Pakistan uses artificial rainfall to try to reduce pollution levels

Lahore, Pakistan, uses artificial rainfall to reduce pollution levels.

The capital of eastern Punjab province, close to the border with India, has some of the worst air quality in the world and is highly polluted due to its growing population (more than 13 million people).

By early December, the city’s air quality had become so bad that schools, markets and parks were closed for four days. By the end of last week, the city’s air quality index (AQI) had reached extremely dangerous levels for health.

In an effort to reduce rainfall, the Punjab government on Saturday used a small Cessna aircraft to carry out artificial rainfall at 10 locations around the city.

In order for clouds to form, clouds in the lower atmosphere need enough moisture. In the summer, planes spray a mixture of common table salt and water onto the clouds. After a few hours, the mist merges with the clouds and produces rainfall. During the winter, clouds are seeded using silver iodide flakes, which can be fired from vehicles or aircraft.

This practice, also known as “blue skying,” has been used to induce precipitation in several countries in the Middle East, as well as in China and India.

Bilal Afzal, the province’s caretaker environment minister, said the cloud seeding efforts had been successful, but acknowledged that rainfall was low because the cloud quality was not very good. Afzal said that despite this, Lahore’s air quality improved with just a few millimeters of rain, with the AQI falling from over 300 to 189. However, this benefit only lasted a few days before the pollution returned to previous levels.

The exercise did not cause any major disruption. Dr Zaeema Naeem, a doctor in Lahore, said that while driving home from the clinic around 3pm, something splattered on my car which I thought was bird droppings.

Afzal said authorities plan to carry out artificial rainfall regularly during the haze season. If we can clean the air at the fuel cost of a small plane, he says, the work is well worth it. However, this means buying or renting a small aircraft. As for emissions, he said they were only equivalent to driving two to three cars for about four hours.

However, climate experts warn that the impact of cloud seeding could be difficult to predict. Malik Amin Aslam, the former environment minister, said once the rainfall is triggered, it may be difficult to stop it. He said that the cessation of heavy rains was determined by nature.

Dr. Ghulam Rasool warned that overdose could lead to hailstorms or heavy rains. He, head of the climate change program at the International Union for Conservation of Nature and former director of the Pakistan Meteorological Department, said that although this may temporarily alleviate the haze, it is not a sustainable solution and may cause very dry weather. Conditions may cause fog and smoke to become more persistent.

Aslam agrees that governments need to study the consequences of destroying nature and use this tool very carefully; it is like using steroids as a last-ditch effort to break a cycle of smog that is unfit for survival. He added that such solutions could shift focus away from addressing the actual sources of smog, such as traffic, industrial emissions, crop and waste burning and disappearing green cover.

He said that 50 per cent of Lahore’s emissions were caused by the transport industry, adding that the government was doing its best to address the issue.

Fehmeda Khan, a local doctor, has seen a threefold increase in patients with respiratory illnesses and allergies caused by dust. She advised residents to: close windows to avoid outdoor air pollution, avoid going out, and wear a mask when going out; and flush the nasal cavity with salt water every morning and evening.