Many of the world’s largest shipping nations decided on Friday to impose a minimum fee of $100 for every ton of greenhouse gases emitted by ships above certain thresholds, in what is effectively the first global tax on greenhouse gas emissions. The International Maritime Organization estimates $11 billion to $13 billion in revenue annually from the fees, with the money to be put into its net zero fund to invest in fuels and technologies needed to transition to green shipping, reward low-emission ships and support developing countries so they aren’t left behind with dirty fuels and old ships. The thresholds set through the agreement will get stricter over time to try to reach the IMO’s goal of net zero across the industry by about 2050.