By Natalya Gallo
As part of the United Nations Framework Convention on Climate Change annual Conference of the Parties (COP), the Ocean Pavilion hosts webinars in its Virtual Pavilion focused on ocean science and policy topics that are relevant to the negotiations. These online events are free to anyone wishing to attend so provide a good outreach opportunity for scientists to share key scientific highlights with delegates attending the COP as well as those following the negotiations virtually. During the last two years, I have had the opportunity to participate in the OceanICU sessions at COP, joining leading experts from around the world.
Recordings of these webinars (The Ocean Carbon Cycle: Bridging science, policy development and concrete action;Â Managing and Protecting Ocean Spaces for Climate, Biodiversity and People by 2030)Â are available on the OceanICU website here.
This year’s programme: “The Ocean Carbon Cycle: Bridging science, policy development and concrete action” was a good opportunity to share recent and ongoing work on key knowledge needs for guiding climate mitigation-related activities that could have implications for deep sea ecosystems. As society looks to the marine environment for additional climate mitigation services through proposed marine carbon dioxide removal (mCDR) technologies, it is important that there is a holistic cost-benefit evaluation of these proposals, including an examination of impacts to the deep sea.
The ocean already plays an essential role in the uptake of anthropogenic CO2 but there is growing interest in how the ocean can play an even greater role in this process through the use of negative-emissions technologies. However, much of the removed carbon from these proposals would be stored in the deep sea and there has been insufficient consideration of how deep ocean ecosystems may be affected. To support informed decision-making, it is important that the deep sea is presented accurately in these proposals — as a zone that contains diverse ecosystems, carries out key ecosystem functions, and is intricately linked to the shallow ocean and coastal zone through key processes such as diel vertical migration, currents, and benthic-pelagic coupling.
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The deep sea is not a disconnected, homogeneous “black box”
It contains diverse ecosystem functions, and is intricately linked to the shallow ocean and coastal zone
To unpack this, I am referencing a two policy briefs that I have been involved in developing as part of the Deep Ocean Stewardship Initiative.
Brief One:
Considerations for deep-sea environmental impact research on marine carbon dioxide removal provides guidance on key deep-sea considerations for five mCDR technologies:Â
- direct ocean capture
- ocean alkalinity enhancement
- ocean fertilization
- organic matter sinking
- carbon capture and storage
This brief also includes a discussion of experimental approaches that can help fill existing knowledge gaps. One highlight concerns changes in food availability, oxygen, and pH in response to organic carbon addition, entrainment and mortality of deep-sea plankton in processes with high water intake rates, and midwater and seafloor disturbance due to material addition to the deep sea or infrastructure installation, as areas needing further assessment.
As a highlight, the brief states that an equitable governance framework is needed as interests in mCDR expand and that evaluation of the economic, political, ethical, and socio-cultural dimensions is essential to understand how diverse communities perceive and may be impacted by mCDR technologies.
Bringing the deep sea into the mCDR conversation is important because lower certainty characterizes our understanding of this part of our planet due to its vast area, technological challenges, and high cost for research. This means that there are many knowledge gaps that limit our understanding of the relationship between the deep sea and climate change (both regarding mitigation, impacts and adaptation, and ocean-carbon feedbacks). A recent meta-analysis of the IPCC AR6 reports and special reports (2015-2023) revealed 219 knowledge gaps related to the deep ocean and seven key areas of priority research. Relevant to the OceanICU and its aim to improve our understanding of ocean carbon processes, the ocean carbon cycle and ocean-based climate interventions, were identified as two of these seven key areas.
Brief Two:
Deep-ocean knowledge gaps in the IPCC Assessment Reports: identifications, implications and critical research needs features the results of this meta-analysis. Similar to other briefs, we found that especially in executive summaries and summaries for policy makers, IPCC reports skew to present high certainty findings, which means that areas of low certainty (which are common for the deep sea) are often omitted from the high-level outputs. Given how common low certainty statements are regarding deep sea research areas, recognizing this tendency in IPCC reports is instructive so that omission is not taken to erroneously imply lack of importance.
I am optimistic that OceanICU will help address some of the identified knowledge gaps related to the ocean carbon cycle and the deep ocean, and thus higher certainty information will be available for future IPCC reports.Â
The COP Virtual Ocean Pavilion programme may only come around once a year but conversations on climate issues take place throughout the months between scientists, policy makers and citizens all over the world, and at OceanICU we have regular, free-to-all webinars where scientists across many marine domains and topics share research and insights with anyone interested in learning. Visit the website for more information.
Natalya Gallo
Dr. Natalya Gallo is a marine ecologist and biological oceanographer working at the Norwegian Research Centre (NORCE) as part of the Horizon EU OceanICU and Marco-Bolo projects. Her overarching interests are in how climate change impacts deep sea ecosystems and how scientific research can support sustainable ocean management and development. She is passionate about the science-policy interface and has participated in eight climate- and ocean-focused United Nations Conferences. She is involved in the Early Career Ocean Professionals group of the UN Decade of Ocean Science for Sustainable Development, the IOC-UNESCO Global Ocean Oxygen Network, and the Deep Ocean Stewardship Initiative. She is also on the advisory council for the Norway-Pacific Ocean-Climate Scholarship Programme, an interdisciplinary PhD programme between the University of Bergen and the University of the South Pacific.
