PAKISTAN’S weather is getting more extreme, less predictable. Concomitantly there is rising temptation to put the onus upon some human agency. Unsurprisingly, sinister and malign forces bent upon reshaping this country’s climatic pattern are being conjured up. But how well can they survive scientific scrutiny?

Yes, extreme weather is hitting Pakistan hard — very hard. There wasn’t enough refrigeration in Karachi’s hospital morgues to store corpses this week after 1,000 people died from a monster heatwave that left Sindh sizzling with 50ºC temperatures. But April was unseasonably cold in the northern areas, where rain and hailstorms destroyed crops and fruit on a massive scale. All these pale before the abnormal events of 2010. Rains of biblical proportion followed a summer of extreme heat. Sheets of water poured from the skies for days leaving 2,000 dead, millions displaced, and 20pc of Pakistan under water.

What is responsible? Some ask a different question: Who did it? A new book, Reality of Floods in Pakistan, purports to give an answer. It echoes the conspiratorial notion, pushed by certain fringe academics in the West, that weather weapons are secretly being used by powerful states against weaker ones. In particular, this book holds India responsible for the 2010 catastrophe.

In a world with multiple tensions, pseudoscientific claims of weather modification can do great harm.

Expecting that my dissent would add variety, last week I was invited to be a speaker at its launch in Islamabad by the author, Waqas Ahmed, a young Pakistani telecommunications engineer. Glowing tribute is paid on the book’s back cover by Pakistan’s famed nuclear scientist, Sultan Bashiruddin Mahm­ood. Mr Mahmood, who also spoke, was awarded the Sitara-i-Imtiaz in 1998 for being the founder-director of the Kahuta Nuclear Enrichment Project. He is better known as Pakistan’s ‘jinn man’ for advocating the capture of these fiery beings, who would then duly add their contributions to our electricity grid. He achieved additional recognition after meeting Osama bin Laden in Afghanistan in early 2001.

One argument in the book closely follows that of Prof Dr Atta-ur-Rahman, former chairman of the HEC and a Fellow of the Royal Society, which was published in this newspaper on Oct 17, 2010. Therein the good professor, quoting political leaders and non-scientists rather than his own research in chemistry, alleged that the massive floods in July 2010, and possibly various recent earthquakes, were likely instigated by an experiment in Alaska called HAARP which directs radio waves at a part of the upper atmosphere called the ionosphere. My objections to this bizarre theory will not be repeated here. The interested reader can google the various subsequent public discussions on the topic.

Less bizarre, but no less wrong, is the book’s contention that seeding clouds can lead to catastrophic floods. I say this is less bizarre because diddling with the ionosphere cannot have the slightest impact upon weather but seeding clouds might have some. The book hints that five years ago India prepared some combination of drones, aircraft spewing chemicals, ground-based cloud seeding generators, ionospheric heaters, and aerosol rockets that nearly drowned its unfriendly neighbour. But even if some of this paraphernalia could have been mustered without being detected, to cause massive countrywide rains is impossible. To understand this we first need to understand both the potentialities and limitations of cloud seeding.

For many decades we’ve known that spraying finely divided particles of certain substances, such as ordinary salt or sodium iodide, can coax the rain out of a cloud. But only sometimes! A cloud has to be of a particular kind with its temperature, density, droplet size, and internal wind currents being just right. Else seeding is useless, which is so about 80-90pc of the time. Most importantly, you cannot alter weather over large areas with multiple clouds through this mechanism.

Today’s extreme weather owes to two culprits. First, plain bad luck — these things just happen! From heat and cold waves to tornadoes and typhoons, nature has turned extreme from time to time over hundreds of centuries. Even today, although we know a lot about jet streams and currents, specific occurrences can be foretold only a little in advance.

Talking of luck (or chance) cries for explanation. Yes, for all its precision, science actually needs this concept! Chance (probability) is a perfectly well-defined mathematical quantity and essential because most systems are not rigidly deterministic. In particular, the atmosphere-ocean system contains chaotic fluids obeying certain equations which suffer from what is famously called the ‘butterfly effect’.

The butterfly effect is a metaphor for the particularities of a hurricane (strength, path, place of formation) being influenced by minor disturbances. Even a butterfly that flapped its wings several weeks earlier in China can make a difference! Before its discovery 50-60 years ago, it was thought that if atmospheric conditions could somehow be known exactly today, with big enough computers we could precisely predict weather for all times to come. But, as mentioned, weather equations are supersensitive to even the tiniest of input variations. This limits our ability for long-term prediction or for controlling individual events. Chance becomes inevitable. On the other hand, short-term forecasts and weather averages are accurately predicted.

The second culprit is global warming. Greenhouse gas emissions from cars and factories have made Earth steadily warmer. Correspondingly, the atmosphere packs greater energy and more moisture. These lead to more and bigger storms, as well as extreme heat and cold events. But when or where an extreme event will hit cannot be controlled or precisely predicted.

In a world crackling with multiple tensions, pseudoscientific claims of weather modification can do great harm by increasing mistrust. Although one cannot vouch for the future, no country today is capable of using weather as a weapon. As increasingly severe storms, droughts, and wildfires in the United States demonstrate, even the world’s most powerful country — one alleged to be at the forefront of weather modification — has not escaped nature’s wrath. Humans have collectively made Earth sicker and more feverish, and now it is lashing back. Rather than lend our ears to conspiracy-obsessed theorists, we need to cut down emissions and go for eco-friendly energy solutions. And, of course, prepare for the tough times ahead.

The writer teaches physics in Lahore and Islamabad.

Published in Dawn, June 27th, 2015

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