Source for that statement? I think that's incorrect.
Of course not -- which is one reason that I don't believe your claim that
solar output measured near Earth is decreasing.
Of course. Would you agree that a dust storm that occurred 36 years ago is not
relevant to changes in Martian climate that are occurring now?
Of course not. Would you agree that that also is irrelevant to any
contemporary climate effects that may or may not be occurring?
Or perhaps you're just a hypocrite who wants to have it both ways. Here's your
position, summed up in two sentences:
Earth gets warmer at the same time human industrial activity increases --
cause and effect. Mars gets warmer at the same time Earth does -- coincidence.
Doug Miller (alphageek at milmac dot com)
On Feb 17, 9:11 am, email@example.com (Doug Miller) wrote:
Sure, in fact I did this several days ago but it appears the
posting failed. Are you, by any chance, an electrical or
First though, let's consider a little sense. Regardiing
Martian warming you wrote:
"That, alone, is more than enough to discount
the entire notion that the Earth is warming due
to human activity.
... Because if Mars is warming, it's pretty clearly
due to increased solar output; if solar output has
increased, that would explain warming here too
-- in fact, it would make warming here pretty much
To be confident in those statements you would have
1) The solar constant is increasing.
2) NO other factors affect warming on either
the Earth or Mars.
Back to facts.
Have you heard of the eleven year solar cycle?
The last solar max was in 2000-2001, we are
now near solar minimum. It is over that same
period that Martian warming was observed.
The studies I have found put an upper limit of about
+0.1 W/sqm on any change in the solar constant over
the last 30 years which is calculated to have at most,
one quarter of the effect of the increased CO2 over the
Have you found anything that estimates it as
being higher? OH, I forgot for a minute, you
don't believe in citing sources.
No. Dust storms are an important feature of the
Long-term climate change is influenced by variation
in the alignment of the solstices, between the polar
axis of the planet and the semi-major axis of its orbit
and the orbital eccentricity.
For Mars, those effects are all
much larger than for the Earth, and obviously
quite independent. Mars also has a thinner atmos-
phere and lacks the Earth's oceans so it does not
benefit from the buffering effect of each.
These days here on the Earth the summer solstice is
near apohelion, which minimizes Northern Hemisphere
heating during the Northern Summer. Thus summer
in the Southern Hemisphere is shorter. IOW we
are in a period of minimal climate forcing due to
orbital considerations. I dunno about Mars.
Why don't you check and get back to us?
OTOH, your approach appears to be based on
steadfastly avoiding any effort to educate yourself.
On Mar 1, 6:11 pm, firstname.lastname@example.org wrote:
Sorry, minimal seasonal variation in insolation occurs when the
equinoxes, not the solstices, are coincident with apo- and
So we are near a maximum, not a minimum. The last maximum
was around the end of the last ice age and we've had one
minimum roughly halfway between then and now, demonstrating
that large scale variation of the Earth's climate are not caused
(at least not soley) by those effects.
On Mar 2, 11:52 am, email@example.com wrote:
And, long-term climate change on the Earth is
driven by or at least heavily influenced by
long-term changes in eccentricity and obliquity.
That is over periods of time greater than the
Those are cyclical effects with periods of several tens
to a couple of hundred thousands of years.
The global warming being modeled based on the observed
change in CO2 concentration is a much shorter-term
phenomenon, over a period of a couple of hundred
years, superimposed on those long-term effects.
Far more important:
While it is difficult to estimate how much CO2 nature
produces and recovers each year it is not difficult
to predict how much CO2 is produced by humanity
each year. Fossil fuel production is sufficiently important
to the world's economy that good estimates are
available. It is reasonable to suppose that annual
burning is pretty much equal to annual use.
The observed rate of rise of CO2 is less than the
total human contribution. This shows, pretty conclusively,
that nature can recover all of the naturally produced
CO2 and some of the anthropogenic.
The spectral characteristics of CO2 are well understood,
so it is clear that absent other factors the Earth's
temperature will rise.
Two other factors that are well studied, but not as
well studied include variation in the solar constant,
and dispersion of particulates and ice crystals in
the stratosphere, primarily by jetliners.
Indications are that the solar constant is either not
changing or slightly increasing. But atmospheric
particulates and ice particles have increased
dramatically over the last 50 years (just look at
a satellite picture of a 'clear day'. That should
drive global temperture down.
Additionally, water and ice provide a strong buffering
effect so that ANY change is going to be slower than
would be expected if the atmosphere alone were
heating or cooling.
So it looks like we've been driving the temperature
I don't have any confidence in the temperature time
series, but it does look like the Earth's ice inventory
has been dropping fast and THAT is strong evidence
that the heating effects are, for now, winning out.
For something truly scary, read up on ocean clathrates
and the methane gun hypothesis. Extermination by
a giant Gaia fart, what a way to go.
I'd like you to show some support for either statement.
Here are some photos showing a buttload of ice lost from Antarctica
If there has been a gain since, it is doubtful that it has made up f
or what was lost.
Ok, you provided that support with your link. The peninsula that you
mention has been retreating for 50 years long before our so called global
warming became the new world problem. OTOH as I said and is backed up by
the link you provided the interior is cooling and the glaciers are
Larsen B is one of five ice shelves -- large floating extensions of ice
sheets covering the continent -- that's been on retreat. While Antarctica's
interior seems to be cooling and its glaciers thickening, studies show the
Antarctic Peninsula has been warming over the past 50 years.
Earlier, Leon wrote:
"Since 1999 it [the Earth, FF] has been
cooling off and the ice at Antarctica has increased by
over 10% in the past few years. "
and I replied"
The link I provided says the Larsen B
ice sheet has been in retreat for the last 50 years. That is
the same period over which most global temperature change
models conclude that warming has ocurred.
So where did you get the information about retreat
of the Larsen B ice shelf over a 50 year period that
preceded global warming?
No, you said that "the ice at Antarctica has increased by
over 10% in the past few years. "
the article says:
"Larsen B is one of five ice shelves -- large floating
extensions of ice sheets covering the continent -- that's
been on retreat. While Antarctica's interior seems to be
cooling and its glaciers thickening, studies show the
Antarctic Peninsula has been warming over the past
Nowhere in that article is that increase quantified.
The amount if ice lost from Larsen B in 2002 alone is
quantified -- 500,000,000,000 tonnes.
Since the article does not quantify any gains at all in any part of
Antarctica, it certainly does not support your claim of a net gain.
No honest person reading and understanding the article would claim
that it does.
On Feb 17, 3:00 am, firstname.lastname@example.org wrote:
And I pointed out that wasn't so, concluding:
However, if I am reading the abstract of this paper correctly,
(Note it is in .pdf format)
There was a net gain of ice in both Antarctica and Greenland
over the period of the study, 1992 - 2002. Averaged over that
ten year period the gain was 27 billion tons per year (Gt/a).
The net gain in Greenland was due to a gain in the interior
despite a loss at the margins. In Antarctica there was a net
loss on land net gain in sea ice.
I don't know if that data includes the March, 2002 collapse of
the Larsen B ice shelf, which was a loss of about 500 Gt.
I'll check with one of the authors to see.
I've also found a lot of information indicating net losses of ice
in the Arctic, and a net loss in the world's glaciers, but
on the former is not easily converted to net mass so I'm still not
clear on the recent net change, if any, in the global ice inventory.
It's worth noting that, whatever the effects of loss of ice in the north polar
cap may be, rising sea level is *not* among them: the north polar cap is
floating, and melting all of it won't affect sea level.
The south polar cap is an entirely different story. Some Antarctic ice is
floating; some of it is on land, above sea level; and some of it is on land
*below* sea level -- that is, it's in the ocean and resting on the ocean
floor. Melting of ice in this last category will cause sea level to *drop*.
Whether sea levels will rise or fall in response to melting polar ice caps
depends on the relative proportion of submarine Antarctic ice to land-based
ice in Antartica and Greenland.
I've not been able to find data indicating what that proportion is.
Doug Miller (alphageek at milmac dot com)
So the only ice that, if melted, would raise the sea level is ice
resting on land masses. When one subtracts out ice on or in the ocean,
how much ice is left, and where is it? Also, that's the air temperature
over the land-based ice? Because if the temperature is 20 degrees F,
and global warming raised the temperature to 22, or even 25 degrees F,
it still isn't going to melt.
And let's suppose the prevailing wind blows form west to east
across someplace like Greenland. If the west coast warms
a bit and melts a bit faster that could increase the local humidity
so that the air moving across it sees evaporative cooling and then
more cooling as it rises across the still below-freezing interior.
The result would be a transfer of ice from the coast to the
interior with no net loss and maybe even a short-term net gain
in total ice.
I think that sort of mechanism is the basis for some of the global
warming predictions of greater snow and ice accumulations in some
Regardless, energy is conserved. If the Earth is warming there will
be lat least ONE of the following: less ice and snow, more humidity
or something will have a higher temperature. There is no intrinsic
reason why one or two of those could not remain stable or go the
other way, so long as the other(s) compensated.
The data in the paper I mentioned does not include Antarctic data
past the Spring of 2001. It also excludes some Antarctic ice that
does not affect, directly or indirectly, sea level as the focus of the
paper was on sea level change. Note that ice shelves do not
directly affect sea level but they do influence their associated
ice sheets that do affect sea level.
So if Leon was recollecting a net increase in Antarctic ice and snow
prior to 2002 or a recent increase in precipitation in the interior he
may well be right. That doesn't tell us about net global change,
one way or the other.
On Mar 8, 7:56 am, email@example.com (Doug Miller) wrote:
Not entirely correct because the meltwater is freshwater that is less
dense than the seawater displaced by the ice. But you are correct
in that effect is very small compared to the effect of an equal mass
of ice melting on land.
It is also worth noting that I used the term "sea ice" incorrectly.
By definitions, an ice sheet is on land, an ice shelf is ice that has
moved out onto water from a glacier or an ice sheet, and sea ice
forms on water by freezing or precipitation. The Arctic ice cap is
all or nearly all sea ice. Antarctica has all three.
Does the ice in that category extend from the ocean floor to some not
insignificant height above mean sea level?
Keep in mind also that if you reduce an ice shelf, the associated ice
sheet accelerates toward the sea.
My interest is not in estimating sea level change, but in estimating
the energy gained or lost by the phase change. That is to say,
isothermal warming or cooling.
The difference in density between the meltwater and the ocean water won't
amount to a hill of beans. Yes, ocean water is more dense (by 2.7%), but
there's also a whole lot more of it, too, and the fresh water isn't going to
just lay there on top of it, either. Once it's mixed in, there won't be a
If it does, I can't find any indication of it in either of my world atlases.
Hmmmm.... now that's an interesting thought. Hadn't considered that
perspective. Certainly, the ice absorbs heat as it melts -- a lot of heat (80
calories per gram) -- whether that's significant on a planetary scale may be a
Doug Miller (alphageek at milmac dot com)
On Mar 9, 8:06 am, firstname.lastname@example.org (Doug Miller) wrote:
I don't think it matters whether the water molecules are
all in one blob or distributed over the entire ocean. So
the effect would be 2.7% of the volume of the meltwater
which we agree is not significant.
NASA probably has the data. Unfortunately net-vandals have forced
NASA into computer security practices that make it harder to get
the data out of the Distributed Data Archives free access to which
NASA was trying to provide to the world. It is hard to overestimate
the damage done to the world by spammers, crackers, and other
I think that a comparison with how much the air temperature would
rise or fall if all of the heat were lost or absorbed by the air alone
Of course the latent heat of evaporation and the high heat capacity
of water overwhelms that. Small global changes in humidity or ocean
temperature absorb or emit huge amounts of heat. That is a real good
thing as it provides us with stability. It also make it devilishly
to tell if the Earth is warming or cooling and at what rate, without
very long observation, unless the rate is dangerously large.
Depends what you mean by drown out.
Minute changes in CO2 would only have a minute
effect in the first place.
Those aformentioned phenomena do not change
the rates at which the Earth absorbs or emits energy.
So they don't nullify the effect of changes in
those rates regardless of what causes those changes,
Milininkov cycles, solar variation, volcanism, asteroid
impact, variations in the concentration of Greenhouse
They slow the effect of those changes. If the small
observed variation in insolation causes an observable
change then certainly the much larger variation in
CO2 concentration will too--unless the net effect of
those two is offset by yet another changing parameter
like global dimming form stratospheric particulates and
Convenient isn't it? If it's hot, it's because of global warming, If it's
cold, it's because of global warming. If it's normal, it's because of
global warming. If we have lots of hurricanes, it's because of global
warming. If we have only a few or no hurricanes, it's because of global
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