APA Policy Guide on Climate Change

Adopted April 27, 2008

Updated April 11, 2011

This page contains the executive summary of the 2011 update to APA's Policy Guide on Climate Change.

Download the complete Policy Guide on Climate Change (pdf)


Climate change will almost certainly prove to be one of the most important planning challenges of the 21st century. Planners are in a unique position to address climate change issues because the problem itself presents the full spectrum of the classical planning dilemma — it is long-range in nature, comprehensive in scope, and significant in impact. Planners will be called upon to address both the causes and consequences of climate change. The issue will require proactive responses across all planning sectors, from land use to transportation to natural resource management to public health and safety to economic development. Existing tools and techniques, such as green building, multimodal transportation and traditional neighborhood development, will be pressed into service. New tools and techniques will be required to be developed. Communication and public involvement will be critical in mitigating the effects and adapting to the impacts of climate change.

The American Planning Association has been a leading organization on the climate change issue, adopting an initial Climate Change Policy Guide in 2008, supporting an energy and climate initiative that provides web-based resources for planners interested in the issue, publishing PAS reports and other documents on the subject, and including the climate change issue in conferences, webinars, and legislative policy development from the international to the local levels. The 2010 APA Climate Change Policy Guide Update continues that work by framing the problem with state-of-the-art climate science and providing a robust and comprehensive list of actions for planners to take in communicating, mitigating and adapting to current and future climate conditions, changes and consequent impacts.

Climate Science

Planners must understand the causes, range and type of impacts, and options for communicating and addressing climate change in order to be effective in whatever sector or geographic scale they operate. Because of the complex — and controversial — nature of the climate change problem, planners must have a sound scientific basis for taking action.

Most climate and atmospheric scientists agree that the earth's climate is warming and that the most likely cause of this phenomenon is human-induced greenhouse gas (GHG) emissions. Global average temperatures have certainly increased; based on instrument measurements, each of the past three decades have been consecutively the warmest on record. These temperature increases correspond with measurable increases in the concentration of greenhouse gases in the atmosphere. Models developed by climate scientists indicate that the connection between our warming climate and increasing GHG concentrations is not accidental. The extent to which the earth is warming cannot be explained without taking GHG emissions into consideration. Consequently, we humans are causing most of the global warming which is changing the global, regional, national, and local climate.

A warming climate will create a variety of impacts that are expected to be long-term and increase in intensity over time. The range of possible impacts include more heat waves, stronger tropical and extratropical storms, drier conditions in some regions and wetter conditions in others, and rising sea levels as water formerly bound up in ice flows off the land into the oceans. These circumstances will affect both natural and built environments.

It is important for planners to understand that there is a difference between climate change and weather variability. Even in a warming world, there will be periods of unusual cold weather. As the science fiction writer Robert A. Heinlein has said, "Climate is what you expect, weather is what you get." The cold, snowy winters that the eastern part of the United States experienced in 2008-2010 are examples of weather variability, not climate change, because, over most of the northern hemisphere, these same winters have been significantly warmer than normal. However, there is reason to believe that climate change will bring about a higher degree of weather variability, because more energy in the atmosphere generally translates to more frequent intense storms. Climate change and weather variability are not entirely unrelated.

As noted in the paragraphs above, many climate change impacts will be regionally variable. Planners in Alaska will have to worry about thawing permafrost while coastal planners will be concerned with sea-level rise. Planners in the Southwest will be forced to deal with the consequences of drier conditions while those in the Upper Midwest will contend with, paradoxically, lower water levels in the Great Lakes from evaporation and more intense precipitation patterns that will cause flooding. Planners along the Atlantic and Gulf coasts will face stronger hurricanes and nor'easters. This regional variability means that there are no one-size-fits-all solutions.

Scientists tell us that climate is "migrating." For example, under certain GHG emissions scenarios, the climate of New Hampshire may change to more closely resemble the climate of the North Carolina Piedmont by the end of this century. Think of the myriad impacts that such changes in temperature and precipitation patterns would have on New Hampshire's tourist and agriculture industries, ecosystems and wildlife habitats, infrastructure, and development standards.

A final scientific concept that planners must understand is that 100 percent certainty about future climate is impossible to achieve. No one can precisely predict what the concentration of greenhouse gases will be in 2100. Even if this critical variable was known with precision, other variables would exist. Scientists address this inherent problem by developing models with certain assumptions about key variables built into them. When these models are run using the most likely scenarios about GHG concentrations and atmospheric reactions, however, they invariably point to an increasingly warm climate with all its attendant impacts.

"Science is there to inform, but the choices of what to do are up to all of us," is a frequent comment by prominent NOAA scientist Dr. Susan Solomon whose research has led to the identification of the cause of the ozone hole in Antarctica and how changes in surface temperature, rainfall and sea level are largely irreversible for more than 1,000 years after carbon dioxide emissions are entirely mitigated. Science tells us that climate change is certain and that its impacts will be increasingly frequent and severe. It is up to planners to heed Dr. Solomon's call for action and help their communities decide what to do about climate change.

Roles for Planners

There are two main ways in which planners can address the climate change issue. The first involves minimizing the extent of the future impact created by climate change, primarily by reducing GHG emissions through reduced fossil fuel consumption and sequestration of carbon that is emitted. Planners refer to the actions taken under this approach as mitigation. Mitigation measures include reducing vehicle-miles-traveled, establishing green building incentives or regulations, and preserving forested areas.

The second approach involves addressing current and future impacts that occur in spite of mitigation efforts. Past GHG emissions have set into motion changes to the climate that will extend hundreds of years into the future even if such emissions were to completely stop today. The approach for building community resilience by addressing climate-induced drought, flooding, sea-level rise, thawing permafrost, storm surge, and the many other impacts of climate change is referred to as adaptation. Adaptation measures include shifting development from flood-prone areas, supporting xeriscaping in drought-prone areas through incentives and regulations, and implementing economic development strategies that are sustainable in future climates.

Beyond these overarching approaches of mitigation and adaptation, planner roles in addressing climate change can be segregated by levels of government and by the individual sectors of planning practice.

The federal government can provide leadership, funding, research and baseline regulation and policy on many topics related to climate change, such as motor vehicle fuel efficiency standards and energy policy. Action at the federal level can establish larger and more predictable markets for emissions reduction systems, funded state and local climate initiatives, create and implement an international framework for reducing greenhouse gas emissions by bringing emerging economies, especially China and India, into an international climate change agreement, and develop and disseminate climate change data and information from a central federal source.

Given the regional nature of climate change impacts, state and local governments are often the most appropriate levels of government to develop plans, incentives, standards, and regulations to address climate change mitigation and adaptation. The American Planning Association has identified five "strategic points of intervention" to be pursued at the state and local levels with regard to energy and climate challenges, all of which should be quite familiar to planners:

  • Long-Range Community Visioning and Goal Setting
  • Plan Making
  • Standards, Policies and Incentives
  • Development Work
  • Public Investment

Planning sectors that have particular promise in addressing climate change issues and impacts include land use, transportation, energy, green development, natural resources management, economic development, hazards management, public health, and public infrastructure. The comprehensive nature of the climate issue crosses each of these sectors and responses can be placed under the "umbrella" of a variety of planning focus areas, such as sustainability, smart growth, housing, and food system planning.

Because of this interrelationship, planners are able to approach climate change solutions from a no regrets perspective. For example, reducing GHG emissions also reduces pollution, promoting public health; further, if these emissions reductions are achieved through green building development and reductions in vehicle-miles-traveled, there are economically measurable savings in energy expenses and traveler convenience. A more compact urban form has the potential to reduce both GHG emissions and infrastructure costs. A public safety program that enhances climate resiliency can also protect property and persons from existing threats. Building a bridge with greater clearance above a coastal estuary accounts for both future sea-level rise and current storm surge potential and may have environmental benefits as well. If these sorts of actions are undertaken to address potential climate change impacts or to reduce its effects, they will have collateral benefits regardless of the future state of the climate.

A final climate change impact that planners must address is an indirect impact. Direct impacts are sea-level rise, drought, wildfires, flooding, and so forth. The indirect impact most likely to be of concern to planners involves population migration. People have always migrated to favorable climate circumstances. For instance, the warm winters in Florida and the Southwest draw people to the Sunbelt. As climate changes, some areas will become more attractive than others, resulting in population migration. In some cases, there will be little opportunity to affect migration in a positive way, such as when water resources prove inadequate to support existing levels of population or when sea-level rise inundates developed areas. In other cases, population migration may open doors for ecotourism, affordable housing, and other positive outcomes. Areas to which population migrates will see economic benefits but will also be forced to handle the impacts of growth.

Policy Guide Framework

Four ideas form a framework for this guide. First, the policy responses to climate change need to be based on the best possible science. Because climate change is bringing about previously unrecorded conditions, projections based on new scientific modeling are the best way to anticipate and respond. Planners must have access to vital data, information and resources to help them interpret these unprecedented changes

Second, many of the specific impacts of climate change are highly regional and even local in nature. Therefore, climate change policies cannot be based on a one-size-fits-all approach. Planners must be aware of what the future holds for their particular geographic region and formulate their strategies accordingly. While plans and policies must reflect the individual needs of local areas, any successful mitigation effort will require a national, and indeed international, framework for addressing GHG emissions.

Third, adapting to climate change is just as important as mitigating it. Planners can have a significant effect on climate change mitigation through a variety of actions, including encouraging higher density development, reducing vehicle-miles-traveled (VMT), using green building techniques, and supporting alternative energy sources. However, due to the extent of potential impacts projected under even the most aggressive mitigation scenarios, planners will also need to address the effects of climate change including rising sea levels, greater drought conditions and flooding in planning for adaptation.

Finally, planners need to communicate about climate change in new and different ways. Policies that we develop now will necessarily have a long-range timeframe. Given that it is often hard to keep people engaged over even the short-term, planners will need new communication tools to explain climate change issues and maintain the focus on long-term adaptation and mitigation responses. Citizen participation and engagement is vital to the success of climate change efforts.

Download the complete Policy Guide on Climate Change (pdf)