Abigail Cook Climate Change, Complexity, and Society: Research Report Fall 2012 The Human Social System and WATER Throughout human history, populations all over the world have continuously interacted with earth’s natural systems. These interactions are complex and increasing. Humans use of land, oceans, and fresh-water, have dramatically changed land cover, biogeochemical and hydrological cycles, and even the climate system. In fact, human influence is now so pervasive that it also dramatically alters the evolutionary trajectories of many species. Our relationship with available and fresh water specifically, is being stressed past the point of return. Although humans have interacted with the environment since the beginning of human history, the scope and intensity of these interactions have increased dramatically since the industrial revolution. Humans depend on ecosystem services to survive, one of these being potable water. Human’s reliance on natural systems – including those which provide us with fresh and accessible water - are increasingly at risk for a few main reasons; global population and per capita use of resources are increasing, and many ecosystems that provide services critical to human well being are degraded. All over the globe, people and nature interact reciprocally across diverse organized levels, forming complex webs of interactions that are imbedded within each other. Humans depend on nature for water, but natural hydrological cycles and water supply are being threatened due to human action and inaction. Currently, more than half of all accessible freshwater worldwide is being used by humans making it extremely scarce. Growing demands for fresh water also dramatically affect species conservation. Globally, at least one-fifth of fresh-water fish species are currently threatened or extinct, and aquatic species currently make up almost half of all animals listed as federally endangered in the United States (Jackson, Carpenter and Dahm). Unfortunately, for many ecosystems, restoration is at the very least more costly than preventing the loss of ecosystem services in the first place. On the other side of the reciprocal relationship between the human social system and water, natural process can devastate human systems through environmental degradation and disasters, such as floods or droughts. At the global level, environmental deterioration now forces more people to cross national borders than wars. Environmental refugees may reach 50 million within the next five years (Jianguo Liu). The impacts of these disasters can range from interruption of work routines, all the way to social conflicts, economic losses, and the spread of disease and death. In the end, accelerating human impacts on natural systems may lead to degradation and collapse of these systems – which in turn compromises the adaptive capacity of humans. Currently, our relationship with the global water system is increasing its vulnerability at an exponential and possibly irreversible rate. In my research, I have found that the primary reasons for vulnerability of global water can be classified into three main sources: vulnerability resulting from human components, from natural components, and vulnerability as a result of the interplays between human and natural systems. The first, (human components) include factors such as pollution and contamination of water supply. The second, (natural components) include temporary rise of water level due to a flood or adversely, a lack of water due to a drought. And finally the third, (the interplays between these human and natural systems) encompass complex relationships. For instance, how our tendency to over fish costal waters, accompanied by pollution and habitat destruction, has simplified ecosystems and caused them to react to external influences in an unpredictable manner; primarily because the buffering mechanisms and resilience in the previous systems have been degraded. We – the human race - are simplifying and homogenizing landscapes and seascapes everywhere making them vulnerable to collapse. All over the world there are local factors as well as global factors that contribute to the vulnerability of water; the primary one however being the uneven distribution of fresh and accessible water. Until recently there has been little debate about sharing water between society and nature. This is not surprising since there is so much water on the planet; roughly two thirds of the earth’s surface is covered with oceans. However, less than 1% of this water is fresh and accessible, the rest being either saline, frozen, or in deep underground aquifers (J. S. Wallace). Usually, the water that is valuable to humans is abundant in developed nations, including the United States, allowing issues such as water quality, environmental impacts, and ecosystem protection to dominate and get addressed in those regions. Consequently however, this leaves an extremely short supply of water for developing nations. Currently, the most severe water shortages are in northern Africa, where the per capita annual renewable freshwater resource is insufficient to meet human needs (J. S. Wallace). Couplings between human and natural systems across locations can also be seen in the comparison of rural and urban areas. Approximately half of the current global population lives in urban areas. As it turns out, cities consume 60% of the water tapped for use by people (Jianguo Liu). Comparably, as the world population rises, human’s uses of freshwater resources are increasing. We are exploiting fresh water, leaving less available to support aquatic and associated ecosystems. Already, some degree of water scarcity exists throughout Africa and the Middle East and it is estimated that by 2050 a staggering 67% of the world's population (6.5 billion people) may experience some water scarcity. Furthermore, by 2050 as many as one in six people (1.5 billion) may have insufficient water to meet their requirements for growing food and domestic water (J. S. Wallace). Already, the state of public water infrastructure is inadequate to meet our needs. Less water is drinkable. Wells provide about 43.5 million people with drinking water, representing 15% of the total U.S. population (Barbara L. Rowe). However, we are draining the wells and decreasing the quality of the fresh water accessible to us. Because we have long had the luxury of seemingly unlimited water, more often than not, that attitude has led us to unnecessary waste and pollution of our water. Throughout the world, water usage in irrigated agriculture, by far accounts for the greatest amount (between 65% and 75%) of total water use (J. S. Wallace). Regrettably, we waste an astronomical amount of water just in the production of our food, through inefficient harvesting, transportation, distribution, processing, and storage methods. While this may not seem to be a prevailing problem right now, improving the efficiency of water use will be important in the very near future in order to balance supply and demand for fresh water and protect aquatic eco-systems. Technologies such as drip irrigation have great potential to reduce water consumption in agriculture (Jackson, Carpenter and Dahm). As Sandra Postel (the leader of the National Geographic’s Freshwater Initiative) put it, “As the world population climbs and water stress spreads around the globe, finding ways of getting more crop per drop to meet our food needs is among the most urgent of challenges.” Among utilities, one of the primary reasons for wasted water is leakage. In fact, it has been estimated that drinking water systems loose 6% - 25% of their finished water through leaks and breaks (Levin, Epstein and Ford). Leaks are also a health risk, a source of contamination in systems that occasionally have negative pressure. Ultimately, the wasting of fresh water through domestic, industrial, and agricultural uses will dominate future water scarcity. It is critical that greater efficiency is encouraged, ideally through economic incentives and a more realistic valuation of water and freshwater ecosystem services. In the 21st century we have seen an increasing amount of evidence of global climate change and in many cases, global warming. Some data predicts that the rate at which warming is occurring is also increasing. If these trends are accurate and they continue, the resulting global warming will adversely affect water distribution, availability, and quality. Ultimately, studies have shown that changes in hydrological cycles have the power to shift the intensity, seasonality, and special distribution of precipitation throughout the world. These changes with only further distress already disrupted ecosystems. Global warming will affect both surface water and ground water in a variety of ways. As discussed in class, a warmer atmosphere holds more water vapor resulting in higher evaporation rates. Warming of the ocean will cause sea level rise form the melting of glaciers and ice sheets, as well as thermal expansion (Levin, Epstein and Ford). Theoretically, higher global temperatures will also result in increased water consumption (drinking water, irrigation, etc.) increasing the demands on water systems even more. Overall, the impacts on climate change on our relationship with water will present themselves in a vast array of consequences, both directly and indirectly. Despite the abundance of water on earth, it is becoming clear that the relatively small portion that is fresh and accessible is under extreme pressure as the population rises and human requirements for water increase. Although we are beginning to gain a better understanding of the necessity of water for species and communities and about the critical levels of water supply needed to maintain ecosystem health, in many parts of the world aquatic ecosystems have been extremely damaged and it is not possible to return them to a natural state. As societies and ecosystems become increasingly dependant on static or shrinking water supplies, there is an increasing risk of severe failures in social or ecological systems. To minimize future human water shortages and undesirable environmental impacts, more equitable sharing of water resources between society and nature is vital. Works Cited Barbara L. Rowe, Patricia L. Toccalino, Michael J. Moran, John S. Zogorski and Curtis V. Price. “Occurrence and Potential Human-Health Relevance of Volatile Organic Compounds in Drinking Water from Domestic Wells in the United States.” Environmental Health Perspectives 115.11 (2007): 1539-1546. J. S. Wallace, M. C. Acreman and C. A. Sullivan. “The Sharing of Water between Society and Ecosystems: From Conflict to Catchment-Based CoManagement.” Philosophical Transactions: Biological Sciences 358.1440 (2003): 2011-2026. Jackson, Robert B., et al. "Water in a Changing World." Ecological Applications 11 (2001): 1027-1045. Jianguo Liu, Thomas Dietz, Stephen R. Carpenter, Carl Folke, Marina Alberti, Charles L. Redman, Stephen H. Schneider, Elinor Ostrom, Alice N. Pell, Jane Lubchenco, William W. Taylor, Zhiyun Ouyang, Peter Deadman, Timothy Kratz and William Provencher. “Coupled Human and Natural Systems.” Ambio 36.No. 8 (2007): 639-649. Levin, Ronnie B., et al. "U.S. Drinking Water Challenges in the Twenty-First Century." Environmental Health Perspectives 110 (2002): 43-52. Loáiciga, Hugo A. “Climate Change and Ground Water.” Annals of the Association of American Geographers 93.1 (2003): 30-41.