A major theme of his presentation was the idea of human "fingerprints" to make better use of statistical models. Teasing out how different factors -- from volcanos to solar flares -- could affect temperature made it possible, he said, to also model the human affect.

It is an "immutable fact," he said, that humans have been and continue to be responsible for changes in the climate.

But a statistician knows as well as anyone that graphs and spreadsheets are not likely to sway public opinion.

"Katrina galvanized people's attention," he said when a member of the audience asked why, after more than a decade of doing this work, the public seemed to be on his side.

"CO2 is an odorless, colorless gas. It's difficult to make it real to people."

In his introduction, Bud Ward, a environmental journalist for more than 30 years, said that because Saner was a better scientist than a diplomat, he was able, in the mid-90s, to write a chapter in the Intergovernmental Panel on Climate Change attributing warming to human activity by arguing, rather undiplomatically, with diplomats.

At the time of the report, however, he was accused of editing it to delete references of scientific uncertainty about the human impact of climate change. Ultimately, the 1995 IPCC report concluded that "the balance of evidence suggests a discernable human influence on global climate."

That statement, Santer said, is "forever in my memory."

The $75,000 Grantham Prize for Excellence in Reporting on the Environment – the largest of its kind – will be awarded to Kenneth R. Weiss and Usha Lee McFarling of the Los Angeles Times for their five-part series “Altered Oceans.”

Awards of special merit, a $5,000 prize, will be given to a team of reporters at NOVA for “Dimming in the Sun;” a team at the East Oregonian Publishing Company for its series, “Our Climate is Changing … Ready or Not;” and for Eugene Linden’s “The Winds of Change.”

The Grantham Prize was created in 2005 through a joint effort between URI's Metcalf Institute for Marine and Environmental Reporting, and the Grantham Foundation for the Protection of the Environment.

The Metcalf Instute was named for Michael P. Metcalf, the late publisher of The Providence Journal, "who was keenly interested in marine and environmental issues and was known for his integrity, vision, and high standards for writing," according to the institute.