Which one of the following countries is the first country in the world to propose a carbon tax for its people to the address global warming?

1. A carbon tax is a tax levied on the carbon content of fuels or greenhouse gas emissions. 2. It is proposed as a market-based instrument to address global warming by encouraging reductions in emissions. 3. New Zealand implemented a partial carbon tax (on energy emissions, excluding agriculture) in 2008, but discussions and proposals were active earlier. 4. Around 2005-2006, New Zealand was prominently discussing and moving towards implementing such a tax, making it arguably the first country in the world to seriously propose and plan for a broad-based carbon tax (even though initial implementation faced delays and modifications). 5. Other countries like Finland, Sweden, and Norway had earlier carbon taxes, but New Zealand's proposal was notable for its intended scope at the time.