Four governors, two Canadian premiers, other dignitaries and as many as 80 reporters descended on Yale on Thursday in anticipation of today’s climate-change conference, headlined by California Gov. Arnold Schwarzenegger.

Before today’s ceremony in Woolsey Hall, when representatives from 18 states will sign a policy statement urging federal and state collaboration on curbing global warming, conference participants arrived on campus for panels, guest lectures and receptions. Yale seized the moment to announce a new push to encourage sustainable behavior.

“The goal is to recognize leadership at state level and, through the policy statement, advance a partnership between the states and the federal government,” said Melissa Goodall, associate director of the Yale Center for Environmental Law and Policy, which is co-sponsoring the conference. “The idea is not to chide the federal government, but to encourage it to work hand-in-hand with the state level.”

The conference echoes President Theodore Roosevelt’s convention of U.S. governors at the White House 100 years ago, which launched the modern conservation movement and prefaced the establishment of the National Parks System. Roosevelt’s partner in early environmentalism, Gifford Pinchot, co-founded Yale’s School of Forestry and Environmental Studies.

With this historical link in mind, Roosevelt and Pinchot reunited — in the form of their descendents — at a dinner reception Thursday night for the conference participants. Theodore Roosevelt IV and Gifford Pinchot III spoke at the dinner to commemorate the centennial of their forefathers’ conservation conference.

The anniversary was first noted by School of Forestry and Environmental Studies Dean Gus Speth, who then gathered a team of officials to organize some form of commemoration. Goodall said today’s conference was the result of that collaboration between the Yale Center for Environmental Law and Policy, the Yale Project on Climate Change, the Center for Business and the Environment at Yale, the Yale Office of Sustainability and the Yale School of Forestry and Environmental Studies.

But unlike the 1908 conference at the White House, today’s conference will be apolitical, Goodall said. As a host, Yale can lend both its prestige and non-partisanship as an educational institution.

Of the four governors attending, Schwarzenegger and Rell are Republicans, while Corzine and Sebelius are Democrats. Of the 18 states signing the policy declaration, three have Republican governors and 15 have Democrats.

Environmental Law professor Dan Esty, director of Yale Center for Environmental Law and Policy, said the conference is an opportunity to bolster Yale’s, and University President Richard Levin’s, reputation as a leader in climate change.

“We’re excited about Yale being front and center in an effort to make climate change a top issue,” Esty said. “I think the time is right to integrate state-level action into what will be a federal program when the next president takes office. Climate change is such a broad and complicated problem that it will take the best efforts of both state and federal officials to achieve a substantive, on-the-ground reduction in greenhouse gas emissions.”

Time-pegged to the conference, the University announced a Sustainability Pledge, which asks members of the Yale community to commit to sustainable energy and waste practices. Robert Ferretti, education manager of the Office of Sustainability, said he hopes 2,500 people will sign by the end of the year.

The concept is modeled after Harvard’s pledge, introduced six years ago, he said.

“They found a great way to engage the Harvard community, and part of the reason we’re doing this is to engage the Yale community in the same way,” Ferretti said. “We’re hoping that it encourages sustainable behavior and will be another way to engage the Yale community in creating a sustainable campus.”

While the governors convene, students have planned demonstrations on Cross Campus, calling for Connecticut Governor Jodi Rell to endorse a bill in the Connecticut General Assembly that would impose mandatory economy-wide emission caps. The demonstration will feature a snowman costume and “emissions cap” baseball caps, said organizer Abby McCartney ’10, lobbying coordinator for the Yale College Democrats.

College Democrats President Ben Shaffer ’09 said he expects around 50 students, but they will be joined by demonstrators from Wesleyan University or brought by the Connecticut Climate Coalition.

“We’re calling for leadership on the state level and calling for Connecticut to catch up to New Jersey and California,” said Roger Smith, an outreach coordinator for the Connecticut Climate Coalition.

New Jersey Governor Jon Corzine is also attending the conference.

Mary Nichols, chair of California’s Air Resource Board and Schwarzenegger’s point-person on climate change, delivered a guest lecture at the Law School Thursday afternoon.