Office of
Biological and Environmental Research Weekly Report
April 27,
2009
Is the Climate Warming
or Cooling? The debate surrounding climate change and
concerns for global warming are complicated by publications, websites, and
blogs that often cite decade-long climate trends, e.g., from 1998-2008, in
which the earth’s average temperature dropped slightly as evidence that the
global climate has stopped warming and begun to cool. In a forthcoming paper accepted for
publication in Geophysical Review Letters, David R. Easterling of the National Climatic Data Center and
Michael Wehner of the Lawrence Berkeley National Laboratory note that due to
natural climate variability it is likely to have periods as long as a decade or
two of “cooling” superimposed on the longer-term warming trend. The authors studied the occurrence of
decade-long trends in globally averaged surface air temperature using observed
climate data from 1901-2008 and the CMIP3 archive of climate model simulations
of the 20th century and found short periods of global cooling. Similarly, computer simulations of 21st
century climate showed that negative decadal trends are possible although the
likelihood of such occurrences decreases into the future. Easterling and Wehner conclude that selectively
analyzing climate records to highlight short periods of either global cooling
or exaggerated warming can be misleading in the context of the longer,
sustained warming caused by human induced emissions of greenhouse gases.
Reference: Easterling, D.R and M.F. Wehner, Is the climate warming or
cooling? Geophysical Review Letters doi:10.1029/2009GL037810, in press.
(accepted 30 March 2009)
Media Interest: Yes
Contact: Anjuli Bamzai, SC-23.1, (301) 903-0294
PNNL Scientist
Media Interest: No
Contact:
Robert
T. Anderson, SC 23.1, (301) 903-5549
Predicting
Biological Behaviors.
The cover article for the March 2009 issue of The Scientist highlighted
advances made by three DOE scientists developing systems biology approaches to
computationally simulate responses of microbes to changes in their
environment. Dr. Nitin Baliga (Institute
for Systems Biology) and his collaborators developed a computer model that
could predict molecular level responses of a free-living cell to genetic and
environmental changes. Remarkably, the
model was able to predict responses to changes that were different from the experimental
data used to construct the model. The
key to these insights is the normal interconnectedness of biological systems,
for example changes in temperature affect solubility. The ability to link and predict novel
biological responses represents an important step toward the ultimate goal of
an in silico model of cell behavior. While the investigators focused on
microbial systems involved in environmental processes of interest to DOE, the
methodology has broad applications to all biological systems and is a major
step forward in the burgeoning field of systems biology.
Media
Interest: No
Contact:
Arthur
Katz (SC-23.1, 3-4932) and Susan Gregurick (SC-23.1, 3-7672)
Human Versus Natural Causes of the mid-1970s Climate
Anomaly. Observations indicate there was a significant
shift in the mid-1970s from cooler to warmer tropical Pacific sea surface
temperatures (SSTs), part of a pattern of basin-wide SST anomalies with impacts
that extended globally. The cause of these
SST anomalies has been a topic of scientific debate in the climate research
community. In a recent paper, scientists
at the National Center for Atmospheric Research and the Program for Climate
Model Diagnosis and Intercomparison at Lawrence Livermore National Laboratory
analyzed observations and climate model simulations showing that the 1970s
climate shift in the Pacific was a combination of warming due to human-produced
greenhouse gases superimposed on what was likely an internally-generated
natural decadal fluctuation of the Pacific climate system. Determining the relative roles of human
influence versus naturally-occurring internal variability is important for
understanding observed climate fluctuations and for the new field of decadal
climate prediction. This new field will
attempt to estimate regional climate anomalies over the next several decades
with contributions from both inherent climate variability and external forcing
from human activities.
Reference: Meehl, G. A., A. Hu, and B.D. Santer,
2009: The mid-1970s climate shift in the
Pacific and the relative roles of forced versus inherent decadal variability, J. Climate, 22, 780--792.
Contact: Anjuli Bamzai,
SC-23.1, (301) 903-0294
Lucy
Shapiro to receive Gairdner International Award. Lucy Shapiro, director of the
Media Interest: No.
Contact: Daniel Drell, SC-23.2,
(301) 903-4742
Ant Symbionts May Provide New Approaches to
Biofuels Synthesis. Leaf-cutting ants are well known
“agriculturalists,” cultivating fungus gardens capable of efficiently breaking
down lignocellulosic plant material and converting it to food for ant
colonies. Cameron Currie, a
Media Interest:
No
Contact: Joseph Graber, SC-23.2,
(301) 903-1239