Featured Research

from universities, journals, and other organizations

Scientists Refute Argument Of Climate Skeptics

Date:
January 10, 2009
Source:
Helmholtz Association of German Research Centres
Summary:
Scientists have investigated the frequency of warmer than average years between 1880 and 2006 for the first time. The result: the observed increase of warm years after 1990 is not a statistical accident.

Global monthly and annual mean near-surface temperatures between 1850 and June 2008 in relation to the average temperature in the period between 1961 and 1990, based on the air temperature measurement data of weather stations.
Credit: HadCRUT

Scientists at the GKSS Research Centre of Geesthacht and the University of Bern have investigated the frequency of warmer than average years between 1880 and 2006 for the first time. The result: the observed increase of warm years after 1990 is not a statistical accident.

Between 1880 and 2006 the average global annual temperature was about 15°C. However, in the years after 1990 the frequency of years when this average value was exceeded increased.

The GKSS Research Centre asks: is it an accident that the warmest 13 years were observed after 1990, or does this increased frequency indicate an external influence?

Calculating the likelihood

With the help of the so called "Monte-Carlo-Simulation“ the coastal researchers Dr. Eduardo Zorita and Professor Hans von Storch at the GKSS-Research Centre together with Professor Thomas Stocker from the University of Bern estimated that it is extremely unlikely that the frequency of warm record years after 1990 could be an accident and concluded that it is rather influenced by a external driver.

The fact that the 13 warmest years since 1880 could have occurred by accident after 1990 corresponds to a likelihood of no more than 1:10,000.

These likelihood can be illustrated by using the game of chance "heads or tails": the likelihood is the same as flipping a coin and getting 14 heads in a row.

Climate is more complicated than a game

"In order to understand and statistically analyse the climate system and its interaction between the ocean, land, atmosphere and human activity, the comparison with a game of chance is no longer sufficient.

The natural sequence of warm and cold years no longer functions according to the simple principle of 'zero or one,'" explains the GKSS scientist Dr. Eduardo Zorita about the challenges of his calculations, because the climate system possesses some inertia.

An example: After a warm year milder years tend to follow, since the oceans have stored some heat. This natural inertia must also be included in the calculations.

"Our study is pure statistical nature and can not attribute the increase of warm years to individual factors, but is in full agreement with the results of the IPCC that the increased emission of greenhouse gases is mainly responsible for the most recent global warming“, says Zorita in summary.


Story Source:

The above story is based on materials provided by Helmholtz Association of German Research Centres. Note: Materials may be edited for content and length.


Journal Reference:

  1. Zorita et al. How unusual is the recent series of warm years? Geophysical Research Letters, 2008; 35 (24): L24706 DOI: 10.1029/2008GL036228

Cite This Page:

Helmholtz Association of German Research Centres. "Scientists Refute Argument Of Climate Skeptics." ScienceDaily. ScienceDaily, 10 January 2009. <www.sciencedaily.com/releases/2009/01/090109115047.htm>.
Helmholtz Association of German Research Centres. (2009, January 10). Scientists Refute Argument Of Climate Skeptics. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2009/01/090109115047.htm
Helmholtz Association of German Research Centres. "Scientists Refute Argument Of Climate Skeptics." ScienceDaily. www.sciencedaily.com/releases/2009/01/090109115047.htm (accessed April 24, 2014).

Share This



More Earth & Climate News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

UN Joint Mission Starts Removing Landmines in Cyprus

UN Joint Mission Starts Removing Landmines in Cyprus

AFP (Apr. 23, 2014) — The UN mission in Cyprus (UNFICYP) led a mine clearance demonstration on Wednesday in the UN-controlled buffer zone where demining operations are being conducted near the Cypriot village of Mammari. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
California Drought Is Good News for Gold Prospectors

California Drought Is Good News for Gold Prospectors

AFP (Apr. 22, 2014) — For months California has suffered from a historic drought. The lack of water is worrying for farmers and ranchers, but for gold diggers it’s a stroke of good fortune. With water levels low, normally inaccessible areas are exposed. Duration: 01:57 Video provided by AFP
Powered by NewsLook.com
Raw: MN Lakes Still Frozen Before Fishing Opener

Raw: MN Lakes Still Frozen Before Fishing Opener

AP (Apr. 22, 2014) — With only three weeks until Minnesota's fishing opener, many are wondering if the ice will be gone. Some of the Northland lakes are still covered by up to three feet of ice, causing concern that just like last year, the lakes won't be ready. (April 22) Video provided by AP
Powered by NewsLook.com
Scientists Warn Of Likely El Niño Event This Year

Scientists Warn Of Likely El Niño Event This Year

Newsy (Apr. 22, 2014) — With Pacific ocean water already showing signs of warming, the NOAA says there's about a 66 percent chance the event will begin before November. 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:
from the past week

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