A fresh water mass extinction: is it on the horizon?

In this blog I have spoken a lot about how fresh water issues such as scarcity and contamination have affected humans, but with the recent release of WWF’s Living Planet Report it seems like a good time to discuss the effect these problems have on fauna and freshwater ecosystems.

Despite covering less than 1% of the Earth’s surface, freshwater contains a disproportionate amount of species, almost 6% in fact (at least 100,000), including around a third of all vertebrates. However there is no doubt that they are under threat, largely, if not entirely, down to human activity. Strayer and Dudgeon, 2010 state habitat degradation, pollution, flow regulation and water extraction, fisheries over exploitation and alien species introduction as the primary causes of this, and there is an increasingly overwhelming case for adding climate change to this list. The Living Planet Index revealed that global populations of vertebrate species had decreased by 58% between 1970 and 2012 with the decline being much more severe in the freshwater ecosystem (81% - as shown in the following diagram) compared to terrestrial (38%) and marine (36%).  

Source: Living Planet Report, WWF.

The fact that 1970 is the starting point of this study makes it likely that significant reductions in population of freshwater species had already occurred. After the Second World War, the building of dams proliferated peaking at around 5500 large dams being constructed per year in the 1970s (Jones, 2014) and although the effects of these are hard to predict, flow interruption can have negative effects on the ecological integrity of flood plain rivers due to changes to patterns of flooding and degradation of downstream channels (Ward and Stanford, 1995) as well as blocking migratory species, and creating calm bodies of water with different temperatures to rivers that may favour different species whilst encumbering others. Dams also block sediment transport which can prevent vital nutrients reaching floodplain soils (Holland, 2016). There were also fewer regulations on industry back then which allowed the likely increased contamination of waterways and in turn habitat degradation.

Since 1970, dam building has remained a driver of this diminution as although construction has reached somewhat of a standstill in Europe and USA, it is still prevalent in developing nations such as China, Brazil and India and there is now 10,000km³ of freshwater stored in dam reservoirs, a staggering five times the amount in surface rivers. The reason for this vast amount of water being needed is of course the increasing consumption of freshwater by humans that has occurred in line with population increases (although these increases were also taking place pre-1970). The following image shows dams being planned and in construction: 

Another side effect of this population rise is the over exploitation of fisheries that has taken place due to an ever-increasing demand for food. This mainly refers to the unsustainable harvest of fish from freshwater, but indirect over exploitation can occur as other species are inadvertently caught in fisheries. Studies have concluded that inland waterways and ecosystems have been poorly managed, and that fish stocking has been prioritised over habitat management (Aps, Sharp, and Kutonova, 2004) which in the long term has resulted in declined numbers.

In terms of how pollution can affect fresh water ecosystems, it is similar to as mentioned in the previous blog post on water contamination. Pollutants can include chemicals and pesticides, raw sewage, petroleum and even thermal discharge. Toxic chemicals, such as PAHs (polycyclic aromatic hydrocarbons) and PCBs (polychlorinated biphenyl) released from industry, and pesticides can have a range of life-threatening effects on aquatic creatures. Depletion of oxygen levels can be triggered by nutrients from agricultural runoff causing eutrophication, as well as the decomposition of faecal matter (WWAP, 2006).

In 1970 when data collection for the LPI started, climate change would not have been considered one of the primary threats to global populations of wildlife. But as carbon dioxide emissions continue to increase and global temperatures exceed 1°C above pre-industrial levels, it can no longer be ignored. Fresh water ecosystems are especially vulnerable to climate change because the species which inhabit them are largely unable to move to a different environment as theirs changes. On top of this, fresh water temperature and abundance are both climate dependent – increased global temperatures can lead to droughts and additional strain being placed on rivers and wetlands with unsustainable extraction levels in order to irrigate crops. This can result in these areas drying up with obvious loss of habitat.

So is there is a solution to this worrying problem of population and species decline?

First of all, it makes sense to protect river and lake ecosystems which are currently untouched. As for those regions which have already been affected by human activity, reconciliation ecology is a term that has been used to ‘encourage biodiversity in human-dominated ecosystems’. It is a recognition that destruction of habitat takes its toll on species. Although it generally applies to smaller, novel ecosystems, this concept is important in changing mind sets towards preservation.

The LPI notes an increase in migratory fish species since 2006, which it puts down to improving water quality in regions such as Europe, and fish passes being added to man-made obstructions to allow migrating fish to move through. If these could be applied globally, especially in the previously mentioned nations where dam construction is still widespread and water quality is generally lower, then it could have a huge effect. Restoration of ecosystems to the condition they were in before humans interacted with them is largely unrealistic, but dam removal projects are the closest thing to this. A number of these have taken place in the USA, where outdated structures are removed often leading to environmental restoration, although due to the huge demand for freshwater from humans it is impossible to make dam removal a widespread process.

There are definite steps forward but the danger is that they are being overwhelmed by the setbacks which could lead to a mass extinction of freshwater species.

Bottled water… a scam or a real threat?

With a global market value of over $150 billion, it is the world’s best-selling soft drink, with a staggering 1 million bottles produced per minute, worldwide. So why has something that is no better than the liquid which comes out of our taps, but can cost 300-1000 times more, become so popular and what are the effects of this on our planet and society?

Tap water in developed countries such as the UK is cheap with the average daily use of 150 litres costing around 21 pence, and regulated to make sure it is of the requisite quality. So why would anyone choose to pay a premium for a small amount of bottled water? The answer lies in how it has been marketed. Companies promote the idea that their product tastes better than tap water, even though blind taste tests have often shown there is no difference. A quick google search shows there is an abundance of different products, with varying claims about what their water can offer (even going as far as claiming to be ‘Earth’s Finest Water’). In reality, they may have differing mineral contents but the differences in taste would be subtle. Between 25-30% of bottled water products are actually just standard municipal water that has been treated, reminiscent of a certain Only Fool's and Horses episode...

Its popularity may also be in part due to a recent push towards healthier lifestyles as people replace sugary soft drinks such as Coca-Cola with bottled water. This is positive in that it cuts the amount of calories in people’s diets (an estimated 74 a day on average in the USA) which has obvious health benefits, but the point remains that the sugary drinks could be replaced with tap water, rather than bottled water. Many of the purchases may also be based upon buying the actual bottle, rather than the water itself, as convenience and cost were shown to be two of the primary factors in decision making when buying bottled water (Ward et al., 2009).

There are negative environmental effects stemming from the bottled water industry too. The single-use bottles which are a regular component of many people’s lunch are made of the plastic polyethylene terephthalate (PET) which requires a large amount of oil to produce. This of course produces the greenhouse gas carbon dioxide, with 6kg of CO2 released for every 1kg of plastic (enough for around 50 water bottles) made as well as the extra released during everything from transportation to chilling the water for consumption. In contrast, Thames water estimate that to produce a litre of their water 0.0003kg of CO2 is released. Water is also used in the production process of bottled water, with estimates of up to 3 litres of water used to produce 1 litre of bottled water. On top of this, only about 25% of plastics are recycled with the remainder entering landfill (taking hundreds of years to decompose), being incinerated (producing yet more CO2) or ending up littering the world’s oceans posing a hazard to many marine life forms. The Great Pacific garbage patch - a gyre of marine debris that comes from both North America and Asia and consists of mostly plastics – has been estimated to be twice the size of Texas, and will only keep growing as more and more plastic bottles are used and thrown away.

Source: Marine Debris

A recent study by Jamieson et al., 2017 also highlighted the dangers of microplastics, which includes the plastics manufactured to be tiny and that are included in various cosmetic products, and those that result from degradation of larger pieces of plastic. These microplastics have been shown to infiltrate even the deepest parts of the ocean, with levels of 'persistent organic pollutants' in some amphipods in the Mariana Trench exceeding levels commonly found in highly polluted industrial areas.

As discussed in previous posts, around 10% of the world’s population does not have access to clean drinking water. One of the UN’s sustainable development goals was to ensure everyone has access to clean and safe water source by 2030, and surely some of the amount unnecessarily spent on bottled water annually would go a long way towards delivering this.

Filling reusable bottles with tap water would be an obvious step forward in reducing the purchasing that we see today. The recent 5p charge on plastic carrier bags in England has seen reductions in use of around 70% and there are also schemes in other EU countries to reduce waste such as a deposit being placed upon bottles meaning they can be returned to the producer and refilled. Similar arrangements could go a long way to reducing plastic bottle use in the UK, as well as other developed nations.

Water contamination: Can we stop the world’s biggest killer?

It may be surprising to some, but water-borne diseases are the leading cause of death in the world. There are an estimated 3.4 million deaths a year according to the World Health Organisation (99% of which occur in developing countries (Prüss-Üstün et al., 2008)), whilst four-fifths of illnesses in developing countries are caused by contaminated water (Fonyuy, 2014). Clearly the problem of water pollution and contamination is now one of the most pressing issues for developing countries.

So how does water get polluted? Surface water is more commonly contaminated, and this can pose a high risk as many public waterways are used for drinking and cooking water as well as sanitation. However, a lack of infrastructure in towns and cities can lead to sewage and garbage being dumped straight into these waterways. Groundwater is usually safer as it gets filtered as it passes through underground layers of sand, clay and rock (Kjellstrom et al., 2006). Nevertheless, industry and mining can affect the mineral and pH levels of both ground and surface water. Arsenic (especially a problem in southern Asia, including Bangladesh) and fluoride, can leech through the soil into groundwater from both natural and anthropogenic sources, and are seen as the most dangerous inorganic contaminants in the world (Farooqi, 2015). 

The overriding contamination of freshwater comes from nitrogen and phosphurus, which are carried into the water from agricultural runoff. This leads to eutrophication of water bodies, and enhanced productivity of algae to form toxic algae blooms. A consequence of the increased respiration rates is that it depletes the water of oxygen, which can create 'dead zones' with devastating effects on local fauna.

It is not just freshwater reserves which are being increasingly contaminated. Go to any beach in Britain and it’s easy to see the amount of waste and debris washed up onto our shores. There are billions of pieces of plastic floating around are oceans, right down to microscale which can have a devastating effect on wildlife. The BP oil spill in the Gulf of Mexico is a well-known example of water pollution, where 780,000 cubic metres of oil were released into the ocean, causing havoc to marine wildlife as well as the local fishing and tourism industries. Meanwhile, Diaz and Rosenburg, 2008 report more than 400 marine dead zones, caused by toxic algae blooms and oxygen depletion. 

 Why is freshwater contamination such an issue in developing countries, whilst in general richer ones are able to get around the problem? The answer, inevitably, focuses around money. Many developing countries lack the finances to build the necessary infrastructure, such as pipes, treatment plants and wells. The problem is being exacerbated in many African countries by high population growth rates, meaning increased use of unsafe water for drinking, cooking and sanitation.

However the developed world has its problems as well. Recently in the USA there have been reports of contaminated groundwater due to deposition of waste water from the hydraulic fracturing, or fracking, process of extracting natural gas. Although natural gas has been hailed as a cleaner alternative to coal, and a transition fuel whilst the world switches to a future which utilises renewable energy sources, it brings its own environmental impacts. Methane concentration has been found to rise with proximity to fracking sites (Holzman, 2011). This video shows an example of how methane levels are so high in some US drinking water supplies that they are actually flammable: 

This has led to a backlash against fracking in regions which are experiencing water pollution. Developed nations have higher expectations with regard to their water supply and are typically willing to take steps to protect the quality of that water.  

How realistic is it though, to expect to radically reduce water contamination in developing countries? Historically poorer agricultural countries are often the ones experiencing the most rapid economic growth, driven by increased globalisation and growing demand for minerals and other commodities.  This typically involves rapid expansion of cities, including the building of new factories and roads, but often without the infrastructure to support dealing with contaminated water.  

However preserving water quality and improving accessibility brings significant potential economic benefits due to a decreased spend on health and less time spent on collecting water, thereby increasing economic productivity. For a developing country to prosper, it is in their interest for economic growth and improvements to the water supply to go hand-in-hand.

In the news this week…

Just a short one. Donald Trump is the President-elect of the United States of America. This divisive result will have numerous effects worldwide, but what does it mean for the future well being of the planet?

In 2012, he wrote on his twitter account, “The concept of global warming was created by and for the Chinese in order to make US manufacturing non-competitive”. Essentially, we now have a climate change denier as the leader of the second most polluting country on Earth. More recently he claimed that he would “cancel all wasteful climate change spending”. As far as our efforts to decrease carbon dioxide emissions in order to slow global warming go, this is not good news.

Just over a week ago, National Geographic released their documentary ‘Before the Flood’. This film explores the real issues threatening the planet such as melting ice caps, massive deforestation and rising sea levels and all in all paints a rather forbidding picture, as well as stressing how the USA is one of the biggest culprits. It ends on an optimistic note, with Johan Rockström, a professor of Environmental Science at Stockholm University, saying he thinks ‘we have tipped the world towards a sustainable future, the fear is are we doing it too slowly?’. Four years of Trump in power will be a stumbling block to any progress that has been made. Not only is he proposing a move back to coal-fired power stations (although the low price and abundance of natural gas due to fracking may end up making this an empty promise), but he has vowed to renegotiate the Paris agreement (there is nothing to stop him just ignoring it anyway) and wants to eradicate the Clean Power Plan which aims to reduce emissions from existing power plants by 30% by 2030.

This will have consequences that reach far beyond the US, as it effectively rules out any remaining hope of limiting global temperature rise to 2 degrees above pre-Industrial levels. 20% of the carbon emission reduction agreed to in the Paris agreement is set to come from the US, so them dropping out may set a precedent for the other most polluting nations.

This blog is focussing on water, and it is worth pointing out that Earth is not the only planet in the solar system with water on. There might not be as much liquid water on Mars as there used to be (de Haas, 2014) but actually there is an abundance of water ice below the surface as the following video explains:

Only time will tell whether we damage our planet so irrepairably that many parts of it are uninhabitable, but with 2016 set to be the hottest year on record (breaking the previous record set in 2015) maybe we shouldn’t be too hasty in ruling out a trip over to our red neighbour! And if we’re still in need of water we could consider this:

http://www.trump.com/merchandise/trump-natural-spring-water/

An update in Central Asia

Just an update to my second blog post. I spoke about tensions in central Asia between five countries, some of which were lacking in water, others in the means to generate electricity.

Well, Tajikistan has officially begun construction on what is set to be the world’s largest dam (a whopping 335 metres tall). More information about the Rogun hydropower project can be found in this BBC article.

The proposed dam had drawn criticism from downstream neighbouring Uzbekistan. However, since the recent death of its President Islam Karimov, relations between the countries seem to be improving.

It will take over a decade to complete, but progress means an end to freezing cold winters is in sight for many Tajikistan residents.

The trucks are rolling in to begin construction on the world's tallest dam.

Desalination: How the Middle East is dealing with its water crisis

As I touched on in my second blog, the Middle East is in a water crisis. This has been brought on by severe droughts, inefficient irrigation techniques and careless water use. I believe that there is hope for the future, due to technological advances in methods to produce more freshwater which are being employed not just in this area, but in water stressed regions throughout the world. However this remaining a privilege enjoyed by wealthier countries only remains a sad likelihood.

The following diagram shows as an example, Saudi Arabia’s renewable water capacity compared the global average. You may have to look quite hard to spot the blue bar which represents Saudi Arabia! Despite this, Saudi Arabia has the third highest use of water per capita of any country worldwide behind the USA and Canada.

Source: 2015 Case Study on Saudi Arabia. Data adapted from this website.

Large scale desalination first emerged in the mid 1950’s, although techniques were developed in the 1600s for use on boats in the event of an emergency. However, technological and material improvements over the last two decades have led to huge advances in methods of fresh water production and also increased the efficiency with which water is used. There are two commonly used desalination technologies: thermal desalination and reverse osmosis. Thermal desalination produces a vapour of fresh water, whilst the reverse osmosis method uses high pressure and a membrane to separate fresh water and salt water.

Israel is a good example of where desalination has risen to prominence over the last decade. A country that in 2004 relied solely on its limited rivers, lakes and groundwater for it’s freshwater, then suffered from the severe drought which hit the Middle East around 2007. It now produces over 55% of its domestic water from desalination plants, which make water taken from the Mediterranean Sea suitable for drinking, and actually has a surplus of fresh water.

Conventional desalination is an energy intensive and costly process. It requires countries to be wealthy and also in relatively close proximity to the sea (not too far inland or at high elevation) for it to be cost effective, otherwise it is often cheaper to transport freshwater from places where it is not a scarce resource, than to desalinate and then transport sea water (Zhou & Tol, 2005). Transport of 1600km, or an elevation of 2000m roughly matches desalination costs. Desalination Countries with only a small amount of coastline relative to overall size such as Syria and Iraq may not find the costs of transportation further inland feasible.

The high energy cost of desalination is still a limiting factor for the poorer countries. It has been estimated that around 15% of domestic oil production in Saudi Arabia goes towards desalination. If increasing fresh water demand requires more and more fossil fuel burning to fuel desalination plants then there is of course a possibility of cycle in which climate change brought on by the release of greenhouse gases leads to droughts, and flash floods which can contaminate the water supply thus decreasing fresh water reserves further (DeNicola et al., 2015). 

There are other environmental impacts to be considered too. The discharge of highly saline brine solution which often has a raised temperature, has the effect of increasing salinity of nearby ocean water by 5-10ppm and increasing the temperature by 7-8°C (Dawoud & Al Mulla, 2012). This can create an adverse environment which can be fatal for marine life.

In an attempt to counter the negative environmental effects, renewable energy is being increasingly utilised to provide the power for desalination. A great, but small- scale example of this is on the Maldivian Island of Gulhi, where excess heat from the local power generator is able to produce 10,000 litres a day for the island’s 1200 inhabitants, reducing its reliance on imported water.

The following diagram, summarises the disparity of water use between the wealthy and less wealthy nations. It shows the total water used in countries which are rich due to their abundance of oil as a natural resource greatly surpasses the amount of water which is available as a renewable resource (which does not include desalinated water). In short, rich countries can afford to overcome their natural shortage of water whilst poorer countries can not.

Source: www.carboun.com

In my opinion, this demonstrates two things. Firstly, the importance of desalination and other methods of producing fresh water, but also that many residents of the countries which cannot currently afford to build these expensive plants are condemned to a life in which water shortage is a chronic problem. Water shortages spread discontent in areas and can lead to dissent against authorities. This of course was a contributing factor in the descent to civil war seen in countries such as Syria and Yemen, and has the potential to cause more conflicts in the future.

Fresh water depletion and contamination: a real problem

When speaking about this blog, several people have questioned why water scarcity is an issue. The overall amount of water on the planet is not going to change any time soon and so why should we be worried about potential water shortages affecting two-thirds of the global population by 2030? 

To answer this, we can look at how water arrived on Earth, and what processes change it now that it's here. 

Water has accumulated on the surface of the Earth over the past 4.6 billion years from various sources: volcanism releasing water vapour into the atmosphere; hydrated minerals inside rocks and the deeper Earth releasing water; and a steady bombardment of extra-terrestrial missiles, some of which are carbonaceous chondrites (undifferentiated stony meteorites) containing water.

The following diagram explains the basic principles of the hydrological cycle. Water evaporates from the surface of the Earth, condensates to form clouds, falls as precipitation back to the Earth where it either infiltrates the land and goes into groundwater supply, or forms rivers and lakes of fresh water which eventually run into the sea.

Human activity interferes with this cycle in a number of ways. Firstly, increasing temperatures due to climate change means water cannot infiltrate the ground as much in arid regions as the ground is harder, increasing surface run off and consequently how much fresh water ends up in the sea instead of groundwater. The increased temperatures will also mean there is less surface water available in rivers and lakes for immediate use due to increased evaporation. Secondly, built up areas also increase the amount of surface run off as water is unable to penetrate hard concrete buildings and roads. Drainage is applied in many agricultural areas to prevent water build up, and this increases run off by 20-30% (Kuchment, 2007).

The quality of the fresh water reserves is also affected by human activity. 70% of fresh water withdrawn from the Earth goes towards agriculture where it is used to irrigate crops that are also sprayed with a wide range of fertilisers and chemicals that are then incorporated into rivers, lakes and the water table, sometimes in significant quantities. On top of this, sewage can leak into groundwater from septic tanks, and is also often deposited into rivers (in developing countries, 80% of sewage is dumped untreated) which can cause them to carry a wide variety of diseases. Lastly, a lot of industrial waste is also discarded into the water supply all over the globe, but more so in developing countries that may have fewer regulations. A UN estimate put this figure at 300-400 mega tonnes annually. A report by the USGS points out there is often interaction between surface and sub-surface flows, which would lead to the transfer of these chemicals between rivers, lakes and aquifers thus polluting all sources of freshwater, not just the one that the pollutants were deposited into.

Groundwater is especially polluted in some developing countries such as India, where high levels of fluoride, arsenic and salinity pose health problems (Kumar & Shah, no date). Future posts will discuss areas like this in more detail, as well as covering means of increasing the fresh water supply for countries located in arid regions.

       Two boys collect water from a leaking pipe, surrounded by 

       polluted and contaminated water in India.

       Photograph: Reuters

Water Wars... a thing of the past, present and future.

I was reading a 16 year old speech by Lester R. Brown from the Stockholm Water Conference in 2000 in which he stated that ‘It is now commonly said that future wars in the Middle East are more likely to be fought over water than over oil.’  Since then The Pacific Institute has compiled a list of conflicts related to water, some of them dating back to 3000BC. It is striking to see how many there have been, ranging from protests leading to violence, to all out military operations. Unerringly it also shows how frequently cutting off water supply to towns, cities and regions has been used as a military offensive tool, most recently in the Syrian civil war.

Water has been called the ‘forgotten cause of conflict in the Middle East.’ Wikileaks revealed cables sent by US ambassador Stephen Seche in 2009 which claimed 14 of Yemen’s 16 aquifers had run dry. He also said ‘70% of unofficial roadblocks stood up by angry citizens are due to water shortages’. In Taiz, the city where major protests played a large part in starting the uprising in Yemen in 2011, piped water flows through the pipes roughly once every 40 days.

Not only has water been used as military tool in the war in Syria, but there is evidence that the severe drought between 2007-2010 in Syria actually was a significant contributory factor to the war (Kelley et al., 2015). Low crop yields caused a displacement of many families to urban areas where there was a strain on resources, fuelling anger and resentment.

The conflicts mentioned so far have been internal ones within a country, caused by a general lack of water as a natural resource, and then poor allocation of it by an either inept or corrupt government.

But of course there are other types of conflict. The main problem with water is deciding who has the right to take what from the water supply. If a river runs through multiple countries, and the first country it runs through withdraws the majority of the water from it, then this will inevitably lead to water shortages in those downstream countries.

This article on the BBC discusses how tensions are rising in central Asia due to a gradual collapse in the system which saw five countries (Kazakhstan, Uzbekistan, Tajikistan, Turkmenistan and Kyrgyzstan) exchange water and energy, resources in which some countries were rich in whilst others weren’t. The fall of the USSR meant no one was regulating the exchanges between these countries. Therefore Uzbekistan (rich in natural resources which generated electricity) realised they could make more money selling electricity to richer neighbours, meaning less for Tajikistan and Kyrgyzstan. These countries in response needed to use more water to generate electricity. The result has been chronic water shortages leading to failure to grow crops in the downstream countries, and power shortages in the upstream countries. This has led to serious clashes between citizens of the affected countries.

A recent article in the NY Times raised the point in 2014 that ‘Syria’s government couldn’t respond to a prolonged drought when there was a Syrian Government. So imagine what could happen if Syria is faced by another drought after much of its infrastructure has been ravaged by civil war’. 4.8 million people have fled Syria since the civil war began, whilst another 6.6 million are internally displaced. The country currently is in disrepair with little hope of an end to the conflict coming soon. Kelley noted in his paper that droughts such as those experienced in Syria are now more than twice as likely in the Eastern Mediterranean due to human induced climate change. It does not seem that we will need to imagine much longer.

Where does it come from and where does it go?

 It takes 150 gallons of water to produce a single loaf of bread and almost 40,000 gallons to produce a car. In short, fresh water is essential to life on Earth, with agricultural, industrial and public use the three main areas of consumption. Looking at a simple map of the Earth it is clear that water is an abundant resource although only 2.5% of this is fresh water (fresh water is defined as water with less than 500 parts per million of dissolved salts) and fit for use in the previously mentioned activities. Most fresh water exists as glaciers and ice caps in the Antarctic and Arctic circles meaning it is unable to be exploited. Another 30% occurs as groundwater which is often hard to access. That means only roughly a quarter of fresh water used on Earth comes from groundwater sources. This leaves around 0.03% of the total global water supply available to humans at the surface. Of that number 69% of this exists as snow, ice and permafrost meaning only around 21% remains as lakes and rivers, the most obvious source of fresh water.

Currently, around 70% of globally accessible water is used for agriculture, although this increases in more arid areas, or countries where agriculture makes up a more significant proportion of the economy. The figure stands at around 20% for industry, although that rises to over 50% in industrialised nations.

The UN predicts a global population of 9.7 billion people by 2050. This, in turn will bring about a huge increase in demand for food, general products such as cars and clothes, and energy, all of which use vast amounts of water. However we are already exploiting our fresh water resources at a rate many may conceive as unsustainable, as it was shown in 2015 that 21 of the world’s largest 37 aquifers (a body of permeable rock that stores groundwater) were being depleted faster than they were naturally refilled by the hydrological cycle (Richey et al., 2015). Likewise, numerous large rivers such as the Colorado River and the Amu Darya (which used to feed the Aral Sea – now 10% of its original size) are no longer reaching the sea because their flow levels have been reduced so severely due to being over tapped.

Earth’s freshwater resources are unevenly distributed and currently almost one in 10 people ‘lack access to improved drinking water sources’. As the Earth's population increases and climate change continues to take effect, we can expect a growing challenge to humanity to ensure that developing countries and arid regions, where fresh water is economically and physically sparse, are able to access clean and safe water. 

This blog will aim to explore various issues regarding water scarcity, and the varying consequences of this problem as well as how it is tackled.