By Paris Edwards
Our understanding of regional climate change effects today will be used to inform management, policy, and the new scientific endeavors of tomorrow. With this in mind, a team of doctoral students from the Water Resources Department at the University of Idaho in Moscow carried out a systematic review of all peer-reviewed studies through 2016 (550 of them) related to climate change in headwater regions of the Columbia River Basin. The purpose of the review was to explore what aspects of climate change impacts on water availability have been well studied, and where additional research is still needed (Marshall et al. 2020). We focused on mountain headwater regions because these critical water-generating areas are vulnerable to increasingly warm winter temperatures that contribute to snowpack losses and increased variability in the timing and volume of water available for multiple uses. Water availability supports values we care about and communities in our region, including irrigation; the future of irrigated agriculture in the Basin depends on water, and at least 20% of surface supply in the Basin is generated from melted snow.
Our systematic review is a resource that provides a detailed look at several important dimensions of climate change research in the Columbia River Basin. Teasing out where the main gaps are can help focus research questions and design so that this gap can be addressed in the future. To accomplish this, we looked for patterns in the focus, scale, topic, and location of all studies. This approach allowed us to ask helpful questions such as: was agriculture-relevant research done at a farm-sized scale, or mostly at larger, regional scales? Did agriculture-relevant studies look at climate change impacts, adaptation, or mitigation? In addition, we examined whether studies combined aspects of climate change (interdisciplinarity) and if so, which disciplines were explored together. For instance, were studies focused on aspects of hydrologic change also focused on agriculture?
We learned that there is a lot of opportunity to improve our understanding of climate impacts on agriculture in the Columbia River Basin, and that improved understanding can help producers adapt into the future. Our review of research topics uncovered an important reality: very few climate change studies, particularly those that focused on the biophysical or hydrological aspects, address agriculture specifically. When we looked at the agriculture-related topics, we found that economics and drought were most commonly studied; drought research is extremely relevant to current and future agricultural production in the Basin. The scale of agriculture-relevant studies from social fields like sociology, policy, and economics tended to be subregional (ranging from regional to plot scale), indicating the potential for greater localized relevance that is helpful to producers on the ground. Adaptation-focused studies are essential for helping farmers and ranchers understand how to adjust to a changing climate and avoid negative consequences, but they constituted only 10% of the total papers reviewed in our study. Nevertheless, the small fraction of agriculture-relevant social disciplines suggests that existing work could provide insight into adaptations useful to agriculture (e.g., irrigation adaptations to drought), albeit indirectly.
Why does this literature review focused on the Columbia River Basin matter now? There is a clear shortage of available information that directly addresses climate change in the Basin’s headwater regions (where irrigation water originates) and agriculture, and that puts the agricultural sector at a disadvantage when it comes to preparing for and coping with change. It is important to note that the information gaps addressed here also represent research opportunities. Given that agriculture dominates water use across the Columbia River Basin and that it is considered culturally and economically invaluable, our hope is that conclusions from the review help to motivate and re-focus a new generation of climate change science for the region that meets the needs of agricultural users on the ground and better reflects these valued regional resources.
Marshall, A. M., Foard, M., Cooper, C. M., Edwards, P., Hirsch, S. L., Russell, M., & Link, T. E. (2020). Climate change literature and information gaps in mountainous headwaters of the Columbia River Basin. Regional Environmental Change, 20(4), 1-14.