A convergence of political, cultural and economic events suggests that a tipping point has been reached in the United States on the issue of global warming.

For years, the issue was controversial and the subject of predictable partisan bickering. Today, there is growing consensus — and even optimism — about the prospects for making changes that improve the global climate picture, and doing so without harming the domestic economy.

One day before President George W. Bush gave his State of the Union address, a group of CEOs of major corporations testified in Washington, D.C., that they believe the time has come to get serious about climate change and greenhouse gas (GHG) emissions.

The corporations represented, including General Electric, Alcoa, DuPont, BPAmerica, Duke Energy, Pacific Gas & Electric, Lehman Brothers and Caterpillar, are among the bluest of blue-chip companies. Yet, the chief executives of these companies told lawmakers that they believe global warming is a reality that needs to be addressed. If new laws are to be passed, they want environmental policies that provide a stable and predictable business climate. Some of the CEOs also acknowledged that they believe there will be profits to be made in various aspects of addressing global warming.

The executives' unexpected coalition with four environmental groups suggests that the CEOs also sense momentum building toward new national laws regarding greenhouse gases and energy efficiency, and by stepping forward now they hope to have input in the making of the new laws.

And as major corporations with operations and sales in different parts of the country, they prefer a single national approach rather than the piecemeal state-by-state approach now developing with California, and a group of Northeastern states taking the lead and eclipsing the federal standards for auto emissions, and other greenhouse gas measures.

The latest ideas involve a market-driven system such as "cap and trade" that would set carbon emission standards, and then allow companies that do meet the new stand-ards to sell their pollution credits to other companies that have not met targets.

The drive for higher efficiency vehicles, appliances and buildings as well as development of renewable energy resources would lead to innovative new, green technologies that would offer significant profit potential. In fact, deep-pocketed investors already are pouring billions of dollars into alternative energy research and development. There will clearly be massive profits to be made, and American capitalism and ingenuity can be expected to produce results.

The recent testimony of the CEOs no doubt caught the attention of global warming doubters in Congress as well as in the larger business community. And the recent arrival in DVDformat of Al Gore's movie "An Inconvenient Truth," having now been seen by millions of Americans, probably also is a factor in building support for action on global warming.

A well-publicized British government study predicting trillion-dolllar consequences for not acting soon to curb global warming is yet another contributing factor in reaching the tipping point, as is the Democratic takeover of Congress.

Altogether, support for addressing global warming seems to have reached critical mass in the United States. Developing domestic and international plans, including a part that deals with the rapidly developing economies of China and India, will be difficult, but most people now see it as necessary. Agreement on how to curb emissions across the globe will be difficult, but it will be equally difficult to agree on measurement, enforcement and penalties.

Still, a multi-faceted approach, involving major industries, environmental groups, energy producers and the petroleum and automotive industries, has the potential to reverse recent carbon emission trends. And as much as Americans are ready to help curb global warming, there is even more support for developing alternative, domestic and renewable fuels to eliminate the U.S. dependence on foreign oil, and escape from the grips of the petroleum industry in general.

The planets appear to be in alignment for major moves forward on addressing global warming.And that means that the debate can shift from being about the existence of global warming to anaylysis of the best ways to reduce carbon emissions.