QUIGS - PAGES-PMIP Working Group on Quaternary Interglacials

Quaternary interglacials can be thought of as a series of natural experiments in which boundary conditions - for example, the seasonal and latitudinal distribution of insolation, the extent of continental ice sheets and atmospheric greenhouse gas concentrations - varied considerably with consequent effects on climate (See Fig.1).

Documenting interglacial climate variability can therefore provide a deeper understanding of the physical climate responses to underlying forcing and feedbacks, and of the capabilities of Earth System Models to capture the patterns and amplitudes of the responses. In addition, past interglacials offer natural case studies in which we can view Earth system processes under a range of warm (comparable to today or warmer) conditions. They also provide the most recent (and therefore well-documented) times in which we can assess the response to regional warmth comparable to that expected in the next century.

QUIGS therefore also addresses highly relevant questions about the impacts of warm worlds. In a recent paper that reviews the state of the art on the interglacials of the past 800,000 years, the PAGES Working Group on Past Interglacials (PIGS, 2008-2015) identified a number of outstanding issues that need to be solved, including:

1. There is no simple astronomical cause for differences in the intensity of interglacials, which seems to arise at least partly from the pattern of CO2. This emphasizes the need to better understand and model the carbon cycle across glacial cycles.

2. Chronological advances, both in assessing absolute ages relative to astronomical forcing, and in aligning different proxies and locations, are essential if we are to assess the dynamics of interglacials and their termination and inception.

3. The paucity of terrestrial records hampers the assessment of many important aspects of climate.

4. Although existing records suggest that sea level is quasi-similar at the apex of each post-800 ka interglacial, obtaining additional data is essential, both to understand the pattern of ice sheet forcing of climate, and to define the questions that need to be asked about the state of the Greenland and Antarctic ice sheets in warmer interglacials.

5. Identifying the controls on intra-interglacial variability remains a challenge.

6. The predictability of interglacials and the prognosis for the current interglacial with and without anthropogenic climate change.

Key aims

QUIGS aims to:

1. Document and synthesize data on the temporal and spatial patterns of climate responses during Quaternary interglacials and assess the governing processes using numerical models;

2. Assess the relevance of interglacials to understanding future climate change.

Within this framework QUIGS examines in particular (i) warm extremes, (ii) glacial terminations, and (iii) interglacials of the Early Pleistocene '41kyr-world'.

QUIGS develops strong synergies between the paleoclimate modeling and data communities who together can provide expertise on experimental design, data compilations and syntheses, model-data comparisons, and interpretation of results.

Phase 1 of QUIGS (2015-2017) formulated the research questions, identified knowledge gaps and the steps to fill these gaps. In particular, it guided the definition of coordinated model experiments as part of CMIP6 and PMIP4 and enabled the collection and the synthesis of datasets (see Fig 1, above).

Phase 2 of QUIGS (2019-2022) aims to return to the research questions identified in Phase 1 with improved datasets and new model experiments that will have been generated by then, ultimately aiming to gain a quantitative understanding of interglacials controls.

In 2018, QUIGS also joined forces with the PALSEA working group to organize a cross-cutting meeting on "Climate, ice sheets and sea level during past interglacial periods" (24-27 September, Galloway, USA). The aim was to foster a more organized collaboration between scientists from the different climate, sea-level and ice-sheet communities working on past interglacials.

Research highlights for Phase 1

Otto-Bliesner et al. (2017) described the scientific objectives and experimental design for the Last Interglacial coordinated equilibrium experiments (refered to as lig127k) performed in the framework of CMIP6-PMIP4. Read here.

Capron et al. (2017) produced a data-based time slice synthesizing high-latitude surface temperature changes at 127 ka and provided a critical evaluation of the latest LIG surface climate reconstructions as well as recommendations for their use for model-data comparison exercises. Read here.

Tzedakis et al. (2017) proposed that an interglacial occurs when a peak in insolation energy exceeds a threshold that decreases with time elapsed since the previous deglaciation; this simple rule correctly predicts the deglaciation history of the past 2.6 million years, including the change in frequency of glacial-interglacial cycles about one million years ago. Read here.

You can read more about our scientific questions and workplan for Phase 1 and Phase 2 on our Scientific goals page.

Learn more and participate

This group is open to anyone who is interested, and early-career researchers are encouraged to be involved:

- Subscribe to the QUIGS mailing list here

- Contact a member of the Leadership Team