[Jerome]

http://thinkprogress.org/wp-content/....pdf?mobile=nc

Reconciling anthropogenic climate change with
observed temperature 1998–2008

Robert K. Kaufmanna,1, Heikki Kauppib, Michael L. Manna, and James H. Stockc

aDepartment of Geography and Environment, Center for Energy and Environmental Studies, Boston University, 675 Commonwealth Avenue (Room 457),
Boston, MA 02215; bDepartment of Economics, University of Turku, FI-20014, Turku, Finland; and cDepartment of Economics,
Harvard University, 1805 Cambridge Street, Cambridge, MA 02138

Edited by Robert E. Dickinson, University of Texas at Austin, Austin, TX, and approved June 2, 2011 (received for review February 16, 2011)


Given the widely noted increase in the warming effects of rising
greenhouse gas concentrations, it has been unclear why global
surface temperatures did not rise between 1998 and 2008. We find
that this hiatus in warming coincides with a period of little increase
in the sum of anthropogenic and natural forcings. Declining solar
insolation as part of a normal eleven-year cycle, and a cyclical
change from an El Nino to a La Nina dominate our measure of
anthropogenic effects because rapid growth in short-lived sulfur
emissions partially offsets rising greenhouse gas concentrations.
As such, we find that recent global temperature records are consistent
with the existing understanding of the relationship among
global surface temperature, internal variability, and radiative
forcing, which includes anthropogenic factors with well known
warming and cooling effects.