Refer to the “World View” below:

World View: Paying to Pollute System Would Limit Emission, Allow Trading of Credits It costs nothing to pump greenhouse gases into the air. . . . That is starting to change. Driven by fears of global warming, countries and states are trying to place a price tag on emissions of carbon dioxide, the gas considered most responsible for rising temperatures. They are turning to a system called “cap and trade,” which limits the overall amount of carbon dioxide an area or industry can emit and then lets individual companies buy and sell credits to release specific amounts of the gas. The cap-and-trade concept is considered an alternative to strict government mandates. It tries to use market dynamics to cut pollution, allowing flexibility on emission levels—for a price. Emissions that were free in the past, regardless of their environmental cost, now would cost an amount set by the market. In theory at least, it allows businesses that emit carbon dioxide to choose the most cost-effective way to cut their emissions. And it gives them leeway in the speed of their cuts. . . . Europe has a carbon dioxide market up and running, with release of a ton of gas now trading at 27 euros, about $32. New York and six other Eastern states plan to open one in 2009. California energy regulators last week took the first step toward such a system. —David R. Baker Source: San Francisco Chronicle, February 19, 2006, p. J1. Used with permission.

How high would its pollution-control costs have to be before a firm would "pay to pollute" a ton of carbon dioxide in Europe.