CO-KRIGING TO INCORPORATE SCREENING DATA: HUDSON RIVER SEDIMENT PCBs1

ABSTRACT: Kriging methods of geostatistical analysis provide valuable techniques for analysis of sediment contamination problems, including interpolation of concentration maps from point data and estimation of global mean concentrations. Sample collection efforts frequently include preliminary screening data of considerably more extensive coverage than the laboratory analyses on which estimation is usually based. How should these be incorporated in kriging? Screening and laboratory analysis constitute two separate estimates of the same spatial field but of very different characteristics. A modified version of co-kriging is developed to include the imprecise screening information in the analysis of contaminant distribution. Use of the method is demonstrated on a data set of sediment PCB samples from the Upper Hudson River, for which preliminary categorical mass spectrometry screening was used to select a smaller set of samples for gas chromatograph analysis. The method is widely applicable to many situations of contaminant and natural resource estimation.     

Democratising planetary boundaries: experts,social values and deliberative risk evaluation in Earth system governance

ABSTRACT

Recent debates about the concept of planetary boundaries recall longstanding concerns about whether ecological limits are compatible with ecological democracy. The planetary boundaries framework (originally set out in Rockström et al., 2009a, 2009b) defines values for key Earth-system processes such as climate change and biodiversity that aim to maintain a ‘safe’ distance from thresholds or levels that could endanger human wellbeing. Despite having a significant impact in policy debates, the framework has been criticised as implying an expert-driven approach to governing global environmental risks that lacks democratic legitimacy. Drawing on research on deliberative democracy and the role of science in democratic societies, we argue that planetary boundaries can be interpreted in ways that remain consistent with democratic decision-making. We show how an iterative, dialogical process to formulate planetary boundaries and negotiate ‘planetary targets’ could form the basis for a democratically legitimate division of labour among experts, citizens and policy-makers in evaluating and responding to Earth-system risks. Crucial to this division of evaluative labour is opening up space for deliberative contestation about the value judgments inherent in collective responses to Earth-system risks, while also safeguarding the ability of experts to issue warnings about what they consider to be unacceptable risks.     

Between environmental and ecological democracy: theory and practice at the democracy-environment nexus

ABSTRACT

Concepts of ecological and environmental democracy seek to reconcile two normative ideals: ensuring environmental sustainability while safeguarding democracy. These ideals are frequently conceived as being in conflict, as democracy is perceived as too slow and cumbersome to deliver the urgent large-scale collective action needed to tackle environmental problems. Theories addressing the democracy-environment nexus can be situated on a spectrum from theories of ecological democracy that are more critical of existing liberal democratic institutions to theories of environmental democracy that call for reforming rather than radically transforming or dismantling those institutions. This article reviews theoretical and empirical scholarship on the democracy-environment nexus. We find continued theoretical and empirical diversity in the field, as well as vibrant debates on democratising global environmental politics, local material practices, and non-human representation. We argue for stronger dialogue between environmental political theory and empirical, policy-oriented research on democracy and sustainability, as well as further exploration of complementarities between ecological and environmental democracy. We identify four main areas of challenge and opportunity for theory and practice: public participation and populism; technocracy and expertise; governance across scales; and ecological rights and limits.