Search for: All records

IntroductionA defining aspect of the Intergovernmental Panel on Climate Change (IPCC) assessment reports (AR) is a formal uncertainty language framework that emphasizes higher certainty issues across the reports, especially in the executive summaries and short summaries for policymakers. As a result, potentially significant risks involving understudied components of the climate system are shielded from view. MethodsHere we seek to address this in the latest, sixth assessment report (AR6) for one such component—the deep ocean—by summarizing major uncertainties (based on discussions of low confidence issues or gaps) regarding its role in our changing climate system. The goal is to identify key research priorities to improve IPCC confidence levels in deep ocean systems and facilitate the dissemination of IPCC results regarding potentially high impact deep ocean processes to decision-makers. This will accelerate improvement of global climate projections and aid in informing efforts to mitigate climate change impacts. An analysis of 3,000 pages across the six selected AR6 reports revealed 219 major science gaps related to the deep ocean. These were categorized by climate stressor and nature of impacts. ResultsHalf of these are biological science gaps, primarily surrounding our understanding of changes in ocean ecosystems, fisheries, and primary productivity. The remaining science gaps are related to uncertainties in the physical (32%) and biogeochemical (15%) ocean states and processes. Model deficiencies are the leading cited cause of low certainty in the physical ocean and ice states, whereas causes of biological uncertainties are most often attributed to limited studies and observations or conflicting results. DiscussionKey areas for coordinated effort within the deep ocean observing and modeling community have emerged, which will improve confidence in the deep ocean state and its ongoing changes for the next assessment report. This list of key “known unknowns” includes meridional overturning circulation, ocean deoxygenation and acidification, primary production, food supply and the ocean carbon cycle, climate change impacts on ocean ecosystems and fisheries, and ocean-based climate interventions. From these findings, we offer recommendations for AR7 to avoid omitting low confidence-high risk changes in the climate system. 

The Challenger Society for Marine Science (CSMS) is the learned society for marine scientists based in the United Kingdom, with a membership of over 470 people from >100 institutions, across all academic career stages. Members of the CSMS have been interested in improving the representation of a diverse range of identities in UK marine science, largely driven by their own experiences of inequity in the discipline, such as the challenges faced by women (Hendry et al., 2020). The structural exclusion of individuals by race, sex, ethnicity, social class, disability, sexuality, and the compound sum of these factors can result in a lack of diversity during recruitment and poor retention. Since 2021, CSMS has formed the first UK-wide equity, diversity, inclusion, and accessibility (EDIA) working group for marine scientists, with the aim of coordinating action to address the causes of exclusion and to improve representation across the discipline. The group of 25 volunteers meets each month to discuss a topical agenda, and the chair of the working group sits on the council of CSMS, providing EDIA input from the working group on society-wide strategic decisions.