Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Greenhouse gases likely drove near-record U.S. warmth in 2006

29.08.2007
Greenhouse gases likely accounted for over half of the widespread warmth across the continental United States in 2006, according to a new study that will be published 5 September in Geophysical Research Letters, a publication of the American Geophysical Union.

Last year's average temperature was the second highest since recordkeeping began in 1895. The team found that it was very unlikely that the 2006 El Nino played any role, though other natural factors likely contributed to the near-record warmth.

When average annual temperature in the United States broke records in 1998, a powerful El Nino was affecting climate around the globe.

Scientists widely attributed the unusual warmth in the United States to the influence of the ongoing El Nino. El Nino is a warming of the surface of the east tropical Pacific Ocean.

The research team, led by Martin Hoerling at the National Oceanic And Atmospheric Administration (NOAA) Earth System Research Lab in Boulder, Colorado, also found that greenhouse gas increases in Earth's atmosphere enhanced the probability of U.S. temperatures breaking a record in 2006 by approximately 15-fold compared to pre-industrial times. The authors also estimate that there is a 16 percent chance that 2007 will bring record-breaking warmth.

"We wanted to find out whether it was pure coincidence that the two warmest years on record both coincided with El Nino events," Hoerling said. "We decided to quantify the impact of El Nino and compare it to the human influence on temperatures through greenhouse gases."

Preliminary data available in January 2006 led NOAA to place that year as the warmest on record. In May 2007, NOAA revised the 2006 ranking to second warmest after updated statistics showed the year was .08 F cooler than 1998. The annual average temperature in 2006 was 2.1 F above the 20th Century average and marked the ninth consecutive year of above-normal U.S. temperatures. Each of the contiguous 48 states reported above-normal annual temperatures, and for the majority of states, 2006 ranked among the 10 hottest years since 1895.

Using data from 10 past El Nino events observed since 1965, the authors examined the impact of El Nino on average annual U.S. surface temperatures. They found a slight cooling across the country. To overcome uncertainties inherent in the data analysis, the team also studied the El Nino influence using two atmospheric climate models.

The scientists conducted two sets of 50-year simulations of U.S.
climate, with and without the influence of El Nino sea-surface warming.
They again found a slight cooling across the nation when El Nino was present.
To assess the role of greenhouse gases in the 2006 warmth, the researchers analyzed 42 simulations of Earth's climate from 18 climate models provided for the latest assessment by the Intergovernmental Panel on Climate Change (IPCC). The models included greenhouse gas emissions and airborne particles in Earth's atmosphere since the late 19th century and computed their influence on average temperatures through 2006. The results of the analysis showed that greenhouse gases produced warmth over the entire United States in the model projections, much like the warming pattern that was observed last year across the country.

For a final check, the scientists compared the observed 2006 pattern of abnormal surface temperatures to the projected effects of greenhouse-gas warming and El Nino temperature responses. The U.S. temperature pattern of widespread warming was completely inconsistent with the pattern expected from El Nino, but it closely matched the expected effects of greenhouse warming.

"That attribution was not confirmed at the time," says Hoerling.
"Now we have the capability, on the spatial scale of the United States, to better distinguish natural climate variations from climate changes caused by humans."

The research was supported by NOAA's office of Global Programs.

Notes for Journalists
Journalists and public information officers of educational and scientific institutions (only) can receive a PDF copy of this paper (a pre-publication copy subject to final editing of any article listed as "in press") by sending a message to Jonathan Lifland at jlifland@agu.org.

Please provide your name, the name of your publication, and your phone number.

Title:
"Explaining the record US warmth of 2006"
Authors:
Martin Hoerling, Jon Eischeid, Xiaowei Quan, Taiyi Xu, National Oceanic and Atmospheric Administration Earth System Research Laboratory, Boulder, Colorado, USA.
Citation:
Hoerling, M., et al. (2007), Explaining the record US warmth of 2006, Geophys. Res. Lett., 34, In Press, doi:10.1029/2006GL0030643.
Contact information for authors:
* Martin Hoerling, +1 303 497-6165 or martin.hoerling@noaa.gov
* Jon Eischeid, +1 303 497-5970 or jon.k.eischeid@noaa.gov
* Quan Xiaowei, +l 303 492-5961 or quan.xiaowei@noaa.gov
* Taiyi Xu, +1 303 497-6343 or taiyi.xu@noaa.gov

Jonathan Lifland | AGU
Further information:
http://www.agu.org

More articles from Earth Sciences:

nachricht The pace at which the world’s permafrost soils are warming
16.01.2019 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Using satellites to measure rates of ice mass loss in glaciers
16.01.2019 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

Im Focus: Mission completed – EU partners successfully test new technologies for space robots in Morocco

Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.

Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...

Im Focus: Programming light on a chip

Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Velcro for human cells

16.01.2019 | Life Sciences

Kiel physicists discover new effect in the interaction of plasmas with solids

16.01.2019 | Physics and Astronomy

The pace at which the world’s permafrost soils are warming

16.01.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>