Characterizing and Dealing With Uncertainty: Insights from the Integrated Assessment of Climate Change

After posing four-broad questions about uncertainty and climate change, Part 1 of this paper provides a review of basic ideas about uncertainty and its treatment in quantitative policy analysis. Part 2 reports very briefly on a series of expert elicitations of climate experts which the author and his colleagues have conducted. The final portion of the paper uses integrated assessment of climate change as a vehicle to explore some limitations to conventional policy analysis and the treatment of uncertainty. Because the climate problem is global in scope, involving many societies, and because it will involve large changes that unfold on a time-scale of several centuries, many standard analytic methods for policy analysis cannot be appropriately applied. Several such difficulties are identified and explored. Strategies for addressing a few of them are discussed. The paper closes by offering answers to the four opening questions

Preferences for Exposure Control of Power-Frequency Fields among Lay Opinion Leaders

The authors report on surveys, differing according to focus on remedial costs, of Pittsburgh-area adults indicating beliefs about possible health effects of electromagnetic fields and the acceptability of options for reducing or eliminating the potential impact

Effectiveness of stratospheric solar-radiation management as a function of climate sensitivity

If implementation of proposals to engineer the climate through solar-radiation management (SRM) ever occurs, it is likely to be contingent on climate sensitivity. However, modelling studies examining the effectiveness of SRM as a strategy to offset anthropogenic climate change have used only the standard parameterizations of atmosphere–ocean general circulation models that yield climate sensitivities close to the Coupled Model Intercomparison Project mean. Here, we use a perturbed-physics ensemble modelling experiment to examine how the response of the climate to SRM implemented in the stratosphere (SRM-S) varies under different greenhouse-gas climate sensitivities. When SRM-S is used to compensate for rising atmospheric concentrations of greenhouse gases, its effectiveness in stabilizing regional climates diminishes with increasing climate sensitivity. However, the potential of SRM-S to slow down unmitigated climate change, even regionally, increases with climate sensitivity. On average, in variants of the model with higher sensitivity, SRM-S reduces regional rates of temperature change by more than 90% and rates of precipitation change by more than 50%.Engineering and Applied Science

Understanding Climatic Impacts, Vulnerabilities, and Adaptation in the United States: Building a Capacity for Assessment

Based on the experience of the U.S. National Assessment, we propose a program of research and analysis to advance capability for assessment of climate impacts, vulnerabilities, and adaptation options. We identify specific priorities for scientific research on the responses of ecological and socioeconomic systems to climate and other stresses; for improvement in the climatic inputs to impact assessments; and for further development of assessment methods to improve their practical utility to decision-makers. Finally, we propose a new institutional model for assessment, based principally on regional efforts that integrate observations, research, data, applications, and assessment on climate and linked environmental-change issues. The proposed program will require effective collaboration between scientists, resource managers, and other stakeholders, all of whose expertise is needed to define and prioritize key regional issues, characterize relevant uncertainties, and assess potential responses. While both scientifically and organizationally challenging, such an integrated program holds the best promise of advancing our capacity to manage resources and the economy adaptively under a changing climate

Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar

A number of analyses, meta-Analyses, and assessments, including those performed by the Intergovernmental Panel on Climate Change, the National Oceanic and Atmospheric Administration, the National Renewable Energy Laboratory, and the International Energy Agency, have concluded that deployment of a diverse portfolio of clean energy technologies makes a transition to a low-carbon-emission energy system both more feasible and less costly than other pathways. In contrast, Jacobson et al. [Jacobson MZ, Delucchi MA, Cameron MA, Frew BA (2015) Proc Natl Acad Sci USA 112(49):15060-15065] argue that it is feasible to provide low-cost solutions to the grid reliability problem with 100% penetration of WWS [wind, water and solar power] across all energy sectors in the continental United States between 2050 and 2055 , with only electricity and hydrogen as energy carriers. In this paper, we evaluate that study and find significant shortcomings in the analysis. In particular, we point out that this work used invalid modeling tools, contained modeling errors, and made implausible and inadequately supported assumptions. Policy makers should treat with caution any visions of a rapid, reliable, and low-cost transition to entire energy systems that relies almost exclusively on wind, solar, and hydroelectric power

Transplantation of canine olfactory ensheathing cells producing chondroitinase ABC promotes chondroitin sulphate proteoglycan digestion and axonal sprouting following spinal cord injury

Olfactory ensheathing cell (OEC) transplantation is a promising strategy for treating spinal cord injury (SCI), as has been demonstrated in experimental SCI models and naturally occurring SCI in dogs. However, the presence of chondroitin sulphate proteoglycans within the extracellular matrix of the glial scar can inhibit efficient axonal repair and limit the therapeutic potential of OECs. Here we have used lentiviral vectors to genetically modify canine OECs to continuously deliver mammalian chondroitinase ABC at the lesion site in order to degrade the inhibitory chondroitin sulphate proteoglycans in a rodent model of spinal cord injury. We demonstrate that these chondroitinase producing canine OECs survived at 4 weeks following transplantation into the spinal cord lesion and effectively digested chondroitin sulphate proteoglycans at the site of injury. There was evidence of sprouting within the corticospinal tract rostral to the lesion and an increase in the number of corticospinal axons caudal to the lesion, suggestive of axonal regeneration. Our results indicate that delivery of the chondroitinase enzyme can be achieved with the genetically modified OECs to increase axon growth following SCI. The combination of these two promising approaches is a potential strategy for promoting neural regeneration following SCI in veterinary practice and human patients

Reflections on an interdisciplinary collaboration to inform public understanding of climate change, mitigation, and impacts

We describe two interdisciplinary projects in which natural scientists and engineers, as well as psychologists and other behavioral scientists, worked together to better communicate about climate change, including mitigation and impacts. One project focused on understanding and informing public perceptions of an emerging technology to capture and sequester carbon dioxide from coal-fired power plants, as well as other low-carbon electricity-generation technologies. A second project focused on public understanding about carbon dioxide’s residence time in the atmosphere. In both projects, we applied the mental-models approach, which aims to design effective communications by using insights from interdisciplinary teams of experts and mental models elicited from intended audience members. In addition to summarizing our findings, we discuss the process of interdisciplinary collaboration that we pursued in framing and completing both projects. We conclude by describing what we think we have learned about the conditions that supported our ongoing interdisciplinary collaborations

The north-south tilt in the Australian Height Datum is explained by the ocean’s mean dynamic topography

Using geodetic and oceanographic data, we show that the apparent north-south slope between the Australian Height Datum (AHD) and the geoid is caused almost completely by the ocean’s time-mean dynamic topography (MDT). This is because the AHD was constrained to zero height at local mean sea level at multiple tide gauges around the Australian continent. Using MDT models and corrected leveling data, almost all of the apparent north-south slope can be removed from the AHD. An auxiliary observation is that a satellite-only MDT model based on only around one year of GOCE data generates results commensurate with geodetic, oceanographic and combined MDT models