Corrections

In “Carbon Regulation: What’s the Most Effective Path?” due to an editing error, the vertical axis of the chart "Historical Global Carbon Dioxide Emissions" showed increments of 1,000 million metric tons of CO2 (June issue, page 38). The vertical-axis increments should have been 5,000 each, with the curve reaching just under 30,000 million metric tons of CO2 in 2004. In the same article, the left side of the chart “Proposed Emission-Reduction Targets” was cut off (page 39).