Climate change, uncertainty and allostatic load

Abstract

Context: Humans constantly respond to environmental stressors challenging their somatic stability. Allostasis, an evolved neuroendocrine/physiological stressor response system, is our main pathway for doing so. Effective allostasis returns somatic systems to their current optima; over a lifetime of stressor responses, related systems fail, effectiveness declines, and physiological dysregulation (i.e. allostatic load) increases. Global Climate Change (GCC) multiplies environmental stressors on human populations and is likely to increase allostatic load.

Objectives: As a population-level stressor, GCC increases risks for multiple stressors, including sociocultural instability and food and water insecurity, while also motivating migration. We predict GCC increases risk for elevated allostatic load. Here, we review pathways by which GCC increases climatic and social stressors contributing to greater stress and allostatic load.

Methods: Based upon published sources and primary ethnographic case studies, this review examines how GCC, by multiplying climate-related stressors, likely increases social instability, food and water insecurity, and migration. Thereby, it is proposed that GCC contributes to allostatic load.

Results: GCC multiplies stressors on local populations. Those experiencing social insecurity related to GCC during growth and development are expected to show the largest influences on their lifetime allostatic load. Similarly, as GCC increases food and water insecurity, it likely will increase allostatic load in those affected and is likely to propel migrants to seek improved living circumstances. These stressors may be continued among their descendants via historical trauma or epigenetic responses.

Conclusion: GCC accentuates effects of environmental and sociocultural stressors on human populations. Those exposed to GCC are likely to show lifelong elevated allostatic load.

Keywords:

• Food insecurity
• climate migration
• social instability
• water insecurity
• stressors

Acknowledgments

An earlier version of this paper was presented at the 2017 Scientific Symposium of the Society for the Study of Human Biology & International Association of Physiological Anthropology: ‘Human Biology of Climate Change’, 12–15 September 2017, Loughborough, UK, organised by Professor Barry Bogin, Loughborough University. Another was presented at the Fourth International Conference, ‘Evolutionary Medicine Health and Diseases in Changing Environment, 5–10 June 2018, Vilnius University, Vilnius, Lithuania, dedicated to the 100th Anniversary of the Restoration of Lithuania’s Independence and organised by the Faculty of Medicine, Vilnius University. A particular thank you to Professor Janina Tutkuviene of the Faculty of Medicine, Vilnius University for inviting our presentation.

Disclosure statement

No potential conflict of interest was reported by the author.