"We need leadership, and I don't think we're getting it," said Russell Train, EPA chief under Presidents Richard Nixon and Gerald Ford, talking about global warming. "To sit back and just push it away and say we'll deal with it sometime down the road is dishonest to the people and self-destructive."
"I don't think there's a commitment in this administration," said Bill Ruckelshaus, who was the nation's first EPA boss, succeeded by Train during the Nixon administration.
Carol Browner, who was President Clinton's EPA administrator, said the White House and the Congress should push legislation to establish a carbon trading program based on a 1990 pollution trading program that helped reduce acid rain.
"If we wait for every single scientist who has a thought on the issue of climate change to agree, we will never do anything," she said.
The Bush record was defended by Johnson, who said the administration has spent $20 billion on research and technology to combat climate change.
"I know from the president on down, he is committed," Johnson said. "And certainly his charge to me was, and certainly our team has heard it: 'I want you to accelerate the pace of environmental protection. I want you to maintain our economic competitiveness.' And I think that's really what it's all about."
All of the EPA chiefs, former and current, raised their hands when the event moderator asked whether they believe global warming is a real problem and again when he asked if humans bear significant blame.
President Bush has kept the United States out of the Kyoto international treaty to reduce greenhouse gases, saying the pact would harm the U.S. economy. Many of the accord's terms were negotiated by the Clinton administration, but it was never ratified by the Senate.
Lee Thomas, Ruckelshaus' successor in the Reagan administration, said "if the United States doesn't deal with those kinds of issues in a leadership role, they're not going to get dealt with. So I'm very concerned about this country and this agency."
Bill Reilly, the EPA administrator under the first President Bush, said, "The time will come when we will address seriously the problem of climate change, and this is the agency that's best equipped to anticipate it."
Christie Whitman, the first of three EPA administrators in the current Bush administration, said people obviously are having "an enormous impact" on the earth's warming.
"You'd need to be in a hole somewhere to think that the amount of change that we have imposed on land, and the way we've handled deforestation, farming practices, development, and what we're putting into the air, isn't exacerbating what is probably a natural trend," she said. "But this is worse, and it's getting worse."
Three former administrators did not attend Wednesday's symposium: Mike Leavitt, the current health and human services secretary; Doug Costle, who was in the Carter administration; and Anne Burford, a Reagan appointee who died last year.