PALSEA2 - PALeo constraints on SEA level rise 2


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. PALSEA2 provides constraints on past sea-level rise ice-sheet change to improve understanding of future sea-level rise.
Learn more via the new external website.


- Document and synthesize data on rates, patterns, and budgets of sea-level variability during Quaternary/Pliocene warm periods and assess the ability of numerical and semi-empirical models to simulate these observations.
- Estimate the sea-level/ice-sheet response time (and governing processes) to past “warm” climates and use this data-driven information to improve future sea-level rise projections; thus bridging the gap between paleo and historical observations and future predictions.


Anders Carlson (Oregon State University)
Andrea Dutton (University of Florida)
Antony Long (Durham University)
Glenn Milne (University of Ottawa)


 2008 -

roup members brave the cold on Eliot Glacier little ice age moraine. Credit: Paul Walczak.


Dusterhus A, Rovere A, Carlson AE, Horton BP, Klemann V, Tarasov L, Barlow NLM, Bradwell T, Clark J, Dutton A, Gehrels R, Hibbert FD, Hijma MP, Kahn N, Kopp RE, Sivan D & Tornqvist TE. 2016, Palaeo sea-level and ice-sheet databases: problems, strategies and perspectives, Climate of the Past, v.12, p.911-921 (link).
Dutton A, Carlson AE, Long AJ, Milne GA, Clark PU, DeConto R, Horton BP, Rahmstorf S & Raymo ME. 2015, Sea-level rise due to polar ice-sheet mass loss during past warm periods, Science, v.349, p.153 (link).

PALSEA2 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. It is a continuation of PALSEA1, which operated from 2008 to 2012.

A third phase of the group is currently "under construction". Learn more about the new PALSEA plans here.


The greatest uncertainty in projecting future sea-level rise lies in the responses of Earth’s remaining ice sheets. The observational period of sea level and ice sheet mass balance spans at best only the last century, at least partly exacerbating present uncertainty in future sea-level rise.

In contrast, the geologic record provides valuable archives of how ice sheets and sea level have responded to past climate variability, particularly during periods of climate warming. The information contained in the geological record can therefore help assess the relationship between ice sheets, sea level and climate change, and provide a firm basis for projecting the future.

PALSEA2 will continue to bring together observational scientists and ice-sheet, climate and sea-level modelers in order to better define observational constraints on past sea-level rise and improve our understanding of ice-sheet responses to rapid climate change.

Link to the external PALSEA website.


Learn more and participate

Read more on the new external website:

Follow the group on Twitter: @PALSEAgroup


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 higer 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.


Figure 1: Small increases in global average temperature may eventually lead to sea-level rise of 6 metres or more according to evidence from past warm periods in Earth’s history. Temperatures shown are relative to preindustrial levels. Present day temperature is around 0.8°C higher than pre-industrial levels.

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

> Read more

> View media coverage