Please use this identifier to cite or link to this item:
Authors: Anderson, B. T.* 
Knight, J. R.* 
Ringer, M. A.* 
Yoon, J. H.* 
Cherchi, A.* 
Title: Testing for the possible influence of unknown climate forcing upon global temperature increases from 1950 to 2000
Issue Date: 2012
Series/Report no.: /25(2012)
DOI: 10.1175/JCLI-D-11-00645.1
Keywords: climate forcing
temperature increase
Subject Classification01. Atmosphere::01.01. Atmosphere::01.01.02. Climate 
Abstract: Global-scale variations in the climate system over the last half of the twentieth century. including long-term increases in global-mean near-surface temperatures. are consistent with concurrent human-induced emissions of radiatively active gases and aerosols. However, such consistency does not preclude the possible influence of other forcing agents, including internal modes of climate variability or unaccounted for aerosol effects. To test whether other unknown forcing agents may have contributed to multidecadal increases in global-mean near-surface temperatures from 1950 to 2000. data pertaining to observed changes in global-scale sea surface temperatures and observed changes in radiatively active atmospheric constituents are incorporated into numerical global climate models. Results indicate that the radiative forcing needed to produce the observed long-term trends in sea surface temperatures-and global-mean near-surface temperatures-is provided predominantly by known changes in greenhouse gases and aerosols. Further, results indicate that less than 10% of the long-term historical increase in global-mean near-surface temperatures over the last half of the twentieth century could have been the result of internal climate variability. In addition. they indicate that less than 25% of the total radiative forcing needed to produce the observed long-term trend in global-mean near-surface temperatures could have been provided by changes in net radiative forcing from unknown sources (either positive or negative). These results, which are derived from simple energy balance requirements. emphasize the important role humans have played in modifying the global climate over the last half of the twentieth century.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
draft.pdfdraft submitted3.31 MBAdobe PDFView/Open
Show full item record

Page view(s)

Last Week
Last month
checked on Jul 19, 2018


checked on Jul 19, 2018

Google ScholarTM