Region Forward Blog

Adapting to Climate Change in Metro Washington

Sep 15, 2011


Last year the Environmental Protection Agency (EPA) awarded MWCOG with a “Smart Growth Implementation Assistance” grant to develop a climate change adaptation plan for metropolitan Washington. To help guide the plan’s development the EPA and MWCOG recently held four workshops with local officials focusing on specific sectors likely to be impacted. This is a two part series based on those workshops. Part one focuses on the water and building sectors while part two focuses on the transportation and land-use sectors.

Even if we completely stop emitting greenhouse gases tomorrow the emissions of the past 100 years will continue to generate climate change. It’s inevitable. This is simply a fact; it’s not an excuse for inaction. On the contrary we should be working feverishly to dramatically reduce our emissions a goal of Region Forward in order to minimize further impacts. These workshops are based on the reality that at the same time that we need to be fighting climate change we should also be preparing for some of its unavoidable foreseeable effects.

Metropolitan Washington is already seeing some of these effects: the National Oceanic & Atmospheric Administration (NOAA) indicates that DC Maryland and Virginia have all seen their average annual temperature increase over the past century (by 0.6°F in VA 1.9°F in MD and 3.3°F in DC); NCPC reports that the Potomac Estuary has experienced a foot of relative sea level rise; the University of Maryland indicates that major weather events in the Mid-Atlantic region have increased significantly (12-20%) over the past century; and the Intergovernmental Panel on Climate Change (IPCC) projects that floods droughts heat waves and record-setting events will continue to increase.

Adapting to these changing conditions requires comprehensive planning. That’s why local jurisdictions are partnering with the EPA to create this adaptation plan. Some of the points of discussion regarding the building and water sectors are summarized below:

Debate: Relocating buildings and structures in vulnerable areas versus rebuilding/retrofitting them to a higher standard. Both are options for avoiding a building’s inoperability or destruction as a result of climate-induced impacts but which is preferable? Participants generally agreed that it depends on the situation. While initially relocation may seem like the most effective solution what will be the second order effects of such a decision? Constrained land assets in our region’s urban areas may mean that relocation would have to occur in far-out suburbs/exurbs. This would result in increased emissions from automobile travel and congestion thus further contributing to the original problem. When rebuilding/retrofitting is the choice standards and regulations be should take into account current conditions and expected future conditions based on projections of climate-induced impacts.

Meaningful relevant standards. Speaking of standards and regulations what time period should they be based on? As mentioned above participants noted that the predicted effects of climate change are adjusted (usually pointing towards worse impacts) as more data is collected. Standards therefore need to be flexible or they risk becoming ineffective. Regular review of building standards and regulations that accounts for or adjusts to changes in current and predicted climate-induced impacts should be built-in to the process. Maryland for example is considering increased setback distances for buildings located near bodies of water due to predicted water level rises and more frequent flooding. This standard would be modified if data shows that the rise is predicted to increase further. Similarly as the region stands to experience more days over 90°F it will be necessary to revisit some older standards. One participant noted that although most building codes include mandatory minimum temperatures at which buildings must be able to operate they often don’t include corresponding mandatory maximum temperatures.

In that sense passive survivability then comes into the discussion. Although this sounds like military terminology it’s essentially a design standard for buildings that accounts for climate-induced impacts and integrates resiliency into building codes. As noted earlier climate changes are going to force buildings to operate in more extreme temperature and weather environments. Add in uncertainties like power outages – from storms or from higher peak demand in summer – and a building’s resilience may be severely tested (especially given that DC is already America’s sixth-hottest city according to The Weather Channel).

“Making the impervious pervious.” The catchment and reuse of water is becoming more mainstream in building policies and stormwater regulations as green building certifications like LEED become more prevalent (the DC region is making a lot of progress in the growth of green buildings). However as the practice of water catchment proliferates participants warned against its perception as a “magic bullet” solution. Even with the marked increase in green roofs and water catchment the region’s urban areas remain very impervious. This represents a major hurdle in a future that may experience more flooding and/or severe storms. As one participant observed “the challenge is making the impervious pervious.”

Part two of this series focuses on the impact of climate change on transportation and land-use.

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