Using of Artificial Rain

by Dr. SS Verma, Department of Physics, S.L.I.E.T., Longowal

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Pollution (land, water and air) in general and air pollution in particular was the buzz word of every body few days back in Delhi and its adjoining areas like Punjab, Haryana and UP.  Breathing have been difficulty for people and schools were closed. Everybody was blaming others for this situation and were expecting a miracle to happen to control it. When people as well as pollution control technologies fail miserably at every level then such situation arises. This is true to some extent that stubble burning might be elevating the pollution problem to some extent but pollution in general and air pollution in particular is always present at its dangerous levels. Nature has all its capabilities to control or nullify all the human sins but many a times it goes beyond that control level also.  Increasing population, its environmental non-friendly activities, industrial growth without bothering about the environmental sustainable use of technology, not using effective pollution control methods in industries, un-concerned individually as well as socially about the menace of pollution creation, we only blame each other and look towards the government to find immediate and effective solution for pollution.

Pollution control technologies like smog towers, wet scrubbers, bio-digesters, and all types of machinery and incentives to people not to burn stubble so promoted with great fun and fare, all fail due to each one of us. Because we never bother about our duties and responsibilities and ignore the importance and working of these technologies when not in need and think of them at the time of need only and blame each other for the upkeep and use of these technologies. Farmers are not ready to put extra hard work in order to make stubble useful for them or for industries or for society and they only think about their leisure and comfort. They blame it to many factors like high priced labour, costly machinery, unavailability of machinery as well as labour, immediate removal of stubble to sow the next crop. To make this happen in spite of all the laws and regulations, farmers are ready to take law and order into their hands without bothering about the consequences, more over well patronised by local political big-wigs.  They do not even hesitate to arrest the government employees gone to the fields to pursue farmers not to burn the stubble. Farmers have many excuses to burn the stubble by saying that they also feel concerned about the air pollution but the contribution of stubble burning to air pollution is however very low.

It is true that the continuous air pollution levels to their dangerous level can not be only assigned one snidely to stubble burning. There are many other sources of pollution like traffic, construction, industries, people’s activities etc. We have to make all possible efforts to control pollution generation at each level. Government can not have a magic stick to make all the pollution to disappear as nature can do it. With one rain in Delhi and Punjab, local air pollution came to its minimum level but people are still not leaving/controlling any activity like burning stubble, using one-man transport vehicles, bursting crackers and making industries less polluting. They again forget about the air pollution and feel more concerned about their comfort/leisure and economic growth.  Technology and policies do provide solace from ills like air pollution if put to effective use. Recently, using of artificial rain to remove the air pollution in Delhi was though one of the possible and effective measure by the experts and government of Delhi in association with experts from IIT Kanpur. However, before the plan was executed, nature bestowed mankind with natural rain which brought the air pollution to its reasonable levels. 

The artificial rain is a very old concept of making man-made rain and is also called Cloud seeding.  This rain-inducing technique, called cloud-seeding, has been around for more than 80 years. Vincent Schaefer, a researcher with General Electric (USA), is often credited with the first cloud seeding experiments in the 1940s. The process involves “seeding” existing clouds with a harmless substance called silver-iodide to give water droplets a particle to converge around, allowing them to form an ice crystal. Artificial rain through cloud seeding involves dispersing substances into the air to encourage condensation, resulting in precipitation. There are two primary methods employed to stimulate precipitation. One, hygroscopic seeding, affects warm cloud processes. The other, glaciogenic seeding initiates cold cloud processes. Cloud seeding is the process of making precipitation fall using substances like dry ice, potassium iodide and silver iodide. When storm systems move through one of our cloud seeding project areas, a solution containing a small amount of silver iodide is burned from ground-based generators or released from aircraft or helicopters. Upon reaching the cloud, the silver iodide acts as an ice forming nuclei to aid in the production of snowflakes. These particles attract water vapour, leading to cloud formation and subsequent rainfall. The amount of rain that a cloud can produce depends on a balance between the number of ice nuclei inside it and the amount of water available to grow around those nuclei. Clouds often lack naturally occurring ice nuclei so injecting them with silver iodide particles increases their numbers. Doing so makes the clouds more efficient at generating ice crystals that fall as rain or snow, depending on the temperatures in and beneath the clouds. 

Artificial rain can assist in reducing the concentration of pollutants, including dust, smoke, and chemicals, by washing them out of the atmosphere and depositing them on the ground. Many countries are working to exploit clouds to its advantage and these are: China, USA, the United Arab Emirates, Russia, Saudi Arabia, South Africa, Thailand, and Mexico. This would have been the first time that clouds would be seeded in India to battle pollution, although the country has tested the technique on a limited scale using two aircraft for research purposes in the rain shadow region of Solapur in Maharashtra.  According to experts, the cloud-seeding technology currently available in India can only induce potential pre-existing clouds, hence the delay in launching operations. Artificial rain is promoted to be a technology with many advantages but this article would like to bring the problems being associated with artificial rain. 

  • Residual silver discovered in places near cloud-seeding projects is considered toxic. As for dry ice, it can also be a source of greenhouse gas that contributes to global warming, as it is basically carbon dioxide.
  • The entire technique that is involved in cloud-seeding cost a huge amount of money and can be said to be expensive. The price of conducting cloud-seeding, according to IIT Kanpur professor, the artificial rain plan proposed by the Delhi government to combat air pollution was estimated to cost Rs 1 lakh per square kilometer.
  • Uncertainty of targeting. – once the “seed” is release, it is then up to nature to do the rest.
  • Not enough time for test to effects of ‘seeds’ 
  • Legal responsibility for disasters caused by artificial rain.
  • Scientists have to wait for the right meteorological conditions, namely plenty of clouds and correct humidity levels. 
  • Wind speed plays a vital role, too. 
  • It’s obviously difficult to predict exactly when atmospheric conditions will fall into place.
  • With the artificial production of rain, the lives of several animals will definitely be at stake. It’s not only the fauna but also the flora which has an equal risk too. Thus, all the living organisms are supposedly threatened too even though it is done for a common benefit.
  • Weather can become unpredictable due to artificial rain. It can lead to sudden changes in temperature or wind patterns, causing discomfort.
  • Flooding is another concern. Too much artificial rain can lead to overflow of rivers and streams, causing property damage and loss of life.
  • Artificial rain might exhaust cloud resources. Excessive use can lead to a decrease in the natural formation of clouds, impacting the global water cycle.
  • If exposed to a higher level one could develop permanent skin problems like argyria. There is no set standard for the amount of silver one can come into contact with, which even makes the impact riskier as they are unknown.

Cloud seeding has various positive effects and negative effects as well. There is no technology that is not tied with negative aspects. It all depends on how we use them to bring out some real improvement or environmental change. It will be better to put the technology to its sustainable use and we as an individual or society also play our environmentally friendly role effectively and sincerely, instead of expecting every solution by using technology. All in all, extensive research should be carried out in order to fully understand the long-term implications that come with cloud seeding. It is not a well-focused on an area of study which makes it rather difficult to grasp every aspect of it. Despite having a good number of positive impacts, it also comes with threats that are not well understood yet which makes it an unreliable solution.