Thanks Archytas, It's a good scientific principle to keep the door open for other explanations than what seems to be the explanation that is widely accepted. However, if the widely-accepted view among scientists is that the future of our civilization is at risk, due to excessive emissions, than it makes sense to strive to reduce emissions.
What puzzles me most is that there are so few scientists trying to work out how such reductions can best be achieved. In this case, it's not so much a question of physics, it's more up to economists, accountants, diplomats and the like to get their act together. That in itself is also a struggle within science. Disciplines like political science, trend analysis and prognosis, economics and accountancy, law, political science, psychology and other social sciences have sometimes been regarded as second-rank types of science, as if the "hard" science such as physics, chemistry and yes, climatology, were based on "truth", while other studies were merely "opinions" and personal views. The struggle in Copenhagen has made it clear that, what we need(ed) is some robust science from areas such as political science, economics, diplomacy, and other social sciences. A huge amount of money is spent on efforts to verify whether temperatures are rising, etc, but - as it turned out - what we need most now is for science to compare the various political instruments on their merits, such as subsidies, taxes, emissions trading schemes, standards, border adjustments and diplomacy. Cheers Sam Carana On Tue, Dec 22, 2009 at 1:08 PM, archytas <[email protected]> wrote: > http://nov55.com/ntyg.html has an apparently well-argued case for > what Chaz may be on about when he mentions saturation. There is a > lot of stuff like this about - it's very well presented and could > quite easily look like science to the lay eye. In fact it's trash and > so well organised one has to suspect a real case of vested interests > intentionally trying to confuse the issues. > > On 22 Dec, 01:46, archytas <[email protected]> wrote: >> Hi Sam, >> Been a while. I wouldn't have bothered with such a lengthy (yet still >> partial) explanation if I didn't like Chaz. I'm by no means convinced >> by the rush to green through carbon restrictions myself - what he says >> other than on the issue of the trace CO2 is pretty sound. Nice offer >> - I don't suppose we could extend it to the 12 year olds I've just >> wasted a few sessions on? I don't usually teach in schools, but was >> asked by a friend to bring a few of my more explosive demonstrations >> along to see if she could get at her class through entertainment (my >> grandson goes there so I felt obliged). Little swines could do with a >> bit of philosophical fundamentals! Bring a big stick! >> >> On 21 Dec, 23:51, Sam Carana <[email protected]> wrote: >> >> >> >> > Chazwin, >> >> > There is plenty of scientific information available on this topic. I >> > think your position results from a philosophical line of thinking, >> > which forces you into denial. I suggest that you rethink the >> > fundamentals of your philosophy. If you like, I'm happy to go over the >> > philosophical fundamentals with you, to see if it adds up. >> >> > Cheers, >> > Sam Carana >> >> > On Dec 22, 10:10 am, archytas <[email protected]> wrote: >> >> > > There is a point at which more CO2 would be just like another set of >> > > shutters nailed over several others already blocking light. This >> > > point has long been factored in. Mars' atmosphere is thought to have >> > > been a lot thicker once. At some point in a pub crawl my mates tend >> > > to say 'are we doing one' when they want to move on. Usual notions >> > > for Mars' atmosphere 'doing one' are: >> > > Possible causes for the depletion of a previously thicker martian >> > > atmosphere include the following: >> > > Catastrophic collision by a body large enough to blow away a >> > > significant percentage of the atmosphere; >> > > Gradual erosion of the atmosphere by solar wind; and >> > > On-going removal of atmosphere due to electromagnetic field and solar >> > > wind interaction. >> > > Others suggest its magnetic field 'walked away' - hence that crap move >> > > The Core. It's not the CO2 on its own or even in combination with >> > > other stuff like methane. On Venus it's held warming isn't greenhouse >> > > at all. Indeed, 'greenhouse' is a misnomer - greenhouses heat up by >> > > restricting convection. This is the gist: >> >> > > There is general agreement that the Earth is naturally warmed to some >> > > extent by atmospheric gases, principally water vapor, in what is often >> > > called a "greenhouse effect". The Earth absorbs enough radiation from >> > > the sun to raise its temperature by 0.5 degrees per day, but is >> > > theoretically capable of emitting sufficient long-wave radiation to >> > > cool itself by 5 times this amount. The Earth maintains its energy >> > > balance in part by absorption of the outgoing longwave radiation in >> > > the atmosphere, which causes warming (black body and all such jazz). >> > > On this basis, it has been estimated that the current level of warming >> > > is on the order of 33 degrees C. That is to say, in the absence of so- >> > > called greenhouse gases, the Earth would be 33 degrees cooler than it >> > > is today, or about 255 K (-0.4° F). There would be little need to >> > > keep the voddie in the freezer. Water is by far the most important. >> > > Although estimates of the contribution from water vapor vary widely, >> > > many sources place it between 90 and 95% of the warming effect, or >> > > about 30-31 of the 33 degrees. Carbon dioxide, although present in >> > > much lower concentrations than water, absorbs more infrared radiation >> > > than water on a per-molecule basis and contributes about 84% of the >> > > total non-water greenhouse gas equivalents or about 4.2-8.4% of the >> > > total greenhouse gas effect (this is a range bigger than economists >> > > often use in their 'highly accurate' predictions). This 33 degree >> > > increase in temperature is not caused simply by absorption of >> > > radiation by the gases themselves. Much of the 33 degree effect is >> > > caused by the Earth's adaptation to higher temperatures, which >> > > includes secondary effects such as increased water vapor, cloud >> > > formation, and changes in albedo or surface reflectivity caused by >> > > melting and aging of snow and ice. Accurately calculating the relative >> > > contribution of each of these components presents major difficulties. >> > > We aren't guessing, but it's clear there is room for dispute. >> > > Infrared radiation comes from two sources: the sun and the earth's >> > > surface. CO2 absorbs some of the infrared radiation and re-emits it in >> > > a random direction. If there is more CO2, the radiation is absorbed >> > > closer to the source. For radiation from the sun, this theory predicts >> > > that increased CO2 would cause cooling in the upper atmosphere and >> > > warming in the lower atmosphere. Thermometer measurements show that >> > > the lower atmosphere was warming between about 1906 and 1944 and >> > > between about 1976 and 1998, and either constant or cooling at other >> > > times. The validity of the temperature figures is hotly disputed. >> > > Traditionally, greenhouse gas levels are presented as dimensionless >> > > numbers representing parts per billion (ppb) multiplied by a scaling >> > > factor (global warming potential or GWP) that allows their relative >> > > efficiency of producing global temperature increases to be compared. >> > > For carbon dioxide, this scaling factor is 1.0. The factors for >> > > methane and nitrous oxide are 21 and 310, respectively, while sulfur >> > > hexafluoride is 23,900 times more effective than carbon dioxide. The >> > > GWP from carbon dioxide is primarily due to the position of its >> > > absorption bands in the critical longwave infrared region at 2, 3, 5, >> > > and 13-17 microns. The increase in the global energy balance caused >> > > by greenhouse gases is called "radiative forcing". >> >> > > Geologists tell us that the residence time of CO2 in the atmosphere is >> > > on the order of five to ten years. In contrast, the IPCC says it is >> > > 50-200 years. Whatever the actual number, there is no question that >> > > emitting CO2 will cause it to accumulate over short periods. But other >> > > processes, such as sequestration, also work against it, causing the >> > > levels to decrease rapidly over time.The arithmetic of absorption of >> > > infrared radiation also works to decrease the linearity. Absorption of >> > > light follows a logarithmic curve as the amount of absorbing substance >> > > increases. It is generally accepted that the concentration of carbon >> > > dioxide in the atmosphere is already high enough to absorb almost all >> > > the infrared radiation in the main carbon dioxide absorption bands >> > > over a distance of only a few km. Thus, even if the atmosphere were >> > > heavily laden with carbon dioxide, it would still only cause an >> > > incremental increase in the amount of infrared absorption over current >> > > levels.Very little of the radiation from the sun at the wavelengths at >> > > which carbon dioxide absorbs reaches the surface of the Earth >> > > directly. Similarly, very little of the radiation at these wavelengths >> > > that originates at the surface makes it all the way to space. Most of >> > > the infrared at these wavelengths is produced by black body radiation >> > > from objects that have been heated up by absorbing radiation at >> > > shorter wavelengths. This means that even if the carbon dioxide levels >> > > increase, it will have little effect on the total amount of infrared >> > > radiation that is absorbed from the sun. The main effect would be to >> > > trap radiation originating at the surface at lower levels in the >> > > atmosphere than before, where it would be slightly more difficult for >> > > the heat to be re-radiated back into space. This is the principle on >> > > which most of the global warming predictions are based.Most of the >> > > ultraviolet light (below 0.3 microns) is absorbed by ozone (O3) and >> > > oxygen (O2). Carbon dioxide has three large absorption bands in the >> > > infrared region at about 2.7, 4.3, and 15 microns. Water has several >> > > absorption bands in the infrared, and even has some absorption well >> > > into the microwave region. There is already sufficient CO2 in the >> > > atmosphere to absorb almost all of the radiation from the sun or from >> > > the surface of the earth in the principal CO2 absorption bands. >> > > The net effect of all these processes is that doubling carbon dioxide >> > > would not double the amount of global warming. In fact, the effect of >> > > carbon dioxide is roughly logarithmic. Each time carbon dioxide (or >> > > some other greenhouse gas) is doubled, the increase in temperature is >> > > the same as the previous increase. The reason for this is that, >> > > eventually, all the longwave radiation that can be absorbed has >> > > already been absorbed. It would be analogous to putting more and more >> > > blankets on your bed -- it soon reaches the point where doubling the >> > > number of blankets can't make it any warmer. We may currently be at >> > > that point where the current ppms are analogous to one blanket and >> > > doubling them would be like adding a second. >> >> > > If we start to sweat, you can bank on someone insisting we don't add >> > > any more water vapour to the atmosphere. Pressures on Venus make even >> > > absorption comparisons bad science by the way. My guess is that the >> > > IPCC has over-stated the case, but this isn't because of the puny >> > > amounts of CO2 -these are currently in critical concentrations, in the >> > > sense that variations have fairly substantial effects. The future >> > > memory may well be that carbon trading was as big a scam as >> > > Collateralised Derivative Options. Go forth and grok mate - I'd use >> > > stronger language but know we are both shrinking violets and would >> > > fade away before the sun gets its chance to fry us to crisps! Beer's >> > > Law is part of the calculation (with limitations) - I shall raise a >> > > glass tonight to the rest of what you say. >> >> > > On 21 Dec, 18:51, chazwin <[email protected]> wrote: >> >> > > > On Dec 21, 3:49 pm, >> >> ... >> >> read more » > > -- > > You received this message because you are subscribed to the Google Groups > "Epistemology" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/epistemology?hl=en. > > > -- You received this message because you are subscribed to the Google Groups "Epistemology" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/epistemology?hl=en.
