DIEP seminar by Max Rietkerk
First developed in ecology, the concept of tipping points between alternative stable states and their early-warning indicators has more recently been applied to major climate system components. However, these indicators are often statistically and interpretively ambiguous, a pattern evident in research on the Amazon rainforest, the Atlantic Meridional Overturning Circulation (AMOC), and the Greenland Ice Sheet. Here, early-warning signals have been interpreted as indicating that these systems are approaching catastrophic tipping points, while the uncertainties surrounding these interpretations have remained underemphasized.
Another notable example is the reported bimodality in tree-cover distributions across the Congo Basin, the largest rainforest in Africa. This early-warning indicator has been used to infer that the whole Congo, though currently forested, may be bistable with savanna and at risk of a large-scale shift. Yet evidence suggests that any such tipping dynamics, if present at all, operate only at much smaller spatial scales (<10 × 10 km) and do not characterize the Congo as a whole. The rationale behind this reassessment is relevant for other climate system elements as well.
Recognizing these ambiguities is crucial for responsible science communication: early-warning assessments for tipping points should explicitly convey their uncertainties to maintain transparency and avoid perceptions of alarmism. Nevertheless, uncertainty about tipping points does not lessen the urgency of climate action, given the well-documented impacts of ongoing climate change. The proposed framework of resilience pathways offers a constructive way to incorporate such ambiguities, supporting climate policies that remain evidence-based and adaptive to future scenarios.
If you wish to attend this seminar online, please send an email to r.lier@uva.nl to receive the zoom-link.