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Roger Coppock
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 Posted: Fri Oct 10, 2008 1:15 am Post subject: Re: September was 5th warmest in the last 129 years on NASA' |
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On Oct 9, 6:06 pm, Peter Franks <n...@none.com> wrote:
[quote]Roger Coppock wrote:
On Oct 9, 1:13 pm, Peter Franks <n...@none.com> wrote:
[ . . . ]
this point, Roger>s 30-years-defines-a-trend is arbitrary and
It>s not original with me.
1) Try almost any climatology text.
2) OR try the first chapter of the recent IPCC WG1
report.
"Climate is usually described in terms of the
mean and variability of temperature, precipitation
and wind over a period of time, ranging from
months to millions of years (the classical period
is 30 years)."
3) OR get it from the source the taught me,
"Bowdich -- The American Practical Navigator."
Reference 2 is in reference to climate. You have shown no relationship
between climate and global temperature, therefore, you have no justified
basis to assume that 30 years is a suitable duration to define a trend
for global temperatures.
[/quote]
LOL!
There ought to be a prize for the stupidest
semantic ploy on this newsgroup. A loser
like you needs to win something once in a
while.. |
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Peter Franks
Guest
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| Posted: Fri Oct 10, 2008 3:12 am Post subject: Re: September was 5th warmest in the last 129 years on NASA' |
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John M. wrote:
[quote]On Oct 9, 10:13 pm, Peter Franks <n...@none.com> wrote:
John M. wrote:
On Oct 9, 8:04 pm, Peter Franks <n...@none.com> wrote:
Roger Coppock wrote:
On Oct 7, 9:43 pm, Joern Abatz <for-spam-o...@abatz.de> wrote:
On Tue, 07 Oct 2008 16:29:42 -0700, Roger Coppock wrote:
September was 5th warmest in the last 129 years on NASA>s global land and
sea record.
Even heavily massaged GISS data finally suggest there>s cooling going on.
September
---- GISS
2005 +0.68 <== Peak
2006 +0.55 |
2007 +0.50 |
2008 +0.49 V Down
Why stop at 2005?
This data set goes back to 1880.
4 points can not establish a trend.
How many points /can/ establish a trend? Please provide supporting
references.
The number depends on the extent to which the trend is a good fit to
each of them. A regression line doesn>t have to pass through any of
the points it joins up, but it needs to pass reasonably close.
A derived statistic representing the slope of the trend line is tested
to see if it fits the points better than one having zero slope. It may
well not pass the test with just a few points unless the trend is very
strong. As the number of points increases the presence of quite weak
trends can be detected, even when the individual points seem to be all
over the place.
Any number of references can be tracked down if you google for "linear
regression"
Yes, that is all fine and dandy, but what is the minimum number of
points that must be considered in order for a trend to be defined?
Roger seems to think anything less that 30 years is not a trend, and
therefore he summarily dismisses any such sub-30 year argument.
But why 30? Why not 300? Why not 3000?
At this point, Roger>s 30-years-defines-a-trend is arbitrary and
unjustified, but that could be said about a lot of what he posts. Some
reasoned justification would be nice, but I>ve asked before and got
nothing that would qualify as a substantive justification for 30-year
trends. Honestly, I don>t expect any deviation from that trend...
Without actually running the data through a stats program, I would
guess that the annual deviations in the global temperature record are
sufficiently large to not give a significant trend if one uses less
than around thirty years.
One also needs to be careful with very small samples. With these there
is a good chance of getting five or six or so that show a trend simply
because random elements just happen to stack up that way.
[/quote]
Ok, now that I can understand and appreciate.
Therefore, what Roger MUST do is to provide a substantive source, or the
results of his own analysis that justifies a 30-year spectrum of data to
define a trend. As far as I>m aware, that justification has never been
provided. |
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Peter Franks
Guest
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| Posted: Fri Oct 10, 2008 6:01 am Post subject: Re: September was 5th warmest in the last 129 years on NASA' |
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Roger Coppock wrote:
[quote]On Oct 9, 3:12 pm, Peter Franks <n...@none.com> wrote:
Therefore, what Roger MUST do is to provide a substantive source, or the
results of his own analysis that justifies a 30-year spectrum of data to
define a trend. As far as I>m aware, that justification has never been
provided.
Then, you haven>t looked.
[/quote]
Yes I have. |
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Peter Franks
Guest
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| Posted: Fri Oct 10, 2008 6:06 am Post subject: Re: September was 5th warmest in the last 129 years on NASA' |
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Roger Coppock wrote:
[quote]On Oct 9, 1:13 pm, Peter Franks <n...@none.com> wrote:
[ . . . ]
this point, Roger>s 30-years-defines-a-trend is arbitrary and
It>s not original with me.
1) Try almost any climatology text.
2) OR try the first chapter of the recent IPCC WG1
report.
"Climate is usually described in terms of the
mean and variability of temperature, precipitation
and wind over a period of time, ranging from
months to millions of years (the classical period
is 30 years)."
3) OR get it from the source the taught me,
"Bowdich -- The American Practical Navigator."
[/quote]
Reference 2 is in reference to climate. You have shown no relationship
between climate and global temperature, therefore, you have no justified
basis to assume that 30 years is a suitable duration to define a trend
for global temperatures. |
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John M.
Guest
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| Posted: Fri Oct 10, 2008 6:23 am Post subject: Re: September was 5th warmest in the last 129 years on NASA' |
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On Oct 10, 3:44 am, Peter Franks <n...@none.com> wrote:
[quote]Roger Coppock wrote:
On Oct 9, 6:06 pm, Peter Franks <n...@none.com> wrote:
Roger Coppock wrote:
On Oct 9, 1:13 pm, Peter Franks <n...@none.com> wrote:
[ . . . ]
this point, Roger>s 30-years-defines-a-trend is arbitrary and
It>s not original with me.
1) Try almost any climatology text.
2) OR try the first chapter of the recent IPCC WG1
report.
"Climate is usually described in terms of the
mean and variability of temperature, precipitation
and wind over a period of time, ranging from
months to millions of years (the classical period
is 30 years)."
3) OR get it from the source the taught me,
"Bowdich -- The American Practical Navigator."
Reference 2 is in reference to climate. You have shown no relationship
between climate and global temperature, therefore, you have no justified
basis to assume that 30 years is a suitable duration to define a trend
for global temperatures.
LOL!
There ought to be a prize for the stupidest
semantic ploy on this newsgroup. A loser
like you needs to win something once in a
while..
Not a semantic ploy, precision in terminology. This is a complicated
subject, and introducing or perpetuating sloppiness in terminology is
inappropriate.
My response stands. You are using a basis for your
30-year-defines-a-trend based on climate -- which everyone (well, most
everyone) knows is a LOCAL characteristic. Extending that to a global
scale, without proper justification, is also inappropriate.
By the way, don>t waste my time any more with your stupid non-responses;
my time is too valuable to spend on your silly antics. Act like a
disciplined adult or go away.
[/quote]
Spoken like a true ignoramus. Why do you keep asking the same
questions, then perpetually refusing the answers? You have been given
references ad nauseum yet I see no evidence that you have read even
one of these.
In future when I see one of your posts, I>ll permit myself a slight
smirk and then pass on to something interesting. |
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Peter Franks
Guest
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| Posted: Fri Oct 10, 2008 6:44 am Post subject: Re: September was 5th warmest in the last 129 years on NASA' |
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Roger Coppock wrote:
[quote]On Oct 9, 6:06 pm, Peter Franks <n...@none.com> wrote:
Roger Coppock wrote:
On Oct 9, 1:13 pm, Peter Franks <n...@none.com> wrote:
[ . . . ]
this point, Roger>s 30-years-defines-a-trend is arbitrary and
It>s not original with me.
1) Try almost any climatology text.
2) OR try the first chapter of the recent IPCC WG1
report.
"Climate is usually described in terms of the
mean and variability of temperature, precipitation
and wind over a period of time, ranging from
months to millions of years (the classical period
is 30 years)."
3) OR get it from the source the taught me,
"Bowdich -- The American Practical Navigator."
Reference 2 is in reference to climate. You have shown no relationship
between climate and global temperature, therefore, you have no justified
basis to assume that 30 years is a suitable duration to define a trend
for global temperatures.
LOL!
There ought to be a prize for the stupidest
semantic ploy on this newsgroup. A loser
like you needs to win something once in a
while..
[/quote]
Not a semantic ploy, precision in terminology. This is a complicated
subject, and introducing or perpetuating sloppiness in terminology is
inappropriate.
My response stands. You are using a basis for your
30-year-defines-a-trend based on climate -- which everyone (well, most
everyone) knows is a LOCAL characteristic. Extending that to a global
scale, without proper justification, is also inappropriate.
By the way, don>t waste my time any more with your stupid non-responses;
my time is too valuable to spend on your silly antics. Act like a
disciplined adult or go away. |
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