ACME - Arctic Cryosphere Change and Coastal Marine Ecosystems

The Arctic cryosphere is changing rapidly due to recent climate change. The accelerated melt of the Greenland Ice Sheet, increased runoff from Arctic glaciers, diminishing sea-ice extent and volume, and thawing of permafrost all have marked impacts on the coastal environments of the Arctic.

The fjords and other nearshore areas form a productive zone that Arctic ecosystems depend on, and that is easily accessible and highly important for sustaining local communities. Increased runoff from land (bringing sediments, nutrients, and organic matter to the ocean), and the declining sea-ice cover affect biogeochemical cycling, primary production, biodiversity and ecosystem services.

A major challenge facing Arctic marine sciences today is the paucity of reference ecological data from which to interpret these changes. Palaeo data series covering the Holocene enable the study of climate conditions analogous to present-day warming. The aim of this working group is to assess and refine current available marine proxies that can be used to reconstruct cryosphere changes and their ecosystem impacts. 

Aims

ACME Phase I focused on producing community-refined criteria for Arctic marine proxy data, including recommendations for best practices in data acquisition and handling.

Phase II will use the outcome of Phase I for producing Arctic-wide reconstructions of cryosphere changes and their effects on coastal ecosystems during past Holocene warm periods.

A particular focus of Phase I was on the techniques and the quality of data, and on the introduction of new protocols to enable projections of the future of Arctic coastal ecosystems with greater confidence. The overarching goal for Phase II will be to provide a reconstruction of Arctic coastal ecosystem status under a warmer climate (Holocene thermal maximum, ca. 1-2 K higher than 20th century) using the “good data” criteria refined in ACME Phase I. The proxy-specific criteria for data and metadata quality and statistical treatment were established in ACME Workshops I (Tvärminne, 2021) and II (Copenhagen, 2022). They encompass common microfossil, biogeochemical and molecular proxies for sea ice, primary productivity, freshwater and terrestrial influence, and ecosystem status (ACME Phase I publication #2, in preparation). The product will have an Arctic-wide coverage, but will probe system-specific responses, covering coastal systems with glacier influence, shelf systems with permafrost influence, coastal systems with landfast vs. drift ice influence

To reach the main goal, ACME intends to apply for PAGES data stewardship scholarship for coordinating collation of quality curated datasets from open access databases. ACME will continue to strengthen dialogue with the open database stewards of PANGAEA and NEOTOMA. Over Phase II, ACME plans to work mainly through online conferencing. One in-person, ECR-targeted, workshop is planned to take place over the three-year life cycle to strengthen next generation networking. Investing in ECR capacity building and stakeholder connections will continue to list high on ACMEs agenda.

Major achievements of phase I:

• ACME Session CR 7.1 Cryosphere Change Impacts on Marine Ecosystems and Biogeochemical Cycling at EGU 2020
• First ACME workshop (Towards reliable proxy-based reconstructions: community perspectives and criteria) Oct 21
• Heikkilä M, Ribeiro S, Weckström K and Pieńkowski AJ (2022) Predicting the future of coastal marine ecosystems in the rapidly changing Arctic: The potential of palaeoenvironmental records, Anthropocene, 37
• ACME session at 6th OSM, May 22: Cryosphere change impacts on arctic coastal environments and ecosystems during the Holocene
• Tailored outreach product “Arctic change and sustainability solutions”
• UN Ocean Conference, Jun 22, side event "Future Earth’s marine networks"
• PAGES Magazine special issue “Sea ice in the polar regions”, co-edited by ACME and C-SIDE, Oct 22
• 2nd ACME workshop (Numerical ecology and time series analysis of marine proxy data), Nov 22
• INQUA 2023 Open ACME Workshop (Best practices and data quality challenges for coastal marine proxies in the Arctic), Jul 23 

Expected timeline for phase II:

Duration: August 2023 – August 2026

• Sept 2023 - Steering group meeting: launching Phase II (Similarly to ACME Phase I, Steering group meetings will be held yearly during ACME Phase II)
• Oct 2023 - WCRP Open Science Conference in Rwanda 
• Oct 2023 – Oct 2025: Filtering available Arctic coastal palaeodata using ACME criteria for publication (key outcome of Phase II)
• Nov 2023 - Greenland Science Week, ACME engagement with Inuit scientists, educators, and the general public
• May 2025 - First ACME Phase II workshop: “Cryosphere change impacts during past Holocene warm periods on Arctic coastal environments” - especially advertised for early career researchers. 
• January 2026 - Second ACME Phase II workshop: Community writing camp to outline and advance Synthesis paper of Phase II 
• June-July 2026 - Submission of Synthesis paper and report

Learn more and participate

Subscribe to the ACME mailing list here or contact a member of the Steering group here.

Follow the group on Twitter.