Kirjoittajan mukaan: Keijo Hyvönen (keijoo.hyvonen_miUku_somero.salonseutu.fi)
Päiväys: 03.12.2005 17:04
Kuten Jumalan olemassa olo perustuu suureen valheeseen niin samaan perustuu
17.000 valistuneen kansalaisen väitteet ilmaston lämpenemättöämyydestä.
Otsikoinnilla
viitataan samaan suuntaa osoittaen käyttäytymisessä saattavan piillä joitakin
ainutlaatuisia
muotoja joiden vapaa ja luonnollinen esiintyminen saattaa olla vahvasti
rajoitettu. Joitakin
jopa laajemman tietoisuuden tavoittavia lausuntoja kuitenkin on ollut jotka
todenäköisesti
vähenevät tajunnantason täyttyessä lähemmin todellisuutta vastaavalla
tietomäärällä.
Fears of Big Freeze as Scientists Detect Slower Gulf Stream by Steve Connor
The ocean "engine" that helps to drive the warm waters of the Gulf Stream and
keeps Britain relatively mild in winter has begun to slow down, say
scientists.
Measurements of ocean currents in the North Atlantic reveal that they have
weakened
by about 30 per cent since 1992.
The findings, published in the journal Nature, fit computer predictions of
what
would happen when Greenland glaciers begin to melt because of global warming.
The models suggest that extra freshwater released into the North Atlantic
could
weaken ocean currents and even shut down the Gulf Stream.Britain benefits from
the enormous amounts of heat - equivalent to the output of a million power
stations
Scientists estimate that the detected 30 per cent weakening of the Atlantic
currents could lead to a fall of about 1C in Britain's average temperatures
over
the next 20 years.They also warn that the weakening could be the first signs
of an
accelerating trend that could eventually lead to a more drastic change,
including
a complete shutdown of the currents. If this were to happen, average
temperatures
in Britain could fall by between 4C and 6C, leading to winter temperatures
similar
to Newfoundland in Canada, which is on the same latitude as the UK but does
not
benefit from the Gulf Stream.
Professor Harry Bryden, of the National Oceanography Centre at the University
of
Southampton, said the ocean currents of the North Atlantic acted as a conveyor
belt
that carried warm water at the surface in one direction and transported cold,
deep-
water currents in the other. "It is a massive system that includes the Gulf
Stream and
it carries heat northward out of the tropics into the northern Atlantic,
warming the
atmosphere and helping to provide northern Europe with a moderate climate,"
Professor Bryden said.
For the past 50 years, oceanographers have measured the strength of these
currents
along a stretch of the North Atlantic situated at a latitude of 25 degrees
north of the
equator, from Florida in the west to the African coast in the east.When they
analysed
that rate of ocean flow - measured in Sverdrups (Sv), or a million tons of
water flowing
per second - they found that in 1992 it was about 20Sv, but in 2004 it had
fallen to
14Sv. "In previous studies over the past 50 years, the overturning circulation
and heat
transport across 25 degrees north were reasonably constant. We were surprised
that
the circulation in 2004 was so different from previous estimates,"
Professor Bryden said.
The study used data from an array of instruments anchored at 22 moorings, nine
of
which are positioned east of the Bahamas, four in the mid-Atlantic and nine
across
the continental slope of east Africa. Each mooring is anchored to the seabed
on
wires 5,000 metres (16,400ft) long, and holds instruments that continuously
record
salinity, temperature, pressure and current flow. Stuart Cunningham of the
National
Oceanography Centre said: "Continuous monitoring could alert us to potential
rapid
climate change."
ne voi ehkäistä "
Heidi Hautala
PUOLUSTUSVOIMA
www.heidi2006.fi