Part 3 of 3

By Stephen Ashkin

Below are the final reasons, features, and benefits that can be attritubed to selling Green.

Reduced global warming impacts
To the extent that green buildings use less energy and generate less carbon dioxide through their operation, require less transportation energy for their occupants, or avoid release of other greenhouse gases (such as HCFC and HFC refrigerants and foam insulation blowing agents), they contribute less to global warming, which is clearly one of the greatest environmental threats we face today. It is important to recognize that climate change impacts are global in nature-what we do in one part of the U.S. affects the world's climate, and, conversely, anything we do to reduce greenhouse gas emissions results in global benefits.

Minimized ozone depletion
Green buildings minimize the use (and release) of ozone-depleting substances. This involves replacing CFC-based chillers, specifying non-HCFC mechanical equipment, and avoiding foam insulation produced with HCFC blowing agents. Note that with refrigerants, there is often a tradeoff to be considered between ozone-depletion and global-warming potential. With renovation of existing buildings, measures can be taken to capture and destroy ozone-depleting refrigerants and blowing agents.

Reduced resource extraction impacts
When we use materials to construct an office building or house, the impacts of that material use are not limited to our building location. The aluminum may have came from bauxite ore mined in what had been tropical rainforests in Brazil, the steel likely came in part from iron ore mined in Minnesota, the mahogany used in our decks or hardwood doors might have come from clearcut land in Indonesia, and the chrome finish on our bathroom vanities most likely came from highimpact mining in Zimbabwe.

These impacts are all embodied in the materials we use. With green building, there is often an effort to consider those impacts-through a process called life-cycle assessment (LCA). Specifying green building materials can help to minimize these impacts of resource extraction.

Reduced toxic emissions
The manufacture of certain building materials, including some types of plastic, results in the emission of toxic air pollutants. The same materials (and others) may also emit toxins at the end of their lives, when they are landfilled or incinerated. There is growing concern about additives such as phthalate plasticizers and brominated flame retardants that are added to some plastics. A commitment to green building materials is a commitment to considering these LCA issues. Natural building materials often pose the lowest environmental risks.

Reduced energy and other impacts of transporting materials
The greater the distance building materials and products need to be shipped (and the distance raw materials have to be shipped in the manufacturing of these finished goods), the greater the energy use and environmental impacts. With green building, there is often an effort to select more local materials-indeed, the LEED® Rating System provides up to two points for use of local materials, and many projects have received innovation credits for significantly exceeding those thresholds.

Reduced contributions to local and regional air pollution
Burning fossil fuels to operate buildings and to transport people to and from those buildings causes local and regional air pollution-so any measures that reduce this energy use will help control air pollution. Some building materials also contribute to air pollution (smog) through the release of volatile organic compounds (VOCs). With green building, and the selection of green building materials, the air pollution sources should be minimized.

Reduced local and regional water pollution
Buildings contribute to water pollution in a number of ways: stormwater runoff that carries contaminants into nearby surface waters, effluent from manufacturing plants that produce the products used in constructing a building, and the wastewater generated by a building that either introduces residual pollutants into surface water after treatment or more directly contributes pollutants to the groundwater with onsite wastewater treatment. With green building, efforts are made to minimize these impacts and select products that carry minimal "upstream" or "downstream" water pollution impacts.

Reduced urban heat islands
Reflective roofs and green roofs do not contribute significantly to the urban heat island effect, which causes urban areas with many dark surfaces to be up to 15º F (8º C) warmer than surrounding, undeveloped countryside. Higher air temperatures result in more smog and higher cooling costs.

Protection of biodiversity
Some environmentalists argue that the greatest damage we are currently doing to the environment-"the folly that our descendants are least likely to forgive us," in the words of Harvard biologist E.O. Wilson-is the catastrophic loss of biodiversity we are causing globally. Green developments can help to protect biodiversity.

They can do this locally by protecting open space, restoring ecologically damaged sites, and creating wildlife habitat-even on top of buildings in cities. They can do this more broadly through the specification of products and materials that do not damage ecosystems elsewhere.

Increased environmental awareness
Green buildings can be learning laboratories for all who use them. Interpretive signs about the benefits of low-water-use faucets in commercial restrooms, about how to sort recyclables in a building, about xeriscaping practices to conserve water outdoors, and about the use of energysaving lighting controls educate those using the building, which in turn should further the penetration of green building practices throughout our building stock. Even in homes there are opportunities to increase awareness about the environment-children growing up with green features will consider that the norm.

Green buildings that offer a direct connection with the natural environment may also nurture a more wholesome relationship with that environment among populations that are increasingly isolated from it.

Support of sustainable economies
A green agenda can extend beyond the built environment into the economy at large. Locally based manufacture of building materials and local agriculture are opportunities that green building helps foster. Putting money into local companies that weatherize homes or install solar equipment can keep money within the community instead of sending it out of the community (and much of it out of the country) in purchasing fossil fuels.

Support of companies with socially responsible policies
While green building products have been identified to date based largely on their environmental characteristics (recycled content, low VOC emissions, and so forth), a next step might be broadening selection criteria to consider such issues as a company's internal environmental policies, labor practices, and other measures that are typically addressed under the banner of "corporate social responsibility."