The North Atlantic heat is on

From izen on January 29, 2011 at 7:54 am:

There is no archaeological or documentary evidence for vineyards that far North, all 46 of the documented vineyards of the period are in the Southern third of England, below Cambridge.

That does seem to be an important point. But that information should have the full context, as when it is stated elsewhere.
Reference 1:

At the time of the compilation of the Domesday Survey in the late eleventh century, vineyards were recorded in 46 places in southern England, from East Anglia through to modern-day Somerset.

But what is the Domesday Survey (aka Domesday Book)?
Reference 2:

Domesday Book is a detailed survey of the land held by William the Conqueror and his people, the earliest surviving public record, and a hugely important historical resource.

Thus one needs to know about William the Conqueror (Reference 3), and also the history of Scotland (Reference 4). From this, it becomes clear that the Domesday Book didn’t concern Scotland, as the land of William the Conqueror and Scotland were separate entities.
Thus your ’46 documented vineyards’ is meaningless when trying to disprove the existence of vineyards in Scotland during the Medieval Warming Period.
Note also the following bits of commentary about the Domesday Book (Reference 5):

It is obvious that, both in its values and in its measurements, the survey’s reckoning is very crude.
—–
To a large extent, it comes down to the king’s knowing where he should look when he needed to raise money. It therefore includes sources of income but not sinks of expenditure such as castles…
—–
On the other hand, Darby points out that “when this great wealth of data is examined more closely, perplexities and difficulties arise.”[8] One problem is that the clerks who compiled this document “were but human; they were frequently forgetful or confused.” The use of roman numerals also led to countless mistakes. Darby states, “Anyone who attempts an arithmetical exercise in Roman numerals soon sees something of the difficulties that faced the clerks.”[8] But more importantly are the numerous obvious omissions, and ambiguities in the presentation of the material.

Thus the presented number of “documented vineyards” needs to be placed in perspective. Some might have wanted to hide assets from “the Conqueror.” There could have been vineyards that weren’t producing income thus weren’t documented. For those reasons and more, that “46” number looks like an undercount.
Now back to you:

Even during the Roman warm period there is scant evidence of vineyards and wine manufacture, certainly none further north than the middle of the country.
In fact while there is evidence of SOMETHING been grown by methods that the Romans used for vines, very little pollen from grape vines is found and no manufacturing tools or utensils.

Nah, not quite. From a definitive-sounding source (link) comes this bit from “The History of English Wine Production”:

The Romans liked their wine – whether home grown or imported. After invading Britain in AD 43, wine drinking became more commonplace and whenever Roman villas, houses and garrisons have been excavated, there is nearly always archaeological evidence of wine amphorae and drinking cups, and occasionally grape pips and stems of bunches of grapes.
Recent archaeological investigations in Northamptonshire have uncovered evidence to suggest that vineyards were established on a commercial scale during the Roman occupation. Initial surveys at a 35-hectare Romano-British site at Wollaston in the Nene Valley (near Wellingborough), has revealed deposits of grape vine pollen dating from this time

It says at the bottom of the complete history:

Attributed to Stephen Skelton MW, author of ‘The UK Vineyards Guide 2010’, published by http://www.lulu.com – further information available here

You may consider that book Reference 6, and for only $34.67 (paperback) you can confirm that is indeed the source. Note the finding of grape vine pollen has been mentioned.
Reference 7 is “Roman vineyards in Britain: finds from the Nene Valley and new research,” originally published in the September 2000 issue of Antiquity. As mentioned here:

Antiquity is an international peer-reviewed journal of world archaeology. The journal is published quarterly in March, June, September and December. Antiquity is read by archaeology professionals and enthusiasts worldwide.

From Ref. 7, concerning those Wollaston vineyards:

In Britain, Roman viticulture has generally been assumed although the palaeobotanical and archaeological evidence has been ambiguous (Williams 1977). The trenches at Wollaston conformed to a pattern of vine cultivation, pastinatio, described in some detail by Columella and Pliny (Pliny XVII.166). The first vineyard at Wollaston comprised at least 6 km of pastinatio trenches, supporting 4000 vines and yielding 10,500 litres of white wine (based upon typical yield values) with total production from the area being probably closer to 30,000 (excluding Grendon). It would appear that the Nene Valley was a major area of wine production and although it is uncertain who the wine was produced for, links to other trades such as the pottery industries of the Nene valley should perhaps be sought.

Previously discovered evidence is mentioned:

With Wollaston providing one model of a British Roman vineyard it is worthwhile considering how widespread viticulture was in Roman Britain. Previously excavated possible vineyard sites include Grendon (Jackson 1995), Stanton Low in Buckinghamshire (Woodfield 1989), North Thoresby in Lincolnshire (Webster et al. 1967) and Gloucester (Medland 1894).

Thus there is ample evidence of grape vines and vineyards in Britain during the Roman Warm Period, and quite a lot of wine making.
More on the pollen:

Samples were taken from a sealed ditch within the area of the trenches (Brown & Meadows forthcoming). An unusually large pollen sum (1000 total land pollen) was used in order to increase the frequency of rare types. [CUT: Info about other pollens found] An unusual feature was a low percentage of Grape Vine (Vitis type) pollen (0.5-0.7% TLP). A second group of four similar trenches were identified 2.5 km away to the south by magnetometry and confirmed by excavation (500 m to the northwest of those identified by Jackson in Grendon). Samples from a well in this area revealed a similar open landscape with both arable and pastoral indicators and Vitis (0.4% TLP). The British palynological record of Vitis type pollen is sparse, occasional grains being recorded from Roman and Medieval levels.

While it is noted the amount of Vitis pollen found is low, that it was there is still significant. Further research was indicated.

The project (PALVIT) has two major aims; firstly to increase our understanding of Vitis taphonomy, and secondly to reassess the record of Roman viticulture in the Nene valley and Britain as a whole. This is involving field-studies of Vitis taphonomy, re-excavation and pollen analysis of new areas of the Wollaston complex and a re-evaluation of the published record. Three organic vineyards in Leicestershire, East Sussex and South Somerset have been instrumented with pollen traps of standard design. One of the reasons for undertaking these studies is that there has been confusion over the pollination mechanism of Vitis, and it appears that although it is fundamentally wind pollinated, insects (largely flies and beetles) may play an important role (Branties 1978; Kimura et al. 1998). There is at present little data on typical pollen dispersal distances. Excavations at Wollaston will take place in the summer (2000) and we are currently undertaking a review of the published literature including the incidence of Vitis in British pollen diagrams.

Thus basically even though the amounts found were small, not enough is known to know if that’s all they should have expected to find from an ancient vineyard.
Now, you had said:

Even during the Roman warm period there is scant evidence of vineyards and wine manufacture, certainly none further north than the middle of the country.

As to the last part, ever hear about Hadrian’s Wall (Reference 8), aka the Roman Wall? Romans to the south, “barbarians” to the north (Scotland), and the Romans were the wine drinkers who brought the grape vines with them. Thus your last part is not only not surprising, it in no way contradicts what I wrote.
Thus we’re down to the last little bit, where you said there is found “…no manufacturing tools or utensils.” The Romans were there, drinking wine, with their wine drinking-related utensils and other equipment. I don’t know what sort of “manufacturing tools” you’re looking for, the Roman winemaking method (Reference 9) is very basic, even crude. Earthenware jugs that would break. Bits of wood and rope, that can rot, be burned, perhaps reused for something else. If you’re looking for metal, remember that metal was scarce, and metal can be easily reshaped and re-purposed. With winemaking abandoned after the Romans left, I don’t see why you’d expect the equipment to survive the post-abandonment recycling of unused equipment, let alone the decay befalling what was left to rot.
Now to your last paragraph:

It is certain that the present magnitude and regional extent of grape production from vineyards for wine is now greater in Britain than at ANY time during its historical past.

Given the increases in population, increases in developed arable land, better varieties, improved agricultural techniques… Seems possible. And it says NOTHING that indicates the temperatures now are greater than, or even equal to, those in the Medieval and Roman Warm Periods.
So, do you actually have any evidence that challenges what Sallie Baliunas said about winemaking in Scotland during the Medieval Warm Period? Haven’t seen any yet.

You know, if global warming is a reality, there is no need for temperature to be minutely or grandly adjusted here and there. If the pot is on the fire, it will eventually get hot enough so that there is no doubt about it. This has been going on since about 1980. Surely a third of a century further on, we shouldn’t need such manipulations…..unless things aren’t going where they were supposed to have gone by now.