US tests 1st cloud-powered ‘sun blocker’ tech to fight global warming

April 5, 2024 in News by RBN Staff



From the “Meddling with the primal forces of nature!” department…



The Earth’s soaring temperature levels have pushed scientists to explore various alternatives.


The Earth’s soaring temperature levels have pushed scientists to explore various alternatives, including techniques to deliberately slow the planet’s warming.

Recently, US researchers conducted the first outdoor test of a cloud-brightening technique that deflects sunlight and may temporarily cool the planet.

This innovative geoengineering method is called marine cloud brightening, and it may allow clouds over the ocean to reflect more sun rays’ light back into space.


A team of researchers led by the University of Washington conducted these experiments to assess the efficiency of their technology in the San Francisco Bay Area.

Cloud geoengineering

Clouds naturally reflect sunlight into space. The team is testing this technique to intentionally amplify this natural phenomenon, effectively bouncing more sunlight away from our planet.

So, how does marine cloud brightening work? To enhance their brightness or reflectivity power, they injected sea salt particles (aerosols) into low-lying clouds over the ocean.

This, in turn, reduces the amount of sunlight absorbed by the Earth, leading to a cooling effect.

This process of bouncing solar energy back into space is sometimes known as solar radiation modification or solar geoengineering.

The team used a specialized sprayer on the deck of the aircraft carrier Hornet to release microscopic sea salt particles into the air. In large-scale versions, ships will be equipped with massive spray machines to inject particles into the air.

As per the New York Times, the team also evaluated the machine’s capability to spray the right size salt aerosols into the air consistently.

The correct droplet size is critical to achieving the appropriate cloud reflectivity. Smaller droplets indicate better reflectivity, but larger drops may result in lesser reflectivity of the sun rays.

This technique may cause potential side effects

While marine cloud brightening holds promise, it’s not without concerns. Some scientists are highly skeptical of this cloud-brightening process, particularly when applied at a larger planetary scale.

This geoengineering approach has the potential to influence climate patterns, including changes in ocean circulation and precipitation patterns.

Even the team behind this technique testing has stated that they are studying the “potential side effects” of this method. Scientists are working to grasp the entire scope of this technology via thorough study and analysis.

Sarah Doherty, an atmospheric scientist and director for the university’s marine cloud brightening program, mentioned that it’s vital to explore and test the feasibility of such intervention technologies “in case society needs them.”

“The goal of the MCB Program is to understand whether it might even be possible to predictably and reliably brighten low marine clouds, and if so, how doing this in different regions of the globe would affect temperatures, precipitation and climate both globally and locally — as well as any other possible side effects,” said Doherty.

“As atmospheric scientists, we think it’s critically important that society has the answers to these questions before making any decisions about whether or not to actually use marine cloud brightening in an effort to reduce climate risks,” she added in the press release.

Nevertheless, the best way (hands down) to mitigate rising temperatures is to halt the use of fossil fuels, which emit planet-warming gases into the atmosphere.

With the unabated emissions, the target of limiting Earth’s global temperature rise to a reasonably safe threshold of 1.5 degrees Celsius over preindustrial levels is slipping away.