Much effort and emotional energy is being invested in the debate about carbon taxing in Australia and similar constraints and profiteering in other places.
Taking a break from individual commentaries ( “Conversations: Climate change is happening” Part 6.), and summarising , my understanding and opinions so far are:
The ABC Drum topic name “Climate Change is happening“, is absurd because it is unscientific and meaningless. Because ‘global warming‘ is not a scientifically justifiable term, ‘climate change’ is offered instead. Now all and any adverse climate changes become erroneously associated with so-called ‘carbon pollution’. More unscientific claims and jargon.
The series title “Clearing up the Climate Debate”, is inappropriate because a one-sided series of papers adds to the debate. Without ‘opposition’ views and an impartial mediator the debate cannot be cleared up!
Issues of CO2 science, greenhouse effects, pollution, peer reviews, computer models, global temperature measurements and trends, natural climate cycles and influences, and agenda bias, all remain in dispute.
Actions – proposed, planned, and in progress, to minimise claimed-to-be damaging increases in global temperature are still based on strongly disputed sciences.
Scientific ‘truths’ are being judged by peer review, usually by selected on-side peers. Un-peer-reviewed opinions are summarily dismissed as having no validity.
Aside from all the other variables, the issue, because the AGW promoters have selected CO2 as the ‘villain’ to be controlled, can be honed down to establishing, with some degree of scientific certainty that there really is a direct, meaningful relationship between CO2 levels and ‘global temperature’.
But it is still not so simple because, there is much doubt whether the measured/assessed/computed/adjusted and then processed-to-a ‘global average’, published temperatures are genuine or influenced by vested interests.
However, the planetary-heating influence from atmospheric (greenhouse) properties and the difference CO2 levels have on this influence is certainly THE issue.
The multitude of other variables may well be of greater influence, of course one of the ‘denier’ arguments, but carbon taxing/pricing/trading, rail-roading activities are the real danger we are facing at the moment.
If the incremental CO2 heating influence cannot be adequately scientifically-proven beyond reasonable doubt, the public should not be asked/?forced to pay. Neither should industries be crippled unless this is resolved, not on paper, not by the public, but by a genuine scientific CONSENSUS of eligible persons from either ‘side’. Then, if involved persons do have a non-scientific motivation or individual technical strengths and weaknesses, a balance of pro and anti “believers” will prevent these factors from biasing the results.
Then, if the evidence is not strong and obvious enough to reach a consensus, the world should not be subjected to unjustified costs and controls .
Admittedly, having no associated relevant qualifications, whatever I say will be disregarded by the believers. However, perhaps it would be fairer if judgement is made on the content of the statement, rather than its source. My sources, referenced below, generally have good technical credentials and seem to be logical and independent of vested interests. The statements can be questioned, the norm for good science procedures. Where I have included differing viewpoints, the reader’s assessment will be interesting. The following is my understanding.
Basic greenhouse theory: (TGR page ‘Carbon Attack’/’An Educational Primer’/ ‘Primer 3: CO2 Aspects’)
In very simple terms, planet surface heating is initiated by UV ( short wavelength electromagnetic) radiation from the Sun. The sun‘s energy output as “seen” by earth is variable on a cyclical basis plus significant variations from solar spots. Portion of the radiation has been blocked by the atmosphere, especially by the ozone layer, but enough heating is available (cloud influence ignored and simple flat receiving area) to measure nominally a little over 1300 Watts/m>2. Its effective heating is determined by polar/tropical and of course, day/night effects, also seasonal and earth/sun distance variations, the average may be something like 240 W/m>2. A reasonable start as a discussion point.
As the earth absorbs some of this radiation, the earth warms. Some radiation, (depending on the surface characteristics – water, snow, ice, man-made surfaces /buildings), is reflected back at the same wavelengths. The areas that warm re-radiate at infra-red frequencies (long wavelength), back into the atmosphere. The amount of reflected energy after stabilization, theoretically would be close to the incoming energy when the stabilised global average temperature was something approximating 30 degC less than the current calculated temperature. Some planet heating must occur from transference from the internal molten core, but the bulk of the temperature difference is assumed to be from re-radiation from the “greenhouse” effect. All manner of variables are involved, but the principle is sound.
The atmosphere comprises a number of gasses, concentrations varying with altitude and each gas having its own reflection and absorption characteristics.
At lower atmospheric levels, water vapour (H2O) in the form of clouds, block UV from above and reflect or absorb IR in both directions. These become a huge variable in the equation.
So the heat radiation from the earth’s surface and the lower level air is radiated back up to the upper atmosphere where it is blocked/absorbed by CO2, water vapour and other GHG’s. There it causes heating of air and water vapour molecules, and results in re-radiation back towards the earth’s surface. Let see what the experts say about the real-life results.
One claimed scenario is that CO2 at a density of 0.04% of the atmosphere and an absorption spectrum of about 5 to 8% of the infra-red range would only absorb and re-radiate a maximum of 8% of the radiation even if the atmosphere was 100% CO2. At 0.04% density and 8% absorption capability, its effectiveness is indeed looking miniscule. (Ref. http://www.middlebury.net/op-ed/global-warming-01.html)
Another claim is that CO2 after initial warming effects, has ever decreasing effect: http://www.energypulse.net/centers/article/article_display.cfm?a_id=1598
Yet another theory, from a practicing climate scientist:
Most scientists, on both sides, also agree on how much a given increase in the level of carbon dioxide raises the planet’s temperature, if just the extra carbon dioxide is considered. These calculations come from laboratory experiments; the basic physics have been well known for a century.
The disagreement comes about what happens next.
The planet reacts to that extra carbon dioxide, which changes everything. Most critically, the extra warmth causes more water to evaporate from the oceans. But does the water hang around and increase the height of moist air in the atmosphere, or does it simply create more clouds and rain? Back in 1980, when the carbon dioxide theory started, no one knew. The alarmists guessed that it would increase the height of moist air around the planet, which would warm the planet even further, because the moist air is also a greenhouse gas. [emphasis mine]
But it didn’t increase the height of the moist air around the planet as subsequent studies have shown since that time. However, that theory or premise became the heart of the modeling that was done by the alarmist crowd.
So far, looking at the IPCC supporting scientist’s theory, which is that CO2 initiates the heating which is supplemented by the heat-created water vapour which itself becomes the predominant greenhouse gas. This would be a dangerous positive feedback situation except for the water vapour increasingly blocking incoming solar radiation and regulating the feedback. The whole cycle becomes extremely complex as the water vapour circulates/cycles due to precipitation. Warmer atmosphere creating higher rainfall is a negative feedback factor.
Precipitation and cloud shielding will both reverse the surface heating trend and the balance, variable in time and location, will arguably be more or less independent of the CO2 level. Then the other GHG’s measurably with even less forcing power individually, but with cumulative effect, reduce the CO2’s individual relative contribution.
It still remains, however, that the CO2, initially at say 0.02% of total atmospheric gasses, with 5-8% blocking effect on IR radiation escaping from the surface, would seem to be a very impotent force in the equation. To say that CO2’s effect is amplified by the water vapour is a circular argument. There may have been sufficient water vapour, not initially perhaps, but certainly after, for it already to have more effect than the smaller density of CO2. The CO2 effect can become negligible unless the water vapour has decreased significantly.
We are told that the greenhouse heating raises the lower atmosphere temperature by an amount up to 30degC above what it would otherwise be, if not for CO2 setting off the heat re-radiation back to the surface. Given the personal experience of being outside in the summer, even at 38 deg S, it is possible to imagine sufficient energy to raise the oceans and lakes and anything containing moisture to evaporative temperature levels required for water vapour production and cloud formation. Then natural release of CO2 from land carbon sources would assist further rises in global temperature.
And there again, in the past, the earth has been able to warm up from very much lower temperatures without the assistance of CO2 levels above 200 ppm. Not only that, but much higher levels of CO2 in the past have not created warming much above what we currently experience.
It is my humble opinion, that this issue should be placed openly on the debating table, until the evidence that CO2 is what IPCC claim, and is clear and convincing. There are simply too many variables, too many inadequately answered questions, so many that even computer modelling has to be based on a lot of assumptions and cannot include all variables. A convenient tool but not sufficiently convincing to justify conclusions of such importance as this.
A brave look at the Hansen science: Ref: http://www.pnas.org/content/101/46/16109.full
the climate system is presently out of energy balance by 0.5-1 W/m2, i.e., solar energy absorbed by the Earth exceeds outgoing thermal radiation by that amount.
indicate that climate sensitivity is ≈0.75 ± 0.25°C per W/m2
These forcings are similar to those of IPCC (3), although our sensitivity for CO2 is ≈10% larger (4.1 vs. 3.7 W/m2 for doubled CO2).
Assuming a linear relationship, 4 W/m>2 per 380ppm, in more realistic terms, is 0.4W/m>2 for a 10% increase of 38ppm CO2 causes approx. 0.1 degC global increase.
What is the total GHG forcing figure? No mention of H2O except that it isn’t included. Hmmm! If there is already sufficient CO2 to get the water vapour cycle started, there is no reason why even a lot more CO2 will make anything other than a minor difference. Does the CO2 molecule have some special characteristic of storing hundreds of times more heat than a H2O molecule?
Mind you, all these forcing and incremental figures are so small compared to the existing range of temperature variations due to equator/polar, day/night, summer/winter, solar radiation output and geographical altitude that it could be suggested that it is a brave scientific exercise to not only predict meaningful future effects with confidence but to also to commit the population to serious life changes on the predicted outcome.
(Minor revisions 28 June 2011)
http://www.anenglishmanscastle.com/180_years_accurate_Co2_Chemical_Methods.pdf (Discussion purpose only)