There are many questions emerging from the recent floods in Pakistan, ranging from attempts to understand the atmospheric phenomena behind the downpours to the search for where ultimate responsibility lies for the ensuing human calamity. This short essay investigates some of those questions.
A pinch of geography is necessary to explain why Pakistan received such an extraordinary amount of rain during this rainy season. The Indian monsoon can be understood as a giant sea-breeze, with ocean moisture sucked in by rising hot air over the South Asian plains. It is influenced by large scale weather patterns such as the jet stream in the northern hemisphere, which this year came to a halt as a consequence of Ross by Waves, powerful spinning wind currents created by the earth’s rotation. Such unusual occurrences called ‘blocking events’ have taken place in the past, and have resulted in unusual weather phenomena. This year, as the jet stream became stationary, unusually hot summers led to the breakout of wildfires in Western Russia, and unprecedented rains poured down the slopes of the Western Himalayas. The blocking event coincided with the summer monsoon, which brought unusually heavy amounts of rain on the mountains that girdle the north of Pakistan.
The intensity of the localized rainfall was fantastic four months worth of rainfall had fallen in just a couple of days. Some areas in Northern Pakistan received more than three times their annual rainfall in a matter of 36 hours. Gushing quickly down the tributaries into the Indus River, the rainwater’s gave rise to floods of catastrophic proportions. Given the immensity of the downpours, some flooding was inevitable. Yet rivers are essentially channels to drain out water; being one of the largest rivers of the world, the Indus should have been able to carry out the excess waters into the Arabian Sea which it joins near Karachi. Why could