Doug wrote on 13th May 2012:
I still havn't made up my mind whether you are trolling or not, Doug, but as I
enjoy such arguments as well, I will answer regardless... :-)
It's both of course, but the effect of CO2 is much stronger. Mercury is closer
to the sun, yet is colder (surface varies between -220° C and 420° C), as it has
no appreciable atmosphere. Venus is the prototype greenhouse planet, having a
dense atmosphere of mainly CO2 with a surface temperature of pretty constant
460°C. See
http://en.wikipedia.org/wiki/Venus.
Without an atmosphere, Venus would be much colder, say -30°C according to
http://answers.yahoo.com/question/index?qid=20101007094209AAmddCT
I cannot resist asking you to update your 3rd grade physics, Doug! :-)
...
Assumptions are not facts, but as the name says, assumptions. Some assumptions
are called axioms. E.g. the axiom that the shortest distance between two points
is a staight line is an assumption which is valid in some circumstances, but not
in others.
Wrong. This is simply the worst case. What is more probable is that life will
get much harder and much of humanity will die. What the momentary established
near-consensus tells us is that we still have a choice. If we change our habits
quickly, we can probably limit global warming to around 2° C with little
likelyhood of runaway warming. But this would mean, for example, to stop driving
cars. As few people are prepared to do this, global warming will continue to
unpleasant levels even without runaway effects.
...
...
You brought this up a while ago, Doug, and I answered you. Bringing it up again
does not make it correct: you are completely wrong. Must be that 3rd grade
physics... :-)
Of course, and so what? You yourself are also a net emitter of heat and it is
about the same amount regardless whether you are lightly clothed in a hot area
or wearing highly insulating clothing in a very cold place. The flow of heat is
something quite distinct to temperture; this is probably where your thinking is
wrong.
The earth without its "clothes" on would be over 30° colder than with its
atmospheric blanket, the surface on average about -18°C instead of the present
+15°C. The internal heat radiating out into space is practically the same in
both cases. What is different is that a *much greater* amount of energy coming
from the sun is absorbed and exactly the same amount of energy is reradiated
away into space. The in comparison minute flux from the internal heat has almost
nothing to do with it.
This is your error: nobody has ever claimed that the Earth is a net absorber. It
absorbs a great deal of energy and re-emits exactly this energy, plus the tiny
amount it produces itself, from as you say mainly radiactive decay and from
tidal friction, which slows down the rotation.
...
Again, totally wrong! Nobody says that most of the heat is absorbed in artic
oceans. Due to the angle of the sun's rays, most radiation is absorbed in
equatorial regions, as you say yourself. This is why they are warmer. Wind and
ocean currents transport some of this heat to polar regions, as you say yourself.
...
It's a little more complicated. The warm water flows in several currents and
eventually reaches polar regions. It continually loses heat, also warming the
air. By cooling it becomes denser and there are about two places (sinks) where
most of the surface water descends and forms deep currents below the surface
ones. The deep water does not come up again in the form of wells, rather it
upwells very slowly everywhere. The complete cycle takes about 20'000 years
(from memory, from ocenaographic courses years ago). This has little to do with
the ice.
...
The annual and decadal oscillations have little to do with the currents, which
tranport much more energy than is used in the freezing/melting processes.
...
Again, this logic is wrong. The absorption has nothing to do with the emission.
The absorption is mostly in equatorial regions, but the emission is more even
over the whole surface. The radiation is a function of the temperature and is
thus higher from the equatorial regions, but not by a great deal, as the
atmosphere's temperature higher up is more even than near the surface.
You are correct that the poles emit more than they receive. So what?
...
Whether this "runs away" or not, it is only one of many effects. A much scarier
one is the melting of *land* ice. Climate change sceptics keep disputing the
very fact that the climate is warming. In Switzerland all (but one, I think)
glaciers are retreating rapidly. This is pretty good evidence of *local*
warming. Now the Swiss glaciers aren't very important, but the Greenland ones
are and they are also melting rapidly. And here is the problem: The top surface,
formed during the last ice age, is at present very high up and yet melting. Once
this gone it will not come back again until the next ice age. And this amount of
ice will raise the sea level considerably and permanetly. Even if it gets colder
again, the high altitude surface will have disappeared and no new glaciers will
be able to form until it gets really cold, e.g. during the next ice age.
...
Exactly. And this abandoning of facts and injecting confusion is exactly what
you and climate change sceptics are doing.
This is where you misunderstand science. Scientists make mistakes just as anyone
does and what science descibes is a process of finding and proving established
facts. And even without mistakes, every answer generates ten questions, so
scientific knowledge is never complete and there are always arguments about
whether this theory or that theory is the right one or how they should be
interpreted. Therefore it *is* important to present a consensus of opinion by
knowlegable people, and this consensus is actually very impressive. There are of
course thoses scientists on the other side. Some have valid arguments on certain
aspects. Most are bought, pure and simple, e.g. by the fossil fuel industry or
right-wing "thnik tanks" employed by them. "Follow the money", as they say...
Cheers,
Theo Schmidt
