A Consideration of the Health and Environmental Risks/Effects of Geoengineering

Abstract:

The views expressed in this abstract are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency.

A number of geoengineering strategies have been proposed and, to date, a few are being seriously investigated as possible approaches to reducing the degree of climate change. Whether under the broad rubrics of solar radiation management (SRM) or carbon dioxide removal (CDR), these projects would involve major, intentional intervention in the world’s climate. Even if successful in off-setting the global radiative imbalance induced by human activities, it is not at all clear how well humans and the ecosystems upon which they depend will weather the climate system perturbations induced by the implementation of a large-scale geoengineering program. It is reasonable to expect that such perturbations could exacerbate the existing health and environmental consequences of anthropogenic climate change at large and small scales, or create entirely new ones.

An accounting of the derivative physical and biological effects of consequence to human health and ecosystems welfare that may result from the use of geoengineering is a necessary part of any policy-relevant analysis. However, the scientific understanding required to quantitatively assess these potential impacts is absent in most cases, and still nascent in others. Furthermore, current discussions and existing literature lack the fully integrated “systems” approach required for adequately assessing the short- and long-term impacts of geoengineering strategies on ecosystems and human populations. We present an overview of critical science questions, including broad questions concerning the potential response of the complex earth system to further human interference and those concerning potential impacts to local environmental metrics such as air and water quality and ecosystem viability.