Defining the Total Environmental Impact: Part 4

One very helpful guide that shows how our everyday purchases effect the environment is the Consumer's Guide to Effective Environmental Choices. This comprehensive book from Union of Concerned Scientists dispels common misconceptions about the relative importance of various environmental impacts and is filled with practical tips and advice. EVO references data from this report in order to create the Total Environmental Impact (TEI) model used in scoring the EVO tree questions.

The scientists Michael Brower and Warren Leon use an input-output tool, standard in economic analysis, to look at all the material and energy resources associated with a product as well as the pollution, land use and water impacts that results from its production and distribution. They not only examined how much land, air and water was polluted to produce each product but also the resources and energy used to distribute it. Their method takes into account global warming (CO2 and CH4 Methane), air pollution, water pollution, and habitat alteration (land and water).

Though the methodology is different than the Ecological Footprint, the attribution of impact percentages by consumption category for CO2 and land impacts is fairly close. EVO's Total Environmental Impact model looks at both data sets, and adjusts for increased consumption (2001-2006) in certain categories (auto, energy, travel, and building) to arrive at a weighting for categories of impact.

For a detailed understanding of how your purchases affect the environment, the Consumer's Guide is a must-own. Especially helpful is the “Environmental Impacts per Dollar” table, which shows the percentage of impact associated with each of the environmental indicators (pollution, water, etc.) for a given product by dollar.

What are our main impacts according to The Union of Concerned Scientists?

Based on the comprehensive data, The Guide to Effective Environmental Choices book outlines the Seven Most Harmful Consumer purchases and activities:

1. Cars and light trucks which account for 27% of CO2, 22% of common air pollution, and 46% of toxic air pollution.
2. Meat, which account for 26% of land use and 20% of common water pollution.
3. Produce and Grains, which accounts for 30% of all water use.
4. Home Heating & Cooling, which accounts for 16% of CO2 and 11% of common air pollution.
5. Electricity, which accounts for 15% of CO2 and 13% of common air pollution.
6. Home Building, 23% of land use impacts.
7. Home Water & Sewage, 11% of common water pollution.

If you want to start making a big move to reduce your total impact on the environment, start with the list above. For all the details, purchase a copy of the Consumer's Guide here.