Every first Tuesday of the month we bring interesting talks on the latest science on climate tipping points and opportinuties to engage with a community of fellow researchers and climate science enthusiasts. Here is the overview of upcoming ClimTip webinars in 2025 with talks from Alexander Robinson (Alfred Wegener Institute Potsdam), Yechul Shin (Seoul National University) and Maya Ben-Yami (Technical University of Munich).
February 4, 14:00–15:00 CET
The stability of the Greenland ice sheet - the big picture
Guest speaker: Alexander Robinson (Alfred Wegener Institute Potsdam)
Abstract:
Melting of the Greenland ice sheet (GrIS) in response to anthropogenic global warming is expected to be a primary contributor to sea-level rise in the future. It is also well known that the GrIS reduced in size during previous interglacial periods. However deep uncertainty remains in the magnitude of forcing that drove such retreat and the minimum size of the ice sheet in each case. Here I will discuss our recent work on understanding GrIS stability both in the context of paleoclimatic changes and future warming, and what remains to be understood.
Tuesday, March 4, 14:00–15:00 CET
Reconciled warning signals in observations and models suggest a nearing AMOC tipping point
Guest speaker: Yechul Shin (Seoul National University)
Abstract:
Yechul Shin: The Atlantic Meridional Overturning Circulation (AMOC), as recorded in paleoclimate proxies, is one of the climate systems with a potential abrupt transition. Increasing identification of statistical signals—critical slowing down—in observational fingerprints empirically raises concerns that the system may be approaching a tipping point. However, state-of-the-art Earth System Models (ESMs) rarely project an abrupt collapse of AMOC, and its loss of stability has yet to be thoroughly investigated, leaving it unclear whether warning signals of AMOC tipping is overlooked in ESMs or exaggerated in fingerprints. Here, a warning signal over the deep convection site of AMOC is consistently identified in both observations and ESM, and we present that the currently observed signal is reconciled with the modeled one, with warming exceeding the Paris Agreement goal. This warning signal is in accordance with physical stability of the AMOC, the AMOC-induced freshwater convergence into the Atlantic basin, is overestimated in the ESM, so that it projects a delayed tipping point. These results suggest that the observed AMOC is approaching a tipping point akin to the projections of models simulating a much warmer Earth, underscoring potentially overlooked risks in ESMs assessments.
Tuesday, April 1, 14:00–15:00 CET
Atlantic Ocean circulation collapse: impacts and uncertainties
Guest speaker: Maya Ben-Yami (Technical University of Munich)
Abstract:
The Atlantic Meridional Overturning Circulation (AMOC) is a key element of the Earth’s climate system, transporting large amounts of heat and salt northward in the upper layers of the Atlantic ocean. A collapse of the AMOC in response to anthropogenic climate change would have catastrophic ecological and societal consequences, with substantial temperature changes in northern latitudes, and a major rearranging of tropical monsoon systems. However, the likelihood of a future AMOC collapse remains highly uncertain, with intense debate over the AMOC's stability and its observed and predicted decline. The collapse of the AMOC is thus a so-called "high impact, low likelihood event".
This presentation will first cover the impacts of an AMOC collapse, with a focus on tropical monsoon rainfall, and then discuss whether or not we can know if such a collapse is approaching. In particular, the presentation will look at the use of critical slowing down as a measure of the changing stability of the AMOC, discussing both the uncertainties of the method and its support from CMIP6 models.
Illustration by Kuat Abeshev. Photo by Gitte Winter on Unsplash.
