Abstract: According to population, Karachi ranks as largest city of Pakistan and the ninth largest in the world. It
is the most urbanized and largest economic centre of Pakistan. During the last three decades, it has faced mass urbanization, huge population growth, many fold increase in vehicles and industrial development. As a result, the demand of more energy in form of fossil fuels has increased for domestic, industrial and transportation purposes. In this research, the maximum available data of Karachi urbanization, population and vehicles growth, industrialization, energy consumption and CO2 emissions are computed using statistical regression method. Time periods considered for this work are according to the availability of data. The results showed that during 1947 to 2008, both urban population and urban area increased to 1500%. During 1990 to 2008, the percentage growth in vehicles versus population is almost twice than before. During 1980 to 2007 the consumption of oil and petrol, natural gas and coal increased to 219, 365 and 287%, respectively. The emission of CO2 jumped from 39 million metric tons in 1980 to 151 million metric tons in 2007. The share of vehicles in emission of CO2 in atmosphere on Karachi through combustion of fossil fuels is more than the industries.
Abstract: Purpose – The purpose of this paper is to explore the trends of changing temperature of Lahore in
Pakistan due to invigorating urbanization process since 1950-2007.
Design/methodology/approach – This research is designed by using the numerical time series data of mean minimum temperature (MMiT), mean maximum temperature (MMxT) and mean annual temperature (MAT). The growth in urban population, area and transportation are also evaluated by using the available data. Linear regression method is applied to investigate the results of change in temperature. Three different approaches to examine the MAT are testified; first as an entire period (1950-2007), and then by dividing the entire period into two equal phases as Phase I (1950-1974) and Phase II (1975-2207). MMiT and MMxT are analysed for the entire period without making any division.
Findings – The results of the paper are significantly indicating an increase in MAT and MMiT which have risen up to 0.89 and 2.518°C, respectively, while MMxT remained resolute throughout the study period. Change in MMiT is observed regular and brisk than other parameters of temperature. Increase in temperature in Phase I is observed only 0.0628°C and in Phase II it is observed 0.948°C. Research limitations/implications – This research can be further worked out by using different meteorological models to study the effects of urbanization on lower surface atmosphere and urban heat island effects in Lahore.
Originality/value – By taking into consideration these results, the town planners and government can make different strategies to mitigate the urban effects on rising temperature in Pakistan.
Abstract: Karachi is the largest city of Pakistan. The temperature change in Karachi is studied in this research by analyzing the time series data of mean maximum temperature (MMxT), mean minimum temperature (MMiT) and mean annual temperature (MAT) from 1947 to 2005 (59 years). Data is analyzed in three parts by running linear regression and by taking anomalies of all time periods: (a) whole period from 1947–2005; (b) phase one 1947–1975 and (c) phase two 1976–2005. During 1947 to 2005 MMxT has increased about 4.6°C, MMiT has no change and MAT has increased 2.25°C. During 1947–1975, MMxT increased 1.9°C, in this period there is −1.3°C decrease in MMiT and MAT has raised upto 0.3°C. During 1976–2005, the MMxT, MMiT and MAT increased 2.7°C, 1.2°C and 1.95°C, respectively. The analysis shows significantly the role of extreme vulnerability of MMxT in rising the temperature of Karachi than the MMiT.
