Posted on 10/07/2005 9:24:58 AM PDT by bikepacker67
Scientists at Armagh Observatory claim a unique weather record could show that the Sun has been the main contributor to global warming over the past two centuries.
I suspect that the greenhouse lobby have under-estimated the role of solar variability in climate change
Dr John Butler The weather observations, made almost daily since 1795, comprise the longest climate archive available for a single site in Ireland.
Dr John Butler, the astronomer in charge of the project, told BBC News Online: "We can see global warming taking place over the past two centuries that suggests that changes in the Sun are at least partially responsible."
The data will confuse some climate experts who argue that the influence of changes in the Sun on rising temperatures has already been studied, and discounted, as a major cause of global warming.
Longer is better
The observations at Armagh began in 1795, a few years after the observatory was founded. Temperature, pressure and, later, rainfall have been measured every day with the exception of a period around 1825.
In all that time, the Armagh meteorological instruments have been moved only about 20 metres.
The Armagh Observatory's weather archive spans two centuries
"What makes the data so useful is that the site of the observatory has not changed all that much in 200 years," said Dr Butler. "Other weather stations have been engulfed by towns and cities that make the long-term reliability of their data questionable."
When analysed, the data allow the average temperature at Armagh to be calculated to an accuracy of 0.1 deg C per decade. Eventually the entire data set will be placed on the internet.
"It's quite apparent from our data that global warming, of about a degree C, has been taking place for at least a hundred years," Dr Butler told BBC News Online.
Shorter is warmer
The researchers point out that the mean average temperature at Armagh seems to be related to the length of the Sun's activity cycle. This cycle is on average 11 years in duration but it can vary a few years either way.
"We have found that it gets cooler when the Sun's cycle is longer and that Armagh is warmer when the cycle is shorter," said Dr Butler.
Scientists cannot yet fully explain how natural variations in the Sun's brightness and activity may affect the Earth's climate. While the Sun is about 0.1% brighter during shorter cycles the effect is not enough to account for the observed warming trend.
"But the Sun's activity does affect the flux of cosmic rays, high-energy particles from deep space, that strike our atmosphere," said Dr Butler.
Consequently it has been suggested that because cosmic rays are the main source of ionisation in the Earth's atmosphere they may have an influence on cloud formation.
Average temperatures in Armagh appear to correlate with solar activity
In general, the more cosmic rays that reach the Earth, the more low cloud there is. However, a higher solar activity leads to lower cosmic ray flux and reduced low cloud. Low clouds cool the Earth by reflecting more solar radiation back into space, so a drop in the amount of low cloud contributes to global warming.
High cloud does the opposite and tends to warm the Earth by reflecting more of the Earth's infra-red radiation back to the ground.
It may be that changing cloud cover has caused global warming over the past century or so.
However, Dr Butler is cautious about this issue: "There is currently very little evidence for a low-altitude cloud reduction over the past century. But there is some evidence for a global increase in total cloud."
"I suspect that the greenhouse lobby have under-estimated the role of solar variability in climate change," he added. "However I am not in favour of polluting the atmosphere, for whatever reason."
I think I read somewhere that the entire solar system was warming up, not just earth.
IT'S BUSH'S FAULT!!
This is another peice of the puzzle but its not sufficient yet. The eventual theory will need to explain why temperatures decreased through the 1800's and why global warming stopped between 1945 and 1976.
There have been several articles posted here on FR regarding a warming trend on Mars. I'll see if I can find a link or two.
Read somewhere that the polar Icecaps on Mars are melting.
Too late!
That global warming is man's fault is already part of "conventional wisdom". Don't expect mere facts to change that.
YA THINK? DUH!
Global warming is truly happening, but man has had nothing to do with it.
The sea level has risen more than 120 meters since the peak of the last ice age, about 18,000 years ago. http://en.wikipedia.org/wiki/Sea_level_rise
Glaciers were up to a mile thick in North Dakota and up to 8,000 feet thick near Hudson Bay during the last ice age . http://en.wikipedia.org/wiki/Glacier
Just wondering. Does the Sun's EM spectrum stay constant? Or does energy output at different wavelengths vary over time?
My suggestion is that the scientists who promote global warming theories launch a manned mission to the suns surface to check it out.
bttt
It's the only way to know for sure....and I agree.
Well, if it confuses them, it would be insensitive to insist that they use it.
Al gore says it is all lies. He says his internet shows proof otherwise. ;)
It has to do with the clouds. Higher cloud cover, versus lower cloud cover.
RIGHT ON! the Sun warming the earth ........WHODA THUNKIT?
.
There ... fixed it ........
LMAO!!
Al Gore invented the Sun, and it worked fine until Bush screwed it up!
"Read somewhere that the polar Icecaps on Mars are melting."
They expand and recede normally. But yes there have been data that points to Mars warming more then "normal".
Heh, what is normal? Puny humans have only been making accurate measurements for a heartbeat of time on planetary scales.
Poppycock!! How could the sun even possibley warm the earth. This doesn't make sense.
True, They have found global warming evidence on Mars. The article is in FR if you want to search. It was on Drudge about 3 weeks ago.
I'm sorry. I just can't. It'd be like shooting fish in a barrel.
Physicist, RadioAstronomer, RightWhale--
Any info on the current model of "normal" fluctuations in the heat / spectral output of stars such as our Sun (e.g. specifically excluding those which occur when changing from hydrogen fusion to say helium fusion) ??
Or on a stellar scale are the changes we seeing lost in the "noise" in experimental measurements?
I'm sorry. I just can't. It'd be like shooting fish in a barrel.
Physicist, RadioAstronomer, RightWhale--
Any info on the current model of "normal" fluctuations in the heat / spectral output of stars such as our Sun (e.g. specifically excluding those which occur when changing from hydrogen fusion to say helium fusion) ??
Or on a stellar scale are the changes we seeing lost in the "noise" in experimental measurements?
Of course it changes.
Algore also says that at the dawn of radio it was predicted that it could be the downfall of democracy and that the demise of the Fairness Doctrine and the rise of the Hatemonger Rush Limbaugh is proof of that.
He also says we need an unfettered marketplace of ideas.
All in the same speech.
The sunspot cycle is actually 22 years rather than the 11 years usually assumed. Polarity reverses for the second 11 years. If sunspots have anything to do with solar output, there might be a 22 year cycle on top of the data.
Right! It's just a yellow circle in the sky which turns on during the day and turns off at night. It serves no other purpose .....
Its those Haliburton NO Bid contracts.....its just GOTTA BE!.
The core of the sun isn't frozen???
I was sold on this idea when I read that the ice caps on Mars are shrinking, too. Kyoto is dead. RIP.
I heard Nuclear Fusion is Bush's fault.
Scientists at Armagh Observatory claim a unique weather record could show that the Sun has been the main contributor to global warming over the past two centuries.
Gee....no idea WHY that big, hot glowing thingy in the SKY might have SOMETHING to do with Earth's surface temperature...
If the "Global Warming" loons were the scientific advisors in the Middle Ages...we ALL would still be told the Earth was flat!
"But the Sun's activity does affect the flux of cosmic rays, high-energy particles from deep space, that strike our atmosphere," said Dr Butler.
Consequently it has been suggested that because cosmic rays are the main source of ionisation in the Earth's atmosphere they may have an influence on cloud formation.
Some other work in support of Dr. Butlers observations, that encompass the entire earth through satellite observations rather than a single location at Armagh observatory:
On the relationship of cosmic ray flux and precipitation
Dominic R. Kniveton 1 and Martin C. Todd 2
http://www.geog.ucl.ac.uk/~mtodd/papers/grl_2001/grl_total.pdf
Abstract
This paper evaluates whether there is empirical evidence to support the hypothesis that solar variability is linked to the Earth’s climate through the modulation of atmospheric precipitation processes. Using global data from 1979-1999, we find evidence of a statistically strong relationship between cosmic ray flux, precipitation and precipitation efficiency over ocean surfaces at mid to high latitudes. Both precipitation and precipitation efficiency are shown to vary by 7-9% during the solar cycle of the 1980s over the latitude band 45-90....S. Alternative explanations of the variation in these atmospheric parameters by changes in tropospheric aerosol content and ENSO show poorer statistical relationships with precipitation and precipitation efficiency. Variations in precipitation and precipitation efficiency potentially caused by changes in the cosmic ray flux have implications for the understanding of cloud and water vapour feedbacks.
Related ongoing studies regarding the links between Cosmic Ray Flux & Clouds:
Cosmic rays and clouds project
Svensmark and Friis-Christensen (Journal of Atmospheric, Solar and Terrestrial Physics, 1997) have shown that there is a strong correlation between the cosmic ray flux and the fraction of earth covered by clouds, as measured by satellite (see Figure). Over a sunspot cycle the cloud fraction varies by 3% absolute fraction, compared with a globally averaged coverage of about 65% (i.e., a 4.8% relative variation). The cosmic ray flux on earth is strongly modulated by magnetic disturbances of the solar wind, whose strength varies with the sunspot cycle. Strong solar magnetic activity occurs at times of high sunspot number and leads to a partial shielding of the earth from cosmic rays.
If this correlation were to be confirmed and substantiated by a causal mechanism, it could have profound consequences for climate. This is because the cosmic ray flux has decreased by as much as 20% over the last 100 years, which would translate into a 3% decrease in global cloudiness. This, in turn, would imply an increased radiative forcing of 1.2 W m-2.
And recent studies on the response to current increases in solar activity, demonstrating the trend in surface solar radiation trending higher throughout the period of 1987 - 2004 yet another interesting factor of note:
Data Show Earth's Surface Is Brighter and Scientists Study Climate Link
Refering to three papers ( Pinker et al., Wild et al., Charlson, R., et al.) in the May 6, 2005 issue of Science
- Pinker, R.T., et al., 2005. Do satellites detect trends in surface solar radiation? Science, 308, 850-854,
- Wielicki, B., et al., 2005. Changes in Earth’s albedo measured by satellite. Science, 308, 825,
- Wild, W., et al., 2005. From dimming to brightening: decadal changes in solar radiation at Earth’s surface. Science, 308, 847-850,
which indicate the amount of incoming solar radiation reaching the surface of the earth has increased dramatically in the last two decades, attributable to clearing of the atmosphere reducing the reflection of solar (albedo) radiation away from the earth's surface.
Here are the wattage changes reported in the may Science articles associated with that increasing solar component at the surface as opposed to your graphic of top of the atmosphere solar incidence:
Change in solar radiation absorbed by the earth from 2000 to 2004, estimated from low-orbiting satellite data, reported by Wielicki et al.: 2.06 W/m2.
Change from 1983 to 2001 in solar radiation absorbed by the earth, estimated at the surface by satellites, reported by Pinker et al.: 2.7 W/m2.
Change from 1985 to 2000 solar radiation absorbed at the surface, as measured at the surface, reported by Wild et al.: 4.4 W/m2.
If we average the results of Pinker et al. and Wild et al. for the period 1985 to 2000 we get 3.55 W/m2;
then adding the results of Wielicki, B., et al. from 2000 to 2004 of 2.06 W/m2 we get a total of 5.61 W/m2.
That is nearly 10 time the change in direct radiation effects reasonably attributable to greenhouse gas concentrations from 1985 to 2004.
The added forcing from increased solar radiation reaching the earth’s surface has contributed nearly 10 times as much energy as predicated for greenhouse gas changes from 1985 through 2004. When compared to the overall forcing attributed to all (natural and anthropogenic) increases in greenhouse gas concentrations since pre-industrial times, it’s four times larger.
Wow! Do you remember the source? Anything?
Well, since our sun is a Variable star, that means that the solar radiation coming from it varies. The IR from the sun (what warms the Earth and everything else) is also variable. That would explain the cycles of hot and cold that the Earth has gone through, from ice ages to times with much higher global temperature than right now.
"Well, since our sun is a Variable star, that means that the solar radiation coming from it varies. The IR from the sun (what warms the Earth and everything else) is also variable. That would explain the cycles of hot and cold that the Earth has gone through, from ice ages to times with much higher global temperature than right now."
It possibly could explain some portion of the change if the sun changes happen at the same time as the temperature change.
The data at the moment does not support that but further investigation is merited.
Thanks!
You also have to take into account other things, like the albedo of the Earth, which changes due to cloud cover and such, as well as the cooling effect of more water in the ocean evaporating (takes a lot of energy for a phase change from liquid to gas). Also, stuff like ash from active volcanos, as well as just dust from around the globe, that would tend to reflect a lot of the solar radiation back out to space. The data in this article does not support a whole lot because there isn't enough data, which is the whole problem with global warming. There hasn't been enough studies of the IR radiation coming from the sun to make an accurate model to show what happens to the temp on Earth when the sun's eminations change by 5% (which is the percentage that the sun is variable by). Also, what astronomers know is that the sun definately has a cycle of 11 years, due to sunspot frequency, and there may be longer cycles of relatively higher or lower radiation coming from the sun, which would fit into the 11 year cycle, meaning that during that cycle, there may be more or less radiation coming from the sun during one of the longer cycles as compaed to each other.
Dude, they knew the earth was round in Phoenician times, and ever since. What the "scientific advisors in the Middle Ages" didn't know was that the Earth went round the sun.
Good enough for me! Time to draw some planetary conclusions.
ping
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