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What feedback loops amplify or dampen global warming from CO2?

I've read about the amplifying effects due to water vapor levels and due to changing albedo from melting ice and snow. Are there other major feedback loops I'm missing? What about negative feedback loops?

Update:

Feedback loops, in this context, are effects which either amplify or dampen the global warming caused by CO2 greenhouse effects. CO2 alone cannot warm the planet by the predicted ~2 to 5 degrees celsius over the next century; the models that produce these figures factor in a number of theorized feedback loops which amplify CO2's effect. The most significant positive feedback loop I know of is the water vapor effect, explained below.

Umm, Jello, you've got it WAY backwards. The supposed effect of water vapor is an AMPLIFYING one. Basically, since water vapor is a greenhouse gas, global warming increases humidity, which in turn causes more warming via the greenhouse effect (alledgedly).

Update 2:

CrazyConservative, thank you for pointing out the (unknown) effect of clouds. I realize that cloud cover has a very high albedo, so I would think that it would have a huge effect. So if, as you say, the effects of global warming on cloud cover are unknown, then those climate models are missing a huge piece of the puzzle. Can someone confirm or refute this statement that the effects of cloud cover are as of yet unknown?

Ken, thanks for reminding me about the issue of trapped methane. I'd forgotten about that one. We better burn that stuff before it gets into the atmosphere, huh? :-p

10 Answers

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  • 1 decade ago
    Favorite Answer

    Yes - Increased levels of water vapor cause more snow, which reflects more light back into space reducing temperatures.

    This causes a positive feedback by increasing more water vapor, increasing snows, reflecting light, and reducing temperatures.

    This is how global warming causes colder temps and more snow.

  • 1 decade ago

    Most all feed back loops in nature are negative. The only one I know of that is not a negative feedback loop is the nuclear bomb. So let's think about this. We KNOW that the climate has been much warmer than today. Why were these same positive feedbacks we hear about not in effect then? Current AGW fanatics say that we just start the ball rolling, then positive feedback loops, like increases in water vapor, will take over. But, if that is all it takes, why did the world not cease to exist back when the temperatures were much higher? Or, how would the earth ever have cooled when for most of its lifetime, there were NO glaciers?

    The problem with AGW fanatics are they deal in a computer room. They plug numbers into a computer and get some results. So far, the results they have publicised have never come true. Are there more hurricanes? Has the climate being steadily increasing?, etc.

    The main feedback loop they are unable to account for are clouds. Yes the same water vapor which is a green house gas, also forms clouds. Clouds are notorious for reducing the temp by blocking the suns rays back into space. If we increase water vapor, then clouds must also increase. Also, as Bob has said, water vapor also can cool by precipitation. These two cooling effects would most likely over power any positive effect. If not, then the world, according to the AGW fanatics, should have burst into flames millions of years ago.

    Never trust those that attack the skeptics, not their ideas.

  • Anonymous
    5 years ago

    More hurricanes would be a negative feedback. Hurricanes reflect an enormous amount of the Sun's energy and the very high and warm clouds radiate a large amount of energy into space. Water vapor and methane from warm tundra are positive feedbacks. Methane ends ice ages and the reason why temperatures started to drop centuries before CO2 concentrations peaked is because the additional CO2 in that ere was due to the oxidation of methane, a more potent greenhouse gas.

  • 1 decade ago

    Also, reforestation in equatorial climates help because there is a conversion from carbon dioxide to oxyden.

    In temperate climates, forests are more asorbant than plain land so the corbon dioxide content would be outweighted

    The soot produced by industrializing countries is a dampening effect. Even if it is a health hazard. Airplane contrails are also a dampening effect. Someone did a study and that on the days after 9/11 when there weren't planes flying, the whole country was noticeably clearer and hotter.

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  • Ken
    Lv 5
    1 decade ago

    Approximately 50% of the fossil fuel emitted CO2 has been extracted from the atmosphere by land and ocean mechanisms. As the ocean surface waters becomes saturated (it takes about 1000 years for the deep waters to circulate to the top) this process will slow down and the atmospheric CO2 rates will increase at a more rapid rate than they have been (assuming steady human emission rates).

    A bigger problem is the trapped methane. As the permafrost warms (and we know northern latitudes are warming up much more than equatorial regions) significant trapped methane will be released. Methane is over 20-times as powerful of a green-house gas as CO2. There is also an estimated 900 gigatons of carbon currently trapped in permafrost throughout the world.

    Source(s): Sinks for anthropogenic carbon: http://www.aip.org/pt/vol-55/iss-8/p30.html
  • Rick
    Lv 7
    1 decade ago

    You might read this web page on percentages of water vapor vs. other GHGs:

    http://mysite.verizon.net/mhieb/WVFossils/greenhou...

    "Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect (4). Interestingly, many "facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold." + " Putting it all together:

    total human greenhouse gas contributions add up to about 0.28% of the greenhouse effect."

  • Rio
    Lv 6
    1 decade ago

    Just a little something you might want to know.They don't include water as a factor for the albedo effect.If it's surfaced based such as a ocean, the light is reflected at angles.If it's atmospheric its only a temporal effect.They are missing some pretty big pieces of this theory and have shown that it may actually be a reverse process in some areas at certian times.

  • Anonymous
    1 decade ago

    here are a few but because the earth is very complex there are plenty more.

    increased levels of water vapour +ve

    more co2 being released from the oceans.+ve

    melting of permafrost releasing trapped methane.+ve

    melting ice, causing less energy to be reflected into space. +ve

    as the earth warms more heat will be lost as radiation. -ve

    there is also weathering which will remove CO2 faster as its concentration in the atmosphere increases. (note this will take a long time so it is not really applicable in human terms)

    CrazyConservative

    current climate models actually have fully simulated clouds. also rain dose not "cool the earth" it just shifts the energy. rain water actually heats up as it precipitates.

  • 1 decade ago

    "Dampen" is what a baby does to a diaper.

  • 1 decade ago

    wat does that even mean????

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