The world is running out of water. But genetic engineering can help

Drought in California, 2014. Image: Getty.

Forget about oil or gas – you should be worrying about the less discussed but far more concerning fact that the world is running out of clean, drinkable water.

I wrote this article while in Kathmandu. Nepal’s capital and largest city has a severe water shortage. Even though all homeowners pay a fee to the government to get water on tap, supplies run only once a week for a few hours. Desperate residents are then forced to purchase water from private suppliers, and, while this is affordable for richer people, it’s a big problem for the lower and middle classes. For many in the developing world, water is really the difference between prosperity and poverty.

More than a billion people around the world have no reasonable access to fresh water. Most of the diseases in developing countries are associated with water, causing millions of deaths each year (a child is estimated to die from diarrhoea every 17 seconds).

Given all this, we have to come up with a solution to global water use fast, before water scarcity becomes a major cause of international conflict.

The vast majority of our water is found in the oceans. Only 3 per cent is fresh and can be used for farming and drinking, and in any case most of this is frozen in glaciers and polar ice caps. That means just 0.5 per cent of the Earth’s water is accessible and, of this, more than two thirds is used in agriculture.

If we’re going to cut back on our water usage, we have to focus on making our farms more sustainable and efficient. With the global population still growing, we’ll need to produce ever more crops using less water, in less agricultural land.

Worldwide, just over a third (37 per cent) of the land that could be used to grow crops is currently used. Potential farmland is available, but it’s not developed due a lack of infrastructure, forest cover or conservation. A lack of land isn’t really a big problem as of now – but water is.

Go beyond traditional farming

So how to grow crops using less water? One option would be to find a sustainable way to remove salt from our (essentially infinite) reserves of sea water. The farm in South Australia pictured below uses energy from the sun to extract seawater and desalinate it to create fresh water, which can be used to grow crops in large greenhouses.

Such farms are based in barren areas, and the plants are grown with hydroponics systems that don’t require soil. Growing crops like this all year round would significantly reduce freshwater usage in hot and dry regions, but the cost of setting up these greenhouses remains an issue.

Water shortages would also ease significantly if farmers could simply use less water to produce the same yield. Easier said than done, of course, but this is especially important in drought-prone areas.

Plant scientists around the world are busy identifying genes that enable plant growth in arid, dry conditions. For example, what is it that makes upland rice grow in dry soil while lowland rice requires well irrigated paddy fields for growth?

Upland rice growing on a hillside in Bolivia, far from any paddy fields. Image: CAIT/creative commons.

Once the keys to drought tolerance are identified, they can be introduced in crops through genetic engineering (and no, this doesn’t involve injecting food with toxins as suggested by a Google image search).

Farmers traditionally bred drought tolerant crops through the slow and painstaking process of selection and crossing over many generations. Genetic engineering (GE) provides a short-cut.

A recent study identified diverse root architecture systems in different chickpea varieties. Future studies hope to identify genes that make some roots efficient at capturing water and nutrients from dry soils. Once a genetic factor is identified, scientists are able to directly deliver the gene that helps plants to capture more water.

A key factor for drought-tolerance in plants is the plant hormone abscisic acid (ABA), which increases plants’ water efficiency in droughts. But ABA also reduces the efficiency of photosynthesis, which reduces plant growth in the longer term, and as a result crop yields decrease.


But plants didn’t always have this trade-off: modern crops have lost a key gene that enabled early land plants like mosses to tolerate extreme dehydration. This enabled early plants to colonise land from freshwater around 500m years ago. Modern desert mosses also collect water through their leaves which helps them to grow in dry conditions.

This is the big challenge for plant scientists. To engineer crops that can be grown with minimum irrigation and that will eventually help relieve water scarcity, we’ll have to reintroduce the dehydration tolerance systems which many “higher” plants have lost but things like moss have necessarily retained.

Genetic engineering remains controversial even though extensive scientific studies report GE crops available in the markets are safe for consumption. This is partly just a communication failure. But the fact is we will eventually need to use all the tech available to us, and GE crops have too much potential to ignore.The Conversation

Rupesh Paudyal is a postdoctoral research fellow in molecular and cellular biology at the University of Leeds.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Leeds is still haunted by its pledge to be the “Motorway City of the Seventies”

Oh, Leeds. Image: mtaylor848/Wikimedia Commons.

As the local tourist board will no doubt tell you, Leeds has much to be proud of: grandiose industrial architecture in the form of faux-Egyptian temples and Italian bell-towers; an enduring cultural legacy as the birthplace of Goth, and… motorways. But stand above the A58(M) – the first “urban motorway”  in the country – and you might struggle to pinpoint its tourist appeal.

Back in the 1970s, though, the city council was sufficiently gripped by the majesty of the motorways to make them a part of its branding. Letters sent from Leeds were stamped with a postmark proudly proclaiming the city's modernity: “Leeds, Motorway City of the Seventies”.

Image: public domain.

During the 1960s, post-war optimism and an appetite for grand civic projects saw the rapid construction of motorways across England. The construction of the M1 began in 1959; it reached Leeds, its final destination, in 1968. By the early 1970s the M62 was sweeping across Pennines, and the M621 loop was constructed to link it to Leeds city centre.

Not content with being the meeting point of two major motorways, Leeds was also the first UK city to construct a motorway through the city centre: the inner ring road, which incorporates the short motorway stretches of the A58(M) and the A64(M). As the council put it in 1971, “Leeds is surging forward into the Seventies”.

The driving force behind Leeds' love of motorways was a mix of civic pride and utopian city planning. Like many industrial cities in the North and Midlands, Leeds experienced a decline in traditional manufacturing during the 1960s. Its position at the centre of two major motorways seemed to offer a brighter future as a dynamic city open for trade, with the infrastructure to match. In response to the expansion of the roads, 1970s council planners also constructed an elevated pedestrian “skywalk” in an attempt to free up space for cars at ground level. Photos of Leeds from that time show a thin, white walkway running through blocky office buildings – perhaps not quite as extensive as the futuristic urban landscape originally envisaged by planners, but certainly a visual break with the past.

Fast forward to 2019 and Leeds’ efforts to become a “Motorway City” seems like a kitsch curiosity from a decade that was not always known for sustainable planning decisions. Leeds’s historic deference to the car has serious consequences in the present: in February 2019, Neville Street – a busy tunnel that cuts under Leeds station – was found to contain the highest levels of NO2 outside London.

City centre planners did at least have the foresight to sink stretches of the inner motorways below street level, leaving pedestrian routes largely undisturbed. Just outside the centre, though, the roads can be more disruptive. Sheepscar Interchange is a bewildering tangle of arterial roads, Armley Gyratory strikes fear into the hearts of learner drivers, and the M621 carves unsympathetically through inner-city areas of South Leeds with pedestrian access restricted to narrow bridges that heighten the sense of a fragmented landscape.

 

Leeds inner ring road in its cutting. Image: author provided.

 

The greatest problem for Yorkshire's “Motorway City” in 2019, however, is not the occasional intimidating junction, but the complete lack of an alternative to car travel. The dire state of public transport in Leeds has already been raised on these pages. In the early 20th century Leeds had one of the most extensive tram networks in the country. The last lines closed in 1959, the same year construction began on the A58m.


The short-sightedness of this decision was already recognised in the 1970s, as traffic began to build. Yet plans for a Leeds Supertram were rejected by successive Conservative and Labour governments unwilling to front the cost, even though smaller cities such as Newcastle and Sheffield were granted funding for light transport systems. Today, Leeds is the largest city in the EU without a mass transit system. As well as creating congestion, the lack of viable public transport options prevents connectivity: the city's bus network is reasonable, but weaker from East to West than North to South. As a non-driver, I've turned down jobs a short drive away that would be a logistical impossibility without a car.

Leeds' early enthusiasm for the motorway was perhaps premature, but there are things we can learn from the 1970s. Whatever else can be said about it, Leeds' city transport strategy was certainly bold – a quality in short supply today, after proposals for the supertram were watered down to a trolleybus system before being scrapped altogether in 2016. Leeds' rapid transformation in the 1960s and 70s, its grandiose visions of skywalks and dual carriageways, were driven by strong local political will. Today, the long-term transport strategy documents on Leeds City Council's website say more about HS2 than the need for a mass transit system within Leeds itself, and the council has been accused of giving up the fight for light rail and trams.

Whilst central government's refusal to grant funds is the greatest obstacle to Leeds' development, the local authority needs to be far more vocal in demanding the transport system the city deserves. Leeds' desire to be the Motorway City of the Seventies might look ludicrous today, but the political drive and utopian optimism that underpinned it does not.