Geoengineering Technology Briefing May 2018

Marine Brightening

marine .1 However, MCB, like Arctic from the Faroe Islands. There POINT OF INTERVENTION all SRM, will have impacts on weather is no indication that this experiment patterns. Who would decide where to is moving forward. Another put these possibly drought or flood- proponent, Phil Rasch of the Pacific causing clouds? Northwest National Laboratory, has argued that based on “very artificial” ACTORS INVOLVED models that assume “perfect cloud OVERVIEW The most prominent advocates condensation nuclei,” engineers Marine Cloud Brightening (MCB) of MCB are John Latham from the could offset warming substantially, refers to manipulating cloud cover to National Center for Atmospheric so long as they seeded the clouds reflect more sunlight back to space. Research at the University of above an astonishing quarter to half It is a proposed Solar Radiation Colorado and Stephen Salter from of the world’s oceans.2 Management (SRM) technique. MCB the University of Edinburgh. Salter could reduce the temperature of the has promoted protecting sea ice by The first major open-air experiment atmosphere and oceans because seeding clouds that move from the was to be overseen by the Silver they would absorb less of the sun’s energy, but it would not reduce levels of greenhouse gases. Proponents of MCB aim to create whiter, more reflective clouds by shooting participles ( from seawater droplets or bacteria) into clouds and increasing cloud condensation nuclei (the tiny particles around which clouds form). One proposal involves spraying seawater from land or via many thousands of robotic boats into

REALITY CHECK

It’s just It’s being a theory implemented

MCB proposes to spray salt water into millions of clouds to increase . GEOENGINEERINGMONITOR.ORGGEOENGINEERINGMONITOR.ORG: Analysis: Analysis and and critical critical perspectives perspectives on climate on . engineering. Contact: [email protected] [email protected]

1 Geoengineering Technology Briefing May 2018

all traces of the project and its scientific collaborators disappeared from the Silver Lining Project’s website.4

A few years later, the Silver Lining Project resurfaced as the Marine Cloud Brightening Project.5 With support from the University of Washington, their first land-based field experiment is scheduled in Monterey Bay, California. They will set up nozzles on shore and spray clouds as they roll in, observing if they are whitened, while sensors on land will assess if this has led to a reduction of incoming solar radiation. They have already conducted wind-tunnel testing of a prototype nozzle in California. They then plan to move experimentation to sea, propelling droplets from a small ship.6 Initially scheduled for the summer of 2017, the experiment has been delayed for lack of funding.

The Ocean Technology Group at the University of Sydney is also proposing Marine Cloud Brightening experiments to save the Great Barrier Reef from bleaching.7

IMPACTS OF THE TECHNOLOGY Reflecting sunlight into space on a mass scale could disrupt global weather patterns and create geographic winners and losers, opening the door to weaponization and the While modelling results predict that use of Cloud Brightening and similar technologies as an implement of geopolitics. MCB would reduce average global temperatures, they also show that Lining Project in San Francisco. nozzle for ships that would fire tiny it could have considerably varied David Keith and Ken Caldeira saltwater particles into the clouds, and potentially detrimental impacts (prominent geoengineering and in 2010 a large-scale experiment in different parts of the world.8 For researchers and proponents) steered involving 10 ships and 10,000 km2 example, global mean precipitation some support from the Bill Gates- of ocean was announced. But after is modelled to decrease along with funded FICER fund3 to develop the media reported on the experiment, temperatures – 0ne study shows that

GEOENGINEERINGMONITOR.ORG: Analysis and critical perspectives on climate engineering. [email protected]

2 Geoengineering Technology Briefing May 2018

Marine Cloud Brightening attempts to make clouds brighter, with more, smaller droplets. Image: NASA precipitation could decrease up to decreases.11 Although researchers termination of the geoengineering, 2.3%. South America is predicted have optimistically suggested that e.g. a rapid increase in temperatures, to become warmer and dryer with precipitation changes “could be would therefore only worsen as MCB.9 Substantial rainfall reduction circumvented by not seeding in a time went on.13 A recent study over the Amazon basin is predicted,10 particular area,”12 these studies show has highlighted how sudden SRM which would be an ecological the extent to which geoengineering termination would significantly is likely to have major increase the threats to biodiversity unintended consequences, from , owing to Models also show that once and how poorly understood these rapid and unprecedented those consequences still are. temperature changes.14 you start cooling the Earth with SRM approaches, you The models also show that Researchers have also pointed must do even more of it to once you start cooling the out the vulnerability of MCB to Earth with MCB (and indeed physical attack, given that spray keep achieving the same all other SRM approaches), vessels would be in the open effect. you must do even more of it oceans. If many or all the cloud- to keep achieving the same spraying vessels were prevented effect. For MCB, this would from operating, there would be a disaster. Another study predicts mean further cloud modification, in rapid rise in global temperature, a massive 7.5% increase in runoff terms of increasing both the regions with all the accompanying changes over land, primarily due to increased where clouds were modified and the in weather patterns and other precipitation in the tropics, even amount by which they were modified. adverse consequences.15 If we can though global mean precipitation The problems created by a sudden imagine a dystopian future where

GEOENGINEERINGMONITOR.ORG: Analysis and critical perspectives on climate engineering. [email protected]

3 Geoengineering Technology Briefing May 2018

geoengineering is widely deployed, 2. Philip Rasch et al., “Global Temperature Stabilization via then the threat of conflict over its Enhancement Geoengineering Options to deployment and its impacts does not Respond to Climate Change,” Response seem far-fetched. to National Academy Call, 2009 3. The Keith Group, “Fund for Innovative It has also been suggested that Climate and Energy Research,” Harvard University, https://keith.seas.harvard. MCB could be deployed alongside edu/FICER other geoengineering techniques (“cocktail geoengineering”), such as 4. ETC Group, “Geoengineering Experiments Contested at UN meeting in Stratospheric Aerosol Injection (SAI) Nairobi,” 2010, http://www.etcgroup.org/ or microbubble ocean whitening content/geoengineering-experiments- contested-un-meeting-nairobi (see corresponding fact sheets16) with MCB used to “fine tune” on a 5. Lisa Krieger, “Cloud brightening more localised level. It could even experiment tests tool to slow climate change,” The Mercury News, 2015, be used to create localised warming http://www.mercurynews. via seeding, to “optimise this fine com/2015/07/11/cloud-brightening- experiment-tests-tool-to-slow-climate- tuning.”17 Marine Cloud Brightening could have change/ negative effects on regional farming, such as strawberry cultivation. REALITY CHECK 6. Hannah Hickey, “Could spraying particles into marine clouds help cool So far, no outdoor experiments the planet?” Washington University, have been conducted with this 2017, http://www.washington.edu/ particular technology, although it news/2017/07/25/could-spraying- 10. Andy Jones et al., 2009 particles-into-marine-clouds-help-cool- is conceivable that this will happen the-planet/ 11. Govindasamy Bala and Nag in the near future given sufficient Bappaditya, “Albedo enhancement of 7. Fiona Ellis-Jones, “Great Barrier Reef: marine clouds to counteract global funding. Making clouds brighter could help to warming: impacts on the hydrological curb coral bleaching, scientists say,” cycle,” Climate Dynamics, 2010 FURTHER READING ABC News, 2017, http://www.abc.net. au/news/2017-04-25/cloud-brightening- 12. John Latham et al., “Marine cloud ETC Group and Heinrich Böll could-help-cool-great-barrier- brightening,” Phil. Trans. Royal Soc. A, Vol. Foundation, “Geoengineering Map.” reef/8469960 370, 2012, pp. 4217–4262 and Alister Doyle, “Scientists dim https://map.geoengineeringmonitor. sunlight, suck up to cool 13. Andy Jones et al., 2010 org/ planet,” Reuters, 2017, https://www.reuters.com/article/ 14. Christopher Trisos et al., “Potentially us-climatechange-geoengineering/ dangerous consequences for biodiversity The Big Bad Fix: The Case Against scientists-dim-sunlight-suck-up-carbon- of implementation Climate Geoengineering, http:// dioxide-to-cool-planet-idUSKBN1AB0J3 and termination,” Nature Ecology & etcgroup.org/content/big-bad-fix Evolution, Vol. 2, 2018, pp. 475–482 8. Andy Jones et al., “Climate impacts of geoengineering marine stratocumulus 15. John Latham et al., 2012 SOURCES clouds,” J. Geophys. Res. Vol. 114, 2009 1. University of Washington, “Could 16. See Geoengineering Monitor, spraying particles into marine clouds 9. Andy Jones et al., “A comparison of “Stratospheric Aerosol Injection” and help cool the planet?” Science Daily, the climate impacts of geoengineering “Microbubbles” Technology Fact Sheets, 2017, https://www.sciencedaily.com/ by stratospheric SO2 injection and by April 2018. releases/2017/07/170725154206.htm brightening of marine stratocumulus cloud,” Atmos. Sci. Let., Vol. 12, 2010, pp. 17. Ibid. 176–183

GEOENGINEERINGMONITOR.ORG: Analysis and critical perspectives on climate engineering. [email protected]

4