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Palaeoclimate constraints on the impact of 2 °C anthropogenic warming and beyond

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Author Fischer Hubertus, Meissner Katrin J., Mix Alan C., Abram Nerilie J., Austermann Jacqueline, Brovkin Victor, Capron Emilie, Colombaroli Daniele, Daniau Anne-Laure, Dyez Kelsey A., Felis Thomas, Finkelstein Sarah A., Jaccard Samuel L., McClymont Erin L., Rovere Alessio, Sutter Johannes, Wolff Eric W., Affolter Stéphane, Bakker Pepijn, Ballesteros-Cánovas Juan Antonio, Barbante Carlo, Caley Thibaut, Carlson Anders E., Churakova Olga, et al. ,
Project iCEP - Climate and Environmental Physics: Innovation in ice core science
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Original article (peer-reviewed)

Journal Nature Geoscience
Volume (Issue) 11(7)
Page(s) 474 - 485
Title of proceedings Nature Geoscience
DOI 10.1038/s41561-018-0146-0

Open Access

Type of Open Access Green OA Embargo (Freely available via Repository after an embargo)


Over the past 3.5 million years, there have been several intervals when climate conditions were warmer than during the preindustrial Holocene. Although past intervals of warming were forced differently than future anthropogenic change, such periods can provide insights into potential future climate impacts and ecosystem feedbacks, especially over centennial-to-millennial timescales that are often not covered by climate model simulations. Our observation-based synthesis of the understanding of past intervals with temperatures within the range of projected future warming suggests that there is a low risk of runaway greenhouse gas feedbacks for global warming of no more than 2 °C. However, substantial regional environmental impacts can occur. A global average warming of 1–2 °C with strong polar amplification has, in the past, been accompanied by significant shifts in climate zones and the spatial distribution of land and ocean ecosystems. Sustained warming at this level has also led to substantial reductions of the Greenland and Antarctic ice sheets, with sea-level increases of at least several metres on millennial timescales. Comparison of palaeo observations with climate model results suggests that, due to the lack of certain feedback processes, model-based climate projections may underestimate long-term warming in response to future radiative forcing by as much as a factor of two, and thus may also underestimate centennial-to-millennial-scale sea-level rise.