A costly weather-modification experiment is underway in drought-hit Karnataka, but scientists remain divided over whether conditions are favourable enough to deliver meaningful rainfall relief.
Karnataka’s decision to launch a cloud-seeding programme in the middle of a severe drought has reignited debate over whether the technology can provide meaningful relief when rainfall deficits are already at historic levels.
The state government rolled out the ₹28-crore Karnataka Emergency Cloud Seeding Programme 2026 in September after large parts of the state experienced an exceptionally weak monsoon. Officials hope the initiative can help ease water stress in drought-affected regions, but several weather and climate experts have questioned whether suitable atmospheric conditions exist for the operation to succeed.
The concerns stem from the scale of Karnataka’s rainfall shortfall. Between June 1 and September 30, the state received only 551 millimetres of rain, resulting in a record 35 per cent deficit. According to data from the Karnataka State Natural Disaster Monitoring Centre (KSNDMC), 30 districts and 209 taluks recorded rainfall levels ranging from deficit to large deficit during the southwest monsoon season.
Experts describe 2026 as one of the state's harshest drought years in recent memory. The situation has been further complicated by El Niño conditions, which have historically coincided with a majority of Karnataka’s drought years.
Cloud seeding is often promoted as a method for enhancing rainfall, but scientists stress that it cannot create clouds. Instead, it attempts to influence precipitation by introducing particles into existing clouds under favourable atmospheric conditions.
The process depends heavily on cloud structure, temperature, moisture levels and atmospheric dynamics. Even when all conditions are suitable, researchers continue to debate how much additional rainfall cloud seeding can generate compared with what would have occurred naturally.
Karnataka has previously experimented with cloud-seeding operations in 2003, 2017 and 2019. The latest initiative is supported by monitoring and technical advisory committees involving multiple government agencies.
Scientists explain that cloud seeding works by introducing particles that encourage water droplets or ice crystals to form and grow inside clouds. As these particles accumulate additional moisture, they may eventually become heavy enough to fall as precipitation.
Scientific Uncertainty Remains Central To The Debate
One of the biggest challenges is measuring effectiveness.
Researchers note that rainfall from seeded clouds is difficult to isolate from natural precipitation. Ground-based rain gauges can measure rainfall, but proving exactly how much resulted from cloud seeding remains complicated.
Previous Indian studies have reported mixed results. Research examining Karnataka's 2017 Project Varshadhare estimated average rainfall enhancement of nearly 28 per cent above natural rainfall levels. Another study in Solapur, Maharashtra, found enhancement averaging around 18 per cent across a defined area, although scientists noted significant uncertainty linked to cloud behaviour and background atmospheric conditions.
Even where increases occur, questions remain about whether the gains are large enough to address severe drought conditions.
The current programme faces an additional complication of timing.
With the southwest monsoon already retreating, experts warn that rain-bearing clouds may be too limited for effective cloud-seeding operations. Scientists stress that the technique requires suitable clouds to exist in the first place. Without them, artificial rainfall cannot be generated.
Some specialists have also highlighted operational challenges, including dependence on existing radar infrastructure rather than dedicated weather-monitoring systems used during earlier cloud-seeding projects.
Despite these concerns, state authorities maintain that the programme is worth pursuing and have indicated that financial considerations are not the primary concern.
Supporters argue that while cloud seeding may not deliver guaranteed outcomes, it remains one of the few available options when rainfall deficits reach extreme levels. Others urge caution, arguing that success remains heavily dependent on weather conditions beyond human control.
