#climate change #mitigation #decarbonization #sustainable development #SDGs

Leading scientists explored in a recent PNAS (Proceedings of the National Academy of Sciences of the United States of America) publication the risk of self-reinforcing feedbacks which could push the Earth System toward a planetary threshold. If the threshold is crossed, stabilization of the climate at intermediate temperature rises could be prevented and cause continued warming on a "Hothouse Earth" pathway even as human emissions are reduced. The co-authors examined the evidence that such a tipping point might exist and where it might be.

Based on the analysis, co-authors concluded that collective human action is required to steer the Earth System away from such a potential tipping point and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System-biosphere, climate, and societies-and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.

Johan Rockström, executive director of the Stockholm Resilience Centre and one of the coauthors, reminded that "We could end up delivering the Paris agreement and keep to 2oC of warming, but then face an ugly surprise if the system starts to slip away".

"In the context of the summer of 2018, this is definitely not a case of crying wolf, raising a false alarm: the wolves are now in sight," said Dr Phil Williamson, a climate researcher at the University of East Anglia. "The authors argue that we need to be much more proactive in that regard, not just ending greenhouse gas emissions as rapidly as possible, but also building resilience in the context of complex Earth system processes that we might not fully understand until it is too late."

Please refer to the original PNAS paper and Guardian report for more details.

(Steffen et.al. (2018) Trajectories of the Earth System in the Anthropocene. Proceedings of the National Academy of Sciences of the United States of America, 115 (33) 8252-8259; DOI: https://doi.org/10.1073/pnas.1810141115)