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"Mr. Wood?" http://en.wikipedia.org/wiki/Robert_W._Wood
Bystander said:"Mr. Wood?" http://en.wikipedia.org/wiki/Robert_W._Wood
chroot said:The IPCC is primarily a political organization, so I believe its views on science should be considered skeptically.
It also wouldn't surprise me at all if CO2 turns out to be mostly irrelevant. Water vapor is a much more effective greenhouse gas than CO2, and the Earth has endured long periods of enormous CO2 concentrations in its geological past without any calamitous increases in temperature. The hydrologic cycle has a much, much larger impact on our climate than our lightbulbs, and it'd be silly to think otherwise.
Right now, all we have to go on are models -- systems of differential equations solved numerically by supercomputers. Obviously, the addition or removal of a term or two can radically affect the predictions of such models, and we all know that these models are still very much in their infancy. We have no evidence that they are capable of predicting anything at all, in fact.
It's actually quite amazing to me that so many people are willing to spend so much money solving a problem (CO2 emission) that exists only as a prediction of some poorly-understood differential equations.
This is not to say I'm not an environmentalist -- I think pollution is terrible, I prefer bikes to cars, and I would love to see governments and corporations held to higher standards with regards to their environmental impact. If anthropogenic global warming is the impetus they need to finally clean things up, great -- I just personally don't believe it for a minute.
I see the entire AGW exercise as nothing more than an illustration of human psychology: people always seek to find patterns in randomness, and people always need something to fear.
- Warren
Integral said:Let me restate that if DR. Wood had more confidence in his results he would have used a stronger word then doubtful.
Happy Bystander?
reasonmclucus said:Preachers and politicians make absolute statements. Real scientists tend to qualify what they say because they realize they do not have perfect knowledge. Historically "scientists" who claim certainty about whatever they are selling have been attempting to con people into giving them money, particularly for medical treatments.
In most fields of science, researchers who express the most self-doubt and who understate their conclusions are the ones that are most respected.
Bystander said:Three hundredths of a percent in solar output corresponds to a 20 mK change in Earth surface temperature. That's over 20 years, and includes no discussion of instrument drift, or measures to correct for instrument drift. Polar "melting" on Mars? Over seven (?) years (I ain't going to reread that one for this post) isn't a long enough time frame to say anything.
As rebuttals of the IPCC arguments these papers are as strewn with bad science as the IPCC --- concatenations of unstated, implicit "if" statements that go on for a half dozen to dozen logical steps to reach meaningless conclusions.
Science is about unambiguous tests of single "if" statements.
pitot-tube said:The fact that the temperature in the Pacific ocean has a 10 year cycle that superimposes itself on the 3-5 year El Nino cycle suggests to me that variation in solar output does not account for changes in global temperature - there is something else going on.
No one has found a 10 year cycle for cosmic ray output that is superimposed on a 3-5 year cycle for cosmic ray output.
And why did the sun suddenly change its output to start the current ice age hot/cold cycle when it hadn't done so billions of years before?
Thousands of measurements have been done over land and sea to check the output of heat from the Earth's interior and this is too small compared to the Sun's output of energy to make a difference.
If the concentration of dissolved substances in the oceans had decreased then the amount of water vapour and other gases could increase in the atmosphere accounting for some global warming - but this is not the case:ther is no evidence of a change in concentration of dissolved substances.
As far as I can see the likely answer to the global warming conundrum is also one that accounts for the local warming in the pacific ocean and for both el nino and the pacific decadal oscillation.In this scenario there is an increase in greenhouse gas emission from the ring of fire - the volcanoes beneath the pacific ocean.One part of the ring of fire is causing heating for 3-5 years and the other for 10 years.El nino starts with high pressure off the coast of south america.Gas emitted from under the sea in the area of central america would be carried on the prevailing wind to the south and central pacific causing warming and high pressure there.The pacific decadal oscillation could start elsewhere on or close to the ring of fire.The jetstream can be shifted by warming in the pacific and thousands of years ago this would have resulted in warm weather in ice bound places in the north, and could have caused the rapid emission of icebergs from north america into the atlantic.Something caused the ice age (which we are still in) and people were not around at the time, so whatever caused global cooling is natural and it is therefore likely that whatever caused global warming is too.It should be kept in mind that in any explanation of the cause of el nino/the pacific decadal oscillation there also needs to be an explanation of why the warming effect goes away and then comes back.I think it is important to challenge the computer whizz kids with their hugely complicated models that say phenomena like el nino have no single cause but result from innumerable feedback mechanisms from sea and air currents on a global scale.Why shouldn't something local cause El Nino? Or the pacific decadal oscillation?
The Earth is rising more in the northern hemisphere than in the south (so I've heard - not from my hairdresser though!).Does this correspond with some sort of increased degassing of the mantle in the north - gas released as pressure is released?
Reducing pollution must necessarily have an associated cost; the study of minimizing these costs in a large society is economics. Being a scientist (physical) has gives one little qualification in the means of efficient reduction. Furthermore, free market pollution credits have a track record demonstrating superiority to central planning. The Acid Rain trading program began in 1995. See for example the http://www.epa.gov/airmarkets/progsregs/nox/index.html" .sysreset said:I am offended by the notion that global warming can be ameliorated by the puchase and sale of "carbon credits." If CO2 has nothing to do with global warming, this practice is particularly noxious. But even if CO2 has everything to do with global warming, it is still just a shell game to shuffle wealth from one place to another, without any true discernable benefit to mankind. I do not understand why scientists around the world have not risen up and publicly decried the promulgation of carbon credits.
vivesdn said:What if high levels of CO2 are the consequence of high temperatures and not the cause?
gendou2 said:I agree. Correlation does NOT imply causation!
What's more, one would expect to the temperature lag behind the CO2 levels just a bit.
This is because rising concentrations of CO2 are said to cause cascading global warming.
Does anyone know if this lag effect is seen?
vanesch said:It is in fact the CO2 which lags the temperature, with 600 years! That was first not seen, and hence the statement was made that it was the CO2 that caused directly the heating.
But now that the heating comes first, that couldn't hold anymore. So now the given explanation is that the initial cause of the heating was not the CO2 but something else (solar irradiance or something), but that through feedback, this caused higher CO2 levels (indeed, that's the causal link: heat -> CO2 and not the original CO2 -> heat), but that the CO2 then took over and amplified the original heating by greenhouse effect.
LightbulbSun said:Either way, too much carbon dioxide in our atmosphere doesn't bode well for us. If you don't believe me, look at Venus.
vivesdn said:But what we all now know is that increasing levels of CO2 are not the cause but a consequence.
Thank you Andre, as I was suspecting that CO2 levels might follow Temperature increases and not the opposite. I thought that this was not possible to state or refute given the resolution with which these data can be obtained. But this chart is pretty clear.
This conclusion is partially good news: climate change does not depend on our CO2 production.
Bad news: what we can do then?
gendou2 said:There seems to be an extraordinary dissonance between the facts given in this thread and the facts given in Al Gore's documentary. How is this resolved? I am very hesitant to conclude in my own mind that anthropogenic CO2 emissions are either extremely dangerous or not dangerous at all.
Also, if C2 is not a significant cause of anthropogenic global warming, what about other substances?
Andre said:But what is too much? 380ppmv is 0.000380 atmosphere. Surface atmospheric pressure on Venus is 91 atmosphere with 95% CO2. So we are talking some 6 orders of magnitude here or a factor 227,5000. What would be the maximum ppvm if we burned all fossil fuels at the current rates and trend?
There is also that little hypothesis that convection -bringing heat to altitudes- causes significant changes in greenhouse radiative effects. On Earth convection is a major player (Hadley cell) while I linked earlier to studies that showed that convection was not a player in the lower levels of Venus atmosphere.
LightbulbSun said:I am not knowledgeable on the carbon dioxide threshold for humans.
In a Geological Society of America abstract, Dr. Don Easterbrook, Professor of Geology at Western Washington University, presents data showing that the global warming cycle from 1977 to 1998 is now over and we have entered into a new global cooling period that should last for the next three decades. He also suggests that since the IPCC climate models are now so far off from what is actually happening that their projections for both this decade and century must be considered highly unreliable...cont'd
LightbulbSun said:I am not knowledgeable on the carbon dioxide threshold for humans.
I think LBS was asking about toxic levels of CO2 for basic human respiration? C02 is only a problem for respiration when it displaces the required oxygen, it is not otherwise toxic.Andre said:Agreed but that's not the point. ...
mheslep said:I think LBS was asking about toxic levels of CO2 for basic human respiration? C02 is only a problem for respiration when it displaces the required oxygen, it is not otherwise toxic.
Comfort (odor) criteria with respect to human bioeffluents are likely to be satisfied if the ventilation results in indoor CO2 concentrations less than 700 ppm above the outdoor air
concentration
Human Respiration
The air that leaves a person's lungs during exhalation contains 14% oxygen and 4.4% carbon dioxide.
Atmospheres with oxygen concentrations below 19.5 percent can have adverse physiological effects, and atmospheres with less than 16 percent oxygen can become life threatening.
Source: Composition of Air
LightbulbSun said:The Earth's atmosphere has 20.95% oxygen. So all it takes is a 1.4% reduction in oxygen to have adverse physiological effects on a human. My point is, an increase in CO2 presents a serious health risk, and it doesn't really matter whether it causes global warming or not.
Andre said:Well, you probably know the routine: refute it, challenge Al Gore and me scientifically. Do everything possible to demonstrate one to be wrong. It's not that difficult.Same story I would say, albeit that global and local effects both of CO2 and CH4 will be eye-openers in the first place, once examined thoroughly.