rudimentary understanding of the dynamics of interactions between different environmental variables in complex systems, making it extremely difficult to predict the combined effects of multiple interacting stresses. Other scientific challenges include understanding the multiple time and space scales on which these interactions take place, developing indicators for “threshold” responses that may lead to sudden and dramatic changes in societal or environmental structure and function, characterizing and quantifying risks and vulnerabilities, and understanding the economic impact of multiple interacting changes. Another critical challenge is proceeding with decision making given the many uncertainties and limited prediction capabilities.
Given the highly interdisciplinary nature of multiple environmental stresses, conducting research on the topic involves a variety of infrastructural and institutional challenges. First, a broad range of observational and experimental/process studies is needed for understanding integrated climate and ecosystem processes. Second, coupled biophysical and biogeochemical models are needed to address the dynamics of exchange of water, energy, carbon, and nitrogen on multiple timescales, with biogeographic models that simulate the effects of climate and other factors on vegetation distribution. New data and information systems may be necessary to enable scientists to integrate knowledge across these disciplines. Further, it appears likely that focusing on natural, managed, and socioeconomic systems on a regional scale may provide a tractable approach to bringing together the diverse researchers and knowledge needed to improve understanding of multiple environmental stresses.
In addition to gaps in the scientific understanding of multiple environmental stresses, there is a lack of understanding of how to devise wise management and policy approaches that address suites of problems and, in particular, options that make sense in the face of uncertainty. These options can be technological, managerial, or institutional and will require much more integrative research in many disciplines. It will also require serious consideration of how we translate information as well as a sense of what we do not know or cannot know, so that it is useful to those who must make decisions. Adaptive management using the best information available, while retaining flexibility to make changes, requires managers to think differently, but it does increase resiliency to risk.
Effective communication between researchers and stakeholders is critical. As research develops more sophisticated understanding of environmental systems and how multiple stresses interact and compound, it becomes even more difficult to translate this understanding to those who must use the information. Although there is no easy answer to this dilemma, the solution appears to require extended interactions, careful attention to including all perspectives, and frankness about the level of certainty and uncertainty of the information.