Safe operating space for humanity at a regional scale

The planetary boundaries framework defined safe limits to human impacts on essential Earth-system processes. Subsequent assessments concluded that impacts exceed most delineated boundaries. Societal responses to these results have been insufficient to restore safety. One factor impeding effective action is differences in scale between planetary boundaries and national, regional, or local scales where many impacts and solutions originate. I have contributed toward a resolution by developing a regional scale framework and an approach to translate boundaries across spatial scales. I developed the framework for a county and river basin in the Pacific Northwest. The framework includes six state variables related to planetary scale analogues. Boundary translation can be achieved by aggregating hydrologic processes across scales. Because of greater process certainty and lower spatial heterogeneity at the regional scale, regional boundaries can be defined with more precision than global analogues. The region has exceeded five boundaries and is close to the remaining one. Effects of existing and proposed policies will be to exceed boundaries further. Likely consequences include irreversible degradation in river functions, severe water shortages, impaired water quality, human health impacts, and extinctions of iconic salmonids. In most cases, policy and enforcement mechanisms to restore conditions within regional boundaries are in place, but they have been ignored or misapplied. New initiatives with potential to restore safety are being pursued by indigenous peoples, who also are most directly affected by boundary transgression. By clearly delineating regional boundaries and identifying consequences of boundary transgression, this framework may complement indigenous efforts with policy imperatives for other stakeholders in the region.