The Intergovernmental Panel on Climate Change (IPCC) was jointly established in the late 1980s by the World Meteorological Organization (WMO) and the UN Environment Programme (UNEP). It was a timely process. Information and concern was mounting about the human potential for contributing to the naturally occurring greenhouse effect. Governments convened meetings to discuss possible approaches to prevent, mitigate, or adapt to the consequences of global warming.

The goal of the IPCC was to assess the state of the science of the climate system as it relates to the increase of carbon dioxide and other greenhouse gases in the atmosphere. A few thousand scientists from around the globe were brought together to focus on the science of greenhouse gas buildup, the impacts of climate variability and climate change, and the policy aspects of global warming. Each topic was attacked by a working group: science, impacts, and policy.

The IPCC assessment reports have been published five years apart, based on the research and review efforts of the scientists, beginning in 1990. To date there have been three major assessments. Lots of new information was included in the 2001 report, when compared to the first. There has been progress on most fronts, and the number of scientists who support the IPCC findings appears to have grown sharply, while those who oppose the idea that the climate is changing as a result of human activities has stayed about the same, with a few vocal spokespersons.

I believe there is value in the undertaking of assessments of the state of our knowledge about the global climate system and about human activities that might affect or be affected by global climate change. Clearly, there are many positive aspects of the IPCC process and its outputs, such as the entrainment of future researchers and capacity building with regard to climate change issues in developing countries.

My primary concern centers on the frequency at which IPCC assessments have been undertaken. Several of my colleagues who have participated in the preparation of IPCC reports have voiced their reluctance to participate in yet another assessment so soon after the issuance of a report. Are scientists being burned out by the numerous meetings and writing assignments? The question people seem to be reluctant to ask is this: is it time to rethink the frequency of the IPCC reports?

Obviously, new and useful scientific research findings do not occur automatically every five years. While these reports are issued every five years, the research going into them is drawn from work done on a shorter time frame. For example, the most recent report was issued in 2001, and senior researchers are already being contacted about serving as lead authors for the next IPCC review in 2005. When does the scientific research that goes toward the next assessment get done?

I am concerned that there is hidden pressure to provide scientific advances in various areas of these reports, when in fact only minor advances may have been made. Is it time to review the IPCC process of the 1990s? Is, for example, the five-year timetable appropriate? Are the numerous consensus-building meetings necessary? Is the institutionalization of the Secretariat an appropriate mechanism, now that the global warming issue has been placed on the agenda for most countries? And what is UNEP's role, given that its Atmosphere Unit has been decimated?

Reviewing past experience, perhaps it would be better to have eight-year intervals between IPCC assessments, allowing a year and a half to digest the previous report, five years for research, and a year and a half for preparation of the new assessment.

I want to say that I believe that, scientific uncertainties notwithstanding, human activities can alter local to global climate conditions. Discussing the IPCC process or raising the possibility of a review could open up the proverbial Pandora's Box. I do not want to see it weakened by the "naysayers" (those who do not believe that human activities can influence global climate). On the contrary, I want to see a more effective IPCC, one that enables researchers more time to do the research.