# Presentation: 372778

## Presented by Dr. Thomas R. Karl
NOAA – Director, National Climatic Data Center
Chief Editor, CCSP Synthesis and Assessment Product 1.1

**NOAA – Director, National Climatic Data Center**
**Chief Editor, CCSP Synthesis and Assessment Product 1.1**

**U.S. Climate Change Science Program****(CCSP)**

***Temperature Trends in the Lower Atmosphere – ***
***Steps for Understanding and Reconciling Differences.******  ***
**Karl, T.R., Hassol S.J., Miller, C.D., and Murray, W. L., editors, 2005. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research, Washington, DC.  In draft.**

## CCSP 1.1 - Temperature Trends in the Lower AtmosphereOutline

***Overview of CCSP Product 1.1 ***
***Milestones 2002 – Current***
***Report Organization:  Key Questions Addressed***
***What’s new since NRC 2000 & IPCC 2001 Assessments***
***Selected Issues***

## Temperature Trends in the Lower Atmosphere  Overview of CCSP Product 1.1

**Objective - An understanding of:**
- Temperature changes in the atmosphere
- Differences in these changes at various levels in the atmosphere
- The causes of these changes & differences
**Available Products & Methods:**
- New surface, satellite, radiosonde data
- New model simulations of the 20th century climate
- Comparisons of models & observed data

*Layers of the Atmosphere of Primary Interest in CCSP 1.1*

## Temperature Trends in the Lower Atmosphere  Milestones 2002 – 2004

_**Milestones**__**	**__**	**__**	**__**	**__**	**__**	**__**        2002/2003**_
** ****CCSP Meeting ****	****	****	****	****	**** ****	****Dec 2002 **
-   White paper on Product 1.1 formally discussed by panel of experts
-   Addressed many areas including NRC (2000) & IPCC (2001) reports
-  Apparent disparity between surface & troposphere temperature trends
** ****CCSP Strategic Plan developed****	****	****	****	**** Jul 2003**
-  **NOAA Workshop – Asheville, NC****	****	****	****Oct 2003**** **
-  Reviewed science for troposphere temperature trends
_**Milestones**__**	**__**	**__**	**__**	**__**	**__**	**__**	**__**     2004**_
-  **Draft Product 1.1 Prospectus posted on CCSP web-page         Jul**
** ****Public comment period on Prospectus closed ****	****	****         Aug**
** ****Convening Lead/Lead Author Meetings (Chicago)   Aug, Oct, Dec**
** ****Exeter, UK meeting  ****	****	****	****	**** ****	****         Sep**
- Designed to complement US CCSP Synthesis Product Development Effort

## Temperature Trends in the Lower Atmosphere  Milestones 2005-2006

**Draft Synthesis Product submitted to NRC for scientific review – ****Jan 2005**
**NRC comments received – ****Apr 2005**
**2nd draft released for public comment –****Nov 2005**
**Public comments received – ****Dec 2005**
**Third draft submitted to CCSP principals for  final review – ****Feb 2006**
**Product accepted by CCSP principals and submitted to National Science and Technology Council (NSTC) for approval – ****March 2006**
**Synthesis Product approved by NSTC and disseminated – ****April 2006**

## Preface --- Editorial team

Executive Summary
		CLA: 	T. Wigley 	LAs:  	V. Ramaswamy,  J. Christy, J. Lanzante, C. Mears,  B. Santer, 			and C. Folland 

Chapter 1 --- Why do temperatures vary vertically (from the surface to the stratosphere) and what do we understand about why they might vary and change over time?
         	CLAs: 	V. Ramaswamy	LAs:  	J. Hurrell and J. Meehl 
Chapter 2 --- What kinds of atmospheric temperature variations can the current observing systems measure and what are their strengths and limitations, both spatially and temporally?
         	CLA: 	J. Christy	LAs: 	D. Seidel, S. Sherwood

**Executive Summary**
**	****	****CLA: ****	****T. Wigley ****	****LAs:  ****	****V. Ramaswamy,  J. Christy, J. Lanzante, C. Mears,  B. Santer, ****	****	****	****and C. Folland **
**Chapter 1**** --- *****Why do temperatures vary vertically (from the surface to the stratosphere) and what do we understand about why they might vary and change over time?***
**         ****	****CLAs: ****	****V. Ramaswamy****	****LAs:  ****	****J. Hurrell and J. Meehl **
**Chapter 2**** --- *****What kinds of atmospheric temperature variations can the current observing systems measure and what are their strengths and limitations, both spatially and temporally?***
**         ****	****CLA: ****	****J. Christy****	****LAs: ****	****D. Seidel, S. Sherwood**

**Temperature Trends in the Lower Atmosphere****  ***Report Organization:  Key Questions Addressed*

## Chapter 3 --- What do observations indicate about the changes of temperature in the atmosphere and at the surface since the advent of measuring temperatures vertically?
         	CLA:  	J. Lanzante	LAs:  	T. Peterson, F. Wentz and K. Vinnikov 
Chapter 4 --- What is our understanding of the contribution made by observational or methodological uncertainties to the previously reported vertical differences in temperature trends? 
          	CLA:  	C. Mears	LAs:  	C. Forest, R. Spencer, R. Vose, and R. Reynolds
Chapter 5 --- How well can the observed vertical temperature changes be reconciled with our understanding of the causes of these changes?
		CLA:	B. Santer         		LAs:  	J. Penner, and P. Thorne  
Chapter 6 --- What measures can be taken to improve the understanding of observed changes?  
		CLA	C. Folland
          	LAs:  	D. Parker, R. Reynolds, S. Sherwood, and P. Thorne
Statistical Appendix
		CLA:	T. Wigley
Glossary/Acronyms

**         ****	****CLA:  ****	****J. Lanzante****	****LAs:  ****	****T. Peterson, F. Wentz and K. Vinnikov **
**Chapter 4**** --- What is our understanding of the contribution made by observational or methodological uncertainties to the previously reported vertical differences in temperature trends? **
**          ****	****CLA:  ****	****C. Mears****	****LAs:  ****	****C. Forest, R. Spencer, R. Vose, and R. Reynolds**
**Chapter 5**** --- How well can the observed vertical temperature changes be reconciled with our understanding of the causes of these changes?**
**	****	****CLA:****	****B. Santer         ****	****	****LAs:  ****	****J. Penner, and P. Thorne  **
**Chapter 6**** --- What measures can be taken to improve the understanding of observed changes?  **
**	****	****CLA****	****C. Folland**
**          ****	****LAs:  ****	****D. Parker, R. Reynolds, S. Sherwood, and P. Thorne**
**Statistical Appendix**
**	****	****CLA:****	****T. Wigley**
**Glossary/Acronyms**

**Temperature Trends in the Lower Atmosphere****  ***Report Organization:  Key Questions Addressed (cont.)*

## What’s New since IPCC and NRC Assessments(Data sets and Models)

- What’s New since IPCC and NRC Assessments*(Data sets and Models)*

**New Sonde data sets (Free et. al. and Thorne et. al.)**

**New version (Mears & Wentz)**
**Corrected Data Set (Christy & Spencer)**

**   ****Addressed stratospheric influence in derivation of tropospheric temperature (Fu et. al.)**

**New data set (Vinnikov et. al.)**

**- 20 New model simulations with many ensemble numbers prepared for IPCC (2007)**

## Temperature Trends in the Lower Atmosphere

*Selected Issues*

## Slide 10

## Paralleled Climate Model Simulations of Zonal-Mean Atmospheric Temperature ChangeTotal linear change computed over January 1958 to December 1999

- PCM simulations of the vertical profile of temperature change due to various forcings, and the effect due to all forcings taken together (after Santer et al., 2000).

**Paralleled Climate Model Simulations of ****Zonal-Mean Atmospheric Temperature Change***Total linear change computed over January 1958 to December 1999*

## Total Global-Mean Temperature Changes

**Total Global-Mean Temperature Changes**

## Temperature Trends for 1979-2004 (oC/decade) by Latitude

**Temperature Trends for 1979-2004 (****o****C/decade) by Latitude**

## The Relationships Between Tropical Temperature Changes at Earth’s Surface and in Two Different Layers of the Troposphere

- (after Santer et al., 2005).

**Observations**

**Observations**

**Observations**

**Observations**

## Temperature Trends in the Lower Atmosphere

**For further information on **
**CCSP Synthesis and Assessment Product 1.1**
***http://www.climatescience.gov/***
**Report available for****45 day comment period**