In article .com,
Thornhill wrote:

djay wrote:
"Thornhill" wrote in message
oups.com...

Persephone wrote:
...or *something*!

Global warming will actually make winters colder. Rising temperatures
will melt the ice caps, releasing fresh water into the ocean. This will
decrease the strength of the gulf stream, which is what brings warm air
from the equator up to the northern hemisphere during the winter. New
England and Europe are going to be hardest hit. In general, global
warming makes everything more extreme.

Here in Philadelphia, December was fairly cold, but this January,
temperatures have often been in the 50s, and it seems to make it to 60
once a week. My tulips and daffodils have already started coming up.

I love gardening too and have to laugh sometimes at the unscientific posts
that occur here at times. Some type of "global warming" caused the last
great ice age to recede too. How the heck did that happen? AND was it a
bad thing?

If one 5 C warming was good, does that necessitate that another 5 C warming
will also be good? What definition of 'good' are you using?

The reason for the last glacial termination is one which offers little good
news. Milankovitch cycles (small variations in the earth's orbit on tens of
thousands of year time scales) have driven ice age cycles for the last 2.5
million years. For the last 700-ish ky, this has meant ice ages of something
like 100 ky duration, emphasis on the 'something like' as it's plus or minus
about 30 ky, depending on how the multiple cycles line up with each other.

The spans between major advances in northern hemisphere ice have been
something like 10 ky -- with similar variation (particularly long interglacial
about 400 kya). That has lead to the sound bite of 'we're due for an ice
age so _should_ be putting more greenhouse gases in the atmosphere to ward
it off'. The thing is, that's false. To the extent that Milankovitch
cycles are the control, we're due for another particularly long interglacial,
with another 50 or 70 ky to go :
Ledley, T. S. "Summer solstice solar radiation, the 100 kyr ice age cycle,
and the next ice age", Geophys. Res. Letters, 22, 2745-2748, 1995.

There's nothing unscientific about this. Lots of studies have been
done.

I'm not talking about another ice age, just weather patterns in the
northern hemisphere. The summers, like the rest of the world, will be
incredibly hot, but a weakened Gulf Stream will result in colder
winters.

... for areas of the northeastern Atlantic. The global picture is more
consistently for heating, even in winter.

--
Robert Grumbine http://www.radix.net/~bobg/ Science faqs and amateur activities notes and links.
Sagredo (Galileo Galilei) "You present these recondite matters with too much
evidence and ease; this great facility makes them less appreciated than they
would be had they been presented in a more abstruse manner." Two New Sciences