Space Forum / Astronomy / July 2008

There are several possible causes, but the one that finds the most
support is that solar output increases/decreases in cycles that last
about 110,000 years. The previous ice ages/interglacial periods have
followed this cycle, and there is no reason to think the present one
won't continue to follow the cycle.

Even with little knowledge as to WHY ice age/interglacial warming
cycles happen, we can study the history as recorded in polar ice
records, for instance, and anticipate the way this present cycle will
most likely progress.

That depends upon your definition of "a few years" but we do have
reason to believe that we are near the turning point, after which we
can expect a drop back into the next ice age. It won't happen
instantly, or even in a few years. The ice records of previous ice age
cycles indicate that the earth will experience about 85,000 years of
cooling to the bottom of the next ice age, followed by about 25,000
years of warming during the next interglacial warm period.

Humans may survive, but our present complex industrial age may not.
And if it doesn't, there will be no electric power grids or electric
heaters. Humans, those who survive, will revert to a very primitive
way of living, and the population will drop to that which can be
sustained by a small fraction of the present agricultural area of the
world. There will likely be an equatorial band that is quite
hospitable to humans and most animals.

No previous ice age ever killed all forms of animal life. There will
likely be some extinctions, but most basic fauna and flora will
probably survive.   Gordon

In sci.physics Sanny <softtanks@hotmail.com> wrote:

What an idiot.

Gibbering nonsense.

Because eventually it always does.

And humans have air conditioners for when it is hot.

A new tropical climate would be far more survivable than an new ice age.

A good part of the world goes under a mile or so of ice.

The places left where food can be produced goes to few and far between.

The best of viable notions have to do with the Sirius star/solar
system.

- Brad Guth Brad_Guth Brad.Guth BradGuth

On Jun 28, 1:12 pm, Timberwoof <timberwoof.s...@inferNOnoSPAMsoft.com>
wrote:

Me likes this explanation man;

The greenhouse effect is the process in which the emission of infrared
radiation by the atmosphere warms a planet's surface. The name comes
from the incorrect analogy with the warming of air inside a greenhouse
compared to the air outside the greenhouse (see "Real Greenhouses"
below). The greenhouse effect was discovered by Joseph Fourier in 1824
and first investigated quantitatively by Svante Arrhenius in 1896.[1]

In the absence of the greenhouse effect, the Earth's average surface
temperature of 14 °C (57 °F) would be about -19 °C (–2.2 °F) .[2]
Global warming, a recent warming of the Earth's lower atmosphere, is
believed to be the result of an enhanced greenhouse effect due to
increased concentrations of greenhouse gases in the atmosphere. In
addition to the Earth, Mars and Venus have greenhouse effects....

...The molecules/atoms that constitute the bulk of the atmosphere:
oxygen (O2), nitrogen (N2) and argon (Ar); do not interact with
infrared radiation significantly. While the oxygen and nitrogen
molecules can vibrate, because of their symmetry these vibrations do
not create any transient charge separation. Without such a transient
dipole moment, they can neither absorb nor emit infrared radiation. In
the Earth’s atmosphere, the dominant infrared absorbing gases are
water vapor, carbon dioxide, and ozone (O3). The same molecules are
also the dominant infrared emitting molecules. CO2 and O3 have
"floppy" vibration motions whose quantum states can be excited by
collisions at energies encountered in the atmosphere. For example,
carbon dioxide is a linear molecule, but it has an important
vibrational mode in which the molecule bends with the carbon in the
middle moving one way and the oxygens on the ends moving the other
way, creating some charge separation, a dipole moment, thus carbon
dioxide molecules can absorb IR radiation. Collisions will immediately
transfer this energy to heating the surrounding gas. On the other
hand, other CO2 molecules will be vibrationally excited by collisions.
Roughly 5% of CO2 molecules are vibrationally excited at room
temperature and it is this 5% that radiates. A substantial part of the
greenhouse effect due to carbon dioxide exists because this vibration
is easily excited by infrared radiation. CO2 has two other vibrational
modes. The symmetric stretch does not radiate, and the asymmetric
stretch is at too high a frequency to be effectively excited by
atmospheric temperature collisions, although it does contribute to
absorption of IR radiation. The vibrational modes of water are at too
high energies to effectively radiate, but do absorb higher frequency
IR radiation. Water vapor has a bent shape. It has a permanent dipole
moment (the O atom end is electron rich, and the H atoms electron
poor) which means that IR light can be emitted and absorbed during
rotational transitions, and these transitions can also be produced by
collisional energy transfer. Clouds are also very important infrared
absorbers. Therefore, water has multiple effects on infrared
radiation, through its vapor phase and through its condensed phases.
Other absorbers of significance include methane, nitrous oxide and the
chlorofluorocarbons.

http://en.wikipedia.org/wiki/Greenhouse_effect