Climate debate not over: MIT study says greenhouse warming theory is wrong — but offers new warming hypothesis

Greenhouse warming only happens for so long. Then the alleged warming villain becomes “visible short-wave radiation.”

The media release is below.

Global warming not just a blanket — in the long run, it’s more like tanning oil

While computer models churn out bleak forecasts for the planet’s future, we also have a more conceptual understanding of what is happening as humans pump carbon dioxide into the air. But the conceptual understanding of carbon dioxide wrapping the planet in a blanket that traps more heat is not quite right.

A new study from the University of Washington and the Massachusetts Institute of Technology hopes to complete the understanding of what happens to the planet under climate change. Instead of carbon dioxide, or CO2, creating a blanket to slowly warm the planet, a paper this week in the Proceedings of the National Academy of Sciences shows the story is a little more complicated – though the ending is, unfortunately, the same.

“This is a neat study in that it changes the way we think about the climate system,” said lead author Aaron Donohoe, a postdoctoral researcher at MIT who is now beginning as a research associate at the UW’s Applied Physics Laboratory. “We looked at processes that are well captured in the models, but the conceptual understanding of how they work hasn’t been fleshed out before.”

When CO2 is first added, it does act as a blanket, trapping long-wave infrared energy coming off the Earth. The atmosphere then emits less of this long-wave radiation to space because the upper atmosphere is cooler than the Earth’s surface, just as the top of your blanket is cooler than your body. But the Earth gradually heats up under this blanket, and hotter objects emit more long-wave radiation, so within about a decade the effect of adding the thicker blanket has been canceled by the warmer body emitting more energy.

So what keeps the planet warming after the first decade? In the longer term, the study shows that the Earth begins to absorb more shortwave radiation – the high-energy rays coming directly from the sun.

Previously people had shied away from talking about shortwave radiation because clouds can reflect this visible light back to space, and clouds remain one of the big unknowns under climate change.

Regardless of what happens to clouds, these researchers say, the planet is likely to have less ice and the air will become more humid under climate change, both of which will act to absorb more shortwave radiation from the sun. Those effects will be like putting tanning oil on the planet, letting it absorb more of the sun’s incoming rays.

Melting ice creates darker surfaces that can absorb more heat, and the more melting the more heat it can absorb. Likewise, warmer air holds more water vapor, causing it to absorb solar radiation that might otherwise bounce back off clouds, ice or snow.

“While greenhouse gases trap one type of radiation, it’s the other type – visible, shortwave radiation – that is really sustaining global warming over the long term,” said co-author Kyle Armour, a postdoctoral researcher at MIT who will join the UW faculty this fall with a joint appointment in oceanography and atmospheric sciences.

The result could help people better conceptualize global warming. It could also help better detect climate change in satellite data, which can measure both shortwave radiation reflected by the Earth and long-wave radiation emitted by the Earth.

Most of the study’s simulations involved a one-time addition of carbon dioxide into the atmosphere. One scenario simulated continuously increasing CO2, as is happening now – in that case, the long-wave radiation effect lasted about 20 years before the shortwave effect took over.

“Our results do not change our overall expectation that the planet will continue to warm due to the burning of fossil fuels, but they do change our fundamental understanding of how that warming comes about,” said co-author David Battisti, a UW professor of atmospheric sciences.

The study supports what scientists are seeing in models and observations, Battisti added.

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5 thoughts on “Climate debate not over: MIT study says greenhouse warming theory is wrong — but offers new warming hypothesis”

  1. Perhaps “An energy absorbing/rediating very loosely woven net” as an analogy rather than the blanket analogy could be closer to the actual mechanics of the atmospheric “greenhouse gas” process. As a percent of the atmospheric “greenhouse” effect, how much IR energy is absorbed by CO2 molecules versus how much IR energy is absorbed by H2O molecules? After being raised to a more excited or higher energy state, how long does a typical molecule of any type remain at the elevated state before emmitting a photon which returns it to the less elevated state?

  2. How can this study support BOTH the Models and the Observations when the MODELS are not supported by the OBSERVATIONS? 95% of the models have over-predicted warming! So any models that are supported by this study would be the 5% which predict a much lower rate of warming than the “catastrophic” 1.5 to 4.5 Degrees C warming the IPCC is hyperventilating about.

  3. Yes, this study may fix the flaw in the current models that shows heating in a single stratum of the atmosphere that observations show does not exist.

    But this is only a fix for a specific flaw and not a new theory at all.

    The bottom line is that NASA cannot say precisely how much the Earth is warming because the best instruments show that the Energy imbalance is 0.5 Wm-2.

    This uncertainty in this estimate is 34 times bigger than the estimate itself as Stephens and other scientists in NASA and other government-supported research agencies have shown.

    Any engineers reading this will immediately understand that if your uncertainty about a measurement is so much bigger than your measurement, the measurement is useless.

    A layperson would understand that if you tell her she has to run a 100-meter race, but the track may actually be anything up to 1700 meters to the north or 1700 meters to the south. You measured the track but are not sure about its length or direction. She might conclude that you really don’t have the right measuring tape or compass.

    Graeme L. Stephens et al, An update on Earth’s energy balance in light of the latest global observations. Nature Geoscience Vol 5 October 2012
    URL: http://www.nature.com/ngeo/journal/v5/n10/full/ngeo1580.html

    Also in 2012 Loeb et al updated James Hansen’s estimate of 0.6 Wm-2 to 0.5 Wm-2.
    Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty. (NATURE GEOSCIENCE j VOL 5 j FEBRUARY 2012)

  4. I don’t know whether it’s THIS interpretation of the study, or the study itself, which gets it seriously wrong but somebody did, somewhere.

    Even if the “trapping of radiation” thing exists (the Stephan-Boltzmann Law suggests it doesn’t, in the way assumed by “warmists”), one way it definitely DOESN’T work is like a blanket. Blankets prevent cooling by inhibiting conduction and convection, not radiation.

    A blanket is a TERRIBLE analogy to use because it presents the OPPOSITE picture, in a way, of the actual radiation physics involved. As such, it gives people very much the wrong idea about how it is supposed to work, and actually misleads them about “global warming”. People say, “A blanket. Yeah. That explains it. Blankets keep me warm. Global warming works like a blanket.”

    But there is no conduction or convection that actually occurs between the atmosphere and space. Real conduction and convection serve to raise any heat that is absorbed by the Earth up to its “effective radiative surface”, which is high in the atmosphere, thereby promoting COOLING. The “back radiation” model of “global warming” does absolutely nothing to prevent any of that… very much unlike a blanket, which would.

    To summarize briefly: ANY comparison of theoretical “back radiation”-caused warming to “blankets” or “insulation” is a 100% INCORRECT description of — or analogy to — the actual physics involved, and in the public’s mind only reinforces the the myth of greenhouse warming.

    If JunkScience would like a more thorough explanation of why comparing greenhouse warming to some kind of “blanket” does damage to attempts to inject actual science into the argument, send me an email address and I will happily elaborate.

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