Temperature Trends in the Lower Atmosphere:
Steps for Understanding and Reconciling Differences

 

This 3rd draft of the CCSP Synthesis and Assessment Product 1.1 reflects consideration of all public comments received during a recent 45-day comment period (November 17, 2005 - January 4, 2006).  Subsequent to the comment period, an open public meeting was held in Chicago, Illinois on February 8-9, 2006, to address the resolution of the comments. Following the Chicago meeting, this revised 3rd draft of CCSP Synthesis and Assessment Product 1.1 was completed in accordance with the rules of the Federal Advisory Committee Act.  As of March 15, this 3rd draft is being posted here.  In conformance with Guidelines for Producing CCSP Synthesis and Assessment Products, the final version of CCSP Synthesis and Assessment Product 1.1 will be released subsequent to consideration and approval by the CCSP Interagency Committee and the National Science and Technology Council.  

Abstract

Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the validity of climate models and the reality of human-induced global warming. Specifically, surface data showed substantial global-average warming, while early versions of satellite data showed little or no warming above the surface. There is no longer evidence of such a discrepancy. This is an important revision to and update of the conclusions of earlier reports from the U.S. National Research Council and the Intergovernmental Panel on Climate Change.

Since those reports, errors have been identified and corrected in the satellite
data and other temperature observations. These data now show global average warming in the atmosphere similar to the warming observed at the surface and consistent with the results from climate models, although discrepancies remain to be resolved in the tropics. The recent evidence has increased confidence in our understanding of observed climatic changes and their causes.