Featured Research

from universities, journals, and other organizations

Sun Could Cause 15% To 20% Of Effects Of Climate Change, Researcher Says

Date:
July 18, 2008
Source:
Plataforma SINC
Summary:
Global warming is mainly caused by greenhouse gas emissions resulting from human activities; however, current climatic variations may be affected "around 15% or 20%" by solar activity," according to one researcher. In the past, the sun was the main external agent affecting climate change on Earth, together with the effects of volcanic explosions and internal factors such as ocean currents. The role of the sun in the Earth's climatic variations "is not inconsiderable," but the researcher pointed out that over the last 40 years solar activity has not increased, and has in fact remained constant or even diminished, which is why it is difficult to attribute a significant global warming effect to it.

In the past, the sun was the main external agent affecting climate change on Earth.
Credit: iStockphoto

Global warming is mainly caused by greenhouse gas emissions resulting from human activities; however, current climatic variations may be affected “around 15% or 20%” by solar activity, according to Manuel Vázquez, a researcher from the Canary Islands’ Astrophysics Institute (IAC) who spoke at the Sun and Climate Change conference, organised as part of the El Escorial summer courses by Madrid's Complutense University.

In the past, the sun was the main external agent affecting climate change on Earth, together with the effects of volcanic explosions and internal factors such as ocean currents. “If man had never started burning fossil fuels, the sun might have been the only agent regulating the climate until the next glaciation. However, back in the 19th century we started an experiment which we are now beginning to suffer the consequences of”, explained the astrophysicist Manuel Vázquez to SINC.

During his conference at the El Escorial summer courses, the researcher pointed out that the possibility of a relationship existing between the sun and climate on Earth is quite “plausible”, since it is the main source of energy of everything that occurs within the Earth's atmosphere, “but empirical tests need to be found that show that such a correlation exists, and over what timescale.” Trying to find a connection over billions of years, where changes in the sun's interior have an effect, is not the same thing as looking for variations over just a few thousand years, “where we think only fluctuations in the magnetic energy of stars can play any type of role” the researcher commented.

Vázquez explained that this type of energy is produced on surface structures of the sun linked to the magnetic field. The most well known are sunspots which have variation cycles of every 11 years and there are others that fluctuate over a longer timescale. The researcher added, “there is evidence to show that after the last glaciation, over the last 10,000 years and before industrial activity commenced, fluctuations in the sun's magnetic energy regulated most of the Earth's climate variations.”

As examples of this correlation, Vázquez said that there is “certain evidence” of a relatively warm period in the Middle Ages, “around about the 11th century” which coincided with a period of high solar activity; on the other hand, in the second half of the 17th century, there was a decrease in solar activity which coincided with a relatively cold period on Earth, “although it appears the effects of the sun might affect certain areas of the planet more than others.”

In any case, based on statistics, “it is necessary to find a mechanism that explains that correlation, which is where the main battlefield of this research lies,” Vázquez acknowledged, because, although over the last 30 years it has been possible to measure the variation in the amount of energy that comes from the sun, with an 11 year cycle differences between maximums and minimums are so small that they would appear to have no direct effect on climate. To explain past variations, scientists believe there must be some type of mechanism that amplifies the solar signal, such as changes in the sun's ultraviolet radiation, in the flow of cosmic rays that reach the Earth or in the average electricity of the Earth's atmosphere.

The IAC astrophysicist explained that the sun's influence in climatic variations over the last few thousand years is clear: “When there is more solar activity, there is more radiation from the sun, and any of the above-mentioned processes will intensify, causing warming.” All these signals are very evident in the upper layers of the atmosphere, as shown by data collected in recent years, “but the major problem is transferring such a clear correlation of solar activity observed in the upper layers of the atmosphere to the lower layers, where we measure climate.”

The role of the sun in the Earth’s climatic variations “is not inconsiderable,” but Vázquez pointed out that over the last 40 years solar activity has not increased, and has in fact remained constant or even diminished, which is why it is difficult to attribute a significant global warming effect to it, “the cause of which needs to be looked for in human activities.”


Story Source:

The above story is based on materials provided by Plataforma SINC. Note: Materials may be edited for content and length.


Cite This Page:

Plataforma SINC. "Sun Could Cause 15% To 20% Of Effects Of Climate Change, Researcher Says." ScienceDaily. ScienceDaily, 18 July 2008. <www.sciencedaily.com/releases/2008/07/080717224333.htm>.
Plataforma SINC. (2008, July 18). Sun Could Cause 15% To 20% Of Effects Of Climate Change, Researcher Says. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2008/07/080717224333.htm
Plataforma SINC. "Sun Could Cause 15% To 20% Of Effects Of Climate Change, Researcher Says." ScienceDaily. www.sciencedaily.com/releases/2008/07/080717224333.htm (accessed August 22, 2014).

Share This




More Space & Time News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Newsy (Aug. 21, 2014) — Russian cosmonauts say they've found evidence of sea plankton on the International Space Station's windows. NASA is a little more skeptical. Video provided by Newsy
Powered by NewsLook.com
Space to Ground: Hello Georges

Space to Ground: Hello Georges

NASA (Aug. 18, 2014) — Europe's ATV-5 delivers new science and the crew tests smart SPHERES. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
Tiny Satellites, Like The One Tossed From ISS, On The Rise

Tiny Satellites, Like The One Tossed From ISS, On The Rise

Newsy (Aug. 18, 2014) — The Chasqui I, hand-delivered into orbit by a Russian cosmonaut, is one of hundreds of small satellites set to go up in the next few years. Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, August 15, 2014

This Week @ NASA, August 15, 2014

NASA (Aug. 15, 2014) — Carbon Observatory’s First Data, ATV-5 Delivers Cargo, Cygnus Departs Station and more... Video provided by NASA
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