Search Results for « tipping »

Stevan Harnad, Tripping on Tipping Points: Jubilatio Praecox, <em> Open Access Archivangelism </em> , September 21, 2007. Excerpt: <strong> Comment </strong> . Well-put. I made some of the same points in the September SOAN. There's no evidence yet for a tipping point (or slippery slope), although there might be later.

Stevan Harnad, Tripping on Tipping Points: Jubilatio Praecox, <em> Open Access Archivangelism </em> , September 21, 2007. Excerpt: <strong> Comment </strong> . Well-put. I made some of the same points in the September SOAN. There's no evidence yet for a tipping point (or slippery slope), although there might be later.

Abstract The Earth's climate system is a complex system that includes key components such as the Arctic Summer Sea Ice or the El Niño Southern Oscillation as well as climate tipping elements like the continental-scale ice sheets or the Amazon rainforest. Crossing warming thresholds of these elements can lead to a qualitatively different climate state, endangering the stability of human societies. Particularly, the cryosphere elements are vulnerable at current levels of global warming (1.2°C) while also having long response times and large structural uncertainties. Investigating a network of interacting Earth system components using an established conceptual model, we systematically assess which uncertainties of key Earth system component have the largest impacts on tipping risks. We find that the cryosphere tipping elements (the Greenland and the West Antarctica ice sheets) are most decisive for tipping risks and cascading effects within our model. At a global warming level of 1.5°C, neglecting the large cryosphere tipping elements can reduce the mean number of disintegrated Earth system components by as much as 56%. This is concerning as overshooting 1.5°C of global warming is fast becoming inevitable, while current state-of-the-art IPCC-type global circulation models do not (yet) include dynamic ice sheets. Our results suggest that urgent integrated Earth system model development and Earth observation efforts including the large polar ice sheets are necessary and a precautionary measure of meeting stringent climate targets is crucial to limit tipping risks.

Tipping points (TPs) – often understood as abrupt changes to a system – have become a popular framework for ecology and environmental science across spatial and temporal scales. The underlying, quantitative foundation of TP theory is built on mathematical models from catastrophe and predator–prey theories. Tipping points based on a cusp catastrophe model were critiqued early, but that history did not happen for TPs derived from predator–prey theory. Here we summarize both histories and resulting flaws in the understanding and application of TPs. Unfortunately, much of what has been written about TPs is derived from predator–prey theory and is not readily defended: multiple assumptions cannot apply; other problems exist; and evidence is weak or lacking. Fortunately, early critique led to a viable approach to evaluate TPs based on the cusp catastrophe model. We suggest TPs based on predator–prey theory be abandoned and many putative TPs be re‐assessed with modern tools based on the cusp catastrophe model and/or other potential approaches. Tipping points may then be useful to understand changing systems if other important problems (publication bias, lack of empirical evidence, stability concepts, scale) can also be surmounted. In the meantime, the science of TPs lags far behind the concept's popularity, and so TPs are not yet a solid foundation for environmental policies.