A Look At The Research Perspective Assessed in IPCC Third Assessment Report (TAR) Climate Change 2001: The Scientific Basis (Working Group 1; Sir John Houghton and Dr. Y. Ding, co-chairs) Presented by Susan Solomon NOAA Aeronomy Laboratory, Boulder, Colorado USA SBSTA-17, New Delhi, India Oct. 28, 2002 On behalf of Dr. Susan Solomon and Dr. Dahe Qin, IPCC WG1 co-chairs for the 4th Assessement Report (2007)

Observations before 1750: a glimpse into Earth’s history, illustrating the needs for better data coverage research on how to analyze the data. Changes in the Earth’s average surface temperature over the past thousand years highlight key data needs

Modern Observations: better coverage for today’s world, but more data are badly needed, particularly in some regions such as Africa, South America, Asia, and others

Some factors contributing to the observed changes in global average temperature. Research needs include: sources and sinks? links to climate? other factors? (land use, solar, volcanoes, aerosols…..) (From ice core and other records)

Global models fail to reproduce the observed record since 1850 when only natural factors are considered Too cold

Model including anthropogenic factors aerosol forcing? feedbacks (esp. from clouds)? More realistic

Some key model research needs Aerosol forcings: sulfate and soot spatial, temporal variations? where, how they absorb/reflect light? Clouds: how do they behave as climate changes? cloud height changes? liquid versus ice? relation to humidity changes? Linkages between anthropogenic aerosols and clouds: a major research challenge

More regional climate records are needed to better understand not just the average, but also variability and extremes (monthly, but even daily, and hourly). Models also need to address these scales of time and space. Source: National climatic data center, regional records for China, India, and the United States ( From Global to Local: Another Scale of Climate

Some Key Needs From An IPCC WG1 Perspective: Observations, both historical and modern; finer resolution in space and time. Research on processes and trends in factors that influence the climate system, including aerosols and greenhouse gases: sources, sinks, forcings, coupling to climate. Research to improve global models (and process understanding). Regional modelling and observations, targetting not only temperature but also for example precipitation, extremes, and patterns of variability (e.g., ENSO). Goal: Better Understand The Earth’s Past History

And better predict its future