Scientists advance in detection and attribution of climate change

Feb 21, 2005

Access to the next generation of climate change experiments has helped scientists obtain more comprehensive estimates of the expected “signal” of human influences on climate.
Improved knowledge of this signal, and a better understanding of uncertainties in temperature observations, have helped to advance “detection and attribution” (“D&A”) studies, which assist in unraveling the causes of recent climate change.

"The climate system is telling us an internally consistent story,” said Ben Santer, an atmospheric scientist at Lawrence Livermore National Laboratory. “We’ve observed warming of the Earth’s land surface and oceans, cooling of the stratosphere, an increase in height of the tropopause, retreat of Arctic sea ice, and widespread melting of glaciers. These changes are difficult to reconcile with purely natural causes.”

Santer reports today on the identification of human influences on recent atmospheric temperature changes during a climate change session at the American Association for the Advancement of Science annual meeting in Washington, D.C. The title of the panel is “Detection and Attribution – Methods and Results – of Climate Trends in Temperature Sensors, Species and Glaciers.”

Santer works in Livermore’s Program for Climate Model Diagnosis and Intercomparison (PCMDI), and has compared new computer model simulations performed at several different research institutes to observational records of recent temperature change.

The climate models analyzed by Santer and colleagues included changes in both manmade forcings (well-mixed greenhouse gases, tropospheric and stratospheric ozone, and the scattering effects of sulfate aerosols) and natural external forcings (solar irradiance and volcanic aerosols).

Earlier Livermore research has determined that human-induced changes in ozone and well-mixed greenhouse gases are the primary drivers of recent changes in the height of the tropopause – the boundary between the turbulently mixed troposphere and the more stable stratosphere. Research with new model and observational datasets strengthens these findings.

“With new model experiments coming online, we’re now in a much better position to estimate how climate changed in response to combined human and natural influences,” Santer said.

PCMDI is archiving data from recently completed experiments performed with coupled ocean-atmosphere general circulation models that took place at more than a dozen research institutes worldwide. “This data will be a very valuable resource for the Laboratory and the whole community,” Santer said. “We are sitting on a real scientific goldmine.”

Founded in 1952, Lawrence Livermore National Laboratory has a mission to ensure national security and to apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy's National Nuclear Security Administration.

Source: Lawrence Livermore National Laboratory

Explore further: Easter morning delivery for space station

add to favorites email to friend print save as pdf

Related Stories

Science academies explain global warming reality

Feb 27, 2014

(AP)—Man-made global warming is worsening and will disrupt both the natural world and human society, warns a joint report of two of the world's leading scientific organizations.

Volcanoes helped offset man-made warming: study

Feb 23, 2014

Volcanoes spewing Sun-reflecting particles into the atmosphere have partly offset the effects of Man's carbon emissions over a 15-year period that has become a global-warming battleground, researchers said Sunday.

A human-caused climate change signal emerges from the noise

Nov 29, 2012

By comparing simulations from 20 different computer models to satellite observations, Lawrence Livermore climate scientists and colleagues from 16 other organizations have found that tropospheric and stratospheric temperature ...

Today's severe drought, tomorrow's normal

Dec 06, 2011

(PhysOrg.com) -- While the worst drought since the Dust Bowl of the 1930s grips Oklahoma and Texas, scientists are warning that what we consider severe drought conditions in North America today may be normal ...

Separating signal and noise in climate warming

Nov 17, 2011

(PhysOrg.com) -- In order to separate human-caused global warming from the "noise" of purely natural climate fluctuations, temperature records must be at least 17 years long, according to climate scientists.

Recommended for you

Testing immune cells on the International Space Station

6 hours ago

The human body is fine-tuned to Earth's gravity. A team headed by Professor Oliver Ullrich from the University of Zurich's Institute of Anatomy is now conducting an experiment on the International Space Station ...

Easter morning delivery for space station

11 hours ago

Space station astronauts got a special Easter treat: a cargo ship full of supplies. The shipment arrived Sunday morning via the SpaceX company's Dragon cargo capsule.

NASA's space station Robonaut finally getting legs

Apr 19, 2014

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Quest for extraterrestrial life not over, experts say

Apr 18, 2014

The discovery of an Earth-sized planet in the "habitable" zone of a distant star, though exciting, is still a long way from pointing to the existence of extraterrestrial life, experts said Friday. ...

User comments : 0

More news stories

Easter morning delivery for space station

Space station astronauts got a special Easter treat: a cargo ship full of supplies. The shipment arrived Sunday morning via the SpaceX company's Dragon cargo capsule.

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.