New Zealand has unveiled a carbon tax to help it meet the goals of the Kyoto Protocol on climate change, which the country expects to ratify by year’s end. The tax, which would be implemented in 2007 assuming Kyoto has come into effect, would boost retail gas prices by up to 6 percent, diesel prices by up to 12 percent, and gas and electricity prices by as much as 9 percent, according to government documents. Coal users would be the hardest hit, with a 19 percent price hike. New Zealand emits between 70 and 90 million metric tons of carbon dioxide per year, making it the fourth-largest per capita producer after the United States, Australia, and Canada. But in Kiwi-land, the problem isn’t only cars, but also farm animals: Half of New Zealand greenhouse gases come from the methane and CO2 emissions of the more than 50 million sheep and cattle that account for a third of the country’s export earnings. New Zealand farmers would be exempt from the new tax plan. What revenue the tax generated would be used for climate-change projects and to offset cuts in other taxes.