Talk:Greenhouse effect

I don't really understand the section "Effects of pressure": do we really need it? Or is it in the right position? It's under "bodies other than Earth" but then it does talk about the situation on Earth. I wonder if it's perhaps too detailed for this high-level article? EMsmile (talk) 14:35, 7 August 2024 (UTC)

:Atmospheric pressure is the key parameter determining the local temperature in any planet's atmosphere, it is responsible for the temperature 'lapse rate' - the fall in temperature with altitude seen in every atmosphere, including stars.

:This relationship between temperature and pressure is a fundamental property of all gasses.

:Gasses comprise freely moving atoms and/ or molecules that exchange energy when they collide with each other, or with the walls of a container, a football etc. As an atmosphere, the gases do not escape into space because they are retained by the planet's (or the star's) gravitation in much the same way a tennis ball returns to the surface. Damorbel (talk) 16:54, 6 June 2025 (UTC)

The greenhouse effect occurs when greenhouse gases in a planet's atmosphere

This is a circular explanation. You should never explain a term with itself. Better is 'ir active gases'. 2003:E5:272D:4A00:6511:D243:C8D4:3A09 (talk) 19:12, 13 December 2024 (UTC)

: This is an encyclopedia, not a dictionary. Here, the term greenhouse gas is wikilinked to its own article. The term "IR active gases" is non-standard. —RCraig09 (talk) 19:45, 13 December 2024 (UTC)

::[https://www.ipcc.ch/help/frequently-asked-questions/#:~:text=The%20greenhouse%20effect%20is%20the,and%20elsewhere%20in%20the%20atmosphere. IPCC]: The greenhouse effect is the infrared radiative effect of all infrared-absorbing constituents in the atmosphere. Greenhouse gases (GHGs), clouds, and some aerosols absorb terrestrial radiation emitted by the Earth’s surface and elsewhere in the atmosphere. 79.127.158.105 (talk) 09:00, 30 December 2024 UCTT

What has she measured? Differences in thermal conductivity? All gases showed significant differences in their physical parameters (density, thermal conductivity). Changed convection? Anything is possible. But not the greenhouse effect. That cannot be measured in a laboratory experiment. 2003:E5:272D:4A00:6511:D243:C8D4:3A09 (talk) 19:24, 13 December 2024 (UTC)

: We're talking about radiant heat (Thermal radiation), not physical-contact thermal conductivity or convection. The GHE is measurable in the laboratory. —RCraig09 (talk) 19:43, 13 December 2024 (UTC)

::There is no laboratory experiment that proves the atmospheric greenhouse effect. The warming in the greenhouse is largely due to suppressed convection. The well-known high school experiments are wrong. If you use the noble gas argon instead of CO2, you get the same results within the limits of measurement accuracy. However, unlike CO2, Argon is not infrared active. If the GHE could be proven in the laboratory, the discussion about it would be over. You will not find any reference to such an experiment in the IPCC reports.

::Paul Wagoner; Chunhua Liu; R. G. Tobin

::Climate change in a shoebox: Right result, wrong physics

::Am. J. Phys. 78, 536–540 (2010) 79.127.158.105 (talk) 08:46, 30 December 2024 (UTC)

:::ok good like and share with friends . and dont read the last one it is wierd. 213.172.149.70 (talk) 11:35, 18 February 2025 (UTC)

:[https://webbook.nist.gov/cgi/cbook.cgi?ID=C124389&Type=IR-SPEC&Index=1#IR-SPEC CO2] has important absorption lines at about 1.5, 5.3 and 15 μm. The 1.5 μm line is very weak (you can change the setting to μm, normal X and absorption). Normal glass is only transparent to the near IR range. From this point of view, Eunice Newton Foote's results cannot be explained by IR absorption. IR-transparent glasses now exist, but they were not yet available in 1856.

:Note: You always have to consider all effects of heat transfer! 79.127.158.105 (talk) 09:36, 30 December 2024 (UTC)

The greenhouse effect occurs when greenhouse gases in a planet's atmosphere insulate the planet from losing heat to space, raising its surface temperature.

That is pure tautology!

It is the same as in the IPCC Assessment Reports.

Assuming the existence of a 'Greenhouse Gas' does not make it exist! Damorbel (talk) 07:03, 22 March 2025 (UTC)

:Go publish that in a reliable source, and we can use it in the article. Until then, it is just some random person's opinion. --Hob Gadling (talk) 11:27, 7 June 2025 (UTC)

At the atmospheric density of 0.040% carbo dioxide cannot possibly redirect radiation.

'Redirection' is the same as reflection. 'Redirection' is a 'change of momentum'. No change of energy takes place.

The radiation from carbon dioxide is a function of its temperature (T^4), the same for all material, be it solid, liquid or gaseous. This is entirely different from reflection.

Reflection is not a function of temperature, the colour of light is not changed by reflection, only the direction of travel (propagation). That is why a Newtonian reflector telescope can focus an image.

All the diagrams in this discussion show the greenhouse effect as reflecting infrared heat, very different from emitting infrared!

In Earth's atmosphere the density of CO2 is far too low to reflect thermal radiation, only high density materials such as water, solids or metal reflect as shown in the Greenhouse Effect diagrams. Damorbel (talk) 16:04, 6 June 2025 (UTC)

: {{reply|Damorbel}} It would help if you would make specific recommendations for exactly what to change, and where. Separately: the parts-per-million value does not affect whether or not something reflects versus radiates versus emitting; ppm just reflects how much is reflected versus radiated versus emitted. Please clarify. —RCraig09 (talk) 17:23, 6 June 2025 (UTC)

:: The temperature gradient of a planet's atmosphere, as with all gases in equilibrium conditions, is a function of the local pressure. A planet's atmosphere, if it has one, is retained by its gravitation. This means the local pressure falls below the surface pressure with increasing altitude, it is a well known effect called the 'Pressure Lapse Rate'. It is the principle of operation of an 'aneroid' altimeter, found in most aircraft.

::The well known principle behind this is - gas pressure and its temperature, again in equilibrium conditions, are directly connected.

::NB 'Equilibrium conditions' means there is no external influence like wind heat input or loss. Heat coming from e.g. the Sun or gravitational energy change with altitude, must be accounted for separately.

::This evidence based explanation of atmospheric temperature gradient, found in all atmospheres - including stars - must replace all 'Greenhouse Effect' temperature explanations.

::'Greenhouse Effect' temperature explanations are defective for two well know reasons, as I explain below.

::Thermal ('heat') radiation from any gas, particularly from gas molecules having a complex molecular structure like CO2, is freely emitted to and absorbed by adjacent molecules, meaning adjacent molecules will quickly acquire the same temperature.

::Thermal radiation from any gas cannot reach a planet's surface directly unless the gas density is so low it does not get absorbed by other molecules in its path. In this case the gas molecules temperature remains as it was, it does not change.

::The so-called Greenhouse gases (GHGs) on Earth form a very small percentage of the total - in the region of 0.04%. These GHGs constantly exchange their energy with the other atmospheric gases, O2, N2 etc. This means they, the GHGs, have the same temperature as the rest of the (local) atmosphere.

::This not original research, it is standard thermodynamics, known since time began, that temperature differences fade with time.

::What remains with planetary atmospheres is the well known temperature effect of (local) gas pressure, that temperature and pressure, when no other heat source (or sink) is involved i.e. the gas is thermally isolated, measure the same parameter but with different units.

::Changes must be made to all Wiki articles that mention an 'Atmospheric Greenhouse Effect' due to 'Greenhouse Gases'. Such claims are not supported by any evidence, they arise from shortcomings and misunderstandings contained in many 19thC publications.

::Scientific enquiry has always stumbled over misinterpreted evidence - Ptolemy's model of our Solar System with Earth at its centre survived for more than 1000 years, until the invention of the telescope and Newton's observations on gravitation showed its weaknesses.

::There are two well known physical effects, not found in any descriptions of 'The Greenhouse Theory of Climate Change', that clearly show its shortcomings :-

::1/ The effect on temperature of the atmospheric pressure gradient.

::2/ The fact that all material, including the so-called atmospheric 'Greenhouse Gases', absorb heat as well as emitting it. This vital property of all materials, gaseous, liquid or solid, is totally absent from the 'Greenhouse Gas explanation of atmospheres', even from the UN/IPCC 'Summaries for Policy Makers'

::The claims for an 'atmospheric Greenhouse Effect' cannot survive the omission of this 'absorption' property, it is an important part of atomic theory, including the Quantum Theory of Radiation.

::To summarise - the increased temperature at the surface of a planet with an atmosphere is due to the atmospheric pressure, quite independent of the composition of said atmosphere.Damorbel (talk) 10:03, 7 June 2025 (UTC)

:::This is well into WP:NOTFORUM territory. If you want to insert your own thoughts into Wikipedia articles, the correct way is via publishing them in reliable sources. Then, and only then, we can use them. This whole section could be deleted without any problem. --Hob Gadling (talk) 06:25, 8 June 2025 (UTC)