On 3/21/2010 10:44 AM, Joseph Gwinn wrote:
In ,
"Ed wrote:

"Joseph wrote in message
...
In ,
"Ed wrote:

[snip]

You're talking about one measurement path, a Great Circle, which may or
may
not cross numerous currents, the initiation site for El Nino, and so on.
From that you're trying to draw a conclusion about global warming. You
don't
know if the pattern between here and NZ is pro-cyclical or
counter-cyclical
to the earth's temperature as a whole. You are talking about a
measurement
taken over a short span of years, while the data being looked at by
serious
scientists is data from decades at least, and hundreds of years in some
cases.

Well, I don't have a dog in the debate from which this is taken, but I will add
that it is not impossible to disentangle all those things. What is done
is the acoustic equivalent of computerized tomography.

Here is a random article dredged up by google:
http://jjap.ipap.jp/link?JJAP/40/5446/.

Joe Gwinn

Joe, I'm going to skip the article, because there are 2,000 or 3,000 that
I'd have to read first.

Not if the intent is to understand the method.


One can "disentangle" the currents, but there is
still fundamental debate about the influences that initiate the El Ninos,
for example. So you can separate some effects but now you will have experts
arguing over the causes -- and reading one article or two or a hundred won't
tell you the full story behind those causes.

Well, it *is* an active research topic for sure, but they are figuring it out.
And this is their tool. My point was that such a tool does exist.


For us non-experts, it's like searching for the golden fleece.

So, there is no reason to believe either side, and therefore no reason to
believe or to do anything at all? That's the obvious conclusion, because the
alternative is to choose on faith alone which of the warring groups to believe.

Joe Gwinn


There are numerous ways to measure what is happening in the environment
and many of them are accurate. I don't know much about sound waves in
water but I have seen quite a bit of the research on ice and I think
that is one of the best measures of how much the planet is warming. Nova
on PBS just had a very good show called Extreme Ice where they gave a
lot of information on the state of glaciers and sheet ice. I think we
can agree that glaciers and sheet ice don't melt when the temperature
stays the same or gets colder. So it's only when the temperature rises
that you see ice melt. Columbia Glacier, Alaska's biggest is melting at
a very rapid clip. They set up lasers to measure how fast it's flowing
and it's moving fast. In fact, ice is melting all over the planet and
glaciers are shrinking. That's a fact. I don't see that happening unless
the planetary temperature is rising. So by the ice alone the evidence is
that warming is happening. Is man causing it is the question. There is
plenty of evidence that says that is the cause of it. Even if it's not
it's better to avoid something than to make an error and have to come
back and correct it. I think that is the prudent course to take when it
comes to global warming. I also expect that energy producers and
industrial businesses won't go along with that view.

Hawke