14 DAY TRIAL // Researchers from Imperial College London and the University of Colorado, carried out a study that suggests that when the Sun's activity declines, the Earth actually become warmer and not cooler, as you would normally expect.
The activity of the Sun increases and decrease during an 11-year cycle, and when the solar activity wanes, the total amount of radiation that reaches the Earth declines.
This new study analyzed the Sun's activity from 2004 to 2007, time during which it was in a descending part of its 11-year activity cycle, and this is how the researchers found out that, as the activity waned, the Earth actually became warmer.
The amount of energy that reached the Earth at visible wavelengths increased instead of declining, and this is what caused the warming effect.
For this research, scientists used satellite data and computer modeling to find out how the spectrum of radiation and the overall amount of energy has changed since 2004.
The Sun's energy output has been measured at several different wavelengths, thanks to the instruments from the SORCE satellite.
The data was then transferred to an existing computer model of the planet's atmosphere, and the results were compared to those obtained from data on the solar spectrum.
Now, scientists believe that it is plausible that when the Sun's activity increases, it tends to cool the Earth, based on what we already know about the relationship between the activity of the Sun at its total energy output.
Professor Joanna Haigh, the lead author of the study and Head of the Department of Physics and member of the Grantham Institute for Climate Change at Imperial College London, said that “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 behavior 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, agrees and adds 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.”
This new study was published yesterday in the journal Nature.