Download PDF Spring Bridge Issue on Engineering and Climate Change March 15, 2020 Volume 50 Issue 1 The seven articles in this issue cannot cover all engineering-related aspects of climate change, but they highlight several areas of concern. Editors' Note: Engineering and Geoengineering Approaches to Climate Change Tuesday, March 17, 2020 Research on and responses to climate change involve observations, numerical prediction models, adaptation, and mitigation strategies. The field of engineering is involved in all of these endeavors. Impacts to the Earth system caused by a warming planet—for example, changes to permafrost, local and global water cycles, and sea level rise—require careful monitoring as well as adaptation and mitigation solutions. These may not solve the climate change problem but can support efforts to cope with the changes and impacts, reduce fossil fuel energy usage, decrease or slow increases in greenhouse gas concentrations in the Earth’s atmosphere, or even change the Earth’s energy balance by introducing upper atmospheric aerosols that mimic the cooling effect of large volcanic eruptions. The latter is a type of geoengineering, a term that refers to deliberate large-scale intervention in the Earth’s natural systems to mitigate climate change. The position of the National Academies of Sciences, Engineering, and Medicine based on their consensus reports is that: Climate change is happening today. Scientists have known for some time, from multiple lines of evidence, that humans are changing Earth’s climate, primarily through greenhouse gas emissions. The evidence is clear and compelling. Earth’s atmosphere and oceans are warming, the magnitude and frequency of extreme climate and weather events are increasing, and sea level is rising along our coasts. Climate change is increasingly affecting people’s lives. It is having significant effects on infrastructure, agriculture, fisheries, public health, and the ecosystems that support society. It is also changing the environment in ways that affect the distribution, diversity, and long-term survival of species of plants, animals, and other forms of life on Earth. Decision makers are taking climate into consideration in a variety of contexts—such as federal energy policies and standards, state infrastructure investments, community adaptation plans, which crops to plant, public health strategies, approaches to ecosystem management, sustainable business practices and procedures, national security policy and infrastructure, and personal financial investments and education. The seven articles in this issue cannot cover all engineering-related aspects of climate change, but they highlight several areas of concern. In the first article, Claire L. Parkinson briefly reviews the Earth’s climate history over the past 2 million years before sketching the evolution of climate change recognition and understanding since the 19th century. She then describes information sources such as ice cores, in situ and satellite measurements, and the critical role of engineering in monitoring and research on climate change. Next, William E. Schnabel, Douglas J. Goering, and Aaron D. Dotson compellingly explain the challenges of infrastructure built at high latitudes on frozen ground. Arctic infrastructure built on permafrost is particularly vulnerable to a warming climate, and the authors consider engineering challenges and mitigation techniques for, among others, unheated structures and water and wastewater services. Dennis P. Lettenmaier and Jay R. Lund explore the impacts of climate change on California’s water resources. The state’s water system was designed and evolved from the late 1800 to 1970s with an assumed stationary precipitation pattern, but climate change is introducing nonstationarity to rainfall patterns. The authors suggest a portfolio of management actions that take into account current and future climate effects to accommodate water users, system managers, and regulators. Soroosh Sorooshian and his coauthors discuss the intersection of hydrology and population growth, especially expanding urban growth, and relate current and future flooding to hydrologic extremes. They are careful to elucidate the challenges and shortcomings of modeling, even when based on regional and global recorded observations of precipitation, to predict trends. Jennifer Wilcox quotes from Shel Silverstein’s poem “The Giving Tree” to draw apt comparisons with the “the giving Earth.” Options for combating rising atmospheric CO2 concentrations and their harmful effects may include negative emissions technologies, direct air capture, and carbon capture and storage. She also considers market and workforce implications. Jochen Hinkel and Robert J. Nicholls address projected climate change effects on sea level rise and examine adaptation responses for different circumstances such as subsidence associated with development, coastal erosion, and degradation of ecosystems. Besides engineering needs, the choice of response should consider economic factors, stakeholder risk tolerance, and differences in impact for populated versus rural, wealthy versus poorer areas. Alan Robock considers possible benefits and risks of stratospheric solar radiation management for climate intervention (often referred to as geoengineering). The author is careful not to recommend this method because of possible adverse side effects and its cost to implement. Many scientists and engineers call for significantly cutting back on the emissions of carbon compounds in the atmosphere. In the issue’s EES Perspective column, Elke Weber provides a sober reminder of the ethical issues related to climate change. We regard climate change as one of society’s major challenges. The articles in this issue illustrate a few of the ways that scientists and engineers are working on novel solutions to it. Acknowledgments We are grateful to the following readers who provided evaluative comments and constructive suggestions to help ensure the coverage, accuracy, and substantiation of the articles: Waleed Abdalati, Roger Aines, Mike Anderson, Ana Barros, Kevin Bjella, Steve Burges, Francis Chung, Miguel Esteban, Peter Gleick (NAS), Ben Kravitz, Colin McCormick, Simone Tilmes, Roderik van de Wal, and John Zarling. Warren Washington (NAE) retired as a senior scientist at the National Center for Atmospheric Research (NCAR). Antonio Busalacchi (NAE) is president of the University Corporation for Atmospheric Research (UCAR). Cameron Fletcher is managing editor of The Bridge.  Posted at the site for Climate at the National Academies, https://sites.nationalacademies.org/sites/climate/index. htm.