Dear EarthTalk: How is it that climate change is negatively effecting the health of rivers and, by extension, the quality and availability of fresh water? -- Robert Elman, St. Louis
Global warming is no doubt going to cause many kinds of problems (and, indeed, already is), and rivers may well be some of the hardest hit geographical features, given the likelihood of increased droughts, floods and the associated spread of waterborne diseases.
For one, rivers are already starting to lose the amount of water they channel. A 2009 study at the National Center for Atmospheric Research found that water volume in the Columbia River in the Pacific Northwest declined by 14 percent since the 1950s. This trend is similar in major rivers all over the world.
"Many communities will see their water supplies shrink as temperatures rise and precipitation patterns shift," reported the nonprofit American Rivers, adding that a rise in severe storms will degrade water quality and increase the risk of catastrophic floods. "Changes in the timing and location of precipitation combined with rising levels of water pollution will strain ecosystems and threaten the survival of many fish and wildlife species."
These shifts will have dramatic impacts, threatening public health, weakening economies and decreasing the quality of life in many places. In the U.S., the number of storms with extreme precipitation has increased 24 percent since the late 1940s -- and the trend is expected to continue.
Another certain impact on rivers is more pollution as more frequent and powerful storms increase runoff from urban and agricultural areas that contain fertilizers, pesticides, chemicals and motor oil.
"In older communities where storm water and sewage are transported together in one pipe, heavy storms can overwhelm the system and send raw sewage and polluted storm water into nearby streams and rivers," American Rivers said. "These combined sewer overflows will grow more frequent as extreme storms increase."
Lower water flows and rising temperatures compound problems caused by more runoff. "More frequent droughts and shifting precipitation patterns lower water levels in rivers, lakes and streams, leaving less water to dilute pollutants," said the group. "Higher temperatures cause more frequent algal blooms and reduce dissolved oxygen levels, both of which can cause fish kills and do significant harm to ecosystems."
American Rivers reports that the health of our rivers in the face of increasing warming will depend largely on community preparedness. Municipalities that fail to address aging infrastructure "will experience greater increases in storm water runoff and sewer overflows." And communities that have damaged their wetlands, forests, streams and rivers will have fewer natural defenses to protect against the effects of climate change.
There is much we can do to protect rivers besides reduce our carbon footprints. American Rivers is promoting green infrastructure -- an approach to water management that protects, restores or mimics the natural water cycle -- as the way to bolster the health of rivers. "It means planting trees and restoring wetlands rather than building a new water treatment plant. It means choosing water efficiency instead of building a new water supply dam. It means restoring floodplains instead of building taller levees."
Contacts: NCAR, ncar.ucar.edu; American Rivers, www.americanrivers.org.
Dear EarthTalk: What is the Living Building Challenge and how does it differ from the LEED certification program? -- Jason Marshall, Richmond, Va.
Both Leadership in Energy and Environmental Design and the Living Building Challenge were created with the same goal in mind: to encourage more sustainability and resource conservation in architecture, design, construction and building operations. LEED, a program of the U.S. Green Building Council, is well known in architecture, building and design circles as the standard for certifying the green attributes of new and retrofitted structures (and even entire neighborhoods).
Developers can reference LEED's 110-point rating system to inform choices regarding design, technology, siting, landscaping and other elements of building or renovation processes. Structures using the greenest versions of each element would qualify for the highest LEED rating, Platinum (followed by Gold, Silver, and just plain Certified). In general, a project gets certified the day its ribbon is cut -- as long as developers followed through on implementing what they committed to on the LEED checklist. Upwards of 7,000 projects spanning some 1.5 billion square feet of development area across the U.S. and 30 other countries have qualified for some kind of LEED certification so far.
Meanwhile, LBC, created in 2006 by the Seattle-based non-profit International Living Building Institute, is a performance-based standard where a building only qualifies if it achieves its energy, water and waste efficiency goals moving forward after the ribbon is cut. In fact, since LBC certification is based on actual, rather than modeled or anticipated performance, projects must be operational for at least 12 consecutive months prior to evaluation by the ILBI.
Given the focus on performance, LBC does not provide as much detailed guidance, let alone a checklist of green attributes, instead letting the developers of each individual project decide for themselves how to best achieve their efficiency and conservation goals via means appropriate to the project and to the region.
That said, each project vying for LBC status must follow 20 general imperatives arranged under a system of seven general performance areas (or in the lingo of LBC: "petals"): site; water; energy; health; materials; equity; and beauty. Given that the imperatives are general, they can be applied to any conceivable project type, be it a building, infrastructure, landscape or community development. But whatever type of project, if it is to meet the exacting standards of LBC it must live up to each one.
One of the imperatives under the energy petal, for instance, is "net zero energy" meaning the structure must harvest or generate as much power as it needs via alternative renewable sources. Within the materials petal, another imperative is avoiding any of hundreds of building materials on ILBI's "Red List" of banned materials and substances. Yes another imperative, under the site petal, is "car-free living."
Fifteen different projects, from New York State to Hawaii, have so far been certified by ILBI as "Living Buildings." The likely 16th is Seattle's Bullitt Center, a six-story solar-powered net zero building designed to make extensive reuse of rainwater and day lighting and which features many other green amenities.
EarthTalk is by Roddy Scheer and Doug Moss of E -- The Environmental Magazine (www.emagazine.com). Send questions to firstname.lastname@example.org.