Costa Rica tops the "Happy Planet Index," a ranking of ecological efficiency among the world's nations, survey officials say.

Costa Ricans reported the highest life satisfaction and have an average life expectancy second only to Canada, said a release from the New Economics Foundation, a British think tank that promotes ecology and sustainable economics.

Nine of the 10 highest-scoring nations were in Latin America, with the United States reportedly "greener and happier" 20 years ago than it is today.

Of the 143 nations surveyed for the Happy Planet Index, the United States ranked 114.

While ecological progress is being made, residents in most countries are far from achieving healthy lives within the Earth's finite resources, said Nic Marks, a foundation spokesman.

"Following the siren's song of economic growth has delivered only marginal benefits to the world's poorest while undermining the basis of their livelihoods," Marks said. "What's more, it hasn't notably improved the well-being of those who were already rich, or even provided economic stability."