This forum is about wrong numbers in science, politics and the media. It respects good science and good English.
I apologise if I was presumptuous in assuming that anyone interested in the topic would be aware of the CO2Science project and its previous work. As for the art, literature etc., Europe is where the practitioners were largely located. Consensus is not a word that has any place in science. Many of the subsequent explanations appear to be examples of Langmuir's fifth Law of bad science. I cite, for example, the attempt to explain away the pictures of ice fairs on the Thames by the weir effect of London Bridge, showing a lamentable ignorance of the law of continuity.
I've never been entirely happy with John's dismissal of the London Bridge effect on the Frost Fairs, as I feel there might be something in it.
Consider; there is a net flow seawards of fresh water. In an unobstructed estuary this will form a wedge over the denser seawater, but with the narrowing of the channel (I've read there was a five-foot drop in surface level at times) the seawater and fresh will be fully mixed below the bridge at low tide. The upstream part of the tidal prism will therefore be brackish at low water and it is this bit that will, when the tide has risen to the point where the level is higher than above the bridge, start to flow through the bridge, thus raising the salinity less than normal and increasing the chance of it freezing. In addition the tidal range above the bridge will be reduced, reducing the stresses on the ice sheet. Any sheets of ice that do get broken off get trapped above the bridge and can then grow out to give a continuous sheet.
As I say, I think there might be something in the idea but it is certainly not enough in itself to explain the recent lack of such events.
Entia non sunt multiplicanda praeter necessitatem.
Disputin may not have the benefit of your classical education.
Once the 'warmers' have finally lost the battle over the MWP and AGW and become 'cooler's' instead, the battle over the LIA will begin.
Michael Mann will be using 'right way up' lake sediment (e.g. Tiljander) proxies to show that the amount of cooling in the first two decades of the 21st century has been 'unprecedented' in the last 'millyun' years and the last C in IPCC won't be short for 'Change' any more but 'Cooling' instead.
The IPCC will be telling us all in its 'Sixth' assessment report that they are 99% certain based on predictions carried using GCMs that man is responsible for anthropogenic global cooling (AGC). They will claim that the 'science is settled' beyond any reasonable doubt as their GCMs show that man's 21st century obsession with building wind turbines has had a disastrous effect on the planets air circulation patterns. These wind turbines have prevented 'hot air' from the land mixing with cold air over the oceans and as a result the sea temperature of our oceans has fallen dramatically in the last decade. We must ACT NOW! to save our planet and immediately revert back to using fossil fuels in power stations located near the coast so that their (no heating rather than cooling) waste water can be pumped back into the oceans in order to warm them up.
I think, KevinUK, that you may have missed the point about the AGE campaign.
The objective would appear not to be to reverse a warming trend that doesn't need reversing nor to actually combat abrupt climate change but rather, to generate sufficient hysteria that a Global government along similar, but even less democratic lines - if that is possible, to the EU.
The creation of a world government with the ability to impose its own legislation and provide its own enforcement (under normal treaties the independent sovereign states are responsible for both the national legislation implementing the treaty and for enforcement) is the objective.
Once that objective is realised and wealth transfer begins, there will be no need to actually spend it of combating climate change but on whatever ideological nonsense the Global Un-elected Commissioners decide. Often this will mean themselves.
About the only other beneficiaries might be the Swiss Banking commission stockpiling your money and mine in numbered accounts for corrupt officials.
What does AGE stand for? Did you mean AGW?
No need to worry about me JMW I most definitely haven't missed the point of what's been going on in regard to the whole AGW saga. Much as it's easy to start thinking that its all part of the 'Club of Rome' inspired Agenda 21 plan, I think that's probably the wrong thing to do.
I prefer rather to think that the whole AGW saga is more consistent with the idea of a 'new world order' due to the continued ambitions of the international socialism movement rather than due to a political elitist club like the 'Club of Rome'. What's often rarely discussed in the whole AGW debate is why there appears to be a need to let China and India 'off the hook' and for that matter for developed countries to be made to transfer part of their wealth and technologies to 'so called' developing countries as compensation for the 'evil' we developed nations have done in making ourselves healthier and better off than developing countries by daring to use fossil fuels to make our lives better?
Is the 'Club of Rome' made up of people who sound like they want to transfer their wealth (and so power) to other people? There are a great many people in the 'Club of Rome' who are ex-senior UN offcials but I really don't think the UN is, has been or ever will be a benevolent organisation. Given that AGW is all about 'global governance' and wealth transfer ts far more likely to me to be backed by a socialist, anti-capitalist agenda as espoused by Socialist International.
Many thanks for your concern, Kevin, but as I have been known to enjoy a pint or so with John he is fully aware that I would have no trouble recognising the good William's dictum.
What puzzles me slightly, though, is what I am supposed to be multiplying? Given that the precise mechanism for Thames freeze-ups is a very minor wart on the backside of a fairly trivial point about the bleedin' obvious fact that there actually was a LIA, and that I am a sea surveyor with a personal interest in tides and oceanography generally, I like to know if I'm missing something.
BTW, re the start of this thread, there is evidence from New Zealand and other parts of the world for cooling during the LIA. Nature (Nature 460, 1113-1116 (2009)) has an interesting report of records from the Indo-Pacific warm pool showing a very clear cooling in the LIA.
The Medieval Warm Period was said to have been 'regional' because little evidence was available for the medieval climate from other parts of the world. Nobody had looked for such evidence. The 'default' assumption, however, should have been that it was a global phenomenon, unless there was evidence of its being purely regional.
Wikipedia cites observations supporting a global Medieval Warm Period and Little Ice Age, but saying that the effects would vary from region to region:
Kevin, thanks for the links.
Frank, I started with Wikipedia, and noted:
"It was initially believed that the temperature changes were global. However......"
etc. Party line in other words.
No probs. Are you ew to the whole AGW issue or are you just curious about the MWP?
I have a suggestion if you are new to this debate. Don't just get sucked into either side i.e. warmer or skeptic side. Do your own research instead. In particular when either side makes a claim and backs it p with a reference, don't just take it as ead, check the referncgive to back their claim and see if it actually does actually back up their claim. You'll be amazed athow often on boths sides, the debate can be become biased. It's not just warmers who cherry pick the data.
If you are a 'skeptic' by nature then don't be put off if you are labelled as one by friends/colleagues as having doubts about an issue is very healthy IMO. In particlar be skeptical of anyone who says you should belive what they say beause they are an expert'.
Good luck in navigatin your way through the 'minefield' that is AGW.
I am to some extent playing devil's advocate. This site is very good, but I feel that its stand on GW isn't expressed concisely anywhere. It would be very good to have a prominent page with an itemised list of issues, eg
1. MWP: The IPCC say blah blah blah but they are wrong because blah blah
2. CO2 increase following temperature increases in the past: It is claimed that this isn't the case but that's wrong because etc. etc.
3. etc. etc.
New Scientist (who I detest) had something very like this at one time, called Climate Change FAQ or something like it. I can't currently find it.
As it is, I see material put out by New Scientist, FOE etc. and it's very very hard to find an answer to some of it on this site. Hence the questions.
Well it seems to be evidence-based. There is no attempt to fit a complex global phenomenon into a simplistic proposition such as we see in relation to climate forecasts.