What will happen if glaciers melt completely?
Glacier ice is a very important part of our global system. It provides drinking water and a vital source of water for agriculture, hydropower and industry in many parts of the populated world. But what would be the reality if all of worlds glacier ice disappears?
Below are just some of the most profound effects supported by various theories, simulations or research (but the future is the future and we can only estimate):
1) Societal/Regional collapse
Sounds extreme perhaps? Maybe a complete societal collapse is unlikely to rise from the lack of glaciers alone, but water shortages for entire cities are a huge socio-economic problem waiting to happen. At current, human consumption of water as a commodity is not treated with the seriousness it deserves, and can often by diverted, polluted or mis-managed 1. Many cities at the base of mountain ‘water towers’ will face serious future insecurities as long term water storage from glaciers are diminished and disappear completely. This has begun to occur already in cases in Bolivia 2 and looks likely to occur for parts of central Chile, Peru 3, India, Pakistan, Nepal, China and Afghanistan as well 4,5, to name but a few. Serious citywide water shortages not related to glaciers have already changed the perception of some urbanites on the preciousness of such a resource and what it means to live in 15 liters of water per day 6. What’s more, as a total resource, we will lose the majority of the remaining freshwater available to us as it is lost to the salt ocean. Currently, only 0.3% of water on earth is in a form safe to drink. Over 68% of this freshwater supply is held suspended in ice 7. You do the math.
2) Dramatic sea level rise
The contribution of small mountain glaciers to total sea level rise is relatively small (estimated at 0.41 m 8). However, if we consider a world with zero ice, even at the poles (so no Greenland or Antarctic ice sheets), that’s a lot of melting. Estimates of completely melted polar ice sheets show a ~65 m rise in global average sea level 8. Think about a near future world where we have a likely 20 cm of addition average sea height…. this already is set to submerge many coastal communities, such as those in Bangladesh, Florida and Northern Europe to name a few. 65 m would really be a different world from what we see right now (Figure 1). The social, political and economic costs of such mass migrations would be very significant indeed!
Figure 1. Europe underwater. A new land surface map considering all ice on earth melting. Source: National Geographic.
3) A new climate system
The worlds regional climates (that is the long term average of weather patterns) are undergoing measurable change as we speak, largely as a result of human-induced emissions of carbon dioxide and other greenhouse gases 8. These changes to climate are bringing increases to the occurrence of extreme events, and have also been connected to recent reductions in the presence of arctic sea ice 9. A world without this ice could bring about changes to the parts of the earth where agriculture is possible. While parts of the current Mediterranean landmass (such as central Chile or southern Europe) are likely to become lost to desertification under extreme climate warming and lack of water, parts of Greenland, and current arctic tundra could become more hospitable and permit crop development. However, if that sounds nice, think for a moment about the potential knock on effects about global heat transport which is balanced by the input of freshwater into the oceans (such as the North Atlantic conveyor belt theory 10). Such reduction in heat transport between equator and pole leads to the possibility of permanently cold northerly regions and permanently hot desert regions closer to the equator. This could potentially limit these new growing geographies and drastically reduce the habitable places of our planet… sounds less fun for a continuously rising human populace, right?
Cited information:
1 10 Critical Water Scarcity Facts We Must Not Ignore. World water reserve (2018). Available at: https://worldwaterreserve.com/water-crisis/water-scarcity-facts/. (Last access 14/04/2019).
2 Shrinking glaciers cause state-of-emergency drought in Bolivia. Guardian (2016). Available at: https://www.theguardian.com/environment/2016/nov/28/shrinking-glaciers-state-of-emergency-drought-bolivia (Last access 12/04/2019).
3 Andean Cities Adapting to to Glacier Retreat to Preserve Water Security. CityFix (2018). Available at: https://thecityfix.com/blog/4-andean-cities-adapting-glacier-retreat-preserve-water-security-kate-cullen/. (Last access 14/04/2019).
4 The Struggle for Asia’s water begins. Forbes (2010). Available at: https://www.forbes.com/2010/09/09/water-china-tibet-2020-opinions-contributors-steven-solomon.html#4ede16ac40f7 (Last access 14/04/2019).
5 Water in the Hindu-Kush Himalaya. ICIMOD (2019). Available at: https://link.springer.com/content/pdf/10.1007%2F978-3-319-92288-1_8.pdf (Last access 12/04/2019).
6 Will Cape Town be the first city to run out of water?. BBC NEWS (2018). Available at: https://www.bbc.com/news/business-42626790. (Last access 13/04/2019).
7 Earth’s Freshwater. National Geographic. Available at: https://www.nationalgeographic.org/media/earths-fresh-water/ (Last access 14/04/2019).
8 Vaughan, D.G., J.C. Comiso, I. Allison, J. Carrasco, G. Kaser, R. Kwok, P. Mote, T. Murray, F. Paul, J. Ren, E. Rignot, O. Solomina, K. Steffen and T. Zhang, 2013: Observations: Cryosphere. 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.
9 Yin, Z., Wang, H., Li, Y., Ma, X., and Zhang, X.: Links of climate variability in Arctic sea ice, Eurasian teleconnection pattern and summer surface ozone pollution in North China, Atmos. Chem. Phys., 19, 3857-3871, https://doi.org/10.5194/acp-19-3857-2019, 2019.
10 Chen, X., Tung, K. (2018) Global surface warming enhanced by weak Atlantic overturning circulation. Nature. 559, pp 387–39. https://doi.org/10.1038/s41586- 018-0320-y
Written by Thomas Shaw.
Edited by Equipo Glaciar.