UNITED NATIONS  The United Nations needs to revise the way it manages its assessments of climate change, with the scientists involved more open to alternative views, more transparent about possible conflicts of interest and more careful to avoid making policy prescriptions, an independent review panel said Monday.

The review panel also recommended that the senior officials involved in producing the periodic assessments serve in their voluntary positions for only one report  a statement interpreted to suggest that the current chairman of the climate panel, Rajendra K. Pachauri, step down.

Ban Ki-moon, the secretary general of the United Nations, has been struggling to make the United Nations the main stage for addressing climate change. Errors in the 2007 assessment report, including a prediction that the Himalayan glaciers could disappear by 2035, have threatened to overshadow the United Nations’ message that climate change is a significant threat requiring urgent collective action.

“I think the errors made did dent the credibility of the process,” said Harold T. Shapiro, a former president of Princeton University and professor of economic and public affairs there. Being more open about the process will help the report withstand the public scrutiny it now endures, Mr. Shapiro, the chairman of the review committee, told a news conference.