Reducing Climate Risks with Natural Infrastructure

As California considers how to adapt to a changing climate, planners often focus on defensive infrastructure with a negative habitat impact: bigger levees, rock walls to protect coastlines or even giant sea gates.

But California can follow a different path. With natural or “green” infrastructure that leverages natural processes to reduce risk to human lives, property and businesses, the state can build resilience to the coming changes while restoring natural habitats instead of degrading them.

“Green” or “natural” infrastructure can include a range of strategies. Some projects focus on preserving existing natural systems, while others are highly engineered, combining green techniques with more traditional “gray” approaches.

This report evaluates nine green infrastructure case studies in California. Each improves flood or coastal protection, provides habitat and preserves or restores the natural dynamics between water and land. We review the available data on the costs and benefits of each case and, where possible, compare this information with the costs and benefits of a gray alternative at the same site.

Land Use Planning Tools for Local Adaptation to Climate Change

This document describes planning tools being used across Canada to help communities prepare for climate change, increase adaptive capacity and build resilience. It is directed to individuals and groups interested in climate change adaptation at the local level, including planners and other local government staff, elected officials, community organizations, local residents and business leaders.

Climate Change Impacts in the United States: The Third National Climate Assessment

The National Climate Assessment assesses the science of climate change and its impacts across the United States, now and throughout this century. It documents climate change related impacts and responses for various sectors and regions, with the goal of better informing public and private decision-making at all levels.

A team of more than 300 experts, guided by a 60-member National Climate Assessment and Development Advisory Committee produced the full report – the largest and most diverse team to produce a U.S. climate assessment. Stakeholders involved in the development of the assessment included decision-makers from the public and private sectors, resource and environmental managers, researchers, representatives from businesses and non-governmental organizations, and the general public. More than 70 workshops and listening sessions were held, and thousands of public and expert comments on the draft report provided additional input to the process.

The assessment draws from a large body of scientific peer-reviewed research, technical input reports, and other publicly available sources; all sources meet the standards of the Information Quality Act. The report was extensively reviewed by the public and experts, including a panel of the National Academy of Sciences, the 13 Federal agencies of the U.S. Global Change Research Program, and the Federal Committee on Environment, Natural Resources, and Sustainability.

Power Failure: How Climate Change Puts Our Electricity at Risk — and What We Can Do

Today, extreme weather events such as coastal floods, wildfires, intense precipitation (snow and rain), heat waves, and droughts are becoming more frequent and severe in some regions. Sea level rise is already worsening coastal floods, and other extreme weather events are likely to become more severe as the planet continues to warm. Building power plants and electricity infrastructure in areas prone to climate-related threats adds to those growing risks.

To ensure a reliable and affordable power supply for decades to come, the electricity sector needs to become more resilient in the face of the changes we are already experiencing, and also adapt to growing risks. Our energy choices are an important part of the solution: energy efficiency and renewable energy can diversify our electricity system and make it more resilient. But there is more to the picture. By investing in those options, we can also dramatically cut carbon emissions, helping to curb further climate change. That is, smart energy choices will create an electricity system that is more resilient in the face of changes we are confronting today while reducing the long-term damage and costs linked to global warming.

Climate Change: Energy Infrastructure Risks and Adaptation Efforts

According to the NRC and the USGCRP, changes in the earth's climate--including higher temperatures, changes in precipitation, rising sea levels, and increases in the severity and frequency of severe weather events--are under way and expected to grow more severe over time. These impacts present significant risks to the nation's energy infrastructure.

Economic losses arising from weather-related events--including floods, droughts, and storms--have been large and are increasing, according to USGCRP. Adaptation--an adjustment to natural or human systems in response to actual or expected climate change--is a risk-management strategy to help protect vulnerable sectors and communities that might be affected by climate change.

GAO was asked to examine the vulnerability of the nation's energy infrastructure to climate change impacts. This report examines: (1) what is known about potential impacts of climate change on U.S. energy infrastructure; (2) measures that can reduce climate-related risks and adapt energy infrastructure to climate change; and (3) the role of the federal government in adapting energy infrastructure and adaptation steps selected federal entities have taken. GAO reviewed climate change assessments; analyzed relevant studies and agency documents; and interviewed federal agency officials and industry stakeholders, including energy companies at four sites that have implemented adaptive measures.

What GAO Found

According to assessments by the National Research Council (NRC) and the U.S. Global Change Research Program (USGCRP), U.S. energy infrastructure is increasingly vulnerable to a range of climate change impacts--particularly infrastructure in areas prone to severe weather and water shortages. Climate changes are projected to affect infrastructure throughout all major stages of the energy supply chain, thereby increasing the risk of disruptions. For example:

  • Resource extraction and processing infrastructure, including oil and natural gas platforms, refineries, and processing plants, is often located near the coast, making it vulnerable to severe weather and sea level rise. 
  • Fuel transportation and storage infrastructure, including pipelines, barges, railways and storage tanks, is susceptible to damage from severe weather, melting permafrost, and increased precipitation.  
  • Electricity generation infrastructure, such as power plants, is vulnerable to severe weather or water shortages, which can interrupt operations.
  • Electricity transmission and distribution infrastructure, including power lines and substations, is susceptible to severe weather and may be stressed by rising demand for electricity as temperatures rise.

In addition, impacts to infrastructure may also be amplified by a number of broad, systemic factors, including water scarcity, energy system interdependencies, increased electricity demand, and the compounding effects of multiple climate impacts.

A number of measures exist to help reduce climate-related risks and adapt the nation's energy systems to weather and climate-related impacts. These options generally fall into two broad categories--hardening and resiliency. Hardening measures involve physical changes that improve the durability and stability of specific pieces of infrastructure--for example, elevating and sealing water-sensitive equipment--making it less susceptible to damage. In contrast, resiliency measures allow energy systems to continue operating after damage and allow them to recover more quickly; for example, installing back-up generators to restore electricity more quickly after severe weather events.

In general, the federal government has a limited role in directly adapting energy infrastructure to the potential impacts of climate change, but key federal entities can play important supporting roles that can influence private companies' infrastructure decisions and these federal entities are initiating steps to begin adaptation efforts within their respective missions. Energy infrastructure adaptation is primarily accomplished through planning and investment decisions made by private companies that own the infrastructure. The federal government can influence companies' decisions through providing information, regulatory oversight, technology research and development, and market incentives and disincentives. Key federal entities, such as the Department of Energy, the Environmental Protection Agency, the Federal Energy Regulatory Commission, and the Nuclear Regulatory Commission have also begun to take steps to address climate change risks--through project-specific activities such as research and development and evaluating siting and licensing decisions under their jurisdiction, as well as through broader agency-wide assessments and interagency cooperation.

Planning for Sea Level Rise in California’s San Francisquito Watershed


United States
37° 26' 9.5532" N, 122° 10' 39.7596" W

Communities along the San Francisquito Creek are facing flooding risks from increased storm events and sea level rise. The San Francisquito Creek Joint Powers Authority is leading four main projects to stabilize, restore, and maintain the channel of the San Francisquito Creek. They are also working with upstream partners within the entire watershed, extending from San Francisco to El Camino Real, to design and plan capital projects to increase flood protection that benefit the natural environment.

Cost Estimates for Flood Resilience and Protection Strategies in New York City

In the aftermaths of Hurricanes Irene, in 2011, and Sandy, in 2012, New York City has come to recognize the critical need to better prepare for future storm surges and to anticipate future trends, such as climate change and socio-economic developments. The research presented in this report assesses the costs of six different flood management strategies to anticipate long-term challenges the City will face. The proposed strategies vary from increasing resilience by upgrading building codes and introducing small scale protection measures, to creating green infrastructure as buffer zones and large protective engineering works such as storm surge barriers. The initial investment costs of alternative strategies vary between $11.6 and $23.8 bn, maximally. We show that a hybrid solution, combining protection of critical infrastructure and resilience measures that can be upgraded over time, is less expensive. However, with increasing risk in the future, storm surge barriers may become cost-effective, as they can provide protection to the largest areas in both New York and New Jersey.

Future Federal Adaptation Efforts Could Better Support Local Infrastructure Decision Makers

The federal government invests billions of dollars annually in infrastructure, such as roads and bridges, facing increasing risks from climate change. Adaptation—defined as adjustments to natural or human systems in response to actual or expected climate change— can help manage these risks by making infrastructure more resilient.

GAO was asked to examine issues related to infrastructure decision making and climate change. This report examines (1) the impacts of climate change on roads and bridges, wastewater systems, and NASA centers; (2) the extent to which climate change is incorporated into infrastructure planning; (3) factors that enabled some decision makers to implement adaptive measures; and (4) federal efforts to address local adaptation needs, as well as potential opportunities for improvement.

GAO reviewed climate change assessments; analyzed relevant reports; interviewed stakeholders from professional associations and federal agencies; and visited infrastructure projects and interviewed local decision makers at seven sites where adaptive measures have been implemented.

GAO recommends, among other things, that a federal entity designated by the Executive Office of the President (EOP) work with agencies to identify for local infrastructure decision makers the best available climate-related information for planning, and also to update this information over time. Relevant EOP entities did not provide official comments, but instead provided technical comments, which GAO incorporated, as appropriate.