HPI

The Happy Planet Index (HPI), designed to challenge well-established indices of countries' development such as GDP and HDI.
It supposedly takes sustainability into account, including measuring ecological footprint per capita in its formula.

check it out: you might want to note that Singapore is the 131st happiest/planet-friendly country (out of 178) or 48th from the bottom, of those measured.

http://en.wikipedia.org/wiki/Happy_Planet_Index

others that may come in handy:
Malaysia, 44th
Indonesia, 23rd

Vietnam, 12th
Sri lanka, 15th
Philippines, 17th
Thailand, 32nd
India, 62nd
Myanmar, 77th

USA, 150th

'happiest':))Vanuatu
'saddest':((Zimbabwe (no.178)