"John T" wrote:
What's the old saying? "Lies, lies and statistics"?
What's that supposed to mean - that we can believe no science that uses
numbers?
Well-poisoning attempt noted.
There is enough ice on Greenland *alone* to raise msl 20+ feet. That
is an incontrovertible fact.
It's also incontrovertible that Greenland was much warmer just 1000 years
ago than it is today. In fact, Greenland temperatures reached a maximum
around 1930, but they have decreased since (based on ice core readings by
Dahl-Jensen, et al). The Greenland glaciers didn't suffer a dramatic melting
event.
The ol' "Greenland paradise" story. It is not incontrovertible that Greenland
was "much warmer" in the MWP than it is now. Modern research shows the late
20th century is warmer:
http://www.ncdc.noaa.gov/paleo/pubs/...oberg2005.html
http://www.ncdc.noaa.gov/paleo/pubs/...o2006/fig5.jpg
Your second statement is misleading. Northern hemisphere temperatures reached
a temporary peak in the 1930s, declined until about 1970, and have been
climbing since. Greeland is not an ice cube on a hot sidewalk. It takes a
while for ice masses the size of Greenland's to absorb enough heat to get a
major melt event going. That seems to be underway now:
http://www.physorg.com/news122749356.html
Will we have a 10 foot rise in 50 years?
Not according to current models, but ominous things are happening in
Greenland and Antarctica that indicate there are previously unknown
accelerating phenomena at work.
The real question is: Why?
It's been getting genarally warmer for the last 100 years.
But let me ask you something: Are you 100% sure your house is going
to burn down this year? If not, why are you wasting your money on
insurance? Why don't you just wait until you see flames, then buy a
policy?
Ah, the Precautionary Principle. Let's throw in "for the children" while
we're at it. 
You against taking precautions?
We had far warmer temperatures earlier in our history, and far
colder.
Far warmer in our history? Says who?
Says just about anybody's temperature reconstruction record which will show
periods such as the Holocene Maximum and the Medieval Warm Period -
assuming, of course, you consider the years 5500-2000 B.C.E. and 1100-1300
C.E. to be "in our history."
I'll grant you the Holocene Maximum, but "just about anybody's temperature
reconstruction" shows the MWP was not as warm as today. Most importantly,
nothing in anybody's reconstruction shows a spike as steep as the 20th
century's.
Speaking of statistics, satellites can measure temperature over a wide area
of the earth at a time and have been doing so continuously for the past 18
years or so. They report a modest rise of 0.05° C per decade
(http://science.nasa.gov/headlines/y2...t21jul_1m.htm). This contrasts
sharply with the 0.25-0.4° C change reported by surface readings between
1978 and 1998.
So?
Oh, I'm sure many of us here also remember the "coming ice age" predictions
of the '70's. It's certainly been mentioned in this thread before.
Puh-leeze. That is one of the moldiest oldies in the AGW deniers' bag of
talking points. What serious scientists of the time really said:
http://www.wmconnolley.org.uk/sci/iceage/nas-1975.html
There is no comparison between a few articles in the popular press of that
time and the near universal agreement among climate scientists today about
what is happening to the planet.
Further, we humans have supposedly warmed the earth due to all the CO2 we've
created since the beginning of the Industrial Age. Human-produced CO2
accounts for a far minority of the atmospheric CO2 (vice natural sources)
and total CO2 content of the atmosphere is 0.054%. What's more, CO2 is a
poor greenhouse gas - far less potent than water vapor, for instance - and
at a mere 0.054%, it simply cannot drive warming trends.
More from the oldies bag. Let's take your points in order:
* Human-produced CO2 accounts for a far minority of the atmospheric CO2
(vice natural sources)
You don't quantify "far minority," but it is empirically established that
human activity has produced a 35% increase in atmospheric CO2 PPMV since about
1800.
http://environmentalchemistry.com/yo...alwarming.html
offers good explanations of how we know.
* and total CO2 content of the atmosphere is 0.054%.
Yes. So? The major gases, nitrogen, oxygen and argon, are transparent to IR.
They don't matter when it comes to stopping heat from being radiated back to
space. It's the GHGs that prevent the planet from freezing. Pointing out that
CO2 is a small part of the total atmosphere is a red herring in this context.
* What's more, CO2 is a poor greenhouse gas-- far less potent than water
vapor, for instance
A good example of using an incomplete and misleadingly stated fact to make a
false point. H2O in the troposphere is a feedback effect; it is not a forcing
agent. Simply put, perturbations in water vapor concentrations are too short
lived to change the climate. Too much in the air will quickly rain out, not
enough and the abundant ocean surface will provide the difference via
evaporation. But once the air is warmed by other means, H2O concentrations
will rise and stay high, thus providing the feedback.
* at a mere 0.054%, it simply cannot drive warming trends
I have already shown why your " mere 0.054%" argument is disingenuous. CO2 is
the most abundant and therefore most important of the *persistent* GHGs. It
is the persistent GHGs that control the long term retention of solar energy in
the atmosphere. The volume of CO2 in the atmosphere has recently risen 35% to
~380 PPM. That is the highest it has been for at least six hundred and fifty
thousand years, and almost all of the increase has happened since about 1800.
1800 roughly marks the beginning of the Industrial Revolution and the
beginning of exponential growth of the human population. Furthermore, carbon
isotope tagging confirms the fossil fuel origin of much of CO2 in the
atmosphere. Therefore, it is logical and empirically demonstrable that human
activities are producing an increase in atmospheric CO2 unprecedented in the
climatological record for its *rapidity*.
Over the same 200-year period, the 5-year mean global temperature has steadily
risen, with well understood peaks and valleys due to other climate forcings
such as solar activity and volcanism and phenomena such as el niņo/la niņa.
Thus it seems obvious to me that human activities are warming the climate by
the massive emission of GHGs, principally CO2.
This combined with ice core records proving CO2 peaks lag temperature by
hundreds of years (as much as 800 years) is a major reason the
"pro-anthropogenic global warming" (pro-AGW) crowd have abandoned Gore's
famous graph trying to link CO2 as the cause of warming.
All the graphs I see on scientific sites still show this lag. It's there; it
can't be "abandoned." What it *means* WRT to the current CO2 rise is the part
that gets "abandoned" by AGW deniers.
In the ice core records to which you refer, CO2 rise is a reinforcing factor
in warming periods begun by earth's orbital cycle. In those cases, the CO2 is
released by the initial warming and then acts to amplify and lengthen the
subsequent warm period.
What's different about the present CO2 rise is that it is independent of the
regular orbital cycles. Nevertheless, it is producing the warming effect that
an increase in CO2 *must* produce.
My point?
1. Earth's climate has changed dramatically over the millenia from
extraordinarily warm periods to very cold ice ages long before humans came
along - only in the current interglacial, by the way.
Yep.
2. It is the pinnacle of arrogance to think humans are capable of changing
*global* climate - especially in a mere 150 years.
Hand waving.
Humans have jacked up the concentration of the most important greenhouse gas
in the atmosphere by 35%. The laws of physics demand that there be a result.
3. A review of the players for the pro-AGW crowd shows a littany of
leftists, former Communists and general anti-capitalists.
Weakest of all your arguments. A review of the denier mouthpieces reveals a
motley collection of crackpots, right wing axe-grinders and energy company
whores. There are indeed leftists who have co-opted the issue, but that's
politics and beside the point. Unless you are claiming that every major
professional scientific organization in the world is composed of leftists,
former Communists and general anti-capitalists, your argument falls flat.
I'm just not buying the "humans are causing global warming" line. There are
simply too many holes in that theory for it to be any more valid than the
former "coming ice age" scare of the '70's.
You've regurgitated all the usual deniers' falsehoods to "support" your
position, but you exposed your real reasons in your #3 above.
--
Dan
"The opposite of science is not religion; the opposite of science is wishful
thinking."
-John Derbyshire