What is Greenhouse effect: Definition and 27 Discussions

The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere.Radiatively active gases (i.e., greenhouse gases) in a planet's atmosphere radiate energy in all directions. Part of this radiation is directed towards the surface, thus warming it. The intensity of downward radiation – that is, the strength of the greenhouse effect – depends on the amount of greenhouse gases that the atmosphere contains. The temperature rises until the intensity of upward radiation from the surface, thus cooling it, balances the downward flow of energy.Earth's natural greenhouse effect is critical to supporting life and initially was a precursor to life moving out of the ocean onto land. Human activities, mainly the burning of fossil fuels and clearcutting of forests, have increased the greenhouse effect and caused global warming.The planet Venus experienced a runaway greenhouse effect, resulting in an atmosphere which is 96% carbon dioxide, and a surface atmospheric pressure roughly the same as found 900 m (3,000 ft) underwater on Earth. Venus may have had water oceans, but they would have boiled off as the mean surface temperature rose to the current 735 K (462 °C; 863 °F).The term greenhouse effect is a slight misnomer, in the sense that physical greenhouses warm via a different mechanism. The greenhouse effect as an atmospheric mechanism functions through radiative heat loss while a traditional greenhouse as a built structure blocks convective heat loss. The result, however, is an increase in temperature in both cases.

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  1. J

    What happens to the IR radiation that the Greenhouse gases don't absorb?

    I have been searching for the answer yet – as I'm here – didn't find it. The current model of climate warming says the lower parts of Earth's atmosphere don't allow the IR radiation to escape freely to the outer space because the GH gas molecules keep absorbing it virtually as soon as it's been...
  2. P

    Environmental Physics - Radiative forcing effect on greenhouse effect

    I think part (a) is simple enough. Here is what I have done. (a) ##G=\sigma T^{4}_{s} - OLR## $$ =\sigma (294)^{4} - 160 = 254 Wm^-{2} $$ Part (b) is where I am confused. I think I'm supposed to apply the second relevant equation, in order to get the change in average surface temperature due to...
  3. Graeme M

    Simple explanation of greenhouse effect - right or wrong?

    This is a very simple question. I've read a fair bit about the greenhouse effect and how GHGs affect the Earth's surface temperature and I know it can get very complex. But if I boil it down, it seems to be a very simple thing. Am I right to think of it this way? Radiation from the sun reaches...
  4. D

    Can someone please debunk this claim that CO2 does not trap heat?

    Hi everybody I follow climate denier pages and every now and then come across a claim that doesn't seem to have been debunked yet. One such claim is made here: <link to uacceptable source deleted> The gist of the article is that scientists experimented with using different gases in double...
  5. P

    Future of the Atmosphere W/Unregulated Pollution?

    In a future (100, 500, and 1000 years in the future specifically) where industrial and domestic pollution is totally unregulated, what does the composition of the atmosphere look like? And what do weather systems look like? I know this is an extremely broad question, I'm just looking for a few...
  6. E

    How would lower oxygen affect the greenhouse effect?

    If a terrestrial, earth-like planet had an atmosphere similar to Earth but with only around 15% oxygen concentration and 84% nitrogen, what impact would that have on the greenhouse effect of the planet's atmosphere? Are there other factors that would be relevant to calculating the greenhouse effect?
  7. R

    Radiative forcing / Greenhouse effect

    How does radiative forcing relate to the greenhouse effect? Is radiative forcing part of the greenhouse effect? Or does radiative forcing cause it? I'm confused. Clear explanation needed. Thanks
  8. haruspex

    Insights Frequently Made Errors in Climate Science - The Greenhouse Effect - Comments

    haruspex submitted a new PF Insights post Frequently Made Errors in Climate Science - The Greenhouse Effect Continue reading the Original PF Insights Post.
  9. G

    NASA's greenhouse effect not correct?

    NASA says Earth's greenhouse effect makes Earth 33 C hotter than the Moon. All of that warming can be explained by Earth having 1 bar of pressure compared to the Moon having no pressure. Going from the Moon to Earth is like going from the top of the troposphere to sea level, roughly speaking...
  10. AotrsCommander

    Greenhouse effect on planetary equilibrium temperature help

    I am trying to back-calculate the greenhouse effect on planetary equilibrium temperature for Earth (in the hope I can then attempt applying it to other calculations.) I know that the actual equilibrium temperature of Earth is 287.89K, +33K above the calculated equilibrium temperature: Teq = (Q...
  11. S

    Why does the heat in the atmosphere mostly go down?

    The wiki article on the greenhouse effect (https://en.wikipedia.org/wiki/Greenhouse_effect) has a top illustration which shows the flow of heat and energy (Watts per meter squared) between outer space, the atmosphere, and Earth's surface. The illustrations shows that of the 519 in the...
  12. RaulTheUCSCSlug

    Greenhouse effect affected by Earths Gravity?

    Hey, so I was thinking how the atmosphere is held close to Earth due to gravity and realized that if certain molecules have a certain amount of kinetic energy, they are bound to leave the atmosphere correct? I mean there is an escape velocity that these molecules must need and I'm sure molecules...
  13. Let'sthink

    Is Greenhouse Gas the Main Cause of Global Warming? Experiments and Evidence

    As I understand and I think correctly, that Green house effect is in essence conversion of lower wavelengths in the Sun's energy to higher wavelength near infrared regions which can heat up the medium more efficiently. So if we have a closed transparent box containing some amount of green house...
  14. UMath1

    Landfill methane gas emissions

    I read that biodegradable waste in landfills produces methane, a harmful GHG. But didn't biodegradable waste always exist? We throw paper away, but the trees we produce paper from would have died eventually. Our organic waste comes from plants and animals that would have died eventually too. So...
  15. avito009

    Quantum Physics behind the greenhouse effect.

    I read that when heat passes through the glass of a greenhouse it gets absorbed by the Earth inside the greenhouse. The Earth reflects this heat but these rays are of longer wavelength so it bounces off the glass and inturn heats the greenhouse more. Now the heat coming from the sun is...
  16. Graeme M

    Greenhouse effect and Earth's surface temperature

    I posed this question in the Earth section of the forums, but I think I wasn't clear enough in how I posed my question, plus I think the question is more physics than Earth science. I have decided to try posing my question as a series of questions building to the main point. This is because I...
  17. K

    Greenhouse Effect and Pets in Automobiles

    I have a question about the greenhouse effect that I hope you all can answer. My neighborhood went bonkers last night b/c an older woman left her dog in her car at 10:30 pm to do some grocery shopping. It was dark, but it was 84 degrees. I know this would be extremely dangerous if the...
  18. N

    Just wondering what has the greatest greenhouse effect

    Which of the following has the greatest greenhouse effect, on a per-pound basis? CFC-11 Carbon Dioxide HFC-23 Methane Nitrous Oxide
  19. W

    Heat (radiation) without direct air transfer - greenhouse effect?

    Hi everyone I realized that I had a mistaken belief about the meaning of the term greenhouse effect. I thought that it refers to the phenomenon whereby there is an exchange of heat due to light but without there being a direct air contact between the body being heated and the surrounding...
  20. M

    Using the greenhouse effect for energy?

    Ok I don’t really know any reasons why this doesn’t happen already so I’m hoping some people can help. Is it not possible to induce a Runaway greenhouse effect in a controlled environment and then use it for energy production? If it is possible why isn’t it being done (too inefficient...
  21. C

    The physics of the greenhouse effect.

    I have to do some research on the greenhouse effect (the physics of it anyway) I am not to familiar with the topic and am on a tight schedule. If anyone has some interesting links, thoughts please share. I am interested in the role of clouds in GHG (greenhouse gases), how much do we know...
  22. V

    Greenhouse Effect & Heat Radiation

    Homework Statement I learned that the solar radiation entering the atmosphere heats up the Earth's surface and the heat then radiates from the surface to the rest of the atmosphere. Is the greenhouse effect mostly dependent on the heat radiating from the surface, or do the greenhouse gases...
  23. S

    The Greenhouse Effect vs. Blackbodies vs. Global Warming?

    Can anyone explain what the right approach to this stuff is? It's an area I am largely ignorant about. According to the Stefan-Boltzmann Law, the Earth should be -18C. Obviously, this isn't true because the Earth isn't a blackbody. But my questions: 1. Why isn't the Earth technically a...
  24. K

    Greenhouse effect (reflection vs transmission)

    Hi, In the study of the greenhouse effect, I know for a fact that short wavelength radiation pass through a glass container and heat up its contents. When its contents get hot, they will re-emit longer wavelength (and hence lower energies) radiation, which will then be unable to pass through...
  25. Andre

    Falsifying the Atmospheric CO2 Greenhouse Effect: G. Gerlich & R.D. Tscheuschner

    G. Gerlich, R. D. Tscheuschner (2009) Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics. International Journal of Modern Physics B, Vol. 23, No. 3 (30 January 2009), 275-364 (World Scientific Publishing Co.) see...
  26. N

    Astronomy - Greenhouse Effect (integral troubles mainly)

    Given equations: \frac{d T^4}{dr} = - \frac{3 \kappa \rho}{a c} F_{rad} where a = 4 \sigma_{B} / c with \sigma_{B} being the Boltzmann constant. Also, define the optical depth \tau = \int \kappa \rho dr Optical depth measured at ground level is \tau_{g} Where \tau_{g} = \int^\infty_{ground}...
  27. K

    Discovering the Father of the Greenhouse Effect: His Origin, Work, and Findings

    Who is considered the father of the greenhouse effect and why? what did he discover? and where was he from and where did he work? If anyone could please help answer these questions it would be greatly appriciated. Thanks Kathleen