Seminar with C. Adam Schlosser - Friday February 15th 10:15 AM

presents

Confronting Global Water Risks into an Unprecedented Era: Successes and Challenges with Risk-Based, Multi-Sector Predictions

C. Adam Schlosser

Deputy Director for Science Research
MIT Joint Program on the Science and Policy of Global Change

Friday, February 15, 2019

10:15 – 11:00 AM

Health Science Research Facility 200


 

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Funding provided by NSF OIA 1556770

Abstract:
Confronting Global Water Risks into an Unprecedented Era: Successes and Challenges with Risk-Based, Multi-Sector Predictions
Society is fast approaching an unprecedented global situation of accessible water supplies no longer capable of sustaining the population's water use at modern standards of living. Now more than ever, the scientific community must conduct assessments of risk that identify the most likely and most damaging trajectories, as well as a balanced analysis to note regions and sectors at low risk. Quantifying risk, and more importantly, identifying adaptive and mitigating measures that reduce future risks, requires predictive tools that describe sectors across the coupled human-Earth system as well as their interactive and interdependent relationships. With these issues in mind, we have assessed trends in managed water stress simulated by the Water Resource System within the IGSM framework (IGSM-WRS). Forced by simulated climate simulated from an Earth-system model and socio-economic drivers from the Economic Projection and Policy Analysis (EPPA), the IGSM-WRS prediction framework constructs large-ensemble scenarios that include a "business-as-usual" future with countries meeting their Paris Agreement commitments - as well as other scenarios that either meet certain global climate targets (i.e. 2 degrees C or 1.5 degrees C) or consider "unconstrained" emission or economic growth pathways. Analyses across this suite of ensemble scenarios reveal important regional aspects of impending water-stress risks. Most notably, a salient skewness in risk can be seen for a number of heavily populated basins across the developing world as well as the United States, that favors a stronger increase in water stress (as compared to an equal likelihood of decreased stress). In particular across the United States, the ensemble central tendency also shows the largest relative increase across the Northeast – and is largely attributable to population growth and economic drivers of water demand. In other regions of the world such as southern and eastern Asia, we find that while socio-economic growth paves an inexorable path toward a risk of increased stress, the effect of climate change has important regional implications that either can exacerbate or offset the risk. Sensitivity simulations have assessed widespread deployment of efficient water-use technologies and stricter mitigation pathways and indicate how hundreds of millions of people can avoid these elevated risks to heightened water stress.