Analysing marine geoengineering technologies

AirClim has published a briefing about how geoengineering schemes would negatively affect the oceans. None of the methods are new or have been tested on any meaningful scale.

Marine cloud brightening: Finely ground sea salt is sprayed up from tall chimneys on ships, manned or unmanned. The most common proposal for achieving such a goal is to inject naturally occurring sea salt into cloud updraughts.

Microbubbles/sea foam: The water in the wake of ships is brighter because of small bubbles. The proposed scheme is to reinforce this effect by adding surfactants such as those used to remediate oil spills and, in lower concentrations, as a widespread pollutant in run-offs from the use of detergents, soap and toothpaste etc. The bubbles would reflect more solar energy back into space, and thus have a cooling effect.

Ocean fertilisation: Some parts of the oceans have low levels of micronutrients, one of which is iron. If relatively small amounts of iron are added there, it will cause an algal bloom. If a substantial part of the algae (or plankton that eat the algae) sink to the sea floor, this will draw carbon from the air and more or less permanently store it on the sea floor.

Upwelling: Cold, deep water that is rich in nutrients can be forced up to the warmer surface by pumping or natural winds. As in ocean fertilisation (above), this would enhance algal growth and fix CO₂.

The critical analysis of marine geoengineering technologies can be found here:

Compiled by Reinhold Pape

The extended analysis of marine geoengineering technologies can be found here:  https://airclim.org/publications/analysing-marine-geoengineering-technol...