Citat:
För att fylla på Xenonens svar. Här har du en som räknat på effekten och kommit fram att den är mättad.
http://www.middlebury.net/nicol-08.doc
http://www.middlebury.net/nicol-08.doc
Frågan angående mättnad är inte ny och har utvärderats i den vetenskapliga litteraturen under tidigt 1900-tal. En vetenskaplig diskussion främst mellan Arrhenius och Ångström. Frågan är alltså avgjord.
Här finns lite värdefullt för dig att läsa. Varsågod.
Citat:
https://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf
The path to the present understanding of the effect of carbon
dioxide on climate was not without its missteps. Notably, in
1900 Knut Ångström (son of Anders Ångström, whose name
graces a unit of length widely used among spectroscopists)
argued in opposition to his fellow Swedish scientist Svante
Arrhenius that increasing CO2 could not affect Earth’s climate.
Ångström claimed that IR absorption by CO2 was saturated in
the sense that, for those wavelengths CO2 could absorb at all,
the CO2 already present in Earth’s atmosphere was absorbing
essentially all of the IR. With regard to Earthlike atmospheres,
Ångström was doubly wrong. First, modern spectroscopy
shows that CO2 is nowhere near being saturated. Ångström’s
laboratory experiments were simply too inaccurate to show the
additional absorption in the wings of the 667-cm−1 CO2 feature
that follows upon increasing CO2. But even if CO2 were saturated
in Ångström’s sense—as indeed it is on Venus—his argument
would nonetheless be fallacious. The Venusian atmosphere as a
whole may be saturated with regard to IR absorption, but the
radiation only escapes from the thin upper portions of the
atmosphere that are not saturated. Hot as Venus is, it would
become still hotter if one added CO2 to its atmosphere.
A related saturation fallacy, also popularized by Ångström, is
that CO2 could have no influence on radiation balance because
water vapor already absorbs all the IR that CO2 would absorb.
Earth’s very moist, near-surface tropical atmosphere is nearly
saturated in that sense, but the flaw in Ångström’s argument is
that radiation in the portion of the spectrum affected by CO2
escapes to space from the cold, dry upper portions of the
atmosphere, not from the warm, moist lower portions. Also, as
displayed in the inset to figure 2, the individual water-vapor
and CO2 spectral lines interleave but do not totally overlap. That
structure limits the competition between CO2 and water vapor.
dioxide on climate was not without its missteps. Notably, in
1900 Knut Ångström (son of Anders Ångström, whose name
graces a unit of length widely used among spectroscopists)
argued in opposition to his fellow Swedish scientist Svante
Arrhenius that increasing CO2 could not affect Earth’s climate.
Ångström claimed that IR absorption by CO2 was saturated in
the sense that, for those wavelengths CO2 could absorb at all,
the CO2 already present in Earth’s atmosphere was absorbing
essentially all of the IR. With regard to Earthlike atmospheres,
Ångström was doubly wrong. First, modern spectroscopy
shows that CO2 is nowhere near being saturated. Ångström’s
laboratory experiments were simply too inaccurate to show the
additional absorption in the wings of the 667-cm−1 CO2 feature
that follows upon increasing CO2. But even if CO2 were saturated
in Ångström’s sense—as indeed it is on Venus—his argument
would nonetheless be fallacious. The Venusian atmosphere as a
whole may be saturated with regard to IR absorption, but the
radiation only escapes from the thin upper portions of the
atmosphere that are not saturated. Hot as Venus is, it would
become still hotter if one added CO2 to its atmosphere.
A related saturation fallacy, also popularized by Ångström, is
that CO2 could have no influence on radiation balance because
water vapor already absorbs all the IR that CO2 would absorb.
Earth’s very moist, near-surface tropical atmosphere is nearly
saturated in that sense, but the flaw in Ångström’s argument is
that radiation in the portion of the spectrum affected by CO2
escapes to space from the cold, dry upper portions of the
atmosphere, not from the warm, moist lower portions. Also, as
displayed in the inset to figure 2, the individual water-vapor
and CO2 spectral lines interleave but do not totally overlap. That
structure limits the competition between CO2 and water vapor.
Samt:
Citat:
In the atmosphere, IR light can be absorbed and re-emitted multiple times before its energy reaches the emission level where it is free to escape to space (Pierrehumbert*2011). The process of repeated absorption and re-emission will result in a more diffuse structure for the OLR at the top of the atmosphere. Hence, for an observer viewing the earth from above (e.g., a satellite instrument measuring the OLR), the bulk IR light source is expected to be both more diffuse and located at increasing heights with greater concentrations of GHGs, as the depth to which the observer can see into the atmosphere gets shallower for more opaque air. This altitude is henceforth referred to as the ’equivalent bulk emission level’ and is the 254 K isotherm*Z*T254K*. It represents the mean height for both cloudy and cloud-free regions.
Higher concentrations of greenhouse gases divert more IR radiation downwards toward the ground (Trenberth*2011), as a deeper optical depth, due to increased absorption, is expected to restrict the radiative energy transfer, everything else being constant. Moreover, a change in the opacity will alter the radiative energy flow from the surface to the emission-level, which needs to be compensated by other forms of energy flow if the planet is to remain in energy balance according to Eq.*1*and if the total energy transfer is to be a continuous flow. In other words, the reduced radiative energy flux must be compensated through increased temperatures or altered latent/sensible heat fluxes.
In the atmosphere, IR light can be absorbed and re-emitted multiple times before its energy reaches the emission level where it is free to escape to space (Pierrehumbert*2011). The process of repeated absorption and re-emission will result in a more diffuse structure for the OLR at the top of the atmosphere. Hence, for an observer viewing the earth from above (e.g., a satellite instrument measuring the OLR), the bulk IR light source is expected to be both more diffuse and located at increasing heights with greater concentrations of GHGs, as the depth to which the observer can see into the atmosphere gets shallower for more opaque air. This altitude is henceforth referred to as the ’equivalent bulk emission level’ and is the 254 K isotherm*Z*T254K*. It represents the mean height for both cloudy and cloud-free regions.
Higher concentrations of greenhouse gases divert more IR radiation downwards toward the ground (Trenberth*2011), as a deeper optical depth, due to increased absorption, is expected to restrict the radiative energy transfer, everything else being constant. Moreover, a change in the opacity will alter the radiative energy flow from the surface to the emission-level, which needs to be compensated by other forms of energy flow if the planet is to remain in energy balance according to Eq.*1*and if the total energy transfer is to be a continuous flow. In other words, the reduced radiative energy flux must be compensated through increased temperatures or altered latent/sensible heat fluxes.
https://link.springer.com/article/10.1007/s00704-016-1732-y
Du och alla andra måste beakta denna höjd (equivalent bulk emission level). Se den som jordens "egentliga temperatur" och inse att växthuseffekten avgör var denna höjd hamnar. Många föreställer sig också den konvektiva temperaturgradienten (temperaturen avtar med höjden) åt "fel håll". Temperaturen ökar snarare med lägre höjd från "equivalent bulk emission level" och får således en längre sträcka på sig att öka när denna nivå hamnar högre upp i atmosfären. På detta sätt kan växthuseffekten sägas driva konvektionen.
Ökande koldioxidkoncentration skulle även öka yttemperaturen på Venus.
John Nicol hör även till "The usual suspects", typiskt sådana källor som jag tidigare varnat dig för. Om du är osäker, håll dig till etablerade och stora vetenskapliga organisationer som NASA och NAS och artiklar publicerade i tidsskrifter med hög impact factor, för att inte dras till rovmaterial som bara försöker lura dig. Många är allt för lätta byten.
https://www.nationalacademies.org/news/2019/06/national-academies-presidents-affirm-the-scientific-evidence-of-climate-change
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Senast redigerad av Trumpetflugan 2020-08-31 kl. 09:44.
Senast redigerad av Trumpetflugan 2020-08-31 kl. 09:44.
