Sunspots reaching 1,000-year high

BBC News ^ | Tuesday, 6 July, 2004 | Dr David Whitehouse

[George W. Bush]

Sunspots reaching 1,000-year high

By Dr David Whitehouse
BBC News Online science editor

Sunspots are plentiful nowadays

A new analysis shows that the Sun is more active now than it has been at anytime in the previous 1,000 years.

Scientists based at the Institute for Astronomy in Zurich used ice cores from Greenland to construct a picture of our star's activity in the past.

They say that over the last century the number of sunspots rose at the same time that the Earth's climate became steadily warmer.

This trend is being amplified by gases from fossil fuel burning, they argue.

'Little Ice Age'

Sunspots have been monitored on the Sun since 1610, shortly after the invention of the telescope. They provide the longest-running direct measurement of our star's activity.

The variation in sunspot numbers has revealed the Sun's 11-year cycle of activity as well as other, longer-term changes.

In particular, it has been noted that between about 1645 and 1715, few sunspots were seen on the Sun's surface.

This period is called the Maunder Minimum after the English astronomer who studied it.

Ice cores record climate trends back beyond human measurements

It coincided with a spell of prolonged cold weather often referred to as the "Little Ice Age". Solar scientists strongly suspect there is a link between the two events - but the exact mechanism remains elusive.

Over the past few thousand years there is evidence of earlier Maunder-like coolings in the Earth's climate - indicated by tree-ring measurements that show slow growth due to prolonged cold.

In an attempt to determine what happened to sunspots during these other cold periods, Dr Sami Solanki and colleagues have looked at concentrations of a form, or isotope, of beryllium in ice cores from Greenland.

The isotope is created by cosmic rays - high-energy particles from the depths of the galaxy.

The flux of cosmic rays reaching the Earth's surface is modulated by the strength of the solar wind, the charged particles that stream away from the Sun's surface.

And since the strength of the solar wind varies over the sunspot cycle, the amount of beryllium in the ice at a time in the past can therefore be used to infer the state of the Sun and, roughly, the number of sunspots.

Latest warming

Dr Solanki is presenting a paper on the reconstruction of past solar activity at Cool Stars, Stellar Systems And The Sun, a conference in Hamburg, Germany.

He says that the reconstruction shows the Maunder Minimum and the other minima that are known in the past thousand years.

But the most striking feature, he says, is that looking at the past 1,150 years the Sun has never been as active as it has been during the past 60 years.

Over the past few hundred years, there has been a steady increase in the numbers of sunspots, a trend that has accelerated in the past century, just at the time when the Earth has been getting warmer.

The data suggests that changing solar activity is influencing in some way the global climate causing the world to get warmer.

Over the past 20 years, however, the number of sunspots has remained roughly constant, yet the average temperature of the Earth has continued to increase.

This is put down to a human-produced greenhouse effect caused by the combustion of fossil fuels.

This latest analysis shows that the Sun has had a considerable indirect influence on the global climate in the past, causing the Earth to warm or chill, and that mankind is amplifying the Sun's latest attempt to warm the Earth.

[Fester Chugabrew]

Paul Erlich has got to stand out as one of THE most deluded minds - ever.

Ha! There's more where that came from!

[Robert A Cook PE]

Thank you for those references.

[cogitator]

I believe that the bulk of the evidence is pointing to the SUN as the major contributor to the warming of the earth during the last century and indeed throughout history. Of the temperature change during the last century or so, my studies indicate human activities have likely contributed a maximum of 20% to the rise, with the remaining 80% due to the sun and its effects.

The Role of the Sun in 20th Century Climate Change does not support your opinion. If you want to catch my interest, make a substantive argument against what's presented there.

The rest of your post was perused. I'm not going to waste my time on it, other than to say that you're wrong about the temperature data. You would be a more diehard skeptic than Roy Spencer or Richard Lindzen to assert that there is something markedly wrong with the observational surface temperature record. They can be contacted; get their opinion.

[cogitator]

By the way, even cogitator has admitted that even a miniscule 1% change in the effect of cloud cover could account for the global temperature rise of the 20th century.

But there is no evidence supporting this mechanism as the cause of the increasing temperature. The main uncertainty is what will happen to cloud cover with further warming. No reputable climate scientist has indicated cloud cover increase as the likely cause of the currently observed warming. I was only addressing the magnitude of the uncertainty.

Try to keep clear what I do and don't say, please. Or ask me.

[stocksthatgoup]

On good authority..... the Left is beginning to change the language from Global Warming To Climatic Change - That way they are covered no matter what any study suggests

[jonrick46]

Is it possible that decrease in cloud cover causes increased temperatures because less solar radiation is reflected away from the surface.

[George W. Bush]

you wrote:

The higher the solar activity, the more cosmic rays get blown away from the solar system. The less cosmic rays, the less clouds formed to reflect solar radiation and the warmer things get. The warmer things get the more CO2.

Case closed.

That was so marvelously concise, it really bears repeating. Especially in a country that neglects science education.

[George W. Bush]

Perhaps we could give the dinosaurs another chance........ Imagine, a world without democrats and incompetent freaks that call themselves scientists. What a beautiful world it must have been.

Actually, the dinosaurs were all Democrats. That's why they're now extinct, IMO.

[Fred Hayek]

Since you beat me to the obligatory BDS statement, I propose that the following action be taken by these envirowackos promoting the extinction of humanity:

Envirowackos, it’s time that you take the leadership position. Set the example. Eat the gun. Wot say, it doesn’t apply to you, because you’re part of the enlightened?

[ChessExpert]

Comparing the graphs in posts 178 and 214 proves very enlightening.

Looking at post 214 one clearly sees increasing solar irradience in the first half on the 20th century. The last half of the 20th century shows a new high plateau of solar irradiance. Basically, solar activity is at an all time high. (Also consistent with the posted article.) Any objective reviewer would expect global warming. More sun, more warmth.



The line in post 178 represents measured temperature. This is even easier to see in post 198. Either way, temperature goes up in the 20th century. The climb is especially steep starting in the late 70s.



So the combined data from the graphs say, more sun, more warmth. Who could possibly deny that? We'll see.

Post 178 gives a blue band that is worth studying. It is entirely theoretical. But we are told that we can rely upon it. It was developed by scientists. They use computer models. If you don’t accept the blue band, either you’re not a scientist or you work for Exon-Mobil. The blue band claims to answer the question, what would happen to temperature if there were no manmade fossil fuel emissions. The band is pretty flat across the century. In the latter half of the century, it is flat or even declining. Compare the blue and pink bands in the last half of the 20th century.



With man’s influence (pink) you get warming. Without man’s influence (blue), there is no warming. Posts 178 and 198 showed warming in the century and especially since the late 70s. But none of this warming is ascribed to the sun or any naturally occurring variable. All warming is due to man-made fossil fuel emissions, especially CO2.

It doesn't matter that solar activity has been increasing through the century and is at an all time high. Global warming theory says the sun does not matter. It could go supernova but as far as our global warming bur according to proven computer models, we’ll all be O.K. if we can only control our CO2 emissions.

[ChessExpert]

Last sentence correction:

It could go supernova but according to proven computer models, we’ll all be O.K. if we can only control our CO2 emissions.

[Gator113]

“Actually, the dinosaurs were all Democrats. That’s why they’re now extinct, IMO.”

Excellent point. ;)

[Gator113]

Well said.

[ohioWfan]

It's been a subtle switch.

First they started saying that extremely cold weather was caused by global warming, but now they're gradually changing it to 'climate change.'

Maybe that's because two of their big global warming conferences had to be canceled because of extremely cold weather. :)

[AaronInCarolina]

The problem with the IPCC and those who place extraordinary faith in their questionable findings is this, they don't understand the sun. (Beyond the fact that they don't want the sun to be the driver because the IPCC has always existed for one and one reason only... to establish CO2 as a harmful gas that the US produces at a higher per/capita rate than any other country).

They just refuse to accept that the sun is the big player in our little neighborhood in the galaxy. Graph after graph shows incredible correlations between changes in solar irradiation and climate. But the problem is they (IPCC) can't quantify why. So they "round up the usual suspects" (like in the movie Casablanca) and that usual suspect is always CO2. As Cogitator points out regularly, the last 2 decades of he 20th century don't necessarily, when viewed at a close-up perspective, show a trend that explains the rise that observational temperature data purports to show. As you pointed out, the sunspot activity remained at a high level at the end of the 20th century, but they weren't increasing, while the purported observed temperature data continued to rise, particularly in the 1990's. Partly based on this fact, they ruled the sun out as the principle driver of 1990's temperature increases. The rest of their reason for denying solar irradiance variability is that they have concluded that while sunspots activity is higher than the past, they claim that ALL sunspot activity increase since 1750 amounts to a forcing of a mere 0.12 w/m**2. This, from page 5 of the 4th Assessment Report SPM from the IPCC:

Changes in solar irradience since 1750 are estimated to cause a radiative forcing of +.12 [+0.06 to 0.30]W/m**2, which is less than half the estimate given in the TAR (Third Assessment Report).

So they are saying that the combination of ALL the irradiance change since 1750 amount to just .12 W/m**2! The graph you posted earlier on Solar irradience for the past 400 years is useful for scrutinizing this finding from the IPCC. Keep in mind, it is NOAA data so detractors can't claim the data is from some denialist author. Now, notice that 1750, the date pulled out of a hat by the IPCC, is actually only slightly higher in irradiance than the Maunder Minimum, which was undeniably caused the Little Ice Age. In fact, according to that graph, the solar irradience was about 1364.3 Wm-2. This was a mere 1 Wm-2 greater than the Maunder Minimum irradience. Now look at the current irradience. It is about 1366.6 Wm-2. This is over 2 Wm-2 greater than in 1750. Now, you can't just compare his 2 Wm-2 increase since 1750 against the IPCC's estimate of 0.12 forcing, because the radiative balance equation involves dividing the TSI (Total Solar Irradience)by 4 and then applying an albedo scaling:

     (2 Wm-2 / 4 ) *  (1-a)   where a=albedo (~0.3)
      2/4 * 0.7 = 0.35 Wm-2

So I don't know where they get the +.12 Wm-2 in the AR4.

I think they understate the sun's effect by almost a factor of 3. And I think they fail to understand that the issue is not the troposhere and whether the sun has been warming the troposphere. This increased irradience has been warming the oceans, the 800 lb gorilla in the room. Oceans take a long time to warm. I think that the warming from the oceans has contributed to warming in the troposhere, and yes, some of that warming from the oceans has been trapped by some green house gas effects. The point is that the oceans mitigate warming from the sun with some amount of lag time through a heat-sink effect. This is why temperatures continued to rise even when solar irradiance leveled off in the last decade or 2 in the 20th century. I believe that is why now we are seeing a clear leveling off of the warming trend since around 2001.

As long as the IPCC and its followers continue to deny the impact of the sun, they will continue to push CO2 as the ONLY major driver. I think CO2 does have some measureable effect, but based upon the calculations I have seen and trust, I would put the contribution at only around 0.15 degC of the so-called 20th century rise of about 0.7 degC. The rest I estimate to be some combination of land-use change impacts on albedo and solar irradience increase, and to all of these combined would be applied a water-vapor feedback to bring us up to around +0.5 degC increase for the century. The rest of the discrepancey against the 0.7 degC figure I would attribute to observational error due to Urban Heat Island effect. The IPCC only allow for about 0.05 degC for the entire century for UHI. This is laughable. Go to the GISS website, and find their temperature data, click on an observation station of an urban area, particularly one that has seen extensive growth in the last half of the century. Then find a rural area nearby and you will likely see a dramatically different chart. The IPCC relied upon a study which examined Chinese observation grids and concluded that the UHI was nearly negligible (0.05 degC/century). It appears that the study was to determine if heat from urban locations, when averaged over the entire globe's surface, would not be significant. And from that perspective, they are quite correct. But that is missing the point entirely. It is not the negligle impact that urban heating has on the global average, it is the error in assuming that observations made in urban locations are representative of surrounding areas. They are not. But they they go on to use observation temperature grid data without correcting for the likelihood that the datapoints are artificially representative of concrete jungles, not the surrounding areas.

[ChessExpert]

Credit foes to AFPhys for the basic insight in this post (post 230). He advanced it in post 214. I just wanted to bring these charts together in one post. I should have scaled one of those charts, but I’m not savvy with HTML.

[ChessExpert]

Thanks for the detailed commentary. Way over my head. I will try to pore over it sometime. Your comments should be a resource to many readers. It seems to me that anyone who contemplates the behavior of a teakettle over a gas stove should realize that temperature rises in response to an application of energy over time. Temperature does not change instantaneously in response to the application of energy. There is some cumulative impact. I am sure others (not me!) understand this in relation to simple systems. The earth is not a simple system. Nevertheless, I don’t see why anyone would expect Earth’s temperature to move in lock step with solar activity. There should be lags. It simply stands to reason.

[bricks4all2]

“The general circulation model we employed had 20 layers in the ocean and 19 for the atmosphere. The experiments simulate the climate back to 1860 (which is when the global records of surface temperature became reliable), and they are projected forward to 2050”

Computer models are not experiments, never have been and never will be. Most 8th graders even know that.

[cogitator]

The lure of solar forcing

for your consideration.

[sand88]

The correlation is between SUVs, Global Warming and Sunspots. The logical conclusion has to be that SUV’s are causing global Warming that is now shown to be affecting the Sun and inducing sunspots.

The sad part, is that a good number of Americans would easily believe this. The AGW crowd will not stop until they destroy America.