Monitoring Changes in Climate Extremes A Tale of International Collaboration
Thomas C. Peterson and Mich ael J. Manton
The nature of the problem. The Second Assessment Report (SAR) of the Intergovernmental Panel on Climate Change (IPCC), published in 1996, concluded that the available data and analyses were inadequate for any assessment to be made about the nature of global changes in extreme climate events. Since the SAR, a number of international projects have moved the focus of climate analysis from monthly to daily data so that today there is a better understanding of the extent and character of changes around the world in extreme climate events, such as heavy rainfall and heat waves.
Because of the traditional focus of climatologists on monthly data and the proprietary view many countries have toward data on shorter time scales, the international exchange of long-term daily climate records has been limited, and in 1996 there was no international dataset of long-term daily terrestrial data available. Analyses of extremes were primarily limited to data from Canada, the United States, the former Soviet Union, China, and Australia. Furthermore, any analyses of extremes from these countries were hard to compare because the analyses used different measures of extremes.
Two-pronged solution. At the November 1999 meeting of what is now known as the joint1 Expert Team on Climate Change Detection and Indices (ETCCDI; www.clivar.org/organization/etccdi/etccdi.php), it was recognized that a two-pronged approach was needed to promote further work on the monitoring and analysis of daily climate records to identify trends in extreme climate events.
The first task was internationally coordinating the exact formulation of a suite of agreed indices of climate extremes from daily data. The use of agreed indices would allow comparison of analyses conducted in any part of the world.
Secondly, the ETCCDI decided to promote the analysis of extremes around the world by organizing regional climate-change workshops following the model pioneered in December 1998 at an Asia-Pacific Network for Global Change Research (APN) meeting in Melbourne. That meeting brought together world-recognized experts in climate change analysis to guide participants from a dozen countries in the Asia-Pacific region. The participants brought their long-term daily data, history about the observing stations, and a willingness to learn about quality control, homogeneity testing, and climate analysis.
1266 BAMS September 2008
