The final installment of a survey of global warming by Elizabeth Kolbert published in The New Yorker (May 9, 2005), sets forth some ideas for attacking the problem advanced by Princeton engineering professor Robert Socolow, co-director of the Carbon Mitigation Initiative. The article features a striking illustration based on a chart Socolow and his colleagues devised. The magazine illustration is not available online, but the original, found here, is even more striking. 
Cutting wedge ideas
Greenhouse gas emissions will continue along the top curve labeled “currently predicted path” here, but more colorfully called “Business as Usual” in The New Yorker. There are seven wedges, each representing something that can be done to reduce emissions by a billion tons per year.
Rather than lay out a specific program by labeling the wedges, Socolow lists 15 alternative actions that could achieve 1/7 of the target reduction, such as
The list appeared in the August 13, 2004 issue of Science and is reproduced at
Environmental Entrepreneurs.
Strength in numbers
What makes this chart so effective, I think, is its insistence that if we choose a goal, we can also evaluate a combination of specific actions to reach the goal. Any seven actions will do, but some combinations might be easier.
By quantifying the problem of global warming in wedges on a graph, the scientists have taken it out of the realm of hand-wringing and into the realm of practical horse-trading. Some people will even see in these wedges ideas for making money with good ideas. That’s what good business graphics should do.
We used a chart like this in a 2-Minute Explainer describing how Activplant’s manufacturing performance management software works.
— BGM