Featured Research

from universities, journals, and other organizations

Decline in Sun's activity does not always mean that Earth becomes cooler, study shows

Date:
October 7, 2010
Source:
Imperial College London
Summary:
The Sun's activity has recently affected Earth's atmosphere and climate in unexpected ways, according to a new study. The research shows that a decline in the sun's activity does not always mean that Earth becomes cooler.

New research shows that a decline in the Sun's activity does not always mean that the Earth becomes cooler.
Credit: iStockphoto

The Sun's activity has recently affected Earth's atmosphere and climate in unexpected ways, according to a new study published in the journal Nature. The study, by researchers from Imperial College London and the University of Colorado, shows that a decline in the Sun's activity does not always mean that Earth becomes cooler.

Related Articles


It is well established that the Sun's activity waxes and wanes over an 11-year cycle and that as its activity wanes, the overall amount of radiation reaching Earth decreases. This latest study looked at the Sun's activity over the period 2004-2007, when it was in a declining part of its 11-year activity cycle.

Although the Sun's activity declined over this period, the new research shows that it may have actually caused Earth to become warmer. Contrary to expectations, the amount of energy reaching Earth at visible wavelengths increased rather than decreased as the Sun's activity declined, causing this warming effect.

Following this surprising finding, the researchers behind the study believe it is possible that the inverse is also true and that in periods when the Sun's activity increases, it tends to cool, rather than warm, Earth. This is based on what is already known about the relationship between the Sun's activity and its total energy output.

Overall solar activity has been increasing over the past century, so the researchers believe it is possible that during this period, the Sun has been contributing a small cooling effect, rather than a small warming effect as had previously been thought.

Professor Joanna Haigh, the lead author of the study who is Head of the Department of Physics and member of the Grantham Institute for Climate Change at Imperial College London, said: "These results are challenging what we thought we knew about the Sun's effect on our climate. However, they only show us a snapshot of the Sun's activity and its behaviour over the three years of our study could be an anomaly.

"We cannot jump to any conclusions based on what we have found during this comparatively short period and we need to carry out further studies to explore the Sun's activity, and the patterns that we have uncovered, on longer timescales. However, if further studies find the same pattern over a longer period of time, this could suggest that we may have overestimated the Sun's role in warming the planet, rather than underestimating it."

Professor Sir Brian Hoskins, the Director of the Grantham Institute for Climate Change at Imperial College London, added: "We know that the Earth's climate is affected both by human activity and by natural forces and today's study improves our understanding of how the Sun influences our climate. Studies like this are vital for helping us to create a clear picture of how our climate is changing and through this, to work out how we can best protect our planet."

The researchers used satellite data and computer modelling to analyse how the spectrum of radiation and the amount of energy from the Sun has been changing since 2004. Instruments on the SORCE satellite have been measuring the Sun's energy output at many different wavelengths. The researchers fed the data from SORCE into an existing computer model of Earth's atmosphere and compared their results with the results obtained using earlier, less comprehensive, data on the solar spectrum.


Story Source:

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


Journal Reference:

  1. Joanna D. Haigh, Ann R. Winning, Ralf Toumi, Jerald W. Harder. An influence of solar spectral variations on radiative forcing of climate. Nature, 2010; 467 (7316): 696 DOI: 10.1038/nature09426

Cite This Page:

Imperial College London. "Decline in Sun's activity does not always mean that Earth becomes cooler, study shows." ScienceDaily. ScienceDaily, 7 October 2010. <www.sciencedaily.com/releases/2010/10/101006141558.htm>.
Imperial College London. (2010, October 7). Decline in Sun's activity does not always mean that Earth becomes cooler, study shows. ScienceDaily. Retrieved November 20, 2014 from www.sciencedaily.com/releases/2010/10/101006141558.htm
Imperial College London. "Decline in Sun's activity does not always mean that Earth becomes cooler, study shows." ScienceDaily. www.sciencedaily.com/releases/2010/10/101006141558.htm (accessed November 20, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, November 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nations Pledge $9.3 Bn for Green Climate Fund

Nations Pledge $9.3 Bn for Green Climate Fund

AFP (Nov. 20, 2014) Nations meeting in Berlin pledge $9.3 billion (7.4 bn euros) for a climate fund to help poor countries cut emissions and prepare for global warming, just shy of a $10bn target. Duration: 00:46 Video provided by AFP
Powered by NewsLook.com
What's The Point Of Climate Conferences?

What's The Point Of Climate Conferences?

Newsy (Nov. 20, 2014) There's optimism about the U.N.'s climate conference in Paris next year, and if climate conferences past are anything to go off, that's notable. Video provided by Newsy
Powered by NewsLook.com
Mysterious Glow Worms Found in the Amazon

Mysterious Glow Worms Found in the Amazon

Buzz60 (Nov. 20, 2014) Wildlife photographer Jeff Cremer teamed up with entomologist Aaron Pomerantz and others to investigate a predatory glow worm found in the Amazon. Patrick Jones (@Patrick_E_Jones) explains. Video provided by Buzz60
Powered by NewsLook.com
N.Y. Snowfall Renews Climate Change Discussion

N.Y. Snowfall Renews Climate Change Discussion

Newsy (Nov. 20, 2014) Record snowfalls in New York are helping to reinforce new climate catchphrases. 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