Moreover, the UN report on marine Geoengineering speculates that further research might be done into the potential to create albedo enhancing algal blooms,
For example, geoengineering includes the removal of carbon dioxide from the atmosphere (also called Carbon Dioxide Removal – CDR) through methods such as direct air capture and storage, ocean iron fertilization, or ocean alkalinity enhancement. These activities are referred to as **Solar Geoengineering** or **Solar Radiation Modification (SRM).** Most proposed solar radiation modification techniques involve adding material to the atmosphere to increase the amount of incoming sunlight reflected back to space. Marine solar radiation management (mSRM) techniques, on the other hand, involve adding materials to ocean waters, sea ice, or the lower atmosphere to increase the amount of solar radiation reflected at or near the ocean's surface to limit surface warming or sea ice melt. * *Marine Cloud Brightening (MCB)* – adding particles, such as sea spray, to the lower atmosphere (near the surface) to increase the reflectivity of clouds over the ocean. Another subset of geoengineering activities intends to cool the Earth by intentionally modifying the concentration of certain gases in the atmosphere, including carbon dioxide.
Report multimedia Depiction of the global carbon cycle changes over time www.gao.gov/multimedia/ interactive/GAO-11-71a Global average energy budget of the Earth’s atmosphere www.gao.gov/multimedia/ interactive/GAO-11-71b Highlights of GAO-11-71, a report to the Ranking Member, Committee on Science, Space, and Technology, House of Representatives Climate engineering Technical status, future directions, and potential responses TECHNOLOGY ASSESSMENT GAO Growing trees trees Growing Cloud brightening at sea Capturing CO from the air 2 Iron fertilization of the ocean 2 Pumping liquid CO into geological formations Aerosols in stratosphere Light-colored roofs and pavements This is a work of the U.S. government and is not subject to copyright protection in the United States.
Ocean fertilization could enhance atmospheric CO2 removal by increasing biological productivity, namely by stimulating the growth of
E. Vaughan: Radiative forcing potential of climate geoengineering 5541 VEGETATION SOIL Nutrient addition Enhance downwelling Sea ice top of atmosphere Sunshades tropopause Clouds Human settlement Agriculture ATMOSPHERIC CO2 Incoming Solar Radiation Increase surface albedo Increase cloud albedo Stratospheric aerosols OCEAN Air capture Bio-char Afforestation & reforestation Carbonate addition Bio-energy capture GEOLOGICAL STORAGE Enhance upwelling COASTAL SEDIMENTS Fig. 1. E. Vaughan: Radiative forcing potential of climate geoengineering P N P P Longwave Shortwave 2050 2100 3000 N N Fe Fe Fe Desert Grassland Cropland Human settlement Urban areas Mirrors in space Stratosperhic aerosols Cloud albedo – mechanical Cloud albedo biological Nitrogen fertilisation Iron fertilisation Enhance upwelling Enhance downwelling Carbonate addition N Fe Afforestation Biochar production Air capture and storage Phosphorus fertilisation P Longwave Options Shortwave Options Radiative forcing potential ( W m2) 0.001 0.01 0.1 1 Fig. 2.
The most notable current geoengineering strategies include sulfate aerosol injection into the stratosphere, cloud albedo enhancement, bioenergy with carbon
#### Reference Manager Citation. With the controversy surrounding the most recent scientific iron fertilization experiment in the Southern Ocean (LOHAFEX) and the ongoing discussion about restrictions on large-scale iron fertilization activities by the London Convention, the debate about the potential use of iron fertilization for geoengineering has never been more public or more pronounced. To help inform this debate, we present a synoptic view of the two-decade history of iron fertilization, from scientific experiments to commercial enterprises designed to trade credits for ocean fertilization on a developing carbon market. We suggest that it is time to break this two-decade cycle, and argue that we know enough about ocean fertilization to say that it should not be considered further as a means to mitigate climate change. But, ocean fertilization research should not be halted: if used appropriately and applied to testable hypotheses, it is a powerful research tool for understanding the responses of ocean ecosystems in the context of climate change.
Working Group 41 is a multidisciplinary group of experts who aim to better understand the potential environmental and societal impacts of proposed ocean-based interventions for climate change mitigation. * Carried out an initial review of 27 proposed ocean intervention techniques for climate mitigation that was published in GESAMP Reports and Studies No. 98 “High Level Review of a Wide Range of Proposed Marine Geoengineering Techniques”, published in March 2019. To address these impacts, various interventions have been proposed to mitigate the effects of climate change on the oceans. ###### Several proposed ocean interventions to mitigate climate change. ### WG 41:Ocean Interventions for Climate Change Mitigation. * WG 41’s work on their initial review of 27 proposed ocean intervention techniques for climate mitigation 2015-2018. * WG 41’s abbreviated Terms of Reference for developing a holistic assessment framework, flow chart and questionnaire to aid assessment of ocean intervention proposals. * WG 41’s work on developing a holistic assessment framework, flow chart and questionnaire to aid assessment of ocean intervention proposals 2019-current.