MCB is a method to create clouds and/or make the clouds whiter. In both cases the clouds reflect more sunshine back into orbit. MCB is already in use at the Great Barrier Reef in Australia compare

https://www.savingthegreatbarrierreef.org/

MCB can be used both locally as well as globally. Unmanned ships (Flettner boats) have been proposed to sail the oceans by the thousands, compare (link 2)

Quote from Wikipedia (Link 1):

Marine cloud brightening also known as marine cloud seeding and marine cloud engineering is a proposed solar radiation management climate engineering technique that would make clouds brighter, reflecting a small fraction of incoming sunlight back into space in order to offset anthropogenic global warming. Along with stratospheric aerosol injection, it is one of the two solar radiation management methods that may most feasibly have a substantial climate impact.^[1] The intention is that increasing the Earth’s albedo, in combination with greenhouse gas emissions reduction, carbon dioxide removal, and adaptation, would reduce climate change and its risks to people and the environment. If implemented, the cooling effect is expected to be felt rapidly and to be reversible on fairly short time scales. However, technical barriers remain to large-scale marine cloud brightening. There are also risks with such modification of complex climate systems.

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Description of picture:

Quote from Royal Society:

A conceptual Flettner spray vessel with Thom fences. The wind would be blowing from the
reader’s right-hand side, the rotor spin would be clockwise seen from above and rotor thrust to the left.
Vessels can also report sea and air temperatures, humidity, solar input, the direction and velocities of
winds and currents, atmospheric pressure, visibility, cloud cover, plankton count, aerosol count,
salinity, radio reception and could even rescue yachtsmen in distress (copyright q J. MacNeill 2006).

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