Should we fertilize oceans or seed clouds? No one knows

Abstract

ANTHROPOCENE Ernst Haeckel named humans' mark on the planet in 1868 p.164 MILITARY TECHNOLOGY US surveillance project shaped by 1998 movie p.162 MACHINE LEARNING Artificial intelligence turns its untiring eye on art attribution p.161 CLIMATE How are dust and soot affecting the warming of the planet? p.158 T he climate clock is ticking. To turn it back, the world is putting its faith in 'negative-emissions technologies'. These would suck carbon dioxide out of the atmosphere and lock it up for centuries on the land, in the sea or beneath the sea floor (see 'Marine geoengineering'). Although such technologies are yet to be developed, they are nonetheless implicit in assessments by the Intergovernmental Panel on Climate Change (IPCC). To limit warming to 1.5 °C compared to pre-industrial levels, as much as 20 billion tonnes (gigatonnes) of CO 2 might need to be removed from the atmosphere each year until 2100 (ref. 1). Storing carbon in the oceans sounds promising to some. The oceans are vast, and there could be fewer political trade-offs to deal with than on land. For example, fertilizing the water with iron would speed up the growth of phytoplankton and thus take up CO 2 , some of which would sink into the deep ocean as carbon when the organisms die. Another proposal is to spray seawater into the air to help form clouds that reflect sunlight and cool the planet. Techniques such as these would need Should we fertilize oceans or seed clouds? No one knows Gather scientific evidence on the feasibility and risks of marine geoengineering to guide regulation of research, advise Philip Boyd and Chris Vivian. The German ship Polarstern was used in a research experiment that fertilized part of the Southern Ocean with iron in 2004.

CO2 Removal With Enhanced Weathering and Ocean Alkalinity Enhancement: Potential Risks and Co-benefits for Marine Pelagic Ecosystems

“…However, comprehensive risk assessments for environment including ethical considerations in an open public discourse would have to be made to assess whether such experimentation would be morally acceptable (Lawford- Smith and Currie, 2017;Oschlies and Klepper, 2017;Pidgeon and Spence, 2017;GESAMP, 2019). Concerning legal aspects, there is currently some unclarity with respect to the governance for NETs (Boyd and Vivian, 2019). OAE may fall into either national regulation if activities were limited to the inland waters, or the global "London Convention (LC)/ London Protocol (LP), " treaties that regulate marine pollution from the dumping of wastes or other matter at sea [The International Maritime Organization (IMO) listed 87 members to the LC and 51 members to the LP where the latter was agreed to further modernize the LC and eventually replace it (July, 2019; www.imo.org)].…”

“…EW is not within the scope of the LC/LP because land-based sources of dissolution products would not be considered within their definition of "dumping" materials in the oceans. The assessment of risks and co-benefits of EW/OAE should therefore be paralleled by the development of a precise regulatory framework that is informed by the independent scientific community (Oschlies and Klepper, 2017;Gattuso et al, 2018;Boyd and Vivian, 2019).…”

“…Under these prospects, it is essential that EW/OAE research expands from feasibility and cost studies to include assessments of risks and co-benefits (Oschlies and Klepper, 2017;Gattuso et al, 2018;Boyd and Vivian, 2019). While this is beginning for terrestrial environments (Beerling, 2017;Beerling et al, 2018), very little is known about impacts on marine systems.…”

100 Opportunities for More Inclusive Ocean Research: Cross-Disciplinary Research Questions for Sustainable Ocean Governance and Management

“…In order for sustainability efforts to be successful, the exchange of knowledge between knowledge generators, such as scientists or public, and the end-users, such as decision and policy makers, must support learning and effectively foster evidence-based decision making (Cvitanovic et al, 2016) and enable transitions in governance arrangements through emerging forms of public participation (Wyborn et al, 2019). Consequently, the knowledge to action framework requires that diverse stakeholders, including the knowledge producers and consumers, be included in the co-production of knowledge to increase the usability of science for society (Bednarek et al, 2018;Djenontin and Meadow, 2018 Addressing New/Emerging Governance Challenges New technologies are opening up possibilities for ocean use, including for-profit extraction of novel ocean resources [e.g., mesopelagic fish (John et al, 2016), seafloor minerals (Hoagland et al, 2010), genetic resources (Harden-Davies, 2017)], and geoengineering interventions to help mitigate damage posed due to global carbon emission (Boyd and Vivian, 2019). The emerging technologies do, however, have unknown indirect effects on the ocean environment and the ecosystem services that oceans provide (Hoagland et al, 2010;John et al, 2016;Boyd and Vivian, 2019).…”

How do we overcome abrupt degradation of marine ecosystems and meet the challenge of heat waves and climate extremes?

“…A further example of such overlap is also for ocean alkalization which has been conducted on individual reef sites (see above) but has also been proposed as a climate intervention approach at the basin scale (Albright & Cooley, ). However, it is also apparent that each of these approaches have not yet been comprehensively or scientifically assessed to be able inform safe implementation within the near‐future (Boettcher et al, ; Boyd & Vivian, ; Hobbs, Hallett, Ehrlich, & Mooney, ).…”