Most leaders of the world's governments will attend. U.S. Secretary of State Condoleeza Rice will represent American interests at the meeting. President Bush will meet with the leaders of the UN and other governments at a dinner tonight.

The United States is the largest emitter of greenhouse gases in the world. But the U.S. has declined to sign a U.N. climate document, the Kyoto Protocol, ratified by most of the world's leading nations in 1997. The protocol expires in 2012.

Those close to the scene are looking for a change in U.S. policy based on a series of reports released this year by a worldwide panel of scientists concluding that the scientific proof for climate change is "unequivocal."

"What the United States does, and how the United States decides to enter this negotiation is going to be a very, very telling commentary on the future of the climate negotiations, and ultimately, I believe, on the fate of the earth," said Tim Wirth, president of the U.N. Foundation and a former U.S. Senator from Colorado. Wirth represented the Clinton Administration during U.N. climate negotiations in 1995.

At a news conference last week sponsored by the National Environmental Trust, Sen. John Kerry (D-Mass.) was hopeful about the meeting.

"I'd like to see the President of the United States take the lead and say the United States of America is going to set fixed targets, that we're going to lead the world in alternative renewable fuels and technologies, and we're going to help contribute to the technical assistance and the technologies, themselves, to less developed countries in an effort to facilitate their economic transformation," Kerry said.

Iraqi government statements have been contradictory on the Sept. 16 gunfire, in which Blackwater USA, based in North Carolina, is accused of having killed Iraqi civilians while escorting an American diplomatic convoy in Baghdad. They range from threats to prosecute Blackwater to promises not to expel the firm from Iraq.

But the government of Prime Minister Nouri al-Maliki has managed to galvanize broad-based opposition to an order issued in the waning days of direct American rule in Iraq that lays out broad immunity from criminal prosecution for U.S. diplomats, troops and private contractors operating in Iraq.

It is known as Order 17, issued by the U.S. Coalition Provisional Authority in 2004. Iraqi officials have long chafed at the law, viewing it as an encroachment on Iraqi sovereignty. But until now, no serious effort has been made to revise it.

The central government, unpopular on the streets and worried about being marginalized, appears to be using the Blackwater crisis to counter U.S. criticism that it is ineffective and to show ordinary Iraqis that it can stand up to Washington.

Authorities said they were amazed that someone would wear such a device eight months after a similar scare in Boston, and six years after two of the jets hijacked in the Sept. 11 attacks took off from Logan.

"I'm shocked and appalled that somebody would wear this type of device to an airport," said State Police Maj. Scott Pare, the airport's commanding officer.

Simpson showed "a total disregard to understand the context of the situation she is in, which is an airport of post-9/11," prosecutor Wayne Margolis said at a hearing where a not guilty plea was entered for Simpson and she was released on $750 bail. Margolis had asked for $5,000 bail.

Simpson, of Lahaina, Hawaii, was arrested Friday morning outside Terminal C, home to United Airlines, Jet Blue and other carriers.

She wore the white circuit board on her chest over a black hooded sweat shirt, Pare said at a news conference. The battery-powered rectangular device had nine flashing lights, and Simpson had Play-Doh in her hands, he said.

Two phrases that looked hand-drawn — "Socket to me" and "Course VI" — were written on the back of Simpson's sweat shirt, which authorities displayed to the media. Course VI appears to refer to Massachusetts Institute of Technology's major of electrical engineering and computer science.

"She said that it was a piece of art and she wanted to stand out on career day," Pare said. "She claims that it was just art, and that she was proud of the art and she wanted to display it."

There was a career fair at the university on Thursday, according to the university's Web site.

Simpson is the secretary of MIT's Electrical Research Society, according to her lawyer. She is a graduate of the Hawaii Preparatory Academy, a private boarding school, has won school prizes for chemistry and leadership and had received a Congressional citation for her work in robotics, said Ross Schreiber, who was appointed to represent Simpson.

He said she was not a risk to flee, cooperated with authorities and was a good student with no prior convictions. He said they would fight the charges.

"I would characterize it as almost being paranoid at this point," Schreiber said of authorities' response.

He said Simpson had gone to the airport to meet her boyfriend. "She was there for legitimate purposes," Schreiber said.

A Massachusetts Port Authority staffer manning an information booth in the terminal became suspicious when Simpson — wearing the device — approached to ask about an incoming flight, Pare said. Simpson then walked outside, and the staffer notified a nearby trooper.

The trooper, joined by others with submachine guns, confronted her in front of the terminal.

"She was immediately told to stop, to raise her hands and not to make any movement, so we could observe all her movements to see if she was trying to trip any type of device," Pare said. "Had she not followed the protocol, we might have used deadly force."

He added, "She's lucky to be in a cell as opposed to the morgue."

The terminal was not evacuated and flights were not affected, airport officials said.

Boston was the focus of a security scare Jan. 31 when dozens of battery-powered devices that featured a character making an obscene gesture with a finger were discovered in various locations. Bomb squads were deployed and some transportation links were closed temporarily. They turned out to be a promotion for the Cartoon Network. Two men were charged in that incident, but prosecutors dropped the charges after they apologized and performed community service.

A Vermont lawyer representing a client being held at Guantanamo, Cuba, is worried that his phone is being tapped by the federal government.

He ought to be. The federal government may have interpreted the revised federal surveillance law to allow it to wiretap the lawyers of Guantanamo prisoners.

The Vermont Public Service Board heard testimony last week about the suspicions of lawyer Bob Gensburg of St. Johnsbury, who says his phone line has inexplicably gone dead and has been subject to strange buzzing noises. Gensburg is one of Vermont's most respected lawyers, and he is not likely to be imagining these occurrences or to be making them up.

The PSB has already involved itself in the issue of unwarranted spying by the government, mounting an investigation into whether Verizon and AT&T had turned over phone calling records to the National Security Agency without warrants. The federal government has sued to block the PSB's investigation, and those in other states, on the grounds that it would jeopardize national security to talk about the activities of the telephone companies.

Mike McConnell, the director of national intelligence, may have undermined the government's case last month when he acknowledged in an interview that the telecommunications companies had helped the government carry out its program of warrantless electronic spying. It will be harder for the government to argue in court that it cannot talk about the phone companies' role now that the nation's spy chief has talked about it. The Public Service Board is now receiving briefs from the parties in the case in response to McConnell's admission.

Meanwhile, Gensburg wonders if his calls to Afghanistan on behalf of his client are being monitored by the government. If so, it would be an unconscionable breach of the lawyer-client privilege.

Gensburg is not the only Vermonter with connections to Afghanistan. Others have relatives working there or friends living there. One editor of our acquaintance telephoned a friend in Kabul within the past two years. The question inevitably arises: Was the telephone contact monitored or subject to the government's efforts at data mining?

Data mining and warrantless spying on international calls are being carried out in the name of the war on terrorism. So is the detention of Afghans and others at Guantanamo, without charges, with limited access to lawyers, and without recourse to the law. The possibility of unaccountable secret detention of American citizens still exists because of the erosion of the habeas corpus rights that are supposed to be part of our constitutional birthright. Last week the Senate failed to end a Republican filibuster of a bill authored by Sen. Patrick Leahy that would have restored our habeas corpus rights.

No one knows if Gensburg's phone has been tapped, but the Bush administration's disregard for constitutional protections creates an atmosphere of fear and suspicion that make the possibility seem real. One of the great advantages of a democracy is that we need not live in fear that the government will be rifling through our desk drawers or spying on private communications.

As for the telephone companies, it was their responsibility to know right from wrong and to stand up to the government when it sought their cooperation in illegal surveillance. The companies are seeking immunity in Congress for their actions. Instead, the investigations in Vermont and elsewhere need to move forward to hold those accountable, in government and the private sector, for actions that compromised our constitutional rights. No one in Vermont or anywhere else should have to fear that a phone call to Kabul is going to get them in trouble — unless the government has reasonable grounds to believe that a particular individual is actually involved in criminal activity.

For the government to monitor the phone calls of a lawyer or to cast out a vast electronic dragnet is for it to practice the methods of the Soviet Union or East Germany. The Vermont PSB now has an important role in checking the excesses of the government and private companies in spying on innocent Vermonters.