Climatic changes to hit Pakistan harder
KARACHI: As the Bay of Bengal is cooling down and the North Arabian Sea is warming up, the number of tropical cyclones has increased owing to the temperature shifting trend.
Data collected from 56 meteorological stations in Pakistan shows a sharp rise in temperature during the first decade of the 21st century, except the year 2005, while a rise of four degrees centigrade is expected to occur within the century in the Indus delta region. Impacts included loss of vegetation, deforestation and irregular precipitation, says a study, part of the Synthesis Report 2012, which was released on Saturday.
The report provides a summary of results of 11 studies carried out over the past two years (2011, 2012) under the Building Capacity on Climate Change Adaptation in the Coastal Areas of Pakistan, a Worldwide Fund for Nature-Pakistan project jointly administered with partners LEAD-Pakistan and WWF-UK with the financial support of European Union.
Conducted by Pakistan’s chief meteorologist Dr Ghulam Rasul, the study titled Climate Data Modeling Analysis presents eye-opening climatic trends that have been observed in the country in a decade.
Referring to the study’s findings, the report states that Pakistan lies in a geographical region where temperature increase is expected to be higher than the global average, making it an extremely climate sensitive country.
“The impacts of climate change felt in Pakistan range from tropical cyclones in the south to glacier retreat in the north. All the impacts of climate change and their manifestations have been looked into in detail in the study which also ident-ifies high-risk areas and make recommendations.
“Warmer nights threaten crop production (due to heat stress) by increasing overall water requirements and higher rates of respiration. The author explains how this leads to lower net dry material production, which in turn can possibly be linked to hikes in food prices and food insecurity,” it says.
Elaborating, the report states: “Winter seasons have shown more of a warming trend compared to the summer seasons. This in turn extends the summer season and shortens the winter season, thereby shortening the kharif crop-growing period.”
Some of the key findings of the study are: changes in thermal regime have occurred and daily temperature variations have increased. The minimum temperature, which is the measure of lowest nighttime temperature, and the maximum tempera-ture, commonly representing the highest daytime temperature, have increased in both summer and winter seasons throughout Pakistan.
“Crops that are expected to undergo and have in many cases already shown visible changes include wheat and bananas. Wheat grains do not gain proper size and weight nor do they accumulate optimum starch contents hence reducing the total grain yield. Bananas growing in the present climatic conditions are expected to bear poor fruit and give dwarf yield,” it says.
Citing the study’s findings on sea level rise, the report says that the data collec-ted over five years at Gwadar shows that there is a rising trend in sea level rise and it is expected that if the thermal regime continued to heat up at the present rate, there would be an average rise of 6mm per annum.
“Impacts of sea level rise are likely to include coastal erosion, wetland and coastal plain flooding, inundation of deltaic plains, salinization of aquifers and soils, and a loss of ecosystem.”
Increase in mangrove cover
One of the key findings of the study consisting of hazard maps is the physical spread as measured in hectares of overall mangrove cover.
“The research over a 10-year period of time slot from 2001-2011 comes with an interesting note that total mangroves cover has been increased by approximately 200 hectares in Keti Bunder while open canopy mangrove cover has increased by 1,000 hectares. The total mangrove cover in Kharo Chan has grown by about 2,000 hectares,” the report says.
The figures on mangrove cover, according to the report, are of practical value as it is a source of a natural barrier against the storms of recent years. The study also incorporates major tropical cyclones that have struck Pakistan’s coastal areas. At least 10 cyclones have occurred since 1895.
The deadliest tropical storm in Pakistan’s history hit Karachi coast in December 1965, killing about 10,000 people. Highlighting the case of land being lost to sea, the report says: “The erosion rate in Kharo Chann is high with a maximum of 60.7 m/year and mean of 35.2 m/year in area along Sonhri Creek. Apparently, this is not a direct t threat but the rate at which we are losing land is alarmingly high. This may result in loss of land worth a lot.”
The key findings of the study, Community-based Vulnerability Assessment, conducted in Jiwani, Kharo Chan and Keti Bunder are: the number of months fishermen spent at sea has decreased, thus shortening the time window within which to match the previous season’s size of catch; decline in the stock of specific species within specific season, growing seasons have altered in both Thatta and Gwadar districts; people have limited access to market and have also experienced losses due to extreme weather conditions.