A former Clinton adviser called for the U.S. to play a greater role in combatting climate change during a forum at the Kennedy School last night.

John P. Holdren, now a professor of environmental policy at the Kennedy School of Government, said the University should use its “extraordinary convening power” to focus attention on the debate.

“If you want the energy system in 2050 to look very different than the one today, you better start changing it now,” he told the audience during his address, entitled “Global Climate Disruption.”

Holdren, who served on Clinton’s Advisory Committee on Science and Technology, said that the U.S. should lead the formation of a new set of global standards that would reduce the ratio of greenhouse gas emissions to economic output in the short-term and develop tradeable rights to emissions based on population in the long-term.

The Kyoto Protocol, which commits nations to reduce greenhouse gas emissions, will expire in 2012. The U.S. has not ratified the agreement.

“The United States must switch from being a laggard in climate change policy to being a leader if the world as a whole is going to act in time,” he said.

According to Holdren, the earth’s surface temperature has been rising steadily since the 1970s, with dramatic environmental effects, including more floods, droughts, and wildfires.

“It’s very hard to look at this data and say that the surface temperature is not an important factor,” Holdren said.

One exhibit focused on rising sea levels, showing that the state of Massachusetts would become partially submerged over time, “a rather sobering prospect,” Holdren said.

“[The speech] made me want to vote for Al Gore,” said William R. Rose ’11. “At least for now, it convinced me that this is a more important issue than I’ve been giving it credit for.”

Many scientists say that burning fossil fuels for energy contributes to global warming. While Holdren outlined possible solutions to the problem—including renewable sources of energy and putting a price on greenhouse gas emissions—he emphasized that “each of these approaches has limitations and liabilities.”

Holdren said it is difficult to find acceptable locations to build wind turbines. People’s mentality has “changed...from ‘not in my backyard’ to ‘build absolutely nothing anywhere near anybody,’” he said.

Yesterday’s address was part of a semester-long series sponsored by the Institute of Politics and the Harvard Environmental Action Committee.