To limit global warming to 2°C or less—the level deemed safe by science—large emitting countries need to take ambitious action.Economists have long agreed that the most effective way to meet the climate challenge is to put a price on greenhouse gas emissions. About 50 countries have a carbon pricing scheme in some form. But the global average carbon price is currently only $2 a ton, far below what the planet needs. A 2019 study from the International Monetary Fund says that price should be $75 per ton by 2030. The report acknowledges that such a price will drive up energy costs associated with fossil fuels, but it concludes that the money could be used to cut other taxes and generate billions of new jobs if properly deployed.