From Mosnews.com

This is not exactly my field of expertise, so I post this here in case you have seen it before and possibly debunked it.

Although on the subject of fluctuating climate, apparently during Roman times they were able to grow grapes near my part of the world , and in the middle ages they had frost faires on the River Thames in London.

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Van Rijn's original Invisible Elf was running for the North Carolina Senate, but dropped out of the contest after the paparazzi snapped him with a cute pixie just outside Disney World in Florida. Now he has settled down with her as they await their first child, writing his biography of life in Van Rijn's backyard, - Now you prove me wrong

The only links to Mr. Absudamatov all have to do with this news item, so I can't chack his credentials or history. As far as I know, the only reasonably accurate predictions for solar activity are for the last few years in a cycle, when the first years have been observed. No long-term predictions have been shown to be reliable as yet.
It looks to me like he has the agenda of convincing people that global warming is purely natural by exaggerating the importance of solar activity while studies that have been conducted and peer reviewed show that changes in solar activity are responsible for between 1/3 and 2/3 of measured temperature changes in the last century, with the rest supposedly coming from human activity (although certainly the latter part is disputed by a lot of people). If indeed about on average half of the temperature change in the last century was due to human processes, then we will need quite a big change in solar activity to overcompensate this, as our impact is becoming bigger and bigger.

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Knowledge is a curse, but ignorance is worse

So would the fact we had a warming period in Roman times and a cool period in the Medieval period should not be considered relevent due to extra CO₂ emissions from human industrial processes?

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Van Rijn's original Invisible Elf was running for the North Carolina Senate, but dropped out of the contest after the paparazzi snapped him with a cute pixie just outside Disney World in Florida. Now he has settled down with her as they await their first child, writing his biography of life in Van Rijn's backyard, - Now you prove me wrong

Sorry for the thread drift here. I am offering an alternative to the cooling period in the medieval period. Climate change is a very complex process that involves far to many variables to be pinned down to a single or even a few causes.

I read an article about the little ice age on the BBC site not long ago. In the article some researchers from Utrecht University, Netherlands were trying to tie the black death into the cooling period known as the little ice age. They said with the depleted human population that a lot of cleared farm land reverted back to forests. With the sudden increase in forested land the carbon dioxide levels dropped causing the cooling period.

Full article is here http://news.bbc.co.uk/1/hi/sci/tech/4755328.stm

So what about the Roman period when they were able to grow grapes in Northumberland?

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Van Rijn's original Invisible Elf was running for the North Carolina Senate, but dropped out of the contest after the paparazzi snapped him with a cute pixie just outside Disney World in Florida. Now he has settled down with her as they await their first child, writing his biography of life in Van Rijn's backyard, - Now you prove me wrong

the possibilty of a cool down soon is good. But not because of solar output because of the amount fresh water going in to the oceans disrupting the oceanic conveyer. the warm parts of the ocean stay at the equator not going north to heat the air above the ocean to give us our nice warm climate.

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echo the sound of silence

Yeah, what about it?

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Knowledge is a curse, but ignorance is worse

Sounds like bad russian literature to me. I think you need a lot of solar radiation history to make this case. There is plenty of evidence indicating planet earth has experienced periodic climactical fluctuations, but not nearly enough to indict solar radiation output as the predominant casual agent.

I was just asking how we accounted for that period of warming, or is there a variety of grape that can flourish in our northern climate. (just in case I have added 2+2 and got 5)

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Van Rijn's original Invisible Elf was running for the North Carolina Senate, but dropped out of the contest after the paparazzi snapped him with a cute pixie just outside Disney World in Florida. Now he has settled down with her as they await their first child, writing his biography of life in Van Rijn's backyard, - Now you prove me wrong

hmm...
2012..
the year the Mayan calender resets itself and the world "ends"..
coincidence...
or




NOT...

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The.. Best.. Thread..Ever...

There are Vinyards in Kent and up into the Midlands today, it's not inconcievable that they could grow a hundred miles further north, they grow inGermany after all, they rely on the frost to concentrate the grape juices Google German Eiswein or Canadian Ice Wine.

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'The eye can only see what the mind is prepared to accept'

There are natural periods of warming and cooling, noone here denies that (I hope). Variance in solar activity, earthly influences (like ocean currents, volcanoes, ...), ... and for those days according to some scientists already human influence (although that would have been, in my view, truly minimal), all combine to change the climate. All these factors have to be taken in account while studying the current climate change, and many serious studies do so. Most of those still end up with a part (around 50%) of the warming which they cannot explain except by human influence (greenhouse gases).

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Knowledge is a curse, but ignorance is worse

What sort of air temperature and river temperature was required to make the fresh-water Thames freeze solid enough to carry human weight?

And to freeze eg the salt-water English Channel?

I wasn't aware that any of the modelling algorithms or their underlying datasets had been put out for public scrutiny. Can you tell me where to find this data?

Often, papers / reports / ... either give the location of the dataset, or have a link to them. As to the used algorithm, I don't know. The method used is often described, but the actual software and so on is often not given, as that is copyrighted (or whatever the correct term in this case is).
Some random examples of climate studies with datasets are this one (link at top right), this one (with also a link to the methodology used), or this one, or this compilation of older studies (dataset given as url). Here the software (code) and datasets are both given.
Another possibility are some datastores, where they have loads of datasets, which in turn get referenced in the papers and studies. This has a link to one of them, from NOAA. Another one is at the World Data Center for Paleoclimatology. A third one is the International Tree Ring Data Bank.

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Knowledge is a curse, but ignorance is worse