Climatic Variability and Linear Trend Models for the Five Major Cities of Pakistan

Abstract

Estimates show that the average temperature of Earth's near surface air and oceans has raised by 0.74 ± 0.18 0 C during last 100 years. In this work the impact of the same has been explored for major urban areas of Pakistan. For this exploration long-term mean, mean-maximum and mean-minimum temperatures for the period 1961 to 2007 have been studied. The precipitation in the major cities of Pakistan, are also studied. The maximum increase in mean temperature is found to be 0.057 0 C per year (in Quetta). The minimum increase is found to be 0.019 0 C per year (in Peshawar). Both these increments are more than the global mean. An isolated discrepancy is found in mean maximum temperature of Lahore but the same can be explained in terms of heavy and prolonged monsoon rains. Moreover, precipitation in Karachi is found to be decreasing that needs to be further explored.

Contemporary Temperature Fluctuation in Urban Areas of Pakistan

“…The analysis for the study period also revealed that annual average temperature showed a slightly higher rate of change than annual maximum temperature. Such results were in accordance with Gadgil and Dhorde [9], Sajjad et al [15], Sadiq and Qureshi [16]. However, Oguntunde et al [45] found variation in minimum temperature highly responsive to temporal trends in temperature in harsh climatic settings.…”

“…Furthermore, an insignificant increasing trend for annual maximum temperature was found at other stations. An unexpected insignificant negative trend for annual average and maximum temperature was detected at Kakul, Lahore and Faisalabad; such an unexpected negative trend was explained by the massive rainfall from monsoons, specifically in the 1990's for Lahore and the nearby city of Faisalabad [16,18,43]. The results are verified by the region adjacent to Lahore in the Indian part of the Sutlej River basin, Himachal Pradesh, where Singh et al [44] found an insignificant negative trend for annual maximum temperature at Kasol and Sunni stations that explaineds the regional trend variation along the Pakistan-India boundary line.…”

“…Heat waves prevailing for several days with 5 • C higher temperature than normal were also evident in the Eastern Mediterranean climate according to Kostopoulou and Jones [22]. However, Sadiq and Qureshi [16] found a maximum increment for annual mean temperature at Quetta (0.057 • C) and the lowest increment at Peshawar (0.019 • C), both greater than the global mean increment. Prolonged monsoon rains and especially rainfall during the 1990's caused a strange negative trend in maximum temperature at Lahore Ahmad, Fatima, Awan and Anwar [18].…”

“…Environmental degradation was neglected and resources were over exploited, and the Pakistan Environmental Protection Agency (PAK-EPA) started operation in 1997. The urban areas of Pakistan are highly vulnerable to global warming and climate change [16]. The cities have grown irregularly and dense buildings enhanced the urban heat island effect.…”

Unpacking Climate Impacts and Vulnerabilities of Cotton Farmers in Pakistan: A Case Study of Two Semi-arid Districts

“…Studies based on the station observations found an increasing trend of temperature in Pakistan (Río et al 2013;Sheikh et al (2009); ADB (2017); Sadiq and Qureshi (2010); Khattak and Ali 2015;Ali et al 2016). Moreover, future projections based on climate modelling also suggest a continuation of this trend (Batool and Saeed 2017;Saeed and Athar 2017).…”