New Climate Model
Reveals "Discernible Human Influence"
From: David A Gabel, ENN.com
The Lawrence Livermore
National Laboratory (LLNL) is a federally funded research and development
center located in Livermore, California. Their mission, in part, is to respond
with vision, quality, integrity, and technical excellence to scientific issues
of national importance.
One such issue, which is tough to dispute, is the
changing climate. The top-rate researchers at LLNL created a new climate model
by comparing 20 different computer models to satellite observations. They found
that tropospheric and stratospheric temperature changes are clearly related to
human activities.
Three different research
groups produced the satellite temperature data sets, relying on microwave
emissions of oxygen molecules. The raw data was processed in different ways by
the three groups, accounting for complex effects such as instrument
calibrations in different ways.
Together, their new
climate model simulations will form the scientific backbone for the upcoming
5th assessment of the Intergovernmental Panel on Climate Change (IPCC) in 2014.
The researchers found
that the lower stratosphere has been cooling over the past 33 years in response
to human-caused depletion of the ozone layer. They also found large-scale
warming of the lower troposphere, with the largest increases over the Arctic
and much lesser warming (if not cooling) over Antarctica.
The conclusion was
that the temperature increase in the lower troposphere was due to human-caused
increases in well-mixed greenhouse gases.
"It's very unlikely
that purely natural causes can explain these distinctive patterns of
temperature change," said Laboratory atmospheric scientist Benjamin
Santer, who is lead author of the paper. "No known mode of natural climate
variability can cause sustained, global-scale warming of the troposphere and
cooling of the lower stratosphere."
The LLNL study has been
published in the journal, Proceedings of the National Academy of Sciences.
Link to video showing
the LLNL climate model animation
