The President's Climate Change Action Plan calls for the development of better science, data, and tools for climate preparedness. Many of the current questions about preparedness for extreme weather events in coming decades are, however, difficult to answer with assets that have been developed by climate science to answer longer term questions about climate change. Capacities for projecting exposures to climate-related extreme events, along with their implications for interconnected infrastructures, are now emerging.
Action by the U.S. federal government to reduce vulnerabilities to impacts of climate change has been a long time coming. A series of climate-related extreme events in 2011 and 2012, however, culminating in impacts of Hurricane Sandy on the metropolitan east coast in October 2012, helped to stimulate the issuance of a “Climate Action Plan” by the Executive Office of the President in June 2013.
This action plan includes a number of commitments to prepare the United States to cope with impacts of climate change, from supporting more climate-resilient infrastructures to enhancing both economic and natural resource protection. It also stresses the importance of “using sound science to manage climate impacts”: strengthening the science base, assessing impacts, improving data, and “providing a toolkit for climate resilience.”
The brief description of the toolkit in the action plan is oriented primarily toward ways to provide climate information to users, very much in the spirit of what in the past has been called “climate services.”1,2 But, in fact, getting to where the nation needs to be with tools to support climate change risk management involves the other science areas as well, for three particular reasons. First, simply transferring information about climate-related experiences in the past is not sufficient when there is abundant reason to believe that the climate is changing.3,4 Second, the climate change projections that are being supplied by major climate and earth system models are very often poorly suited to answer questions about exposures to extreme events in the next several decades. And third, impacts on people and the infrastructures that assure their quality of life do not depend on climate variables alone; they are shaped by other factors as well, especially characteristics of the infrastructures and how they connect with and depend on each other.
A part of achieving climate preparedness, then, is putting the “toolkit for climate resilience” in a larger context and considering the main challenges in developing appropriate tools to support effective risk management by localities, sectors, and the population at large in coming decades.
Some Challenges to Tool Development
For several decades, the United States and other countries have invested in developing science and modeling structures for projecting climate change under different scenarios of greenhouse gas (GHG) trends. For understanding relatively long-term implications for global and regional climates of different factors affecting emission trends, these models are invaluable. For answering other questions about climate-related risks and risk reduction strategies, however, they are often not very useful. Four needs are particular challenges in developing useful tools for anticipating and responding to threats.
A Focus on Climate-Related Weather Extremes and Extreme Events
The years 2011, 2012, and 2013 saw an unusual number of extreme weather events in the United States. Examples include super storms such as Irene and Sandy (see Figure 1), droughts in the southern Great Plains and their eastern margins, record floods in the Mississippi River Valley, destructive tornados in unusual times of the year, and dramatic wildfires in the West. Even for observers who tend to be skeptical about climate change, these experiences indicated a very real need to improve U.S. preparedness for such events, because impacts were real regardless of causation. As a result, much of the current policy focus of policymakers at national and state levels and the preparedness focus of economic sectors and localities has shifted from gradual climate change over periods of decades toward vulnerability and resilience issues posed by threats of climate-related extreme weather events in the next several decades. Informing these policy discussions calls for some kinds of climate science that have not historically had a major emphasis within the research community.
A Focus on Events in the Relatively Near Term
Besides a focus on extreme events, a preoccupation with the relatively near term has not been characteristic of climate science in general, although some steps have been taken toward “climate predictions” for the mid 2030s.5 The general understanding is that the global climate is determined several decades into the future by greenhouse gas emissions that have already occurred. Modifications of climate change trajectories through climate policies to reduce the rate of increase in emissions do not start to show differences in the global climate for three decades or more. If this is truly the case, then the shared trajectory to that time period represents a kind of prediction.
If the policy concern is with exposures to extreme events within the next several decades, however, such “climate predictions” remain limited by the fact that so many extreme events are not reliably forecasted by large-scale climate models. Some examples are events driven by climate, such as storms (coastal, frontal, and tornados) and sea-level rise. Other events are driven by a combination of climate and other forces, such as floods, droughts, heat waves, and wildfires. Projecting these threats in the relatively near term is a legitimate scientific objective, but it is not the primary objective of current climate science.
A Focus on Impacts That Reflect Factors Other Than Climate and Weather Variables Alone, Such as Vulnerabilities of Infrastructures at a Relatively Granular Scale
Since the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report in 2007, it has been increasingly recognized that climate change impacts are shaped by driving forces beyond changes in climate and weather parameters alone. Vulnerabilities and risks also depend on population characteristics and distributions; economic systems and activities, including linkages with each other and with other locations; institutional and social capacities for resolving issues and responding to threats and disruptions; and the resilience of potentially affected systems, natural and human. Among the most vivid examples in the United States are vulnerabilities of the Gulf Coast region to a combination of coastal storms, sea-level rise, land subsidence, and dense economic and demographic concentrations near the coast (Figure 2).6,7
The ability to account for multiple drivers is limited by several current realities. One is that many of the socioeconomic drivers, such as land use, are not projected very far into the future. Another reason is that some of the drivers are difficult to associate with metrics and data as a basis for assessing the significance of their roles. Yet another is that the capacity to integrate the various driving forces in a valid and consistent way is still very limited.
A Focus on the Interdependence of Infrastructures
For decades, it has been becoming ever more clear that impacts and costs of major climate-related extreme events are shaped not only by how resilient built infrastructures are to stresses (e.g., age, condition, and level of usage compared with design capacities) but also by how such infrastructures are connected with and interdependent with each other (Figure 3). As one dramatic example, on July 18, 2001, a CSX freight train derailed in a through-route tunnel under Howard Street in Baltimore, Maryland. This accident started a chemical fire that continued for more than five days. By the end of the first day, a water main ruptured, flooding streets in the downtown area for five days. Fire and water effects damaged an electric power cable, leaving 1,200 buildings without electricity. The accident also destroyed a communication-system fiber-optic cable passing through the tunnel, slowing Internet service in the Northeast; train, bus, and boat transportation were also disrupted.8
Obviously, understanding such interconnections requires a great deal of data about each infrastructure of interest, along with the capacity to trace out the linkages between components of one infrastructure and another.
The Complex Real-World Context for Tool Use
The development and use of analytical tools to support infrastructure protection are shaped by two current realities. First, some of the dominant driving forces transcend analytical tools. Second, an immense variety of analytical tools are already in use for infrastructure analysis, assessment, and planning, even if they are not ideal for some of the emerging issues.
Tool-based analysis is not essential to tell us that infrastructures tend to involve large structures with high capital investment costs, and many of them have historically been considered public services that are funded by governments: federal, state, and local. For most governments, finding sizeable funding for replacing or revitalizing infrastructures is hard to contemplate in a level-budget, no-tax-increase political environment. Thus a predicament: infrastructures that are not resilient, new threats being added to the threats that infrastructures must face in maintaining reliable services, and limited financial capacity to respond.
Resolving this predicament will not be easy, but there are some approaches worth considering — as alternatives to simply waiting for painful events to happen and responding piecemeal in their aftermath. One is public sector leadership in the public interest, such as the proposed federal government “Climate Resilience Fund,” coupling resilience to climate threats with other benefits such as job creation. Another is innovative partnerships that address financial needs in new ways. An example is Philadelphia's “Green City, Clean Waters” program, a 25-year commitment to convert more than one-third of the city's impervious land cover to green facilities, along with stream corridor restoration and preservation, through leveraged funding from the development community as a part of every new development project. Yet another is the fact that every large complex of infrastructures, public or private, is constantly changing through normal engineering and business practices. A significant part of any set of infrastructures will be replaced or revitalized over a period of three decades or so. If these actions, which always include attention to risk management, begin to incorporate climate resilience in the changes that they introduce, then the infrastructures will become significantly more resilient through time. Toward this end, the American Society for Civil Engineers (ASCE) is considering ways that changes in codes, standards, and other engineering design criteria and decisions that would incorporate further climate-related risks might enhance the resilience of our nation's infrastructures, public and private.
Meanwhile, infrastructure analysis is under way every day in industry, government, and the research world, using analytical tools that are often well-established. For instance, a very large number of programs at the national level are focused on infrastructure planning and action at state and local levels and with the private sector, most of them dependent at least in part on currently-available analytical tools (for example, see Sidebar Box: Federal Government Partnership Programs for Infrastructure Resilience). Clearly, the toolkit is not empty, even if it is not ideal for answering questions about a number of emerging risks of infrastructure exposures to climate-related extreme events.
Emerging Science and Tools to Meet New Needs
Responding to these challenges is no easy task, especially in times when government budgets for tool development are constrained, but several recent developments are very encouraging.
Projecting Extremes and Extreme Events
The widespread use of climate science, models, and scenarios for impact assessment can tend to overshadow the fact that much good scientific research is being carried out on extreme events and changes in their likelihood and impacts in coming decades, mostly by particular agencies and/or research communities not directly concerned with global climate modeling. Examples include:
Hurricanes and other disruptive storms: Research on hurricanes is being supported by the U.S. National Oceanic and Atmospheric Administration (NOAA), including its National Climate Data Center, Geophysical Fluid Dynamics Laboratory, Coastal Service Center, Regional Integrated Science and Assessment (RISA) program, National Hurricane Center, HURDAT program, and academic research at the National Center for Atmospheric Research (NCAR); Massachusetts Institute of Technology (MIT); Louisiana State University (LSU); and elsewhere. The state of the science for projecting exposures to hurricanes and their impacts is improving steadily. Science for projecting exposures to other types of extreme storm events is less active but also making progress; e.g., research on climate change and tornado formation at the National Weather Center
Federal Government Partnership Programs for Infrastructure Resilience
Stimulated in part by Hurricane Sandy, the federal government has stepped up its efforts to assess needs and identify avenues for enhancing the resilience of U.S. critical infrastructures, related to such threats as climate change, and in some cases to provide infrastructure improvements. For example, a National Infrastructure Preparedness Plan (NIPP) provides an overview; and an interagency Council on Climate Preparedness and Resilience, chaired by the White House, includes a Task Force on Infrastructure Resilience. A specific thrust of many of these and other related efforts has been to link federal government programs and perspectives with local and state governments and often the private sector as well (including the insurance industry). Examples include a variety of partnership structures of the Federal Emergency Management Agency (FEMA), including support for infrastructure risk assessment; many programs of the U.S. Department of Transportation (e.g. the Federal Highway Administration); the Department of Housing and Urban Development (HUD)'s sustainable communities assistance; and a wide range of partnerships with state and local governments and business of the U.S. Department of the Interior, related to water infrastructures and other natural resource management issues, especially in the West. Also relevant are the very productive State, Local, and Tribal Leaders Task Force on Climate Preparedness and Resilience (2013–2014), established as a part of the President's Climate Change Action Plan; and a National Research Council Roundtable on Risk, Resilience, and Extreme Events, created in 2013.
Providing increased federal funding for infrastructure-related partnerships continues to be a challenge, but the President has proposed a $1 billion Climate Resilience Fund, along with a Grow America Act for transportation infrastructure revitalization over a six-year period, and HUD is carrying out a $1 billion Natural Disaster Resilience Competition for community disaster recovery. Because these funding levels would address only a fraction of national needs (and because of uncertainties about federal budgets), an equally strong push has been to encourage more investment by state and local partners and the infrastructure sector's private sector.
Sea-level rise: Research is under way at the Potsdam Institute for Climate Impact Research (PIK), NCAR, NOAA, Rutgers, and elsewhere, generally suggesting higher estimated levels than previously by the mid- and longer terms in such regions as the Gulf Coast.
Floods: Research is being supported by NOAA, the U.S. Geological Survey (USGS), the Federal Emergency Management Agency (FEMA) and its National Flood Hazard Layer (NFHL), and is summarized in the regional chapters of the 2014 National Climate Assessment (NCA).
Droughts: Research is being supported by the National Drought Mitigation Center and the National Integrated Drought Information System (NIDIS), with information available from the U.S. Drought Monitor and U.S. Drought Portal, as well as by NASA and other federal and state agencies. Some of the current projections indicate reasons for serious concerns in vulnerable regions of the United States.
Heat waves: Research is being carried out by NCAR, Climate Central, Rutgers, and others, although scientific projections are complicated because the definition of a heat wave is complex.
Wildfires: Research is being supported by NASA, the U.S. Department of Agriculture (USDA), and others, and informative projections of regional risks by mid-century are available.
Recent assessments by these communities are offering interesting insights. For instance, research by Emanuel indicates for the first time that not only the intensity but also the frequency of tropical cyclones will increase with climate change (Figure 4).9 In his analysis, global cyclone frequency increases by more than 10% by 2025 compared to 1985 and 1995. The U.S. National Climate Assessment (NCA), 2014, projected that extreme daily precipitation events will occur up to five times more often in 2081–2100 under downscaled CMIP5 scenarios.10 Meehl et al., in 2012, projected that maximum temperatures during heat waves in the United States will increase by more than 10°F.11 NASA projects that, under Representative Concentration Pathway (RCP) 8.5, burned areas from wildfires will increase by mid-century by 407% in the Southern Plains and 202% in the Southeast.12 Such threat projections are sobering enough to demonstrate the value of emerging science for understanding risks of extreme events.
Modeling Infrastructure Impacts and Interdependencies
Meanwhile, an extremely promising set of analytical tools and geo-coded asset-specific data emerged from Department of Homeland Security (DHS) initiatives a decade ago to establish National Infrastructure Simulation and Analysis Centers (NISAC) at the Los Alamos National Laboratory and the Sandia National Laboratories, in order to strengthen capacities to analyze actual and potential impacts of disruptive events due to intentional disruption and other threats.
The NISAC approach sees infrastructures as a “system of systems” (Figure 5), representing 18 interconnected infrastructure layers in considerable detail and connects subcomponents that are linked, such as traffic lights with electricity supply. This makes it possible to trace out cascading impacts that can add up to systemwide disruptions from initial interruptions of a few components of one or a few infrastructure categories (Figure 6). The modeling approach is associated with advanced visualization tools.
The main uses of these capabilities have been in connection with extreme weather events, beginning in 2003 with Hurricane Isabel by the Department of Energy's Visualization and Modeling Working Group and continuing through recent storms such as Irene and Sandy, providing real-time emergency managers with information as they try to anticipate and account for infrastructure impacts and interdependencies. A particular topic of concern has been energy system threats from such phenomena as western wildfires and electricity system outages13 (Figure 7). Given this remarkable opportunity to compare model predictions with actual effects, the modelers have been able to improve the structural representations to a point where they are quite reliable.
With the support of DHS, the Department of Energy (DOE), and other federal agencies, these capabilities have been significantly strengthened, especially for energy-system vulnerability and impact modeling (e.g., Visualizing Energy Resources Dynamically on the Earth [VERDE] and Energy Awareness and Resiliency Standardized Services [EARSS]). These enhanced versions are referred to as “CIDM,” which DOE interprets as Connected Infrastructure Dynamics Models and DHS interprets as Critical Infrastructure Disruption Models.
An example of an application is the projection of future electricity demand, given that climate change is likely to increase demands for electricity for cooling when the U.S. electricity system is vulnerable because of physical aging and outdated maintenance.14 CIDM has been expanded by methods to simulate how electricity demand might be altered by temperature increases and population shifts, including shifts motivated by exposures to climate-related extreme events.15
Moreover, CIDM approaches are being linked with extreme event science as well as climate scenarios in order to respond to policy questions about vulnerabilities and also adaptation needs and potentials. For example, a version of the CIDM approach that has been expanded to include threats from climate change and extreme events (Homeland Security Extreme Weather Event Anticipation Tool [HEAT]) is being developed by the Department of Homeland Security not only to consider implications of possible extreme events but also to engage local infrastructure system leaders and staff in discussing responses to risks.
Some Challenges That Will Need to Be Overcome
As this enterprise develops—and it is moving rapidly—it faces at least three challenges, all of which are being currently addressed.
Infrastructures Are Changing
The representation of infrastructures in current CIDM data sets is based on current assets, when infrastructures are constantly being replaced and/or revitalized. This means that for projecting future vulnerabilities and impacts beyond the near future, the models grow increasingly unrealistic. Efforts are underway, supported by the Department of Energy, to add a capacity to consider potentials and trajectories of technological change in selected infrastructures, including possible adaptive responses to climate change.
Resilience Depends on More Than the Extreme Events Alone
As mentioned earlier, both impacts and resilience are shaped by contextual variables such as demographic and economic drivers and changes through time. For example, work is under way to simulate population migration as a factor in climate change impact assessments, including migrations in response to experience with emerging climate-related risks, although literatures on “environmental migration” suggest caution about oversimplifying causation.16 Moreover, resilience to impacts is a complex subject, including a number of research literatures: for example, articles related to resilient materials and structures, to resilient emergency preparedness institutions, and to resilient social dynamics in communities.17
Likewise, projecting other contextual changes continues to be a challenge, but the “sustained assessment” commitment of the U.S. National Climate Assessment is planning an effort to improve the ability to project changes in land use, and the international research community is developing a family of Shared Socioeconomic Pathways, or SSPs, to depict a range of changes of socioeconomic conditions through time, as the RCPs depict a range of changes in climate conditions through time.18
Some contextual variables continue to be especially problematic, such as projecting technological change and institutional change, but a few pioneering efforts are showing signs of progress.19
Users Need Access to Tools and Data
Finally, a longstanding challenge has been helping those who operate and manage critical infrastructures, along with a wide range of stakeholders and users of the infrastructure services, to understand implications of extreme weather events—not only by listening to an external research community but also by accessing, displaying, and using the actual data and science.
Several recent reports summarize current knowledge about how to interact productively with users of climate change related information.20,21 Meanwhile, work is under way with the U.S. Department of Energy to make more of the CIDM-type data available through open access, which is complicated more by the sources of some of the data than by security concerns. And work is beginning with the U.S. Department of Homeland Security to develop versions of HEAT/CIDM that can be used hands-on by operational emergency preparedness and response staff. Another example of a very promising approach for making user access less complicated is the Local Climate Analysis Tool (LCAT), developed by the National Weather Service to enable local weather forecasters to access climate data and forecasts by submitting questions to an artificial intelligence tool that converts them into requests to the National Climate Data Center for data, accesses the data, and converts the data into answers to the initial questions. The Department of Energy is exploring an application of the LCAT approach to ease access to climate change scenarios, called the DOE Climate Analysis System (DCAS).
Providing a toolkit for climate resilience enhancement is an important national objective, but this commitment needs to be seen as a sustained process of tool development and improvement, related to high-priority user needs. A number of bodies of science and sets of tools for analysis and simulation of impacts of extreme weather events on connected infrastructures are emerging, and they offer great promise for strengthening this national toolkit.
1. C. Koblinsky, Climate Science and Services: Providing the Information that People Need for a Changing World (Miami, FL: World Climate Research Programme, January 2010).
2. National Research Council, Informing an Effective Response to Climate Change, Panel report prepared for the America's Climate Choices study (Washington, DC: 2010).
3. Climate Change 2013: “The Physical Science Basis,” Working Group I contribution to the IPCC Fifth Assessment Report (Geneva, Switzerland: 2013).
4. Climate Change Impacts in the United States, U.S. National Climate Assessment (Washington, DC: U.S. Global Change Research Program, 2013).
5. J. Hurrell, G. A. Meehl, D. Bader, T. Delworth, B. Kirtman, and B. Wielicki, “A Unified Modeling Approach to Climate System Prediction,” BAMS, 90 (2010), 1819–32.
6. CCSP, Impacts of Climate Change and Variability on Transportation Systems and Infrastructures: Gulf Coast Study, Phase I. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research, ed. M. J. Savonis, V. R. Burkett, and J. R. Potter (Washington, DC: Department of Transportation, 2009).
7. Entergy, Building a Resilient Energy Gulf Coast: Executive Report (Houston, TX: 2010), http://entergy.com/content/our_community/environment/GulfCoastAdaptation/Building_a_Resilient_Gulf_Coast.pdf (accessed December 2, 2014).
8. T. J. Wilbanks, S. J. Fernandez, et al., Climate Change and Infrastructure, Urban Systems, and Infrastructures (Washington, DC: Island Press, 2014).
9. K. A. Emanuel, “Downscaling CMIP5 Climate Models Shows Increased Tropical Cyclone Activity Over the 21st Century,” Proceedings of the National Academy of Science 110 (2013): 12219–24, doi/10.1073/pnas.1301293110
10. NCA Climate Change Impacts in the United States, U.S. National Climate Assessment (Washington, DC: U.S. Global Change Research Program, 2014).
11. G. A. Meehl, W. M. Washington, J. M. Arblaster, A. Hu, H. Teng, C. Tebaldi, B. N. Sanderson, J. F. Lamarque, A. Conley, W. G. Strand, and J. B. White III, “Climate System Response to External Forcings and Climate Change Projections in CCSM4,” Journal of Climate 25 (2012): 3661–83.
12. “Fire in a Changing Climate,” US wildfires projected, (NASA). http://www.nasa.gov/pdf/710932main_AGU2012_Firebriefing_2.pdf (accessed 4 November 2014).
13. E. Barker, E. B. Freer, O. Omitaomu, et al., “Automating Natural Disaster Impact Analysis: An Open Resource to Visually Estimate a Hurricane's Impact on the Electric Grid,” Proceedings of IEEE Southeast Conference (Jacksonville, FL: April 4–7, 2013).
14. American Society of Civil Engineers, 2013 Report Card for America's Infrastructure, http://www.infrastructurereportcard.org/a/documents/Energy.pdf (accessed November 3, 2014).
15. M. R. Allen, S. J. Fernandez, J. S. Fu, and K. A. Walker, “Electricity Demand Evolution Driven by Storm Motivated Population Movement,” Journal of Geography and Natural Disasters 4:2 (2014).
16. For example, UK Office of Science, Foresight: Migration and Global Environmental Change, Final Project Report (London, UK: 2011).
17. Community and Regional Resilience Institute (CARRI) research reports, http://www.resilient.org/puublications (accessed November 4, 2014).
18. N. Nakicenovic, R. Lempert, and A. Janetos, eds., “A Special Issue of Climatic Change Journal on the Framework for the Development of New Socioeconomic Scenarios for Climate Change Research,” Climatic Change, (2014) 122:351-361
19. For example, B. Hughes et al. Strengthening Governance Globally. Patterns of Potential Human Progress, vol. 5 (Denver, CO: Pardee Center for International Futures, 2014).
20. National Academy of Science/National Research Council (NAS/NRC), Informing Decisions in a Changing Climate. Committee on Human Dimensions of Global Change (Washington, DC: National Academies Press, 2009).
21. National Academy of Science/National Research Council (NAS/NRC), Informing an Effective Response to Climate Change, America's Climate Choices (Washington, DC: National Academies Press, 2010).
Thomas J. Wilbanks is a corporate research fellow at the Oak Ridge National Laboratory. He conducts research on such issues as sustainable development, resilience as a goal for human and natural systems, and impacts of and responses to such global issues as climate change. He has been active for more than three decades in a wide variety of energy and environmental science and policy assessments, including IPCC, the Millennium Ecosystem Assessment, committees of the U.S. National Academy of Sciences/National Research Council, the series of U.S. National Climate Assessments, and programs of the U.S. Department of Energy and other partners. He is a contributing editor of Environment.
Steven J. Fernandez is a research professor at the University of Tennessee. Formerly a senior research and development staff member at the Oak Ridge National Laboratory, his experience includes directing the National Infrastructure Simulation and Analysis Center efforts in the electric grid, economic analysis at Los Alamos National Laboratory, and leading critical infrastructure protection efforts for national security research organizations at the Idaho National Laboratory. In Idaho, Dr. Fernandez established the national SCADA test bed, currently a critical component of the Department of Energy Office of Electricity Delivery and Energy Reliability strategy.
Melissa R. Allen is a research staff member at the Oak Ridge National Laboratory. She holds a master of science degree in environmental engineering and a PhD in energy science and engineering from the University of Tennessee. Her additional work with scientists at both Oak Ridge National Laboratory and the University of Tennessee has included global modeling and analysis of atmospheric species transport, statistical and dynamical downscaling of various climate model output, analysis of direct and indirect effects of climate change on electricity demand, and consideration of climate change issues that impact the evolution of the electrical grid.
The authors gratefully acknowledge programmatic support from the Integrated Assessment Research Program, Office of Science, U.S. Department of Energy.