We just recently implemented a CO2 emissions tax on all new cars in an effort to appear to be doing something about the environment. (robertstavinsblog.org)
All countries could agree to impose a common carbon emissions tax, which would increase the price of fossil fuels in proportion to their carbon content. (carbon-price.com)
Examples include a carbon tax to combat climate change, fuel taxes to limit congestion and oil dependence, and vehicle / plant emissions taxes to improve air quality. (energypost.eu)