Photograph by John Tomaselli/Alamy
There are four major components to this study:
Qualitative Survey of Experts
The original 2008 survey questionnaire, much of which was used for tracking purposes in 2009, 2010, 2012, and 2014 was developed based in part on a qualitative survey of experts addressing what they believe are important actions for individuals to take in terms of sustainable consumption. These experts are professionals who have demonstrated an outstanding commitment to advancing global sustainability in their positions as leaders of relevant sustainable development organizations—typically think tanks, academic research institutions, major NGOs, and consultancies. A number of panelists representing the private sector were also included. Potential respondents were identified from GlobeScan's network of colleagues and clients and the firm's database of expert sustainability practitioners, as well as National Geographic's own network of scientific experts.
Panelists were categorized as associated mainly with environment-related science, social science, or business, and divided by region (North America, Europe, Asia, Africa, and Central and South America). Interviews were conducted by telephone, although a small number of interviews were completed electronically to facilitate communication across time zones and language barriers. The interviews took place between September 10 and October 2, 2007.
This project component was not repeated in subsequent years, as the results were intended to provide a long-term perspective. Click here to download a topline summary of the expert interviews.
The National Geographic/GlobeScan Greendex findings result from an international consumer survey conducted between March 25 and May 6, 2014. Approximately one thousand adult consumers, age 18 and older, completed this online survey in each of 18 countries. GlobeScan's Internet panel supplier, GMI, conducted the online fieldwork. The countries included in the survey are:
- South Africa
- South Korea
- Great Britain
- United States
The survey was quantitative in nature and included questions on food source and consumption, transportation, energy use, waste disposal, purchase of environmentally friendly products, and attitudes and opinions toward a variety of related issues.
To ensure that no demographic groups were over-represented in the quantitative survey sample, quota caps were set for education, age, and gender. The data for each country were weighted according to the latest census data to reflect the demographic profile of each country.
The margin of error of random probability survey samples of this size is approximately +/- 3.1 percent 95 percent of the time in each country.
In 2008, GlobeScan conducted a thousand face-to-face interviews among adults 18 and older in Nigeria and Egypt. While these face-to-face results are not comparable to the online results detailed above for online studies in 2008 through 2014, National Geographic chose to include them in the initial study in the interest of gathering stand-alone findings for these countries and with the expectation that Internet penetration will reach sufficient levels in the future to include Nigeria and Egypt in later years' online surveys.
The Greendex measures consumer behavior and material lifestyle according to 65 different variables. Using many variables avoids skews that can occur within a smaller set of variables. Structurally, the Greendex is a meta-index composed of four subindices: housing, transportation, food, and consumption of goods. The goods subindex takes into account both everyday purchases and waste disposal, as well as ownership of big-ticket items such as appliances.
Each respondent earns a score that reflects the environmental impact of his or her consumption patterns. Points are awarded or subtracted for specific forms of consumer behavior, resulting in a score out of a maximum total for each respondent.
Most forms of sustainable consumer behavior are weighted equally within the main components of the Greendex. Forms of behavior that have obviously larger environmental costs or benefits are weighted more heavily (e.g., home heating and driving alone in a large motorized vehicle). That is, these activities have a greater impact on Greendex scores.
No allowances are made for consumer behavior that is determined by geography, climatic conditions where respondents live, culture, religion, or the relative availability of sustainable products. The Greendex is intended to be an overall indicator of one's environmental footprint.
The "Market Basket" is a set of indicators of actual consumption in four areas important to environmentally sustainable behavior—energy, transportation, travel, and consumer goods. A Market Basket for each country was assembled in both 2008 and 2009 using a set of independently collected macroeconomic indicators, gathered by the Economist Intelligence Unit and OAG Worldwide, that mirror, in part, the consumer behavior measured by the Greendex survey. This Market Basket will be repeated periodically going forward.
Market Basket indicators include the following variables:
- Population size and rate of growth
- GDP per capita based on Purchasing Power Parity (PPP)
- Per capita energy consumption
- Passenger car registrations
- Number of domestic and international aircraft passengers per 1,000 people
- Expenditure by households on hotels and restaurants
The purpose of the Market Basket is to provide an external estimate of the results of changes in consumer behavior over time. The Greendex, for example, measures things consumers are doing to save energy in a country; the Market Basket measures whether total energy consumption in the country is actually going up or down. It will also establish a framework for comparing the relative environmental impact of each country's size and rate of growth over time.
For 25 years, GlobeScan has helped clients measure and build value-generating relationships with their stakeholders. Uniquely placed at the nexus of reputation, brand, and sustainability, we partner with clients to build trust, drive engagement, and inspire innovation within, around, and beyond their organizations.
Explore the Greendex
See how your behavior stacks up against consumers in other countries on this interactive map.
Figure out how sustainable your own behavior is. Calculate your personal Greendex.
Are you as savvy about the environment as you think? Find out in this quiz.
How to Feed Our Growing Planet
National Geographic explores how we can feed the growing population without overwhelming the planet in our food series.
@NatGeoGreen on TwitterTweets by @NatGeoGreen
Help conserve the world's natural resources.
Energy Tips From the Green Guide
CFLs still offer the best value for lighting. Learn the lingo and how to shop for a better bulb.
Read our shopping and usage tips and learn how to pick a more energy-efficient set.
Tour the Green Guide home to learn how you can reduce energy and water use.
The World's Water
NG's new Change the Course campaign launches. When individuals pledge to use less water in their own lives, our partners carry out restoration work in the Colorado River Basin.
A special series on how grabbing water from poor people and future generations threatens global food security, environmental sustainability, and local cultures.