WASHINGTON The Obama administration and the Democrat-controlled Congress appear to be in lock step on the need for far-reaching environmental legislation designed to reduce greenhouse gases and expand alternative energy sources.

While most of the interest generated by the legislation has focused on its impact on giant power plants and consumer electric bills, the ground transportation industry is likely to be swept up in a major way -- in its reach.

Thats because vehicles are considered a major contributor to global warming pollution. For example, more than 38 percent of the carbon dioxide and other greenhouse gases in California come from burning diesel in trucks and buses and gasoline in cars, according to state officials.

Last month, cabinet-level officials from the Obama administration went before Congress and rejected claims that the carbon emissions bill would result in massive U.S. job losses and large increases in fuel bills.

"The no, we cant crowd will spin out doomsday scenarios about runaway costs," said U.S. Environmental Protection Agency Administrator Lisa Jackson. "But EPAs available economic modeling indicates that the investment Americans would make to implement the cap-and-trade program of the American Clean Energy and Security Act would be modest compared to the benefits that science and plain common sense tell us a comprehensive energy and climate policy will deliver."

The proposed clean energy law calls for a host of energy independence and greenhouse gases reduction initiatives, including a cap-and-trade program.

"Aggressive action to reduce the impacts of climate change is needed, and the U.S. must be a leader in the global effort to reduce greenhouse gas emissions," Transportation Secretary Ray LaHood told a House committee.

But several members of the House panel, most of them Republicans, predicted a cap-and-trade program would be costly not only for business, but for consumers as well.

"Cap-and-trade, cap-and-tax will simply kick American families when they are down," said Rep. Fred Upton, R-Mich.

"This is the largest assault on democracy and freedom in this country that Ive ever experienced," said Rep. John Shimkus, R-Ill. "Ive lived through some tough times in Congress - impeachment, two wars, terrorist attacks - I fear this more than all of the above activities that have happened."

The 640-page draft legislation seeks to lower carbon dioxide emissions to 20 percent below 2005 levels by 2020 and more than 80 percent by 2050, through a cap-and-trade system.

Under the program, carbon emitters would receive tradable federal permits called "allowances" for each ton of pollution emitted into the atmosphere.

Entities that emit fewer than 25,000 tons per year of carbon dioxide equivalent would not be considered large enough emitters to be covered by the program.

The USEPA has estimated that the cost of the allowances would range from $13 to $17 per metric ton CO2 equivalent in 2015, and from $17 to $22 in 2020.