PALSEA - PALeo constraints on SEA level rise
Phase 1 | Phase 2 | Phase 3 | Phase 4 |
2008-12 | 2013-17 | 2019-22 | 2024-27 |
Image: Free stock photo from pexels.com
The PALSEA Working Group started in 2008.
Phase IV, PALSEA-next, starts in 2024.
The greatest uncertainty in future sea-level rise is the responses of Earth’s remaining ice sheets. The geologic record provides archives of how ice sheets and sea level responded to past climate warming. PALSEA provides constraints on past sea-level rise and ice-sheet change to improve understanding of future sea-level rise.
This group is open to anyone who is interested, and early-career researchers are encouraged to be involved:
- Read more on the external website
- Sign up to the PALSEA mailing list
- Follow the group on Twitter: https://twitter.com/palseagroup
- Contact the group leaders
The goal of PALSEA-next is to advance our understanding of the magnitudes, rates, and processes of past sea-level change. This improved understanding will allow us to inform predictions of future ice-sheet, sea-level and coastline evolution, as well as elucidate the response of past societies to sea-level change.
The PALSEA community is by nature interdisciplinary and brings together researchers from the proxy-reconstruction to the geophysical process modeling ends of the geoscience spectrum. The role PALSEA plays is to bridge these different disciplines to answer shared research questions.
Some of these research questions are:
1) What are the climatic and geophysical drivers of ice sheet change on centennial to millennial timescales?
2) How does global or regional-scale ice volume change influence global mean to relative sea level? What rates of change are possible?
3) How does ice sheet and ocean mass change drive solid Earth response?
4) How does sea-level change drive coastline evolution and human society over multidecadal, centennial and millennial timescales?
5) How does quantitative past sea-level data improve future projections?
To address these questions, the PALSEA-next working group will facilitate workshops and meetings that will focus on:
1) Improving model-data comparisons by by identifying key regions and time periods for targeted data collection.
2) Producing a comprehensive global relative sea-level dataset by applying improved interpretive frameworks to existing data.
3) Modeling of the physical processes involved in rapid ice sheet collapse and its solid earth response.
4) Investigating coastline response to sea-level change by studying submerged landscapes and archaeological records, within a coastline modeling framework.
5) Providing constraints for testing coupled climate-ice sheet models, from which future predictions can be made.
PALSEA is a PAGES and INQUA working group focused on using past changes in sea level and Earth’s cryosphere to constrain future sea-level rise in response to climate change.
PALSEA is a continuation of PALSEA1, which operated from 2008 to 2012, and PALSEA2, which operated from 2013-2017.
The third phase of the group ran from 2019-2022 (extended for one year due to coronavirus disruptions).
The fourth phase, PALSEA-next, begins in January 2024.
Overview
Sea-level rise driven by ice sheet retreat in a warming world is one of the most pressing yet uncertain outcomes associated with future climate change. The paleo record presents an unique opportunity to quantify the magnitude, rates, and drivers of sea-level and ice sheet variability over 100s, 1000s, and millions of years. Recent advances — largely directed by previous PALSEA working groups— have seen the establishment of international standards for the collection, reporting, and availability of past sea-level data, in addition to significant advances in modeling and proxy reconstruction. This broad work has revealed the complexities associated with reconstructing past ice sheet and sea-level change and also key future directions.
In this new phase of PALSEA, PALSEA-next, we will address these complexities by facilitating interdisciplinary collaborations that bridge state of the-art modeling with geological and archaeological records to provide crucial context for modern observations and future projections.
Learn more and participate
This group is open to anyone who is interested, and early-career researchers are encouraged to be involved:
- Read more on the external website
- Sign up to the PALSEA mailing list
- Follow the group on Twitter: https://twitter.com/palseagroup
- Contact the group leaders
Timeline
We plan to hold the following annual workshops:
2024: Location TBC (and to trial a multi-hub conference, with hubs in Tokyo, London, and Melbourne). The meeting will focus on objective #1: improving model-data comparisons. Bringing together modelers and field scientists, this meeting will explore the largest uncertainties in datasets and modeling for both solid Earth processes and cryosphere processes. Identifying key targets for future fieldwork and modeling efforts will provide a blueprint for this phase of the working group.
2025: Location TBC - The meeting will focus on objective #2: producing a high quality global relative sea-level data set. We will use this meeting as an opportunity to connect with research communities that focus on coastal geomorphology and submerged landscapes, achieving objective #4. Part of the workshop will be a focus on the data stewardship aspects of PALSEA continuing to develop open access datasets, building upon past success.
2026: Location TBC - The meeting will focus on objective #3 and/or #4: connecting terrestrial ice sheet data to relative sea-level records and understanding the processes involved in ice sheet collapse and solid Earth response. This meeting will include experts in geodynamics and glaciology to bridge disparate datasets using process-based modeling.
To achieve objective #5, each workshop will dedicate a half-day to brainstorm the aspects of that meetings' theme most pertinent for future predictions of sea level change.
Past highlights
Published: 9 July 2015
In a review paper in Science, PALSEA2 have analyzed sea levels during recent warm periods in Earth’s history when global average temperatures were similar to or slightly warmer than today – about 1°C above preindustrial temperatures.
They concluded that global average temperatures similar to today, but slightly higher polar temperatures, resulted in more than 6 metres of global average sea-level rise due to polar ice-sheet loss.
The study confirms that our present climate is warming to a level associated with significant polar ice-sheet loss in the past and even our present temperature targets may commit Earth to at least 6 metres of sea-level rise.
Reference: "Sea-level rise due to polar ice-sheet mass loss during past warm periods", Dutton et al., Science, 10 July 2015, DOI: 10.1126/science.aaa4019
Coordinators
Lauren Gregoire (University of Leeds)
Tamara Pico (UC Santa Cruz)
Juliet Sefton (Monash University) – ECN representative and mialing list coordinator
Matteo Vacchi (Universita di Pisa) - Data liaison
PAGES SSC liaison
Emilie Capron (CNRS, France)