Following the recent abandonment of a national cap-and-trade system in the United States and the winding-down of the Chicago Climate Exchange voluntary carbon-trading program, traders and exchanges are now focusing their efforts on California. A recent Wall Street Journal article describes estimates of the potential size of California's carbon market ranging from $3 billion to $58 billion, which has exchange operators competing with each other to become the dominant trading hub. Many in the exchange industry view carbon allowances and related derivative products as a key long-term asset with global potential. California currently has several operators interested in launching exchanges, the first of which could begin trading operations as early as next year.