As per a study of 14 countries conducted by the National Geographic Society and the international polling firm GlobeScan, India and Brazil have come at the top, jointly.
"This first-of-its-kind study reveals surprising differences between consumers in developed and developing countries in terms of environmentally friendly actions," NatGeo said.
The survey was conducted online earlier this year among 14,000 consumers in Australia, Brazil, Canada, China, France, Germany, Great Britain, Hungary, India, Japan, Mexico, Russia, Spain and the United States.
However, while Indian consumers (along with Brazilians) outranked others on the 'Greendex' survey of environmentally sustainable behaviour, they came in last on a short quiz of environmental knowledge, correctly answering on average only two of the six questions posed.
Indian and Brazilian consumers topped the 14-country index, and have the highest Greendex score for environmentally sustainable consumption at 60 points each, because of their relatively lower environmental impact from housing and above-average performance on transportation and food.
They are followed by consumers in China (56.1), Mexico (54.3), Hungary (53.2) and Russia (52.4). Among consumers in wealthy countries, those in Great Britain, Germany and Australia each have a Greendex score of 50.2, those in Spain register a score of 50.0 and Japanese respondents, 49.1.
The US consumers have the lowest Greendex score at 44.9. The other lowest-scoring consumers are Canadians with 48.5 and the French with 48.7.
Indian (and Chinese) consumers are more likely than other respondents to say they have installed solar panels at their residence to heat water, live close to the places they need to go most days in order to reduce their impact on the environment.
About six in 10 people in developing countries report that environmental problems are negatively affecting their health twice as many as in most developed countries.
People in developing countries are more likely to live in smaller residences, prefer green products and own relatively few appliances or expensive electronic devices, walk, cycle, or use public transportation, and choose to live close to their most common destination.
By contrast, consumers in developed countries, have larger homes and are more likely to have air-conditioning, they generally own more cars, drive alone most frequently rather than using public transport. US consumers scored worse than those in any other country, developing or developed, on housing, transportation and goods.
There are signs that index rankings are set to change as people in developing countries become more economically successful and adopt more consumptive behaviour.
The National Geographic Society is one of the world's largest non profit scientific and educational organisations.
