Climate Change affecting agriculture in Karachi

Here's a chilling article about the effects climate change is having on our urban areas.

Climate change affecting agriculture in Karachi

Friday, March 13, 2009 By Perwez Abdullah Karachi Researchers from the University of Karachi (KU) Department of Geography have discovered the relationship between climate change and increase in the incidence of diseases, and the decrease in agricultural products in and around Karachi. Former chairman of the department Dr Syed Jamil Hasan Kazmi along with his team of researchers worked on the impact of global warming on agriculture in Karachi on vector-born diseases (Malaria and Dengue) and the transformation of ecological systems within the mega city. Dr Kazmi has been working in Gadap, Kathor, Malir, Memon Goth, Darsano Channa and Hub agricultural areas for 20 years. “These were the fertile areas in 60s and provided fresh fruits and vegetables to the city. The mammoth growth of the city adversely affected the agriculture. Now the city meets only 10 per cent of the demand for fruits and vegetables from these areas.” The irrigation of these agricultural lands was usually through the wells that were providing water after digging 20-30 feet below the surface. The rainfall pattern in the city has changed drastically since 1985, decreasing the frequency and intensity of rain in the city. This has resulted in drought of underground water levels. Now water can only be 400-500 feet deep. The high temperatures have evaporated the rain water quickly leaving the underground water levels dry. Two small ‘Check Dams’ have been built in Thuddo (North East of Super Highway) but it is sufficient for a 20 km area only. “These people are living in the area for more than 300 years. Agriculture, which is their livelihood, is threatened by the change in climate and urban encroachment over the suburbs of the city. Now they have started sand mining in their areas to compensate for the loss of the agricultural production. This is very harmful as the unchecked removal of sand will create more ecological problems”, says Dr Kazmi. According to Dr Kazmi, fruits and vegetables grown in the area cost more than the ones coming from Badin, Thatta, Sajawal, Hyderabad, Mirpurkhas, Tandojam and Rahim Yar Khan. “It is highly priced due to the shortage of water and extensive labour required to grow the crops in a semi-arid environment”, he explains. Another effect of the lowering of the ground water level is the advance of sea water which causes salinity, due to which land ceases to be fertile. The Total Dissolved Solids (TDS) in these areas have a density of 3500 mg/litre compared to the World Health Organisation’s standard of 500 mg/litre. Elevated total dissolved solids can result in water having a bitter or salty taste, and can result in incrustations, films, or precipitates on fixtures, corrosion of fixtures, and reduced efficiency of water filters. “Water is a good solvent and picks up impurities easily. Dissolved solids include any minerals, salts, metals, cat ions or anions dissolved in water. TDS comprise inorganic salts (principally calcium, magnesium, potassium, sodium, bicarbonates, chlorides and sulfates) and some small amounts of organic matter”, Dr Kazmi elaborates. The mangroves also need fresh water, and due to saline water, these valuable plants wither and ultimately die. This has resulted in Pakistan sliding down the world ranking for mangroves from 13 to 21. With the country heading for an environmental disaster, concerned individuals in the government and in the civil society have pinned their hopes on the Intergovernmental Panel on Climate Change (IPCC). IPCC is a scientific intergovernmental body set up by the World Meteorological Organisation (WMO) and by the United Nations Environment Programme (UNEP) to provide the decision-makers and others interested in climate change with an objective source of information about climate change. It was established by the WMO and UNEP in 1988 given that climate change is a complex issue, and policymakers need objective sources of information about the causes, consequences and measures necessary.