Shrinking Freshwater Resources: Part I

Despite our dependency on freshwater resources, the unsustainable and over-consumption of the resource has led to irreversible consequences, and one famous case study that you may know of is the shrinking of the Aral Sea. I will be focusing on the impacts of unsustainable consumption of surface freshwater resources and looking specifically at the Aral Sea case study.

The Aral Sea, located in Central Asia, used to be one of the world’s largest lakes until the 1960s, and now it is known as one of the world’s largest environmental disasters (Spoor, 1998). The Aral Sea is largely controlled by its tributaries, the Amu Darya and Syr Darya rivers, due to the absence of surface outflows and prior to the 1960s, lake levels were relatively stable with water levels fluctuating between 20 – 40m. However, human action was the largest cause for the decline in the lake (Micklin, 1988). Irrigation practices existed for many millennia and irrigation posed no threats to the lake levels, however when irrigation expanded from 5 million to 7.9 million ha of land from the 1960s to 2000, huge changes can be seen in the lake levels (Micklin, 2007). The Former Soviet Union in Central Asia planned to build large damns, canals and reservoirs for the expansion for the cotton industry. This saw 700,000 km of canals, of which the Karakum Canal is the largest (1,370 km), being built and the water was solely derived from the Amu Dayra and Syr Darya rivers (Waltham & Sholji, 2001). Ultimately, lower inputs and high evaporation rates in the hot desert climate saw the steady shrinking and salinization of the Aral Sea whereby the sea is now made up of three residual lakes and the salt content of two of these lakes no longer contains any fishes. See the video below for a time lapse of the shrinking of the Aral Sea from 1985 to 2015. 

The shrinking of this freshwater resource has huge consequences on the populations who depends on this freshwater resource, and the biological and ecological services provided by the lake. For example, the fishing industry has suffered massively due to declining indigenous fish populations; the decline of fish populations occurred due to the increasing salinity of the lake as well as the loss of feeding and spawning areas (Micklin, 2007). Many people had lost their jobs in the 1980s due to this collapse in the fishing industry. Health problems have also occurred; whereby intestinal illnesses are attributed to the declining quality of drinking water (Micklin, 1988), and respiratory illnesses are associated with increasing airborne salt and pesticide content which is blown into populous areas or deposited as aerosols in the form of rain (Micklin, 2007). The Aral Sea was full of flora and fauna, however many plant communities and fish populations have declined where the lack of floodplain inundation made conditions worse for plants to grow. The habitat of the flora and fauna saw the decline of many species, such as wild boar, deer and a few tigers, from 178 to 38 animal species (Micklin, 1988). The decline in the quality of the land proved also to be a problem for agriculture, where degraded soils and the lack of floods made it difficult to grow crops or graze cattle and these areas soon started experiencing desertification.

The negative impacts of the shrinking of the Aral Sea is undeniably large, however the efforts and focus that should now be paid attention onto the lake is the restoration of the lake, and how we can go about achieving this. Micklin and Aladin (2008) explains that the only way to restore some significant amount of the lake would be to stop or significantly reduce the amount of water used for irrigation from the Amu and Syr Darya rivers as the source. However, this is idealistic since many of the former soviet republics do not intend to do this. Uzbekistan intends to expand their cotton industry to gain foreign currency. Although other countries such as Kazakhstan made attempts to restore water in the northern Small Aral Sea. In 2005, an $85 million fund was provided to rebuild an earthen dike of 13km to block the unnecessary outflow that was prone to evaporation. Results of this project has shown that the surface area of the northern Aral increased by 18% and salinity levels had declined from 20 to 10 g/l (Micklin & Aladin, 2008). Fish species are returning and thus providing hope for local fishermen and the fishing industry in resuming business once again (See this video below for more on the prospects of fishing). 

Prospects are looking hopeful again, however more work is required to restore lake levels and quality in the large Aral Sea. Micklin and Aladin (2008) suggests that large scale engineering can help to significantly restore the larger Aral Sea (See below).

These proposals and solutions have the potential to encourage the sustainable restoration of the lake but despite certain successes in the small Aral Sea, there has been backward progress in other areas. A shocking article in the national geographic by Howard, B. (2014) explains that the eastern basin of the large Aral Sea has completely dried up. The decline of this part of the lake was the result of continuous withdrawals from the rivers and a decline in rain and snow which fed into the Amu Darya river.

Human activity has pushed this ecosystem to an irreversible state and both humans and the environment has suffered consequently. Solutions have been implemented to restore parts of the Aral Sea but these efforts seem futile in the face of another decline residual lake. Therefore, despite our attempts to restore this lake, can humans ever restore the Aral Sea before it ultimately ceases to exist?

Freshwater Crisis

One of the major questions that we are facing is whether there are enough freshwater resources to sustain a global population of more than 7 billion people. It leads to questions such as “Are we facing a freshwater crisis?”, “How much water do we have now and how much in the future?”. With major issues, such as climate change, many scientists can only confirm that freshwater resources are likely to become more variable and unpredictable, heavily affecting some countries more than others such as Africa (IPCC, 2007). Hence, I would like to explore ideas concerning the freshwater crisis. 

Out of the total amount of water on earth, freshwater only takes up 2.5% of this global sum, and it can be found in surface water, groundwater and glaciers/icecaps (Figure 1). However only, less than 1% of this freshwater is accessible to humans, and as explained in the previous blog, humans are using freshwater in an increasingly unsustainable manner. Water scarcity is on the rise and the World Water Development Report 4 (2014) explains that 1.8 billion people will be living in absolute water scarce conditions by 2025. Water scarcity is multi-dimensional, whereby water scarcity can be experienced physically, economically and institutionally. Central Africa, and some parts in East Asia are experiencing high levels of economic water scarcity, and areas in northern china, Saudi Arabia and the coastal areas of northern Africa is experiencing physical water scarcity (Figure 2;WWDR, 2016).

Figure 1. Distribution of  freshwater resources. (USGS)

Figure 2. Different types of water scarcity. (WWDR, 2016)

The freshwater crisis is on the rise due to increasing demand for freshwater. The world’s population is rising; and so, an increasing population needs to be fed, and freshwater is largely used on irrigation and agriculture compared to industrial and domestic sectors (Figure 3). In 2000, agriculture used approximately 67% of the world’s freshwater and this is expected to increase by 1.3 times of its current use (Shiklomanov, 1999). Industries store a large amount of freshwater in the form of dams to generate electricity and for irrigation. However, evaporation rates ultimately lose a large amount of water and the opportunity cost of using this freshwater elsewhere is lost. Domestic consumption is increasing due to increasing affluence and the number of people living in urban areas.

Many governments and international organisations are attempting to fight this water crisis, and one measure, the water footprint, is used in national policy to develop and manage freshwater use (Hoekstra & Mekonnen, 2011). The water footprint measures the amount of freshwater that is used to produce goods and services which is consumed by individuals or a community (Hoekstra et al., 2011). This measure includes 3 types of consumed freshwater, blue (surface and groundwater), green (rainwater), and gray water (Polluted water that can be recycled). Hoekstra & Mekonnen (2011) study concluded that 38% of global production of the water footprint is shared among 3 countries, China, India and the United States, two of which have incredibly high populations and the US having a large affluent population. India has the largest blue water footprint of 24% of the global total, and 33% of this is used for irrigation. China has the largest gray water footprint of 26% of the world’s total; this is quite alarming for just one country to hold more than a quarter of the world’s gray water but this measure can raise issues regarding the environmental effects of human freshwater resource consumption, and possibly bring it into national policy. If you’re interested in your own personal water footprint, you can calculate it here. 

(a)

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Figure 3. (a) Water demand for OECD, BRIICS, RoW and the world (WWDR, 2016). (b) Water demand for agricultural, domestic and industrial sectors (UNEP).

Issues regarding water scarcity and the freshwater crisis, on one hand is very important to people’s livelihoods, but on the other hand, it does not bring to mind the issues of how freshwater resources are being mis-managed or over-consumed unsustainably, which leads to environmental and ecological problems for example. I tend to submit myself to these ideas of water scarcity as something that needs to be resolved no matter the cost because of e.g. images of people in Africa suffering due to the lack of freshwater. The water footprint is a useful tool that can be used is water assessment but it is limited in looking at the relationship between human activates and freshwater resources. For example, the crisis explains that the lack of freshwater will have adverse effects on human activities such as agriculture in the future, but what should also be mentioned is the impacts of these human activities on freshwater resources and their renewability and sustainability in turn. Freshwater resources are being threatened by pollution and waste disposal, over-consumption and ultimately depletion (Rogers, 2008). Are we facilitating water scarcity due to irrelevant uses of water, and have we caused this crisis due to our unsustainable uses of water? I ask these questions because I feel that there should be more to the water crisis than just the insistent need to satisfy human demands for freshwater, and that we should look more at how our demand for water have impacts on freshwater resources themselves. 

Global Trends of Freshwater Use

Sustainability is very important in both earth system sciences and global development. Water is a renewable source that transitions between many phases of the water cycle, however this consistent supply of freshwater can be interrupted if water is not consumed sustainably. Thus the sustainable consumption is crucially important for supporting human life and development.

A study by Wada & Bierkens (2014) explores global freshwater use over a historical period and for future projections using the blue water sustainability index. Results have shown that globally, there have been increases in water consumption of non-sustainable surface and groundwater resources since 1960. In 1960, approximately 20% of human consumption of blue water came from non-sustainable resources (surface and groundwater), however this value increased by 50% by 2010 (Figure 1). The steepest increase of non-sustainable water consumption occurred during the late 1990s and it has been associated with changes in global temperatures where increased rates of evaporation resulted in further demand for water (Wada & Bierkens, 2014). 

Figure 1. Consumption of blue water resources from non-sustainable resources e.g. non-renewable groundwater, and over-abstraction of surface water levels. (Wada & Bierkens, 2014)

Not surprisingly, the increased reliance on non-sustainable resources would only cause increases in demand of water from other sources, namely groundwater. Studies (Doll et al., 2012; Wada et al., 2012) have shown that the reliance of groundwater, including non-renewable groundwater resources, are being heavily relied upon. This has been evident in areas such as India and Saudi Arabia (Wada et al., 2012). Increases in population has also been associated with increased consumption of groundwater in e.g. the US, and Mexico, however China’s population had little impact on surface and groundwater resources. Wada & Bierkens (2014) also projected the consumption of water from non-sustainable resources to increase by 40% by the end of the century. 

Concluding thoughts

Globally, the consumption of freshwater has increased over time and dangerously so has the consumption of freshwater from non-sustainable sources. If freshwater is consumed beyond its sustainable limits, then it will only help to exacerbate the world’s water security problems. This blog only discusses simple linear trends of freshwater use over time, however, the reasons to this increase in freshwater consumption, and the regional consequences of unsustainable consumption has yet to be explored. Hence, the next few blogs will discuss the causes for increased freshwater use and the regional consequence of unsustainable consumption. 

Introduction: Why Water?

In the wild, the ‘rule of 3s’ can make a big difference to your chances of survival in the wilderness. Bear Grylls, famous adventurer made sure to remind everyone on twitter, “3 minutes without air, 3 minutes without water, 3 weeks without food”. 

Now given that air isn’t going anywhere and we don’t mess it up, what caught my interest was how we cannot survive any longer than 3 days without water. Many environmental issues now greatly stress the importance of climate change and global warming – true, climate change is of great importance but what I find not being as equally as discussed is the issues concerning water and how sustainable our consumption of it is.

Water is an important resource to sustain life and currently our consumption appear to remain within planetary boundary levels. Steffen et al. (2015) explains that planetary boundaries concept was established to show the limits to which humans can emit to and extract from the environment before surpassing levels which would drive the earth system to a less thriveable rate.

However, future projections prove to say otherwise, changing water supplies into the future is becoming more uncertain. According to a WorldBank report published earlier this year, water shortages are expected to increase all over the world. Key findings show increased demand for water due to population growth and urbanisation, and increased water scarcity in areas where water is currently abundant such as Central and East Africa. However, the IPCC Fifth Assessment Report (2014) have projected that rainfall levels are expected to increase in the same area. These conflicting reports show that the issues concerning water scarcity, insecurity and wider impacts on agriculture, economies and industries is highly complex, from the physical distribution of water and the access to this water and distribution from different stakeholders.

This blog aims to explore and discuss freshwater use over time and sustainable consumption is being ensured. This blog will reflect on past examples of freshwater use and its sustainability such as the Aral Sea case study, the causes for unsustainable use (both anthropogenic and physical causes) and the implications it had on different earth related systems. In addition, I will continue to explore current practices and consumption levels towards freshwater in some areas, and whether or not we have learnt from past experience in sustainable use and irreversible choices. 

For now, watch the TED talk on the importance of water by Dr.Kaveh Madani below: