The South Pacific nation of Tavalu, population 12,000, has committed to going climate neutral by 2020 by switching to 100 percent renewable energy.

In just over a year, ten nations have vowed to reduce their greenhouse gas emissions to reach zero emissions in the next decade.

Zeroing out the emissions of New Zealand, Pakistan, Iceland and Costa Rica won't reverse the course of climate change, but it sends a signal: If these countries can muster the political will despite their small size and relative lack of wealth, so can the western giants.

"In a sense, they are paving the way for medium and larger economies which have to move if we are going combat climate change," Nick Nuttal, spokesman for the United Nations Environment Programme, told Associated Press environmental writer Michael Casey [story]. "These smaller economies are out to prove you can do it, and do it faster than some people previously thought."

Tavalu is only 10 square miles and emits barely any CO2 today. Nonetheless, the country hopes to stop shipping in fossil fuels and replace them with solar energy and wind power. It's getting help from e8, an international nonprofit organization of ten leading power utilities from G8 countries. Cost: $20 million.

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