Wednesday / Dec 23 2015
Newspaper : The News
About 98 percent of water on our planet is seawater, another one percent is brackish water (having more salt than freshwater but less than seawater) and only about one percent is freshwater. As global warming results in increased water shortages, people must look for alternative ways to grow crops.
According to the 2006 UN report, two out of every three persons on our planet will be living under water-stress conditions by 2025. There are about 1.5 million new mouths to feed every week, aggravating the situation. Clearly science has an important role to play in developing processes that will allow the world population access to water for agriculture, drinking and for other needs.
The unsustainable use of water and land has led to increased volume of food crops over the last several decades. This is a bubble, stretched to a point of bursting, and it could send the world spinning into a crisis of unprecedented magnitude. The World Bank has estimated that about 175 million people in India are able to eat from grain crops only due to overpumping – water being pumped from underground aquifers much faster than it is replenished. The water table is therefore receding at an alarming rate. Saudi Arabia had become self-sufficient in wheat by using water from an aquifer.
The source, however, is running dry, so that the wheat production could stop before long. The unpredictability of weather pattern is another serious factor that can send us over the precipice. The 2010 heatwave in Moscow caused a loss of 40 percent of their hundred million ton grain crop. Had this happened in India, China or the US, it could have had a devastating impact on the world grain production.
Food prices have been rising at an alarming rate in most countries, making life miserable for the poor billions. The highly controversial building of dams in India, which would divert water from Pakistan, could eventually lead to a nuclear conflagration between these two nuclear states.
About two-third of our planet is covered by water but it is saline, making it useless for most agricultural purposes. However, you may have noticed that some plants, such as mangroves, can grow well with seawater near the seashore or under the sea. Nature has evolved certain genetic mechanisms that make them salt tolerant. Some other plants, known as ‘halophytes’, can grow in coastal regions, deserts, marshes, brackish aquifers and even in seas and oceans, and can serve as sources of food and oil. Growing them in such areas will not compete with land used for food crops.
The identification of salt-tolerant genes and their incorporation into wheat, maize or rice can also impart salt tolerance into food crops, thereby allowing them to be grown in seawater or brackish water. Some halophytes can also help remove salt from soils affected by salinity.
The process of reverse osmosis has been widely employed for the production of drinking water from seawater. It involves pumping saline water through a polymeric membrane that results in the salt remaining on the one side and purified water being pumped through to the other side of the membrane. However the process is expensive since it consumes a considerable amount of energy. The membrane used is also costly and it has to be regularly replaced because it has a limited life.
An exciting breakthrough has occurred in this field, involving a ‘going with the flow’ (forward osmosis) approach instead of trying to oppose it. This involves placing a high concentration of another solute (such as sugar) on one side of the membrane with saltwater on the other side. This results in the natural forward flow of water from the side containing saltwater to the side containing the solute, such as sugar, resulting in a process for the preparation of soft drinks from seawater through ‘forward osmosis’.
This process harnesses the energy gradient, instead of opposing it, and therefore consumes up to 80 percent less energy because the pump pushes water through the membrane in the same direction as its natural flow tendency. Hydration Technology Innovations in Albany, Oregon, USA was one of the first companies to use this technology. US soldiers started using ‘X-packs’ that contain sugar and flavours on one side of the forward membrane. When such packs are dipped in seawater, or even in a dirty puddle of ordinary water, they suck pure water molecules into the pack leaving salt and dirt particles behind, thereby creating a pure sweet flavoured drink.
A fact associated with the production of fruits, vegetables and other food crops is that most crops are seasonal. This is because there are certain underlying chemical mechanisms that control the time when plants should flower so that insects may be attracted for propagation. Scientists have been trying to understand how these functions are regulated, and the genes responsible for the process.
Xing Wang Deng, the Daniel C Eaton professor of molecular, cellular and developmental biology at Yale and colleagues have discovered the precise gene (named DET1) responsible for regulating these functions in plants. By controlling these biological clocks that nature has built into plants, it has now become possible to obtain crops throughout the year, instead of only having the crops in certain seasons. The day is not far when you will have mangoes, for example, available around the year instead of just in the summer months.
The roadmap for agriculture and other important fields for Pakistan was built under my supervision as part of a two-year long exercise which involved consultation with thousands of scientists, agriculturists, industrialists and government officials. It led to a 320-page document ‘Technology Based Industrial Vision & Strategy for Pakistan’s Socio-economic Development’ that was approved by the cabinet in 2007. It is time we integrated it into our national development plans and implemented its recommendations.
There is urgency to act before it is too late. Answers lie in education, curbing population growth, adoption of modern and sustainable farming techniques, restoration of nature’s balances by cutting carbon emissions, afforestation, restoring soils, and adopting water conservation methods at all levels.
The present government has committed to increasing the allocation to education to four percent of GDP but this has not happened in reality. The previous government too had committed through a cabinet decision to increase the allocation to education to seven percent of GDP but that proved to be hollow words, because there was no intent to invest in education. It is time we woke up from our slumber and invested heavily in education, science, technology and innovation so that we can stand with dignity in the world.
The writer is the former chairman of the HEC, and president of the Network of Academies of Science of OICCountries (NASIC).