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1 in 500 year event, oh really? And we have several millennia of accurate data to truly know this?

One of the assumption in the global warming hoax is that weather outcomes have a normal distribution, so the probability of tail events can be calculated. And yet we know that these "1 in 1000 year events" have occurred many times in the past. You only have to look at the history books.

Weather has persistence. Faulty climate models assume weather from one day to the next is independent. This is why events always happen more than these "1 in 500 year" statements suggest.

It was only 10 years that the Met Office and the Climategate Unit in East Anglia were telling us our children won't know what snow is.

Pingosan. I was born in 1964 and the snow we had in Sheffield, was probably the worst I remember. But then again the mind is very subjective. I am sure we will be seeing more snow like that, as the world cools down.

"And we have several millennia of accurate data to truly know this?"

No but we do have hundreds of years. Also you can plot the data you do have to discover the distribution and then use that to determine how likely the event is. You don't have to assume a normal distribution.

"Weather has persistence. Faulty climate models assume weather from one day to the next is independent."

Weather is not climate. Your understanding of how weather models work is completely wrong. Weather models simulate the processes over time so you are incorrect to say they ignore the previous days state. Quite the opposite, the previous days state is key to predicting the following day.

Well said quake. Normal distribution is the key to prediction in chaotic systems. Interestingly this is more mathematics than science and the 'bell curve' of normality will drift over time.

The last time I remember it being so nice in April was 2007 and look at the summer we got that year!!!!

Also when was the last time we had a smog alert - I can't ever remember one and I'm 33. It's not surprising really - last nights sunset reminded me of August's when I was younger before they banned stubble burning. Guessing all the oil seed rape and tree pollen is going to be a huge factor in this?

"No but we do have hundreds of years [of accurate data]."

I take it this is the stuff that Michael Mann and Keith Briffa invented, prior to the latter gaining a conscience and releasing the Climategate emails and documents?

PingoSan wrote:
"I take it this is the stuff that Michael Mann and Keith Briffa invented"

Thousands of scientists and researchers from many countries for over more than a century have been collecting and recording data. There is no evidence that any data used in credibly published science papers has been 'invented'. Unless you have actual credible evidence showing different.....

#4 quake seems to have too much faith in climate models. There are many out there and non of them have had any success at hindcasting, ie. producing a readout of a previous years climate knowing the inputs. So these climate models will have to have a lot of work before any sort of faith can be placed at their door. At the moment they are not good enough for formulation of government policy. Unfortunately the government do not realize this.

"here are many out there and non of them have had any success at hindcasting, ie. producing a readout of a previous years climate knowing the inputs"

But they have

John Marshall
All models are tested against known data - hind casting - before they are even published. If a model can predict for the last century or more then it must be credible for the next decade or so.

#11 - Lazarus wrote:
"All models are tested against known data - hind casting - before they are even published. If a model can predict for the last century or more then it must be credible for the next decade or so."
Sorry, I beg to differ.
Presumably if the models had failed to "predict" known figures for the past, they would have been excluded. Simply because the ones which were chosen "predicted" past figures, doesn't mean they will predict future figures accurately.
Suppose I create 1000 random models and run them to "predict" past temperatures.
By the "law of averages" some of those are going to get them right (a bit like an infinite number of monkeys typing Shakespeare). It doesn't mean they are more likely to get future predictions correct. I know this is an extreme example, as models are not entirely random, but I believe that the principle holds true.
This is similar to the stocks and shares markets, where some advisors will guess the market correctly purely by chance, but it doesn't mean they will guess the way the market is going in the future any more accurately.
There's probably a name for this phenomenon, but I don't know what it is.

As Niels Bohr said, "Prediction is very difficult, especially about the future".

QV @ 12 - you have absolutely hit this particular nail on the head here. The stock market is a very good anology of models failing to predict future events even though they are based on past ones and tuned accordingly. There are many different theories on stock market prediction, such as Elliot Wave, and while patterns may often repeat anybody who bets their shirt on the outcome of these models often loses that shirt, and their car, and their house!
There are countless "experts" that time and time again have their predictions shown to be complete hogwash even though they do it for a living. Who can really say they foretold the lowest interest rates in all time perpetuating for such a long time, that in real terms the stock market still has not got anywhere near it's 2000 peak 11 years later?
Yet that same modelling of a chaotic stream of data in which we humans see patterns is used by Govts to bet the shirts of the entire country on predictions that are far LESS likely than predicting the FTSE 100 level on a certain date.
In climate prediction, as in the stock market, there are some big winners - but these are funded by the far larger number of losers. Those with something to gain will concentrate on the wins to perpetuate the cycle of moving money from the masses to the few.
We are all being forced to gamble in a rigged game - the house always wins.

The weather men can't even predict accurately over a weekend. There was supposed to be terrific thunder and lighting storms Saturday and Sunday, but it was a bit of a whimper. The longer the forecast, the greater the inaccuracy.

And yet again you fail to understand the difference between weather and climate.

(I'll give you a clue, climate is a long term trend. Weather is local 'noise')

Is it cold in your back garden at the moment? You was using that in december as a sign of global cooling if i remember right!

#14 - millennia wrote:
"QV @ 12 - you have absolutely hit this particular nail on the head here. The stock market is a very good anology of models failing to predict future events even though they are based on past ones and tuned accordingly."
Thanks.
I am sure that the predictions of climate science have a lot in common with those of Economics. There are a lot of "laws" in Economics, such as "the law of suppy and demand", from which predictions can be made, although those predictions usually should be accompanied by the phrase "other things being equal". I don't recall that phrase ever being used in relation to climate predictions, although I may be wrong.
I think that "climate science" is currently close to Economics than to say, astro-physics, where it is possible to use the laws of gravity to simulate the motions of celestial bodies and, for example, predict eclipses to a very high degree of accuracy.
The latter is a genuine case where "the science is settled", or good enough for me anyway. We don't get eclipses occurring a couple of days, or even minutes early, for no apparent reason.
I was searching for some evidence to support my contention that "hind-casting" wasn't necessarily a reliable method of validating climate models and a possible name for the underlying fallacy, but I haven't been able to find anything yet. I did find this page on "Skeptical Science", (which of course is anything but sceptical), which repeats the mantra that " If they get the past right, there is no reason to think their predictions would be wrong." If there was ever an example of a closed mind at work, that is it. The fact is, the predictions have been substantially wrong, so a reason must be found. I was hoping that there would be some response from a non-sceptic, but no such luck. I don't suppose that means they think I am correct!

QV - I suspect that your knowledge of Economics and Astrophysics are equally as superficial as your understanding of Climate Science. You have decided you know the answer (hind-casting is dodgy) and so conclude that the evidence must be there! Consider this - maybe the reason you couldn't find it is that you are wrong

john-cogger

Any body who believes in Global warming to me is a little confused, between weather and climate change. Because they are looking at such a small period of time, they are confusing global warming and natural climate change, due to the temperature of the sun and the orbit of the earth around the sun.

Marcus Garvey,

Thank you for your constructive comments.
When you think for yourself, it is possible to have opinions not shared by others.
Unfortunately, the evidence points to the possibility that the models are not as
good at predicting the future as the past.
We shall see who is correct.

I agree with QV, 20th century hindcasts don't impress me. I think it's a lot to do with tuning aerosols right so they offset the ghg warming correctly.

That said while I don't think the 20th century hindcasts are evidence the models are right, the inability of models to hindcast if human emissions are not included is one reason I think a significant amount of recent warming isn't natural.

I haven't checked the full UK but it looks like April will be warmest on record in central england temperature record beating previous record held by 2007 by a mile. That is pretty staggering as 2007 itself beat the previous record (1865) by a mile.

By a "mile" I mean the the previous warmest average Aprils have been fairly clustered around 10.4C or so:

10.1C
10.1C
10.1C
10.2C
10.2C
10.2C
10.3C (1987)
10.4C (1798)
10.5C (1943)
10.6C (1865)

Then April 2007 comes in at 11.2C, which is quite a jump above that cluster. A kind of statistical extreme that I wouldn't expected to be equalled let alone beaten anytime soon by a similar magnitude, but now April 2011 threatens to end with an average of about 12.0C

The rankings are here:


As the figures are absolute means it's interesting comparing months. For example this April has been so warm that it's actually warmer than the vast majority of Mays and even warmer than a handful of past Junes!

I am not saying global warming did any of this, these kind of extremes have happened before. There a few other wild extremes in other months, like May 1833 which is way ahead of other recorded Mays. But the double extreme for April within 4 years is unique.

To Quake #22

Yes, I can well believe what you say about this April being exceptionally warm.

Observing signs from nature as I do, many trees and flowers are well in advance of average - which I know from records I have kept for about 20 years or more.

One plant I use a lot as a "thermometer" for mid spring is the common double pink cherry - Prunus 'Kanzan'. Although a non native, it is almost ubiquitous and is a single clone (unlike hawthorn, oak and other species often suggested as guides for spring growth but which display great individual variation) and responds quickly to temperature.

Normally it begins to flower here around the last week of April or v. early May and finishes about 2 weeks later. The latest year I remember was 1979 when it was not fully out until Whitsun (late May) bank hol.

However this year, I think, is unprecedented in that many trees are already well past their peak and will virtually have FINISHED blooming by the end of April!

As you say, one has to be cautious about attributing such things to GW (particularly on this blog - it's like waving a match over petrol!). However it could be said to be another "brick in the wall"; particularly as it concerns the behaviour of the living world - which after all, is arguably the most important thing, rather than pure statistics. Ouch....... run for cover!!

jkiller - surely that is the prime example of cherry picking!

Seriously though, it's been a great spell of weather (since the kids were off school) but we really could do with a few days of rain now. Must have been a month or so without any at all, here in sunny Lincolnshire.

lateintheday

Likewise here in sunny East Yorkshire. My lawn is starting to go brown - another April rarity.

I think some people are forgetting we've had a record cold December. I take it that was due to global warming as well?

Or maybe we should accept that 150 years of weather records do not cover all the natural variability our regional climate possesses. You can call that the null hypothesis, if you like.