This month the Intergovernmental Panel on Climate Change (IPCC), the United Nations–affiliated body that serves as the world's foremost authority on climate science, is scheduled to issue the first installment of its new climate assessment, six years in the making. The massive report, the panel's fifth, is being released in four parts between now and October 2014. It is stuffed with science, woven together by more than 800 scientists. And it is already out-of-date.

Here are a few recent results that you won't find in the new report: A study published last November found that Arctic permafrost is thawing much faster than we thought, an ominous development that could expel massive quantities of the greenhouse gas methane into the atmosphere, accelerating climate change. Ice sheets in Greenland and the Antarctic are also melting faster than anticipated, which could make the IPCC's estimates for sea-level rise read like yesterday's newspaper.

The IPCC reports also won't make use of the latest advances in the models used to predict climate change. In July, Kerry Emanuel of the Massachusetts Institute of Technology updated the computer models used by the IPCC with more fine-grained data about cyclones, revealing that these storms could increase in number, not just intensity, as the current report holds.

The missed opportunities are an inevitable result of the IPCC's laborious review process, as well as the organization's strategy of releasing all its findings at more or less the same time. That approach made sense in the group's early years, when the painstaking work of creating the enormous assessments—culling research, drafting reports, administering reviews and making revisions—established academic and political credibility for an organization attempting to inform public policy with well-supported science. But the process also forces the IPCC to stop considering new results a year or even two years before the assessment comes out, and it may not fully integrate research that is older than that.

Without the latest data, the IPCC, already conservative in its proclamations, tends to underestimate the risks of climate change. And the slow update schedule gives foot-dragging governments cover, as they can always claim that they should wait for the next report to come out before taking action.

The IPCC has to move faster. To do so, it should drop the major assessments. Instead it should issue frequent, tightly focused reports on specific topics, such as sea-level rise, water scarcity and agricultural yields. Such reports would allow it to incorporate science that is only months old rather than years old.

The organization should also conduct its reviews publicly, online. Scientists would post drafts and comments in a wiki-style repository that would grow daily. This format would mute criticisms that the drafting process is overly secretive. Occasional errors, such as a mistake in the 2007 assessment about how rapidly Himalayan glaciers are receding, would be caught right away. Any alleged bias from an author would be revealed. A more transparent system would also help neuter the unfounded (yet enduring) accusations that the IPCC is some sort of political conspiracy, rather than a research review board. Mostly, a wiki approach would ensure that all reports reflect up-to-the-minute science.

Unfortunately, the IPCC is not built to do quick work. The organization currently relies on an army of volunteer scientists encumbered by their day jobs. The group should instead become a permanent, global agency that relies on a nimble, dedicated staff. Institutional models abound, as Eduardo Zorita of the GKSS Research Center in Germany wrote in Nature (Scientific American is part of Nature Publishing Group): “The European Central Bank, the International Atomic Energy Agency, the International Energy Agency and the U.S. Congressional Budget Office all independently navigate their way through strong political pressures, delivering valuable assessments, advice, reports and forecasts…. These agencies are accountable and respected.”

If the IPCC is to maintain its status as the world's most relevant and respected summarizer of climate science, it must evolve. Knowledge moves fast. The rest of the world needs the IPCC to keep up.