are expected to hit these estimates by 2050, however, the consequences will be severe long before we reach the millions.
In addition to the water insecurity created by temperature increase in alpine regions, flooding events will increase in severity and frequency (Sharma, 2008). As glaciers retreat at increasing rates they begin to overwhelm the banks of their drainage lakes. When heavy precipitation events occur the natural dams holding these lakes begin to fail and severe floods are released. These sudden flooding events pose two risks. The first is obvious, floods destroy homes, farmland, and livelihoods. Secondly, these events represent the lack of an intermediate reservoir, there’s no physical place where melt can be stored effectively between the glaciers and the oceans. Therefore, in flooding events, and as melt increases in general, water is being used less and less efficiently. There have been efforts to adapt to this new reality. The most popular strategy is to construct artificial dams which store water and protect communities against flooding events. This is illustrated by the recommendations made by Bharat R Sharma and Devesh Sharma in a report issued by the International Water Management Institute of New Delhi, India. They point out that India has a dam storage capacity of only 200 m3/capita, significantly lower than other nations, China has a dam storage capacity of 1000 m3/capita (Sharma, 2008). In order to adapt to intense melting in alpine regions and mitigate the consequences nations must begin to take action immediately.
Warming trends in alpine regions also pose a significant threat to biodiversity. High elevation zones harbor unique and fragile ecosystems. The organisms found in these ecosystems require a very specific habit. As temperature increases, alpine zones undergo habitat change, and organisms which can not tolerate this shift are forced to high elevations. Eventually, these organisms will reach the top and go extinct. A common example used to illustrate this plight is the pika, a small alpine dwelling mammal. The pika, and hundreds of other cold loving, alpine dwelling organisms, have been moving up mountain slopes in search of a diminishing habitat (Krajick, 2004). Eventually our fragile alpine ecosystems will be destroyed by temperature increase.
Temperature increase in alpine zones will significantly alter their characteristics, creating a cascade of consequences. Which will radiate throughout the global hydrological system.
- How have changes in temperature impacted melting in alpine regions?
- What mechanisms have contributed to melting in alpine regions?
- Why is temperature increase compounded in alpine regions?
- How does temperature in alpine regions affect the surrounding populations?
- How have populations which rely on these reservoirs adapted?
- How can water shortages and changes in melting patterns be mitigated/compensated for?
GEOL 280 (The Fundamentals of Hydrology): I will learn more about complex water systems. I will also gain knowledge regarding how water flows between different storage reservoirs as a part of the hydrological system. I plan to take this course fall 2021.
GEOL 170 (Climate Science): I will gain more knowledge about Earth’s complex climate systems. I will also understand how those systems interact and how they are being impacted by climate change. I plan to take this course fall 2021.
GEOL 340 (Spatial Problems in Earth System Science): I will learn how to situate natural systems within a spatial context. I will also deal with real data and gain more knowledge about how to conduct my own research, which will be valuable for my thesis and my future career. I plan to take this course spring 2022.
PHIL 215 (Philosophy and the Environment): I will learn more about how humans interact directly with Earth’s natural systems. This course will also address the question of ethics within the field of environmental studies and how we deal with consequences which impact some more than others. I plan to take this course spring 2022.
Here are the required breadth courses I will include in my ENVS major/minor: CHEM 100, GEOL 150, ECON 260, ENVS 460, SOAN 305, HIST 239, HIST 261, PHIL 215. These are in addition to my ENVS core courses, and the area of interest courses I propose above.
Revisions to date
My consultant is Elizabeth Safran
Her feedback as of March 2020 has been:
- Talk about mitigation efforts, adaptation efforts (enhance storage methods)
- Expand evaluative to include temperature increase
- Descriptive reword (how have changes in temperature affected . . .)
- Barnett, T. P., J. C. Adams, and D. P. Lettenmaier. 2005. “Potential Impacts of a Warming Climate on Water Availability in Snow-Dominated Regions.” Nature 438 (7066): 303–9.
- Bradley, R. S., M. Vuille, H. F. Diaz, and W. Vergara. 2006. “Threats to Water Supplies in the Tropical Andes.” Science 312 (5781): 1755–56.
- Immerzeel, W. W., L. P. H. van Beek, and M. F. P. Bierkens. 2010. “Climate Change Will Affect the Asian Water Towers.” Science 328 (5984): 1382–85.
- Krajick, K. 2004. “All Downhill from Here?” Science 303 (5664): 1600–1602.
- Scherler, D., B. Bookhagen, and M. R. Strecker. 2011. “Spatially Variable Response of Himalayan Glaciers to Climate Change Affected by Debris Cover.” Nature Geoscience 4 (3): 156–59.
- Sharma, B., and Devesh Sharma. 2008. “Impact of climate change on water resources and glacier melt and potential adaptations for Indian agriculture.” New Dehli: International Water Management Institute.
- Viviroli, D., D. R. Archer, and W. Buytaert. 2011. “Climate Change and Mountain Water Resources: Overview and Recommendations for Research, Management and Policy.” Hydrology and Earth System Sciences 15 (2): 471–504.
- Xu, J., R. E. Grumbine, and A. Shrestha. 2009. “The Melting Himalayas: Cascading Effects of Climate Change on Water, Biodiversity, and Livelihoods.” Conservation Biology 23 (3): 520–30.