One of the most seductive arguments for a carbon tax tries to have its cake and eat it too: Proponents claim that so long as it’s “revenue neutral”—meaning that the receipts from a carbon tax are used to offset other taxes, not to increase spending—then a new carbon tax gets us the best of both worlds. They claim that it would reduce greenhouse gas emissions, thus slowing climate change, and the tax cuts on labor and investment would spur economic growth.