WASHINGTON To the surprise of virtually no one, the U.S. Environmental Protection Agency has declared that greenhouse gas emissions from vehicles and industrial facilities are a danger to human health.

The declaration is a first step the agency must take before developing regulations limiting the levels of combustion by-products from exhaust tailpipes.

While it is unclear how USEPAs "endangerment" finding might directly affect the commercial vehicle industry, many transportation industry executives think that regulation of bus and truck greenhouse gas emissions is likely at some point.

The USEPA is known to be working on various approaches on how to establish a carbon metric and how to regulate carbon emissions from mobile sources.

USEPA Administrator Lisa Jackson announced the endangerment finding at a news conference last month, even as climate-change legislation makes slow progress in Congress.

The House already has passed a cap-and-trade bill to reduce carbon emissions, but the Senate bill has yet to be adopted.

If the Senate is unable to agree on a climate change bill, the Obama administration has made it clear it would move forward with its own regulations to cut greenhouse gas emissions.

Jackson said that scientific evidence convincingly shows that greenhouse gases are the primary driver of climate change, which can lead to hotter, longer heat waves and increases in ground-level ozone pollution linked to asthma and other respiratory illnesses.

"Business leaders, security experts, government officials, concerned citizens and the United States Supreme Court have called for enduring, pragmatic solutions to reduce the greenhouse gas pollution that is causing climate change," Jackson said.

EPAs finding "continues our work towards clean energy reform that will cut greenhouse gases and reduce the dependence on foreign oil that threatens our national security and our economy," Jackson said.

Sen. Barbara Boxer, D-Calif., author of the Senates leading climate change legislation, said EPAs endangerment finding "confirms what we have been told by Americas top scientists and leading scientists of the world - that unchecked global warming is perilous to human health and our environment."

The EPAs action was a response to a 2007 U.S. Supreme Court decision that concluded the Clean Air Act required EPA to regulate greenhouse gases if the agency established that they harm public health.

The endangerment finding covers emissions of six key greenhouse gases - carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride.