It is now entering the public consciousness that future warming triggered by near-term anthropogenic greenhouse gas emissions will last for many millennia. It is not possible to understand the scale of these long-term impacts based on the short history of human scientific observations. Climatic and environmental informations stored in natural climate archives together with climate model results allow us to draw a comprehensive picture of how different components of the Earth system with long response times will change in a warmer world.
This joint workshop of PAGES and the Oeschger Centre for Climate Change Research (OCCR) is part of the PAGES Integrative Activity "Warmer Worlds" and will assess the knowledge of such long-term changes and the existence of planetary boundaries associated with a globally (and potentially rapidly) warming planet. The goal is to draw a comprehensive picture of climate and environmental conditions associated with past global warmth above preindustrial conditions.
Scope of the conference
The goal of the workshop is to summarize the current status of knowledge on the response of the Earth System to a 1.5-2°C warming. It will also lay out future scientific actions to add to this knowledge in order to come up with authoritative assessments of future long-term changes in the Earth system as expected from past examples of warmer climate conditions.
We expect this workshop to address cross-cutting questions such as:
- Climate with its impacts and feedbacks in past warmer interglacial periods: analogues for a warmer future? How will our planet look in a warmer climate (in terms of vegetation/ecosystems, ice sheets and permafrost, sea level, sea ice etc.)
- Relationship between climate change and greenhouse gas concentrations (cause, effect, and feedback, such as CH4 release from permafrost during warmer worlds or carbon storage in peat).
- Dynamics of change associated with warming; are there limits to the speed of warming in the phase space of past climate evolution?
- What will be the long-term ocean response to continued warming (both in heat content as well as ecosystem and carbon storage services)
- Were there global environmental "Tipping Points" associated with warming in the past? And how can these past tipping points inform us about possible near-term future tipping points? For example, irreversible loss of polar ice, positive carbon feedbacks etc.
- Change in variability and the recurrence of extreme events associated with warmer worlds.
Format and Sessions
The workshop will comprise plenary talks and discussions as well parallel sessions on:
Day 1: Plenary talks on:
- what time periods in the past can inform us about potential long-term changes in the future,
- what caveats exist to use this paleo-information, and
- key examples of past changes of different components of the Earth system in a warmer world.
Day 2: Three breakout groups presenting and summarizing the state of our knowledge on:
- paleo-responses of the physical climate system to a 1.5-2°C warming, such as sea ice, land ice/sea level, albedo, atmosphere/ocean circulation (and their impact on nutrient supply), and thresholds and non-linearities in the physical system ...
- paleo-responses of hydroclimate and ecosystems to a 1.5-2°C warming, including, changes in the distribution of hydroclimatic parameters and their extremes, climate and CO2 induced long-term changes and tipping points in marine and terrestrial ecosystem composition, ecosystem resilience, and
- paleo-responses of biogeochemical cycles to a 1.5-2°C warming including climate/greenhouse gas feedbacks, such as carbon accumulation/release in peat, permafrost, soils, the risk for rapid CH4 release, changes in the nitrogen cycle and their impact on the capacity to sequester CO2.
Day 3: Plenary talks on:
- what time periods in the past can inform us about potential long-term changes in the future,
- what caveats exist to use this paleo-information, and
- key examples of past changes of different components of the Earth system in a warmer world.
Summary report of the breakout groups and synthesis, planning of a review paper summarizing the state of our knowledge and identifying future research objectives, identification of a writing team to push this paper forward.
Support
We thank PAGES the Oeschger Centre for Climate Change research for financial and organizational support of the workshop.
No registration fee is asked for, however, participants of the workshop are expected to cover their travel expenses. Only very limited travel support exists.
Confirmed Invited Speakers
Quing Yan, Chinese Academy of Science, China
Katrin Meissner, U. New South Wales, Australia
Erin Mc Clymont, Durham University, U.K.
Bette Otto-Bliesner, NCAR, USA
Emilie Capron, University of Copenhagen, Denmark
Victor Brovkin, MPI for Meteorology, Hamburg, Germany
Max Holloway, University of Bristol, U.K.
Nerilie Abram, Australian National University, Australia
Anders Carlson, Oregon State University, USA
Eric Wolff, University of Cambridge, U.K.
Liping Zhou, Peking University, China
Sheri Fritz, University of Nebraska Lincoln, USA
Fortunat Joos, University of Bern, Switzerland
Willy Tinner, PAGES & University of Bern, Switzerland
Daniele Colombaroli, University of Bern, Switzerland
Valerie Masson-Delmotte, IPCC WG1 & LSCE Paris, France
Hubertus Fischer, PAGES & University of Bern, Switzerland
Anne-Laure Daniau, University of Bordeaux, France
Sarah Finkelstein, Canada
Kelsey Dyez, Lamont Doherty Earth Observatory, USA
Jacky Austermann, University of Cambridge, UK
Jennifer Marlon, Yale University, USA
Alan Mix, Oregon State University, USA
Pepijn Bakker, Marum, Bremen, Germany
