From: Monte Davis 

"Geo"  wrote:

>
>Do we really know that it is increasing? I mean the samples they use and the
>methods to detect change are good over thousands of years but can they tell
>the difference between 1920 and 2000?

It's a tradeoff: whether in sea level or temperature, you get clearer
"signal" from the larger changes over longer periods -- but OTOH
you have many many more data points for recent periods, which strengthens
confidence in detecting small changes. I give the latter more weight.

Of course, scientists have an unfortunate habit of routinely critiquing,
correcting and refining their own data and methods. That opens the door for
ideologues to say "see, the eggheads were wrong so I must be
right!"... as has happened twice recently, with the discrepancy
between satellite and surface temp data and with the "hockey
stick" graph. Both have been sorted out already, but those who get
their science from Michael Crichton and Glenn Reynolds will keep citing
them forever.

--- BBBS/NT v4.01 Flag-5