<p>This data visualization is part of a report by McKinsey of measures to reduce greenhouse gas (GHG) emission in the US. </p><p>At first glance this graphic is hard to understand. But with context, it does a good job of conveying a lot of information about various measures (with over 250 investigated). The graphic has done such a good job visualizing information it has become prevalent enough in discussions of climate change to refer to it simply as "the McKinsey curve". </p><p>Later on in the report, the abatement curve is explained succinctly. Each bar represents one option or group of closely related options. Width indicates amount of carbon dioxide reduced annually by means of the option. Height indicates the average cost of avoiding 1 ton carbon dioxide equivalent with the option as measured against emissions reference case. Negative cost (below the horizontal axis) indicates a net benefit or savings to the economy over the lifecycle of the option. Postive cost (above the horizontal axis) means it would cost the economy over the lifecycle of the option.</p>