Economists have for decades recommended that carbon dioxide and other greenhouse gases be taxed--or otherwise priced--to provide incentives for their reduction. The United States does not have a federal carbon tax; however, many state and federal programs to reduce carbon emissions effectively...

When it was launched in 2005, the European Union emissions trading system (EU ETS) was projected to have prices of around €30/ton CO2 and to be a cornerstone of the EU's climate policy. The reality was a cascade of falling prices, a ballooning privately held emissions bank, and a decade of low...