In 2000 and 2001, while Barack Obama served as a board member for a Chicago-based charitable foundation, he helped to fund a pioneering carbon trading exchange that is likely to fill a critical role in the controversial cap-and-trade carbon reduction scheme that President Obama is now trying to push rapidly through Congress.

During those two years, the Joyce Foundation gave nearly $1.1 million in two separate grants that were instrumental in developing and launching the privately-owned Chicago Climate Exchange, which now calls itself "North America's only cap and trade system for all six greenhouse gases, with global affiliates and projects worldwide."

One of those gases is carbon dioxide, the most ubiquitous greenhouse gas and the focus of the most far-reaching -- and contentious -- efforts to combat "climate change." On Monday, Obama's Environmental Protection Agency declared carbon dioxide a public health threat.

The President of the Joyce Foundation in 2000, when the foundation made its first grant to the Climate Exchange, was Paula DiPerna, who is now executive vice president of the Chicago Climate Exchange in charge of corporate recruitment and public policy, as well as president of CCX International.

DiPerna left the foundation in November 2001 and joined the Exchange. It was the same year in which the foundation gave its second and much larger grant to the exchange. The Exchange finally launched in 2003.

Reached at her office in New York, DiPerna said President Obama, who in 2000 was a candidate for Congress, was involved as a director of the foundation and voted on the proposal but declined to detail that involvement other than that "he read the proposal and voted on the grant."

Obama's espousal of cap-and-trade, a system that is intended, among other things, to increase the price of fossil fuels and force their replacement by energy sources that produce less greenhouse gases, has drawn fire from many economists as a huge energy tax that will weigh heavily on an economy that is already in steep recession. The price tag has been put high as $2 trillion dollars over eight years. That figure, nearly three times higher than originally projected, was given in a White House briefing to Senate staffers last week and reported by US News and World Report and the Washington Times.

The scheme has also drawn attacks from 28 U.S. Senators, including West Virginia's Robert Byrd and Michigan's Carl Levin, both Democrats, who have criticized Obama for floating the idea that he would attach the measure to the current budget reconciliation process, to avoid a filibuster in Congress.

An open letter signed by the dissident senators declared that "enactment of a cap-and-trade regime is likely to influence nearly every feature of the U.S. economy. Legislation so far-reaching should be fully vetted and given appropriate time for debate, something the budget reconciliation process does not allow."

Obama served as one of 12 directors on the Joyce Foundation board from July 1994 until December 2002, according to a Joyce foundation spokesman. But it was only in 2000 and 2001 that the foundation gave money to the Climate Exchange -- funds deemed by the exchange itself to be fundamental to its successful launch, and in fact to its early survival.