Posted on 4/19/2007, 3:34:22 PM by dangus
The following is based on observations accepted by the global-warming consensus, and does not attempt to refute or even provide contradictory evidence.
Is the Earth warming?
Yes. With extremely advanced statistical techniques, scientists have been able to cut through all the background noise of weather patterns and cyclical fluctuations to detect a tiny increase in temperature over the past 100 years. To be precise, there have been two warmings in the past century, each about three decades long, and each of about one third of one degree, separated by a pause of about three decades.
These increases are by no means unprecedented. 11 of 12 attempts to recreate Holocene (modern)-era temperatures show similar rapid fluctuations repeatedly over the last twelve thousand years. (This is ignoring the black "trend line", an activist-created measure which averaged out all measurements.)
The most recent fluctuation was the “little ice age,” during which temperatures dropped about one degree centigrade.
Are sea levels rising?
Apparently. They’ve risen about 20 centimeters in the past 115 years. Notice in the chart below, however, that there is zero correlation with accelerated or decelerated global warming. They rose steadily even during the three-decade pause in global warming. On the other hand, the sort of devestation speculated about by alarmists is often based on the notion that the polar ice cap will melt (not caps; there is no polar ice cap on the North Pole.) For that to happen, the temperature of Antarctica would have to increase by 100 degrees for 10,000 years.
Why are temperatures rising?
It is very difficult to tell. It is possible, but not certain that both periods of recent warming had a common cause. That is, a common factor may have warmed the Earth steadily throughout the past decade, but a mitigating factor may have suppressed the warming for a time. Aerosol pollution (referring to microgranules, not to CFCs, which cause ozone depletion and used to be found in “aerosol hair spray”) has been shown to increase cloud cover, which reflects away the warmth of the sun. The widespread existence of such pollution corresponds with when this mitigating factor would have existed.
The following chart shows how cloud cover has decreased globally by between four and five percent between 1987 and 2001. Note that this is the time frame of the most dramatic warming in the past century.
Aerosol mitigation of global warming poses several tricky problems for the alarmists. The rate of increase in global warming correlates horribly with carbon-dioxide output. The fastest increases occur during the 1930s, when the worldwide Great Depression resulted in dramatic decreases in carbon-dioxide output, and since the late 1980s, when, industrial nations’ production of carbon-dioxide leveled off. (China has been responsible for 80 percent of the increase in CO2 production, since then.) Contrarily, during the massive and care-free industrial expansion of the 1950s and 1960s, the globe actually cooled somewhat.
Aerosol mitigation could explain the cooling of the 1950s and 1960s in a manner consistent with the alarmists’ explanation of global warming. But the removal of aerosol mitigation also explains away some of the recent increase in global temperatures. Global warming alarmists have used the supposed recent acceleration of warming to extrapolate far more rapid warming in the next century, perhaps three to ten degrees. With aerosol mitigation, the gross trend in global warming is a harmless 0.06 degrees per decade. Without aerosol mitigation, observed temperatures in no way support any model of carbon-dioxide-induced global warming.
The existence of aerosol mitigation resuscitates other causes of global warming. Scientists actually observed an increase in solar output during the first half of the century, which has not reversed since then. This would be an obvious cause of warming, but the timing is off. Aerosol mitigation explains how the effects of such an increase could be delayed.
Don’t ice cores show global temperature correlates well with carbon dioxide?
Yes, in fact they correlate quite well, recently. But correlation isn’t causation. In the past 400,000 years, there have been six spikes in global temperatures, and in each case, there has been a spike in carbon dioxide in the atmosphere. If carbon dioxide was a cause of warming, one would expect temperature to follow carbon dioxide, but in each case there was a reversal in temperatures before there was a reversal in carbon dioxide levels. An increase in temperature makes the Earth’s vast oceans less soluble to carbon dioxide, so the warming probably caused the carbon dioxide, and not the other way around.
If carbon dioxide isn’t causing global warming, why isn’t it?
Chemists can easily explain how carbon dioxide could cause global warming, and even predict how much. The problem is that the Earth is an amazingly complex system. For every environmental change, there are numerous reactions that reinforce or mitigate the effects of the change. The alarmists see the Earth’s lack of response to warming factors and suppose that mitigating factors have been preventing a calamity, and, further, that we must be approaching some tipping point where the mitigating factors fail, and calamity ensues. In such complex systems, however, the opposite usually happens. The more changes stress the balance of a system, the more mitigating factors usually respond.
One obvious mitigating factor is that a warming object radiates more heat. Another mitigating factor may be a godsend. Most of plant growth over most of the earth is limited, not by a lack of fresh water, but by a lack of carbon dioxide. Plants dry out because they release their water in order to capture carbon dioxide. An increase in carbon dioxide means an increase in carbon-dioxide-consuming plants. This means that vast arid regions will become arable, and food production will skyrocket.
Don’t like it so hot? Move north. Shipping lanes will open, and the vast expanses of Siberia and the Canadian shield, which would the most largest and most fertile farmlands in the world if not for their permafrost, will thaw.
Oh, and don’t worry about the polar bears. Yes, retreating ice cover in mid-summer will mean the bears will have trouble hunting in July and August as they currently do. But they’ll be able to hunt in May, June, September and October. That’s right: their hunting seasons will increase, not decrease. Those skinny bears you’ve seen? They’re a result of overpopulation. It seems that polar bears like to make love around oil pipelines. I’m not kidding!
BFL
I love how some of these plots exaggerate to the eye the present C02 level. Yes 375 PPM, but it has been 300 PPM in the past few hundred thousand years. So were only 75 PPM more then then past max CO2 level in the last few hundred thousand years.
Big deal huh? Run for the hills. Jeez.
BUMP!
That paticular chart is too small to read the text, in my browser in any case.
I’m particularly interested in last chart, the one showing the CO2 and temperature variation with time. It does seem clear that temperature change does lead CO2 change. If we had a link to the original data, some smart statistical whizkid, of the kind that is found in abundance in the wilds of FR, he/she could surely run some meaningful calculations.
For example, can anyone provide the mean and standard deviation of the time lag between temperature and CO2 change? That would be the ticket.
What if, with all the “sequestration” of carbon dioxide, we have a huge die-back of vegetation in this planet? Have the “Greenies” thought this all the way through yet?
Or do they have to have a NEW set of “problems” when the current “global warming” problem recedes in importance?
Err....I have always been under the impression that the Artic’s free-floating polar ice is still considered an ice cap, just not an ice cap made of a solid sheet of ice or other frozen material as in the Antarctic and on Mars.
Maybe we could get them to drop the carbon tax in place of funding time travel so they could send someone back 800 years to change the weather.
You can’t trust anything in wiki on a subject that anyone has a difference on.
Within 100 years, the contraction of the land will become so severe that the sphere of the Earth will become imbalanced. The Earth will affect a wobble that will alter its axial tilt and wreak havoc with the seasons. Within 500 years the Earth's orbit will begin to degrade so that the planetary plane will shift into the path of an asteroid belt.
With the resulting bombardment of so much additional mass, the Earth's altered orbit will become ever more pronounced. Within 1,000 years, the Earth will shear away from the Sun and go hurtling through space. Without the warmth of the Sun, all life on the Earth will die.
Or not.
;-)
Please read point #5 in my profile. The above brief statement is incorrect.
Me too, but for the purposes of ocean levels, when you melt floating ice it does absolutely *nothing* to the level of the water it floats in. It melts precisely into the space it occupied below the waterline before it melted.
I read that point and found it utterly unconvincing. I did find it interesting that in your entire page there is only *one* passing mention of water vapor, the *dominant* greenhouse gas.
Let me guess - we have about ten years to fix it?
I have explained it as best possible in a short space. What points leave you unconvinced?
Regarding water vapor, temperature increase caused by higher atmospheric CO2 concentrations induces increased relative humidity, which also increases global temperature. This is called the "positive water vapor feedback effect". I will add this to the explanation. Thanks for noting this omission.
If your "tipping point" arugment, which is what it really is, were true and was the cause of the temprature rise, then the temprature would continue to rise or at least level out at a new higher equilibrium given the amount of atmospheric CO2, until something lowered the CO2 concentrations in the atmosphere.
However, as you can plainly see in the chart below, after each temprature peak, the temprature decline preceeds the CO2 concentrations by 800-1,000 years, without exception.
To finish your analogy, it would be as if I'm still pushing my finger on the bowling ball, but it suddenly stops halfway down the hill anyway, and refuses to roll again despite my continued application of pressure from my digit. After a time, I finally give up pushing. If that is the case, was it really my finger driving the system?
What could possibly explain atmospheric CO2 concentration level decline laging, not leading, atmospheric temprature decline? Due to their thermal mass, the oceans warm and cool more gradually than the atmosphere. After atmospheric temprature drops, due to some other mechanism than CO2 concentrations, there is a lag before the oceans cool enough to accept more CO2 in solution, thus lowering atmospheric concentrations.
So, unless you have a different Vostok chart that shows atmospheric CO2 levels dropping before atmospheric temprature levels do, your whole point #5 needs a serious re-think. I see why you retired from debating the issue.
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