Featured Research

from universities, journals, and other organizations

Understanding Earth's climate prior to the industrial era

Date:
February 3, 2013
Source:
Swiss Federal Institute for Forest, Snow and Landscape Research WSL
Summary:
Climate signals locked in the layers of glacial ice, preserved in the annual growth rings of trees, or fingerprinted in other so-called proxy archives such as lake sediments, speleothems, and corals allow researchers to quantify climate variation prior to instrumental measurements. An international research team has now investigated hundreds of these proxy records from across the globe and compared them with both simulations of the Earth’s climate and instrumental measurements of temperature and precipitation.

Section of annual tree-rings of Scotch pine (Pinus sylvestris) from Valais (Sitzerland). The tree-rings consist of thick- and thin-walled cells and can be wide or narrow depending on the weather, species, tree age and site.
Credit: WSL

Climate signals locked in the layers of glacial ice, preserved in the annual growth rings of trees, or fingerprinted in other so-called proxy archives such as lake sediments, speleothems, and corals allow researchers to quantify climate variation prior to instrumental measurements. An international research team has now investigated hundreds of these proxy records from across the globe and compared them with both simulations of the Earth’s climate and instrumental measurements of temperature and precipitation.

Related Articles


Climate extremes not always recognized in proxy archives

The scientists learned that these proxy archives provide an incomplete record of climate variation. The annual width or density of tree-rings is not only influenced by temperature while the ring is developing, but also from the climate of the past years and other factors like tree age. This makes it difficult to extract pure temperature signals from these natural archives. Importantly, the researchers found out that proxy data underestimate climate fluctuations of, for example, air temperature over the land surface where large year-to-year variability is common. In contrast, long-term trends in precipitation tend to be exaggerated by the proxy records. These findings indicate that the proxy data often result in a “blurry picture” of climate variation. The researchers were able to conclude from their work that short-term extreme climate events, such as individual years with hot summers, are not well captured by the proxy reconstructions.

Temperature trends can’t be used to understand rainfall

Investigations on the individual factors and processes fingerprinted in tree-ring, ice-core and speleothem records are needed to develop a more accurate history and understanding of the climate system. The authors explicitly warn that proxy records that predominately reflect temperature variation should not be used to make conclusions about precipitation change and vice-versa. "Our results point to uncertainties in the global climate system that were previously not recognized," says David Frank, co-author of this study. He continues: "This might be surprising because we know more about the Earth’s climate now than say 20-years ago. Part of the scientific process is to confront and uncover these unknowns while developing climate reconstructions." There is still a lot of basic research needed to reduce uncertainties about how the Earth’s climate system operated prior to the industrial era and how it may operate in the future.


Story Source:

The above story is based on materials provided by Swiss Federal Institute for Forest, Snow and Landscape Research WSL. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jörg Franke, David Frank, Christoph C. Raible, Jan Esper & Stefan Brönnimann. Spectral biases in tree-ring climate proxies. Nature Climate Change, 2013 DOI: 10.1038/nclimate1816

Cite This Page:

Swiss Federal Institute for Forest, Snow and Landscape Research WSL. "Understanding Earth's climate prior to the industrial era." ScienceDaily. ScienceDaily, 3 February 2013. <www.sciencedaily.com/releases/2013/02/130203145513.htm>.
Swiss Federal Institute for Forest, Snow and Landscape Research WSL. (2013, February 3). Understanding Earth's climate prior to the industrial era. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2013/02/130203145513.htm
Swiss Federal Institute for Forest, Snow and Landscape Research WSL. "Understanding Earth's climate prior to the industrial era." ScienceDaily. www.sciencedaily.com/releases/2013/02/130203145513.htm (accessed October 26, 2014).

Share This



More Earth & Climate News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) — EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) — Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) — A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) — Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins