The government of New Delhi recently launched
a cloud-seeding programme in collaboration with IIT Kanpur, intending to
trigger artificial rainfall. The clear aim was to help reduce the capital’s
persistent air-pollution problem by inducing rain that could wash away
particulate matter.
Why It
Didn’t Work
The primary reason for the failure: the skies
simply lacked enough moisture. Cloud seeding only works when there are clouds
with sufficient water-vapour content. In New Delhi’s case, humidity levels at
the time were around 10 % to 20 % far below the 40–50 % or more often considered
necessary.
According to the meteorological analysis, the
general atmospheric conditions during the trial were very dry: water-vapour
levels were low, cloud cover was minimal, and moisture flow was being drawn
away toward the Arabian Sea or Bay of Bengal rather than accumulating over the
city. In such conditions, there were simply no robust rain-bearing clouds to
“seed”.
What the
Trials Showed Anyway
Although no meaningful rain fell over Delhi
during these attempts, there were some noteworthy observations. Monitoring by
IIT Kanpur recorded a 6 %-10 % drop in fine-particulate pollution (PM2.5/PM10)
after the trials. This suggests that even limited cloud-seeding under
sub-optimal conditions may affect air-quality by altering particle settling or
cloud-dynamics, though not by causing full-blown rain.
However, experts caution that such reductions
are likely short-lived and cannot substitute for long-term measures to cut
emissions. A study by IIT Delhi found that Delhi’s winter climate is largely
unsuitable for frequent or effective cloud-seeding because there are only very
few days in the year when all conditions align.
The Costs
and Context
Cloud-seeding is pricey. For example, the
recent Delhi trials cost several crores of Indian rupees the
equipment, aircraft sorties, sensors, and logistics add up. Some reports
estimate that a full winter-season of trials could cost ₹ 25-30 crore.
Moreover, scientists stress that cloud-seeding
is an enhancement tool — it cannot create clouds or moisture out of thin
air. In truly dry situations, the method has little to no chance of generating
significant rainfall.
What
Happens Next?
Officials have already said that further
trials will only be carried out when the measured cloud-moisture crosses higher
thresholds — for example, when the observed humidity or moisture content rises
above 30 %. Trials are thus on hold until conditions improve.
At the same time, the cloud-seeding efforts
will likely remain one component of a broader pollution-control strategy rather
than a standalone fix. Cutting emissions from vehicles, industry and
crop-burning remains central to improving Delhi’s air quality.
Final
Thoughts
The recent cloud-seeding experiment in Delhi
is a revealing case: it shows that even well-intentioned and scientifically
supported interventions can fail if the basic atmospheric conditions aren’t
right. The idea was bold to call upon technology to produce rain and
thus cleanse the air but the skies simply weren’t cooperative. In
dry months when humidity is low and clouds are few, cloud-seeding has very
limited scope.
For Delhi and similar cities, the lesson is
that while artificial-rain techniques can complement pollution-control efforts,
they cannot replace the foundational work: reducing emissions, improving
air-flow and tackling sources of pollution directly. Until the skies bring the
moisture, the seeds alone cannot sprout rainfall.
0 Comments