- Global warming impacting twin cities with mean annual temperature rise reaching 3.5 degrees Celsius
The two cities are an ideal case for triggering and intensifying climate change impacts due to global warming, experts said.
Dr Fawad Ahmad of Sustainable Development Policy Institute (SDPI) said the mean annual temperature rise in the suburbs of Islamabad between 1960 and 2010 was one degree centigrade, while it was 3.5 degree centigrade in residential sectors, which was double the global average.
According to Kashif Salik, another environmental expert of SDPI, rainfall ratios in the twin cities also dropped from 1991-2010 than those from 1961-1990.
“This trend is attributed to the tremendous temperature increase during the same period,” he added.
Salik said projected temperature for future showed rising trends with high variability, which might lead to worsened hydro-meteorological disasters.
Dr Syed Faisal Saeed, an environmental researcher at COMSATS University, said the global warming had not only resulted in massive encroachment on watersheds and aquifers, but also destabilised the ecological balance and sustainability of fragile ecosystem in the twin cities.
Due to urban sprawl and stress on basic urban infrastructure service, ground water level had gone down from 50 to 300 feet, he added.
Dr Saeed said due to lack of proper planning and development of an effective rainwater drainage system, recurring urban flooding roughly once every three years in Nullah Leh caused huge loss of human life and property in Islamabad and Rawalpindi.
The built-up urban areas have become urban heat islands due to an increase in local atmospheric and surface temperatures as compared to the suburban areas, he added.
Dr Mehmood Khalid Qamar, who has accomplished PhD research work on environmental issues, said another phenomena contributing to climate change effects, was higher influx to trace elements, excessive amount of particulate matter and volatile organic compounds, atmospheric aerosols, and ozone depleting substance in the atmosphere, emitted from industries, brick kilns, stone crushers and automobiles.
These factors were exceeding the permissible limits prescribed under National Quality Standards (NEQS) in the urban areas since the climate change impact was a recent phenomenon and its impacts were likely to become more and more severe in Islamabad and its peripheries, he added.