Plan to spray seawater into the sky to fight climate change

“We are starting to see extremely serious environmental impacts, causing huge losses in human lives and money,” Professor Hugh Coe at the University of Manchester, leader of the research team, told Times about the impact of global warming. According to the European Union’s Copernicus Earth observation program, the average global temperature in the past 5 years (2021-2025) is estimated to increase by 1.3-1.4 degrees Celsius compared to the second half of the 19th century.

Coe and his colleagues are exploring cloud brightening methods to protect fragile ecosystems in places like the Great Barrier Reef from extreme heat waves. The new research is part of the REFLECT project, funded by the UK’s Advanced Research and Invention Agency (ARIA) through the Climate Cooling Discovery programme. This is one of 22 climate geoengineering projects allocated a total of £57m by ARIA.

Theo Independentthe REFLECT team is conducting experiments inside a three-story stainless steel cloud chamber. They studied how water droplets behave in cloud chambers, developed specialized spray equipment, used computer modeling, and began contacting several coastal communities where future testing could be held.

No locations have yet been selected, and no outdoor experiments are scheduled to take place before 2028. Even when launched, these experiments must pass ARIA’s independent monitoring, safety assessments and other requirements.

One of the main challenges, the team said, is the lack of real-world data on the best way to create moderately sized and uniform water droplets. If they are too large, they risk absorbing all the moisture before smaller droplets form. If they are too small, they will not be effective, meaning they will not make the clouds bright enough.

Over the next three years, they will test different spraying methods, compare results with predictive models, and collaborate with local communities for real-world testing. In the future, salt water could be shot into the clouds using large mist cannons, the kind commonly used in festivals.

Any outdoor testing will be small-scale, time-limited and closely monitored, using only seawater and simulating natural ocean spray. If approved, initial testing will involve short sprays of mist at sea with the effects dissipating within 24 hours.

The research team at the University of Manchester believes this method will be effective. Previously, experts found that pollution from dirty transportation fuels makes clouds brighter, but since international regulations requiring cleaner fuels were issued six years ago, a side effect is that ocean clouds darken, unintentionally promoting global warming.

Despite pursuing a new approach, the research team emphasizes that it is still essential for humans to reduce greenhouse gas emissions. “Reducing carbon emissions is the only sustainable path out of the climate crisis. However, this process is not happening fast enough to protect many regions of the world from the worst impacts of global warming,” Mark Symes, Program Director at ARIA, explained to Independent.

He said debates about climate cooling are stalled because of a lack of objective data. “The Climate Cooling Discovery Program will provide the objective database the world needs to make safe, informed decisions about these climate interventions.”