A recalibration of data describing the number of sunspots and groups of sunspots on the surface of the Sun shows that there is no significant long-term upward trend in solar activity since 1700, contrary to what was previously thought. Indeed, the corrected numbers now point towards a consistent history of solar activity over the past few centuries, according to an international team of researchers. Its results suggest that rising global temperatures since the industrial revolution cannot be attributed to increased solar activity. The analysis, its results and its implications for climate research were discussed today at a press briefing at the IAU XXIX General Assembly currently taking place in Honolulu, Hawaii.
Measuring the sunspot number – or Wolf number – is one of the longest running scientific experiments in the world today, and provides crucial information to those studying the solar dynamo, space weather and climate change. Scientists have been observing and documenting sunspots – cool, dark regions of strong magnetism on the solar surface – for more than 400 years, ever since Galileo first pointed his telescope at the Sun in 1610. Scientists have also known about the solar cycle – an approximately 11-year period during which the Sun’s magnetic activity oscillates from low to high strength, and then back again – since the mid-18th century, and they have been able to reconstruct solar cycles back to the beginning of the 17th century based on historic observations of sunspot numbers.
Although solar activity has oscillated consistently, the timings and characteristics of individual cycles can vary significantly. Between 1645 and 1715, for example, solar activity did not pick up, and the Sun remained in an extended period of calm known as the Maunder minimum. Historically, this period coincided with the “Little Ice Age”, during which parts of the world including Europe and North America experienced colder winters and increased glaciation than today. These suggested that there exists a strong link between solar activity and climate change.
Until now, the general consensus was that since the end of the Maunder minimum, solar activity has been trending upwards over the past 300 years, peaking in the late 20th century – an event referred to as the modern grand maximum. The trend has also led some to conclude that the Sun may play a significant role in modern climate change. However, a long-running and contentious discrepancy between two parallel series of sunspot number counts has made this role difficult to pin down.
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The new correction of the sunspot number, called the sunspot number version 2.0, led by Frédéric Clette, director of the World Data Centre for Sunspot Index and Long-term Solar Observations (WDC–SILSO) and based at the Royal Observatory of Belgium, Ed Cliver of the National Solar Observatory in the US and Leif Svalgaard of Stanford University in the US, nullifies the claim that there has been a modern grand maximum. Indeed, the researchers say in their abstract that their study is “the first end-to-end revision of the sunspot number since the creation of this reference index of solar activity by Rudolf Wolf in 1849 and the simultaneous recalibration of the group number”, and that their results mean that there is no longer any substantial difference between the two historical records.
I am really glad they clarified this. There are still so many people–knowledgeable people who are not deniers–who still think solar activity is a significant cause of climate change.
By definition, anyone who believes sunspot activity is a significant cause of climate change is NOT well-informed or “knowledgable”. There have been a number of papers over the past ten years that have debunked that idea. These people are not paying attention.
Even the obvious idea that a decrease in overall radiation from the Sun will lead to less warming has been “clarified” and overpowered by the fact that GHG’s trap so much of the incident radiation that the Earth is warming. These people are not paying attention to that either.
Oh, the horror! Sunspotters like Inhofe and the whole list of Heartland stooges like Singer and Spencer will have to tear the Sunspots page out of their handy “Lying BS for Deniers Manual”.
If they hold true to form, they won’t do that for at least 20 or 30 years, and will keep repeating the lies forever. They’re still lying about tobacco, aren’t they?
PS to gingerbaker, who is making a “list”. Came across this piece on Heartland, which is a good read on it’s own, but it has a great list of deniers at the end that is complete with short bios. Check it out.
http://mediamatters.org/blog/2014/07/07/climate-denial-goes-vegas/199974
But I’m sure the deniers will just add this to their list of co conspirators in the “global warming” conspiracy!
They will claim that the numbers have been massaged to get the desired result, and they know PLENTY about THAT.
Here’s my question – so if the “science of climate change” has been “settled” for awhile now, as some claim – then why would this study be needed?
Assuming the conclusions are correct, then will the claim now be that it was almost settled before, but now that this study it is in, it is finally, completely settled?
So in other words, for the last few years, when I’ve heard the “debate was over” and the “science was settled”, it wasn’t really true. But if I’m told that now – NOW I should believe it.
Are you the Michael Davison who considers himself to be a “”Solvable Catastrophic Continual-Future-Warming-Crisis Unconvinced Observer”?
That tidbit came from a rather long and very run-on comment here:
http://climate.nasa.gov/blog/1059
And are you the Michael Davison responsible for all this horseshit on Twitter?
https://twitter.com/mdavisoncpa
Or are you THIS Michael Davison? http://www.parliament.nz/resource/0000084771
Item of business : Climate Change Response (Moderated Emissions
Trading) Amendment Bill
Submission name : Michael Davison
Re ETS
I find it unbelievable that the western world can so readily and
happily sign up to taxing itself to hell and back on the distorted
orchestrations of IPCC.
IT IS VERY CLEAR THAT THERE IS NO CORELATION BETWEEN MAN MADE CO2 IN THE ATMOSPHERE AND WARMING TEMPERATURES.
One can go over the information available and clearly see periods of
increasing C02 associated with lowering temperatures and very high
CO2 levels being associated with static low temperatures. This is
total CO2 not just the smaller man made contribution
It is beyond belief that governments can just accept the IPCC
distortions of information without any realistic scientifically
robust proof of their claims.
They have been shown time and time again to have distorted
information to make their claims look good and their credibility is
in tatters.
However we just trot along like sheep running over a cliff and sign
up to ridiculous theories without a thought as to the real proof that
is not there.
Not only do we propose to sign up but we think it is best if we
really crucify ourselves by going even further than all the rest of
the silly buggers.
We are going to look extremely stupid when the world goes on cooling
and the IPCC predictions continue to fail time and time again until
their sleezy agenda is exposed.
Why cant we just wait and see if this dreadful warming happens
because all the signs at present are that it is not happening and
will not happen?
Taxation is theft at the best of times. What taxes are for “climate
change” is beyond logic.
Wake up politicians it is becoming a joke and it looks like NZ is the
leading clown
Very very sincerely
Michael Davison
I was a grad student long ago, at Stanford Solar Observatory, and was there when both Leif and Todd Hoeksema (grad student then, full time researcher now) were there. There in fact was some legitimate belief that in the FIRST half of the 20th century that solar luminosity contributed significantly to the rise in global temps during that time, when co2 was still tiny compared to the past 50 years.
Very glad to see this study! I’ll get immediate linking in my web material.
For climate, note that the rising solar cycle activity of the early 20th century remains in the newly calibrated data, so it’s plausible that some of the early 20th century rising global temperatures were due to increasing solar luminosity, at a time when the CO2 effect was still pretty small. But yeah, the claim that we’re in a longer term solar luminosity rise extending 400 years now looks wrong.