No Warming Since 1995 - Jones?

[SAT]

I see so yet again you're going to show up and declare predictions have not come through thus falsifying the theory of AGW yet you're completely unable to name a single prediction within a single scientific paper that hasn't occurred.

You're unable to get to even step 1 of supporting your own claims instead relying on random assortments of words in sentences containing "hockey stick" which is a well known reconstruction of past temperature that you seem to think you can employ in place of an argument.

There is a clue to one of the core (and failed) predictions of Anthropogenic Global Warming Theory in the name. See if you can spot it

[feargach]

I am reading all your posts. Amazing work. Keep it up. Thank you

I find his work "amazing" too. That "Venis" twaddle had me in stitches.

[Fortesbrand]

I find his work "amazing" too. That "Venis" twaddle had me in stitches.

Touché, feargach, touché.

So which planet was Bill Nye (the science guy) referring to and was it an appropriate analogy?

Misleading, Feargach, misleading.

Now why would Bill Nye (the science guy) be using a wholly inapropriate analogy when popularising AGW on network television? Could it be because James Hansen did his initial research on Venus and then never shed the incongruous comparison with its climate when forming his basic belief in what drives the earth's climate?

"The greenhouse effect of the sulfates could be calculated, and by the late 1970s, NASA climate modeler James Hansen stated confidently that the sulfates together with CO2 "are responsible for the basic climatic state on Venus." Hansen had originally become interested in the greenhouse effect when, in response to Sagan's primitive calculations, he tried to derive a better explanation of why the planet's atmosphere was so hot. Now Hansen's findings about sulfate aerosols strengthened his belief that these particles could make a serious difference for the Earth's climate as well. Sulfates were emitted by volcanoes and, increasingly, by human industry, so Venus had things to tell us about climate change at home."

Venus & Mars - The Discovery of Global Warming

But the suggestion that the Earth and Venus are comparable climatic models is fundamentally flawed. The following link has an explanation of why Venus developed the climate it has:

Why is Venus much hotter than Earth? | Herkinderkin

Perhaps Hansen is a bit eccentric and Nye is sychophanting up to him. Or perhaps Nye is role-playing a game favoured among the AGW crowd and using a plot from their favourite Chicks with Anthropomorphic Climatic Events flick!

I concede that your twaddle is of a finer quality of twaddle than any twaddle that I could possibly twaddle since it mostly originates from climatetwaddle.org

[feargach]

So, the BBC, decided to ask Professor Jones, famous for having his private emails hacked into, an extremely weird question:

BBC News - Q&A: Professor Phil Jones

Do you agree that from 1995 to the present there has been no statistically-significant global warming?

This is like asking the LAPD Chief "Do you agree that from 1997 to the present, O.J. Simpson has not committed any blood-soaked double murders?"

The answer to the question is likely to be a tad misleading, and tells us more about the motives of the questioner rather than the core issue. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

Back to the BBC's weird question. They actually specify four time-frames, none of which begins or ends in 1995! The time frames are: 1975-2009, 1975-1998, 1910-1940 and 1860-1880. All of these time frames are accepted by both parties as being periods of significant warming. And all of them are 20 years long or longer. Because you need long periods to achieve statistical significance. The shorter the period, the less possible it becomes to derive significant results.

So the weirdo 1995 question is basically the 1975-2009 series chopped in half. Why would any honest person ever do this? Nobody knows.

I asked tombo about it, and he gave me this:

1995 isn't any "cutoff" that is your term, so we can dispense with that. The actual verifiable statement sis that there has been no statistically significant warming trend since 1995.

Now if you made a more reasonable request to ask why should you care if there was no significant trend since 1995 specifically, you only need to revert to logic to realise this.

The alarmist AGW hypothesis rests on the assertion that as CO2 concetrations rise in the atmosphere the global mean temperature will rise as well (i.e. display a positive trend).

Ergo, if we can not detect a positive trend - for example if we wistnessed a significant positive trend and it simply stopped at some point - the the hypothesis would be falsified.

Of course a halt in the trend over the last 1 year would not be long enough.

A halt in a signficiant trend over the last 5 years would not be long enough

A halt over the last 10 years might or might not be long enough.

A halt over the last 15 years and it is getting even less consistent with the alarmist hypothesis.

And that is it. There is a signfiicant positive trend over the last 50 years, but the hypothesis can be falsified without having to wait another 50 years without a significant trend.

The last 15 years suggest the trend may not actually be present anymore. Our certainty is now dimisihed and it continues to diminish each year that the trend does not reassert itself.

Now I see nothing in that to suggest that judging over the 1995-2009 period is better or even as good as judging over the 1975-2009 period, which is simply a bigger sample of data.

But I intend to get some statisticians to pore over it, and see if Tombo's justification holds water. Watch this space! And, of course, if you know any statistics yourself, have a go!

[Tombo]

So, the BBC, decided to ask Professor Jones, famous for having his private emails hacked into, an extremely weird question:

BBC News - Q&A: Professor Phil Jones

Do you agree that from 1995 to the present there has been no statistically-significant global warming?

This is like asking the LAPD Chief "Do you agree that from 1997 to the present, O.J. Simpson has not committed any blood-soaked double murders?"

The answer to the question is likely to be a tad misleading, and tells us more about the motives of the questioner rather than the core issue. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

Back to the BBC's weird question. They actually specify four time-frames, none of which begins or ends in 1995! The time frames are: 1975-2009, 1975-1998, 1910-1940 and 1860-1880. All of these time frames are accepted by both parties as being periods of significant warming. And all of them are 20 years long or longer. Because you need long periods to achieve statistical significance. The shorter the period, the less possible it becomes to derive significant results.

So the weirdo 1995 question is basically the 1975-2009 series chopped in half. Why would any honest person ever do this? Nobody knows.

I asked tombo about it, and he gave me this:



Now I see nothing in that to suggest that judging over the 1995-2009 period is better or even as good as judging over the 1975-2009 period, which is simply a bigger sample of data.

But I intend to get some statisticians to pore over it, and see if Tombo's justification holds water. Watch this space! And, of course, if you know any statistics yourself, have a go!

Wow, what a rant. I couldn't seem to find where Jones made that strange (and flawed) OJ Simpson analogy.

There was a statistically significant warming trend from the 1950s up to 1995 The doesn't appear to have been one since. There is no strong evidence of anything but random variation at work for the last 15 years. No clear signature from AGW over the last 15 years.

Let me put this to you.

Say we go another 5 years and there is still no statistically significant trend since 1995 (1995-2015).

What about another 10 years? (1995-2020)

What about another 15 years? (1995-2025)

Will you still be demanding that I "justify the cutoff"? Will you still claim that a trend from 1950-2025 is still sitatistically significant so it doesn't matter?

[ibis]

So, the BBC, decided to ask Professor Jones, famous for having his private emails hacked into, an extremely weird question:

BBC News - Q&A: Professor Phil Jones

Do you agree that from 1995 to the present there has been no statistically-significant global warming?

This is like asking the LAPD Chief "Do you agree that from 1997 to the present, O.J. Simpson has not committed any blood-soaked double murders?"

The answer to the question is likely to be a tad misleading, and tells us more about the motives of the questioner rather than the core issue. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

Back to the BBC's weird question. They actually specify four time-frames, none of which begins or ends in 1995! The time frames are: 1975-2009, 1975-1998, 1910-1940 and 1860-1880. All of these time frames are accepted by both parties as being periods of significant warming. And all of them are 20 years long or longer. Because you need long periods to achieve statistical significance. The shorter the period, the less possible it becomes to derive significant results.

So the weirdo 1995 question is basically the 1975-2009 series chopped in half. Why would any honest person ever do this? Nobody knows.

I asked tombo about it, and he gave me this:



Now I see nothing in that to suggest that judging over the 1995-2009 period is better or even as good as judging over the 1975-2009 period, which is simply a bigger sample of data.

But I intend to get some statisticians to pore over it, and see if Tombo's justification holds water. Watch this space! And, of course, if you know any statistics yourself, have a go!

Here you go.

[Tombo]

You are all over the shop. You don't seem to have a clue about what you are dealing with here. Let's look at this piece:

Back to the BBC's weird question. They actually specify four time-frames, none of which begins or ends in 1995! The time frames are: 1975-2009, 1975-1998, 1910-1940 and 1860-1880. All of these time frames are accepted by both parties as being periods of significant warming. And all of them are 20 years long or longer. Because you need long periods to achieve statistical significance. The shorter the period, the less possible it becomes to derive significant results.

That question was to address the issue of causality. You don''t seem to understand that. Plus you get the question wrong. The question posed 3 time periods, not 4.

The question was framed that way; three periods with statistically signficant warming over very simialr periods, but only one could be attributed to AGW.

The pre-1940 trend increases in temperatures did not span a period over which CO2 concetrations could have explained the cause.

If CO2 is supposedly the only thing that can explain warming post WW2, what explains similar periods of warming??

WHat is the data or evidence that makes us certain that on those two previous occasions it was a perfectly natural even, but this time it is our fault and a global danger (potental calamaty according to some).

[feargach]

Look how quick the P.ie pro-denier censors move to bury a thread that's embarassing to p.ie's chief denier. This morning I reported two personal attacks made by deniers against a non-denier, and I expect they will still be ignored this time next week.

But put egg on the face of the head honcho of deniers, and they leap into action!

from ibis' link:

Time and time again, denialists try to suggest that the last 10 years, or 9 years, or 8 years, or 7 years, or 6 years, or three and a half days of temperature data establish that the earth is cooling, in contradiction to mainstream climate science. Time and time again, they’re refuted — shown to be either utterly foolish or downright dishonest or both. Logic seems to have no effect on them.

The simple fact is that short time spans don’t give enough data to establish what the trend is, they just exhibit the behavior of the noise. Of course that raises an interesting question: how long a time span do we need to establish a trend in global temperature data? It’s sometimes stated that the required time is 30 years, because that’s the time span used most often to distinguish climate from weather. Although that’s a useful guide, it’s not strictly correct. The time required to establish a trend in data depends on many things, including how big the trend is (the size of the signal) and how big, and what type, the noise is. Let’s look at GISS data for global temperature and test how much data we need to establish the most recent trend.


To do so, we’ll need to know how the noise behaves. We can get an idea of that by modeling the data since 1975 as a linear trend plus noise. We can estimate the trend by fitting a straight line to the data using linear regression

[Akrasia]

Wow, what a rant. I couldn't seem to find where Jones made that strange (and flawed) OJ Simpson analogy.

There was a statistically significant warming trend from the 1950s up to 1995 The doesn't appear to have been one since.

Let me put this to you.

Say we go another 5 years and there is still no statistically significant trend since 1995 (1995-2015).

What about another 10 years? (1995-2020)

What about another 15 years? (1995-2025)

Will you still be demanding that I "justify the cutoff"? Will you still claim that a trend from 1950-20225 is still sitatistically significant so it doesn't matter?

Tombo, the more you talk, the more obvious it is that you haven't a clue what you're talking about.

You clearly don't know what the words 'statistically significant' mean.

For those who care (I doubt Tombo will listen) It means (in this context) that we can say with a greater than 95% certainty that the changes in temperatures over the 15 year period are greater than we would expect from purely natural variability.

That means we can be 94.9% certain that the temperatures have increased abnormally but it would still be considered 'statistically insignificant'

The shorter the sample period, the more difficult it is to achieve statistical significance.
If 2000 is an average of a full degree hotter than 1999, that's a highly significant difference in terms of the effects on the global weather, but it could not be considered 'statistically significant' as the sample is far too small

Jones, in his interview with BBC stated that they were very close to statistical significance with a .12 degree increase over the 15 year period, so this implies the confidence level is about 90-95% What does this mean? That Tombo and the other deniers are claiming as a matter of fact that there has been no warming, based on only a 10% uncertainty in the statistical analysis.

If Tombo was truly a sceptic he would be saying "There is a 10% chance that the warming from the last 15 years is natural" not "There has been no statistically significant warming in 15 years"

[ibis]

That means we can be 94.9% certain that the temperatures have increased abnormally but it would still be considered 'statistically insignificant'

Well, not quite - it would still be statistically significant at the 90% level. The problem here is that the shorter the interval used, the lower the confidence, or the wider the margin within which you can be confident something lies.



The red lines above indicate the limits of confidence for a trend analysis from the stated time to the present. You'll note that when we start using the 1995 start date carefully chosen by the climate opposition, the confidence bands are just wide enough that the range of possible values for the temperature trend just tips over the zero line. That means that it is just barely possible that there is no warming trend - the chances are very very slight, but sufficient that a positive warming trend will fail the 95% confidence test.

Essentially, what has been done is that the climate opposition have chosen the longest possible period in which there isn't 95% confidence of a warming trend. That's the whole explanation of the choice of 1995. They could also have picked any year since then, because the error range would also be so large on such a short trend as to make the warming trend fail the confidence test - but 1995 is the longest possible such period, and thus the most dramatic.

Of course, the same trick may not work next year, because if, as Jones said, the trend only narrowly fails the 95% test at the moment, then 1995-2010 is likely to pass it. I doubt we'll hear much about that from the climate opposition, of course.

None of this is anything other than a clever piece of data cherry-picking, though. Indeed, you might call it a 'confidence trick'.