Solar rhythm: The Sun's corona as imaged by NASA and the ESA's SOHO space observatory.
Credit: SOHO/NASA
PARIS: A solar radiation study is evidence that global warming over the past two decades cannot be blamed on the Sun, a theory espoused by climate-change sceptics.
British and Swiss researchers looked at data for radiation from the Sun, levels of which can cool or warm our planet's atmosphere. They factored in a cycle of solar radiation, which goes through peaks and troughs of activity over a period of about 11 years.
Writing in the British journal, the Proceedings of the Royal Society A, the team said that the Sun had been less active since 1985, even though global temperatures have continued to rise.
The study also puts to bed an idea that a decrease in the activity of the Sun's magnetic field – affecting the amount of galactic cosmic rays that reach Earth – could have recently altered weather patterns, causing warming.
Overwhelming consensus
"Over the past 20 years, all the trends in the Sun that could have had an influence on the Earth's climate have been in the opposite direction to that required to explain the observed rise in global mean temperatures," said the scientists.
The study is co-authored by physicists Mike Lockwood of Britain's Rutherford Appleton Laboratory and Claus Froehlich of the World Radiation Centre in Switzerland, who analysed over 100 years of solar data.
The overwhelming consensus among scientists is that human activity is to blame for the rise in global temperatures.
In its latest report, issued this year, the United Nation's Intergovernmental Panel on Climate Change (IPCC) said that this warming is already affecting the climate system. Since 1900, the mean global atmospheric temperature has risen by 0.8degC, and the sea level by 10 to 20 cm.
Levels of carbon dioxide, have risen by around a third since the Industrial Revolution and are now at their highest in 650,000 years. Eleven of the past 12 years rank among the dozen warmest years on record.
In the past few years, glaciers and snow and ice cover have fallen back sharply in alpine regions, the edges of the Greenland ice sheet and on the Antarctic peninsula have shrunk, Arctic summer sea ice has thinned and retreated and Siberian and Canadian permafrost have shown signs of thaw and fallback.
Sun in the clear over global warming
"Over the past 20 years, all the trends in the Sun that could have had an influence on the Earth's climate have been in the opposite direction to that required to explain the observed rise in global mean temperatures."
...Whatever ones views on global warming, I am staggered to read the above quote taken from the report.
As a non-scientific person I usually try to believe the results published by scientific research, but this is incredible to me. Surely the sun, a yellow star, bursting with much more power than many nuclear explosions, and the reason for life on earth,( combined with water on our planet and oxygen in our atmosphere) HAS to have some influence on Earth's climate!
I just cannot believe the above statement.
Of course the sun has
Of course the sun has influence on Earth's climate. The report doesn't deny that. All that it states is that the global warming trend we are witnessing is NOT caused by the sun, as some people have suggested.
sun effect on climate
To have life live for billions of years means the sun has been incredibly constant for long time periods. If the sun has changed output recently a large amount, that would indicate an unstable system, not one to be consistent with life in the long term. A long term is not thousands or hundreds of thousands, but millions of years. A one percent change in solar output would probably cancel all life on earth in less than 100 years.
Solar effects
This research is suspect....I have seen trend lines of solar luminosity only over more than the 20 year they are limiting themselves too and if you do a least squares regression on it ..the trend is up and to the right!!!! (which means an increase)... How can they say this and ingore the data on Mars and other planets also warming up???? this begs the answer....the solar output is having some effect they are not considering in thier research. ...perhaps the oceans have a lag time on aborbing the heat over a decade or so before the atmosphere heats?????....or is the research only looked at Luminosity or "visible light"...how about ultraviolet band of radiation changes???? Ultraviolet carries much more energy than visible light!!!.... did they look at that?........ This article and BS research sure is leaving out a lot....probally financied by the IPCC....!....and to who's funding benefit?...
Solar effects
In support of the above comment ....another approach...
There are equally striking "hockey stick" correlations to both cosmic and solar radiation. Google the name "Henrik Svensmark" to see 90,000 references to the guy you never heard of, the bona fide Danish climatologist/physicist who is the Al Gore of cloud-based, not carbon-based, global warming.
His Hypothesis is....Shamelessly simplified, the earth is constantly bathed in cosmic rays from outer space, which initiate cloud formation. The sun's solar winds peak over multiyear cycles; unfortunately peak levels significantly squelch incoming comic rays, which in turn slows reflective cloud formation, which in turn allows the earth to heat. We're in an unusually long solar wind activity spell right now, the worst in several hundred years. But if known cycles hold true - and they will - by 2020 the winds abate, the cosmic ray levels increase, increased reflective cloud cover appears, and the earth cools. Just like it always has.
Svensmark and other voices - ignored by the media as politically incorrect - can correlate sun spot radiation history precisely to cosmic ray levels, to cosmic-formed carbon 14 and oxygen 16-18 ratios in sea shells, to tree rings, to sediment definitions, to ice core revelations, all proven proxies for associated temperature swings. Not to put too fine a point on it, Al Gore simply can't do that.
And then, when the solar
And then, when the solar rays increase again, and the world cools because of the clouds, watch everybody pat Al Gore on the back and say,"Nice going, dude, we really did it. We saved the planet."
so true
Isnt your comment so true!.. the media is so Miotic.
Environmental Geology
DON'T BLAME IT ON SUN
I am convinced with the opinion of the authors that global warming over the past two decades cannot be blamed on the Sun. We all know that climate has undergone dramatic changes in the past also, from very warm equable conditions (Green house state) to very cold conditions with strong latitudinal temperature variations. Large scale changes in the global climate have been documented by paleontologists from the fossil record.
Paleocene - Eocene boundary interval has been noted to be an interval of a short lived warming event termed the Paleocene-Eocene Thermal Maximum as PETM. Ocean water warmed up considerably at the high latitudinal and equatorial regions during this interval possibly as a consequence of methane oxidation which increased the level of carbon dioxide in the atmosphere.
The Permian age is one of the most interesting climatic intervals because of the variety of climatically significant rocks.
Thus we see that earlier too there was climatic change from cool to warm factors may be different. Though sun plays an important role in climate changes but there are other factors too which influence climate change like green house gases. Carbon dioxide has now increased 31 % since 1750 to a higher level than any time in the last 420,000 years. Methane concentration in the atmosphere has increased 150% since 1750. Since 1950s the lower part of the atmosphere has warmed at about 0.1 degree C per decade. In parts of Africa and Asia the frequency and intensity of droughts and floods have been observed to increase in recent decades. The observed changes are attributed almost entirely to increasing concentrations of green house gases caused by human activities. So Don't "BLAME IT ON SUN".
Dr. Nitish Priyadarshi
Geologist
Ranchi, India
Email: rch_nitishp@sancharnet.in
nitish.priyadarshi@gmail.com
Some science
So, Dr Priyadarshi, CO2 has risen by 31%. OK. But we know that CO2 concentrations, as measured in ppmv, have to literally DOUBLE in order to force a global temperature rise of about 0.4 degrees C. And you say CO2 has risen a mere 31% in the last 250 years?
And tell me, what do you think the 'correct' climate should be? What is the ideal state? And where were you in the early 1970s, when many scientists were scaring us all with warnings of catastrophic global cooling? Funny how both 'cooling' and 'warming' lead to more intense weather (if one looks at comments from certain scientists in both the early 70s and now).
I don't 'blame' anything on the sun. Climate change has always happened, and always will happen. We need to live with it, and adapt to it.
I would have thought one
I would have thought one hundred years worth of Solar data would be equal to looking at a micro second of a persons life and coming to the conclusion they have cancer because you just saw them pick their nose.