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The greenhouse effect is real: here’s why

CLEARING UP THE CLIMATE DEBATE: Bureau of Meteorology scientist Karl Braganza explains why we know the climate is changing, and what’s causing it. In public discussions of climate change, the full range…

The decade ending 2010 was the warmest on record for Australia. AAP

CLEARING UP THE CLIMATE DEBATE: Bureau of Meteorology scientist Karl Braganza explains why we know the climate is changing, and what’s causing it.

In public discussions of climate change, the full range and weight of evidence underpinning the current science can be difficult to find.

A good example of this is the role of observations of the climate system over the past one hundred years or more.

In the current public discourse, the focus has been mostly on changes in global mean temperature.

The greenhouse effect is fundamental science

It would be easy to form the opinion that everything we know about climate change is based upon the observed rise in global temperatures and observed increase in carbon dioxide emissions since the industrial revolution.

In other words, one could have the mistaken impression that the entirety of climate science is based upon a single correlation study.

In reality, the correlation between global mean temperature and carbon dioxide over the 20th century forms an important, but very small part of the evidence for a human role in climate change.

Our assessment of the future risk from the continued build up of greenhouse gases in the atmosphere is even less informed by 20th century changes in global mean temperature.

For example, our understanding of the greenhouse effect – the link between greenhouse gas concentrations and global surface air temperature – is based primarily on our fundamental understanding of mathematics, physics, astronomy and chemistry.

Much of this science is textbook material that is at least a century old and does not rely on the recent climate record.

For example, it is a scientific fact that Venus, the planet most similar to Earth in our solar system, experiences surface temperatures of nearly 500 degrees Celsius due to its atmosphere being heavily laden with greenhouse gases.

Back on Earth, that fundamental understanding of the physics of radiation, combined with our understanding of climate change from the geological record, clearly demonstrates that increasing greenhouse gas concentrations will inevitably drive global warming.

Dusting for climate fingerprints

The observations we have taken since the start of 20th century have confirmed our fundamental understanding of the climate system.

While the climate system is very complex, observations have shown that our formulation of the physics of the atmosphere and oceans is largely correct, and ever improving.

Most importantly, the observations have confirmed that human activities, in particular a 40% increase in atmospheric carbon dioxide concentrations since the late 19th century, have had a discernible and significant impact on the climate system already.

In the field known as detection and attribution of climate change, scientists use indicators known as fingerprints of climate change.

These fingerprints show the entire climate system has changed in ways that are consistent with increasing greenhouse gases and an enhanced greenhouse effect. They also show that recent, long term changes are inconsistent with a range of natural causes.

Is it getting hot in here?

A warming world is obviously the most profound piece of evidence.

Here in Australia, the decade ending in 2010 has easily been the warmest since record keeping began, and continues a trend of each decade being warmer than the previous, that extends back 70 years.

Globally, significant warming and other changes have been observed across a range of different indicators and through a number of different recording instruments, and a consistent picture has now emerged.

Scientists have observed increases in continental temperatures and increases in the temperature of the lower atmosphere.

In the oceans, we have seen increases in sea-surface temperatures as well as increases in deep-ocean heat content. That increased heat has expanded the volume of the oceans and has been recorded as a rise in sea-level.

Scientists have also observed decreases in sea-ice, a general retreat of glaciers and decreases in snow cover. Changes in atmospheric pressure and rainfall have also occurred in patterns that we would expect due to increased greenhouse gases.

There is also emerging evidence that some, though not all, types of extreme weather have become more frequent around the planet. These changes are again consistent with our expectations for increasing atmospheric carbon dioxide.

Patterns of temperature change that are uniquely associated with the enhanced greenhouse effect, and which have been observed in the real world include:

  • greater warming in polar regions than tropical regions
  • greater warming over the continents than the oceans
  • greater warming of night time temperatures than daytime temperatures
  • greater warming in winter compared with summer
  • a pattern of cooling in the high atmosphere (stratosphere) with simultaneous warming in the lower atmosphere (troposphere).

How do we know it’s us?

By way of brief explanation, if the warming over the 20th century were due to some deep ocean process, we would not expect to see continents warming more rapidly than the oceans, or the oceans warming from the top down.

For increases in solar radiation, we would expect to see warming of the stratosphere rather than the observed cooling trend.

Similarly, greater global warming at night and during winter is more typical of increased greenhouse gases, rather than an increase in solar radiation.

There is a range of other observations that show the enhanced greenhouse effect is real.

The additional carbon dioxide in the atmosphere has been identified through its isotopic signature as being fossil fuel in origin.

The increased carbon dioxide absorbed by the oceans is being recorded as a measured decrease in ocean alkalinity.

Satellite measurements of outgoing long-wave radiation from the planet reveal increased absorption of energy in the spectral bands corresponding to carbon dioxide, exactly as expected from fundamental physics.

It is important to remember that the enhanced greenhouse effect is not the only factor acting on the climate system.

In the short term, the influence of greenhouse gases can be obscured by other competing forces.

These include other anthropogenic factors such as increased industrial aerosols and ozone depletion, as well as natural changes in solar radiation and volcanic aerosols, and the cycle of El Niño and La Niña events.

By choosing a range of indicators, by averaging over decades rather than years, and by looking at the pattern of change through the entire climate system, scientists are able to clearly discern the fingerprint of human-induced change.

Case closed

The climate of Earth is now a closely monitored thing; from instruments in space, in the deep ocean, in the atmosphere and across the surface of both land and sea.

It’s now practically certain that increasing greenhouse gases have already warmed the climate system.

That continued rapid increases in greenhouse gases will cause rapid future warming is irrefutable.

This is the second part of our series Clearing up the Climate Debate. To read the other instalments, follow the links below:

Join the conversation

104 Comments sorted by

Comments on this article are now closed.

  1. James Szabadics

    BSc

    This article is good and deals with the science - I would like to put to Karl a few questions so I better understand the scenario he has painted.

    I curious about the data set for observations of outgoing longwave radiation. Have we also been measuring the rate of conversion of incident light and ultravilet light sprecta into energy in the longwave spectral bands corresponding to carbon dioxide using these or other satellites to adjust raw OLR data measured at the Satellites? This rate of conversion…

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  2. Kris Baum

    logged in via email @krisbaum.com

    I have some general queries about the accuracy of this article.

    'Here in Australia, the decade ending in 2010 has easily been the warmest since record keeping began, and continues a trend of each decade being warmer than the previous, that extends back 70 years.'

    I'm curious to know what other proxy records indicate about Australian climate - am I wrong to assume that the warming generally called the Medieval Warming Period does show some pronounced warming as much or greater than the recent warming…

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  3. John Dodds

    Retired Engineer

    First a philosophical point: Climate Change is claimed to be complex . I claim it is NOT. It is simple physics- add more energy and the world warms up.

    Points of conflict:
    'Yes the Greenhouse Effect is real. The basic principle is that an energy photon is absorbed by a molecule of Greenhouse gas, & this absorption delays the release of the photon to space. This delay results in a longer residence time & we get warming. The effect happens everywhere a molecule can absorb the energy. It happens…

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    1. John Dodds

      Retired Engineer

      In reply to John Dodds

      Also forgot to say that another source of info similar to this is Realclimate.org run by many of the original scientists who wrote the papers at NASA/GISS in NY. They have years of scientific information.

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    2. Jimmy Green

      In reply to John Dodds

      John, you say CO2 cannot produce warming because it cannot produce energy. Carbon dioxide is a greenhouse gas as it transmits visible light but absorbs strongly in the infrared and near-infrared. With additional CO2 in the atmosphere energy comes in as visible light just as easily, but outgoing infrared light is partially blocked. The earth has to come to a warmer temperature and emit more infrared light before new thermal equilibrium is reached.

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    3. Jimmy Green

      logged in via Facebook

      In reply to John Dodds

      John, you say CO2 cannot produce warming because it cannot produce energy. Carbon dioxide is a greenhouse gas as it transmits visible light but absorbs strongly in the infrared and near-infrared. With additional CO2 in the atmosphere energy comes in as visible light just as easily, but outgoing infrared light is partially blocked. The earth has to come to a warmer temperature and emit more infrared light before new thermal equilibrium is reached. No extra energy needs to be created, instead there's a continuous energy flow and we're holding each bit for a little longer than usual.

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    4. Tom Curtis

      Mr

      In reply to John Dodds

      John Dodds

      1) The thermal inertia you describe as your first point of conflict is a genuine effect, and does result in some warming of the Earth, but not in the manner you describe. Specifically if an increase in temperature due to energy being delayed raised the temperature too high, outgoing thermal radiation would exceed incoming solar radiation, cooling the Earth. An equilibrium is established when outgoing thermal radiation equals incoming solar radiation. Because the energy content of…

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    5. Ian Orchard

      logged in via Facebook

      In reply to John Dodds

      John, I can't find any mention in your comments about the heat TRAPPING qualities of GHG. It's not necessary for any new energy to be created to warm the atmosphere, it just needs heat that would otherwise be radiated into space to be absorbed and released in random directions. If a photon emitted by your pet rock escapes into space, the earth is a little cooler (in fact according to our distance from the sun we should be frozen solid) but if it is absorbed by a CO2 molecule and emitted any direction but up it's maintaining the temperature. Add a lot of extra CO2 and methane molecules and your pet rock's photons are going to struggle to escape.

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    6. Ken Sekiya

      logged in via Twitter

      In reply to John Dodds

      "Climate Change" in mapping and modelling the system to a 100% is complex.
      The basic science however is Year 10 geography.

      Sometimes, as a communication specialist, I think that the "climate change debate" needs to go back to basics

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    7. Michael J. I. Brown

      ARC Future Fellow and Senior Lecturer at Monash University

      In reply to John Dodds

      To be blunt, the theories and paper discussed by Mr Dodds are not science. The relevant physics is not used correctly (if at all) and this is an example of the multitude of fringe theories that abound online.

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    8. John Dodds

      Retired Engineer

      In reply to Jimmy Green

      What about conservation of energy? In order to be warmer you have to have absorbed more energy Your scheme does not.
      The sequence for the GHE is that an IR photon is radiated from the Earth, it is absorbed by a GHG (mostly water vapor and CO2) the GHG molecule is then hot - like 900C, it vibrates and hits the neighboting air molecules thus tranferring energy to them and the air gets warmer. THe GHG does NOT trap the energy It delays its normal release to space by a few microseconds. Inorder to…

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    9. John Dodds

      Retired Engineer

      In reply to Ian Orchard

      See reply above. CO2/GHGs does NOT trap photons It absorbs the photon and since it is then at about 900C it vibrates and transfers the enrgy to the neighboring molecules within microseconds which then radiate energy up or down & complete the continouous energy in equals energy out process. If ther are no photons available the GHG doex not absorb one. This is why there are continuously excess GHGs available ie there is cold water and CO2 in the air and the ocean. If you want more warming than the normal 33C then you HAVE to add more energy photons. The sun has to increase (it hasn't changed since the 1960s) or we have to get more energy from gravity such as when the moon in its eccentric orbit gets closer.

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    10. Jimmy Green

      logged in via Facebook

      In reply to John Dodds

      John. Ok. Well. There are a few things that seem funny about your approach. Firstly something very odd I noticed:

      "Normally at the average temperature there is a fixed number of GHG absorbtions. The number stops when there is no more energy available to be absorbed, but there are lots of GHGs left over in the air and in the ocean." "The fact that there are water and dissolved CO2 in the ocean is proof that there are NOT any more photons available to increase the GHG warming."

      You seem to operating…

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    11. John Dodds

      Retired Engineer

      In reply to Tom Curtis

      Tom I am working on a full reply It takes time. Start with this & I will get to 2, 3 & 4 soon I hope.

      Tom. thank you very very much for reading thinking and then rsponding. Usually I do not get responses. Naturally I disagree with your conclusion that my arguments are weak. If ind that some of then are so strong that they completely invalidate the conventiaonal IPCC scenario. But be that as it may I will explain my take on each of your 4 concerns.

      1.The thermal Inertia Concern: I do NOT think…

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    12. John Dodds

      Retired Engineer

      In reply to Jimmy Green

      Jimmy,
      I appreciate your reply.
      I struggled with the same question.
      We are in an equilibrium situation energy in equals energy out. Whenever a GHG absorbs a photon it becomes unavailable to absorb another photon (for a few microseconds). It does return to the ambient temp (since the photon came from the ambient temp air & is returned there is no change in temp!) & is ready to absorb another photon. Apparently it takes many absorptions & releases before a photon gets to space. The key point for…

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    13. Bryce W. Johnson

      logged in via email @gmail.com

      In reply to John Dodds

      I am a retired nuclear engineer who became interested in global warming about 4 years ago, and have been studying it ever since. The article takes all the scientific malfeasance issues that the AGW promoters are guilty of and assigns them to the skeptics--an easy way to make an argument. All of the comments by John Dodds are absolutely correct.

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  4. Timothy Curtin

    Economic adviser

    Karl Braganza: - "For example, our understanding of the greenhouse effect – the link between greenhouse gas concentrations and global surface air temperature – is based primarily on our fundamental understanding of mathematics, physics, astronomy and chemistry". Really? Why then does the IPCC ignore atmospheric water vapour (hereafter [H2O]) in ALL of its primary radiative forcing scenarios in AR4 WG1? There [H2O] is reduced to a feedback role, albeit positive, and enough to raise the climate sensitivity…

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    1. Tom Curtis

      Mr

      In reply to Timothy Curtin

      Timothy Curtin is to be congratulated for rediscovering the well known fact that H2O is a strong greenhouse gas, and more abundant than CO2 in the lower atmosphere. The consequence, that H2O is far more important in determining short term fluctuations in temperature has long been known to climate scientists.

      What Timothy Curtin now needs to rediscover is that:

      a) H2O is largely confined to the lower reaches of the troposphere because of the rapid cooling of air with greater altitude; and

      b…

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  5. Douglas Cotton

    B.Sc.(Physics), B.A.(Econ), Dip.Bus.Admin

    Scientists world-wide need to question the cover-up of accurate temperature measurements by satellites (which correlate well with balloon measurements also) details of which are discussed on my webpage http://earth-climate.com and in the final paper referred to therein. These measurements showed no significant rise in the Southern Hemisphere and much smaller rises in the Northern Hemisphere than ground-based measurements. (There are numerous problems with ground based measurements.) You also need…

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    1. David Jones

      Head of Climate Monitoring and Prediction Services at Australian Bureau of Meteorology

      In reply to Douglas Cotton

      The IPCC AR3 and AR4 reports both include the MSU lower troposphere temperatures (though these are not global as they cannot capture the poles nor high altitudes) - these data are wildely known and reported in the science literature including data from UAH and RSS. The trend in the MSU LT from UAH are available at http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt in real time and get considerable exposure. The global trend is hardly different from that in the global surface data (such as from…

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    2. Douglas Cotton

      B.Sc.(Physics), B.A.(Econ), Dip.Bus.Admin

      In reply to David Jones

      Then how about the temperature of the oceans which has been falling since about 2004?

      Furthermore the mean satellite temperature at sea surface was slightly lower in the 12 months ending yesterday than in the 12 months ending 31 Dec 2003.

      See http://earth-climate.com/2003-2011.jpg

      This levelling out (actually a decline below the long-term trend) is in keeping with the 62 year cycle which peaked in 2002. So I suggest for a start that this information should lead to open-minded scientists having…

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  6. Michael Borgelt

    engineer, Borgelt Instruments

    Mr Braganza should look at the whole of the current interglacial, not the last hundred years or so.
    There have been several periods of higher and lower temperatures going back to the Holocene Optimum. So what caused them? There weren't enough humans or enough human activity to cause those changes. The changes in the last couple of centuries are merely the rebound from the LIA.
    I'm not disputing the basic physics of infrared absorbing gases, just how much extra surface heating it can cause. That after…

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    1. Peter Doidge

      Mr

      In reply to Michael Borgelt

      Michael Borgelt: your arguments against Karl Braganza’s piece are not compelling to me. I wish to make a number of specific responses.
      If , as you claim, “Venus [is] hotter [than Earth] because it is closer to the [S]un and receives about twice the incoming solar radiation and has an atmosphere 90 times as dense as Earth's at the surface”, why is the effective radiating temperature of Venus lower than that of Earth? In fact, there are several factors that come into the picture, including the albedo…

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    2. John Dodds

      Retired Engineer

      In reply to Peter Doidge

      I would like to add the point that Radiated E/M energy from planets etc (measured by satellites) is NOT the sole form of energy out. There is also energy in the form of Gravity and as magnetic field energy.
      The argument that satellite measurement balances or doesn't tthe E/M energy coming in as solar insolation is irrelevant since both are incomplete..
      It is a fact that Jupiter radiates more energy than comes in as solar insolation. (likewise for planets further out. This argument for the Venus temperature is not complete.

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  7. Michael J. I. Brown

    ARC Future Fellow and Senior Lecturer at Monash University

    It is a shame that the comments on this considered article have been dominated by those who are ignorant of the relevant science.

    Water vapour is discussed in the IPCC's 2007 Synthesis Report and is a well known greenhouse gas. Scientists are well aware that Venus is closer to the Sun than the Earth, but its temperature wouldn't be so extreme without the addition of greenhouse gases. It is impossible for thousands of scientists from dozens of countries to conspire to hide temperature records. Scientists do know how to apply the relevant laws of physics to their work.

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    1. Douglas Cotton

      B.Sc.(Physics), B.A.(Econ), Dip.Bus.Admin

      In reply to Michael J. I. Brown

      With due respect, please read (carefully) my site http://earth-climate.com (which has had over 300 hits in its first 24 hours) and note the reference to the cover-up of the highly accurate satellite temperature measurements (down to 5000 feet in the lower free troposphere) and then show me research that has taken these results (showing no increase) into account. Surely any analysis of temperature should not ignore such important data. Most research it seems only uses (spurious) ground level measurements.

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    2. Douglas Cotton

      B.Sc.(Physics), B.A.(Econ), Dip.Bus.Admin

      In reply to Michael Searcy

      Michael: The trend lines in the graphs you referred to are affected by the El Nino spike which, being only temporary, should have been eliminated from the data. Granted there would still be a somewhat lesser increase in your graphs. Can you clarify what altitudes were considered "lower troposphere" because I have been talking about the "free troposphere" which is usually taken to mean the whole troposphere above 5,000 feet. The graph I have used from p.84 at http://www.geocraft.com/WVFossils/Reference_Docs/satanic5.pdf

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    3. Michael J. I. Brown

      ARC Future Fellow and Senior Lecturer at Monash University

      In reply to Douglas Cotton

      There are a multitude of climate denial errors in this thread, and my original comments stand.

      There is no conspiracy by thousands of scientists to hide data. As Michael Searsy has shown, scientists often release their data to the public. There is a strong incentive for scientists to release data, as it can lift their profiles within the scientific community and increase their chances of gaining funding.

      The luminosity of the Sun over the past few decades has been remarkably constant. For an illustration…

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    4. Douglas Cotton

      B.Sc.(Physics), B.A.(Econ), Dip.Bus.Admin

      In reply to Michael J. I. Brown

      Michael:

      Just for the record ( as per the link on my site http://earth-climate.com ) the "cover up" to which I was referring related to the following excerpt:

      ‘‘We’ve got to do something about the satellite,’’ said the Union of Concerned Scientists’ Harold Ris at a White House global warming pep rally held in October 1997, prior to the UN meeting in Kyoto designed to make the climate treaty ‘‘legally binding." In turn, California rocket scientist Frank Wentz calculated that the slight drag that…

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    5. Michael J. I. Brown

      ARC Future Fellow and Senior Lecturer at Monash University

      In reply to Douglas Cotton

      So where are your sources for the quotes? Is Frank Wentz really a rocket scientist? Do you know the size of the correction Frank Wentz applied to the data? Do you know how an MSU works? Do you know why a correction is applied for orbital decay? Who discredited Wentz's analysis and why? What is your primary reference for the correlation between sunspots and global temperature? Why should we trust sunspot data over direct measures of the energy received from the Sun?

      Before you can discuss the science…

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    6. Michael Searcy

      In reply to Douglas Cotton

      A few items of note....

      (1) The ENSO signal over the satellite temperature era has been steady with little impact on overall temperature trends during that time.
      http://scentofpine.files.wordpress.com/2011/05/enso_1979-2009.jpg
      http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

      (2) Your graphs use the same MSU satellite data utilized by UAH and RSS. However, your data and graphs are considerably out-of-date for both duration and correction. Wentz's concerns about orbital…

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    7. John Dodds

      Retired Engineer

      In reply to Michael J. I. Brown

      If you accept the Arrhenius 1896 conclusion that "more GHGs means more warming," then you get Michael's viewpoint and the IPCC "true believer" accepted view. and the recent Joe Romm conclusion that a reduction in Solar insolation due to reduced sunspots will NOT diminish the "forcing" by GHGs. (just how can simply adding a GHG which does NOT add any energy result in more energy for warming?)
      HOWEVER, If you accept the idea that that it is not the GHGs but the energy change in the number of photons…

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  8. Timothy Curtin

    Economic adviser

    In reply to Michael J. Biercuk who commented on "Climate change is real: an open letter from the scientific community":
    "Tim, Can you comment on why you do not publish your research in peer-reviewed outlets?"

    I have, close to 30 in fact, albeit on a wide range of subjects.
    a
    The paper I have provided links to here (Econometrics and the Science of Climate Change) has been accepted by the Economic Society of Australia for its 2011 Conference at ANU 10th - 14th July). That is a first step to potential…

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    1. Douglas Cotton

      B.Sc.(Physics), B.A.(Econ), Dip.Bus.Admin

      In reply to Timothy Curtin

      And. Michael, please show me a proof that both the points in the last paragraph on my webpage http://earth-climate.com are also wrong after studying the full content carefully. How do you explain the observed stable temperatures from 5,000 feet upward? And how do you explain the lack of increase in the rate of increase in temperature in the two successive 62-year cycles I mention?

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    2. Michael J. I. Brown

      ARC Future Fellow and Senior Lecturer at Monash University

      In reply to Douglas Cotton

      There is an 11-year solar cycle and potentially several longer Solar Cycles (see http://en.wikipedia.org/wiki/Solar_variation for a summary and references). None of these cycles works like clockwork and none of these cycles corresponds to 62 years. Provide an original reference for there being a 62-year Solar cycle.

      Greenhouse gases should warm the lower atmosphere and cool the upper atmosphere. Unsurprisingly, somewhere in the middle the temperature will be relatively stable. Given several of your other comments have been in error, providing original references for your claims would improve their credibility.

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    3. Douglas Cotton

      B.Sc.(Physics), B.A.(Econ), Dip.Bus.Admin

      In reply to Michael J. I. Brown

      On my site http://earth-climate.com there are links to eleven sources and each of these have several references. Regarding the "62 year cyle" it is referred to as a 60 year cycle and you could have found this link from my site ... http://www.appinsys.com/globalwarming/SixtyYearCycle.htm

      From the overlay, I have deduced that it was closer to 62 years at least for the last two cycles, but it apparently varies a little around the 60 year mark. If you have studied the overlay I suggest it is fairly obvious.

      The key issue here is, that if this author is correct, then there is no evidence of any GH warming in the period since the late 1940's and this would surely explode the GH theory. As I see it, most GH exponents have found what are only relatively short term trends in recent years and the 60 year cycle debunks their analysis.

      It's over to you now to prove the 60 year cycle wrong!

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    4. Ian Orchard

      logged in via Facebook

      In reply to Douglas Cotton

      There's a firm belief that the AGW science is a house of cards that a single misplaced weather station or misinterpreted satellite reading will bring crashing down. It's not. It's a vast jigsaw puzzle, with no edges and no guide picture on the box. Even if you find a piece of blue sky that's been misplaced it doesn't negate the rest of the puzzle.

      It's not enough to find problems with details like 60 year cycles, you simultaneously have to explain, justify and/or dismiss: the basic physics of GHGs…

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    5. Michael J. I. Brown

      ARC Future Fellow and Senior Lecturer at Monash University

      In reply to Douglas Cotton

      Your only evidence for a 60 year solar cycle (in contradiction to the results and conclusions of many thousands of professional and amateur astronomers) is a crank website with suggestive lines overdrawn on plots. Very definitely not science.

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  9. Kip Hansen

    Retired IT Professional, Humanitarian Missionary

    Dear Mr. Barganza,

    You say 'For example, it is a scientific fact that Venus, the planet most similar to Earth in our solar system, experiences surface temperatures of nearly 500 degrees Celsius due to its atmosphere being heavily laden with greenhouse gases.'

    This statement, while commonly repeated, is a scientific urban legend. It is simply not true at all. Please take yourself over to the Physics Department of your local university and get yourself set straight on this. Ask them to calculate…

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    1. Michael J. I. Brown

      ARC Future Fellow and Senior Lecturer at Monash University

      In reply to Kip Hansen

      I suspect Dr Barganza can visit his local physics department without fear.

      There is an extensive scientific literature on Venus's atmosphere and its runaway greenhouse effect (including papers by Carl Sagan and collaborators). Measurements taken from Venera probes reveal that atmospheric transmission of light is very low at infrared wavelengths (e.g., http://adsabs.harvard.edu/abs/1981SSRv...29....3M), blocking heat leaving the surface, and resulting in a vast greenhouse effect.

      Can you provide a reference for "adiabatic lapse rate" origin of Venus's spectacular surface temperature? Can you provide a link to the original calculations? If not, what conclusions should we draw from this exchange?

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  10. Anthony Cox

    logged in via email @optusnet.com.au

    Whether the atmospheric temperature profile of Venus is due to the high concentration of CO2 in its atmosphere or is a product of its lapse rate created by the pressure of that atmosphere is an issue which was debated at length and at a high level of expertise here:

    http://scienceofdoom.com/2010/06/22/venusian-mysteries-part-two/#comment-3947

    The issue is unresolved despite a follow up discussion at the same site.

    The Wentz paper on precipitation touches on two aspects of the AGW debate; the first is the unreliability of computer modelling, in this instance in respect of predicted precipitation levels; secondly, it removes the crucial parameter which AGW relies on, increasing atmospheric water levels with increases in evaporation being matched by increases in precipitation.

    Even an increase in atmospheric water levels may not support AGW with growing evidence that water is not a positive feedback.

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  11. Scott Brown

    Mathematician turned Engineer

    "Energy in equals energy out" has nothing to do with global mean temperature, does it? Seems to me that's a statement about equilibrium conditions. The moon's average temperature is much colder than Terra's, but they have the same solar radiance.

    Run water from a hose continually into a tank and water in will not equal water out until the tank fills up, which I guess could be called equilibrium potential energy. Drill a column of 1" holes through the side of the tank and depending on the fill rate…

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    1. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Scott Brown

      Hi Scott; the notion of the veracity of a global average temperature [GAT] being a true indicator of whether the planet is retaining energy and heat has been debunked, initially by this paper:

      http://pielkeclimatesci.files.wordpress.com/2009/10/r-321.pdf

      A fairly detailed analysis of this paper and its critics is here:

      http://rankexploits.com/musings/2008/spatial-variations-in-gmst-eli-rabbett-vs-dr-pielke-sr/

      The basic problem is that temperatures may be rising in a cool region but stable or…

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    2. Peter Doidge

      Mr

      In reply to Anthony Cox

      Anthony Cox: the papers I have seen on, for example, oceanic heat content indicate that this is measured in Joules, or energy units. I am not sure what point you are trying to make, unless it be a point of a lawyerly kind.

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  12. Michael Kottek

    logged in via Facebook

    "For increases in solar radiation, we would expect to see. . ."

    I have to say I was disappointed to read that because you must have deliberately chosen to ignore the possibility that the sun's magnetic effects could affect albed; by affecting condensation nuclei and cloud formation.

    My understanding is that the modelling of cloud formation is in any case very very poorly understood, and the relevant parameters are not constrained by observation. Choose a few different parameters, who knows you might end up with negative feedbacks.

    So, given that "In the short term, the influence of greenhouse gases can be obscured by other competing forces" and the unconstrained cloud parameterisation in the modelling; can we really be sure that the doomsday scenarios have been adequately validated. Might it not be better to adopt no regrets measures, and prepare for adaptation if it proves necessary.

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    1. Peter Doidge

      Mr

      In reply to Michael Kottek

      Michael, the main problem for me in what you have written is the sheer vagueness and speculative nature of your comment. Several years ago, when reading the last edition of Houghton's The Physics of Amospheres, the consensus on clouds, as described there, was that there is, overall, positive feedback. If you want to speculate that cloud feedback is negative, then please produce evidence.

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    2. Michael Kottek

      logged in via Facebook

      In reply to Peter Doidge

      Well this what the IPCC say:

      Narrowing the uncertainty in cloud feedback may require both improved parametrizations of cloud microphysical properties (e.g., Tsushima et al., 2006) and improved representations of cloud macrophysical properties, through improved parametrizations of other physical processes (e.g., Williams et al., 2001) and/or increases in resolution (Palmer, 2005).

      A s far as I am aware a consensus that is barely constrained by observation would be best described as the experts' best guess, would it not? Is that really an adequate basis to re-engineer society from on high?

      Cloud formation and the sun is the subject of the CLOUD experiment at CERN. Nothing may come of CLOUD, but I don't see why anyone holding themselves out as a disinterested expert could ignore CLOUD if they are going to comment on the effect of the sun on climate.

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  13. Richard Lawson

    logged in via Twitter

    I would like to ask the sceptics here this question: What is your statement of affairs? Do you deny that CO2 is a greenhouse gas? (I guess not, since that is a physical fact) Do you deny that CO2 has increased since 1750? (I guess not, since that is a matter of observation). Do you assert that the climate sensitivity of CO2 is lower than the generally accepted value of 3*+ or - 1.5*C? I guess so.

    In that case, let us debate the matter of climate sensitivity, and find how whether your thesis of <1.5*C is confirmed or refuted by the facts. If the debate on this point is inconclusive, let us devise an investigation that can answer the question conclusively.

    A lot hangs on this debate. As things stand, it can go on indefinitely. We need to resolve it one way or the other as soon as possible.

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    1. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Richard Lawson

      That's strange; the title is:

      On the observational determination of climate sensitivity and its implications

      Richard S. Lindzen1, and Yong-Sang Choi

      It was published:

      May 22, 2011 18
      Asia-Pacific Journal of Atmospheric Sciences

      And the Abstract is:

      We estimate climate sensitivity from observations, using the deseasonalized fluctuations in sea 26 surface temperatures (SSTs) and the concurrent fluctuations in the top-of-atmosphere (TOA) 27 outgoing radiation from the ERBE (1985-1999) and CERES…

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    2. Peter Doidge

      Mr

      In reply to Richard Lawson

      Richard, the link worked for me. However, Anthony has neglected to mention a couple of things. This paper has been criticised by Roy Spencer, a noted contrarian. And there is a detailed examination of the paper and the issues at Real Climate. We should always consider the response accorded to papers that go against the mainstream (as this one does). It is not good enough to acclaim it, simply because its conclusions fit one's preconceptions.

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    3. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Peter Doidge

      I haven't neglected anything. This is the 3rd version of Lindzen and Choi's paper; unlike some these 2 scintists are prepared to take constructive criticism on board and have continually addressed issues with their previous work.

      Spencer's objections were in respect of previous versions of the paper. I don't consider RC a meaningful critique of anything, but perhaps Mr Doidge can be more specific in detailing what the RC crew have brought to the table.

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    4. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Anthony Cox

      I might add that Spencer's work in respect of climate sensitivity has been subject to revisions:

      http://www.drroyspencer.com/Spencer-and-Braswell-08.pdf

      http://noconsensus.files.wordpress.com/2010/08/spencer-braswell-jgr-20101.pdf

      And that Spencer and Braswell conclude a similar climate sensitivity to Lindzen and Choi; 0.6C to 0.7C.

      The profound aspect of Lindzen and Choi's finding is that there is no equilibrium sensitivity; the temperature response we have from the existing level of CO2 is all we are going to get and there is no further 'pipeline' heating.

      As I say, this is profound and susbstantially undermines the doomsday predictions emanating from the IPCC.

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  14. Timothy Curtin

    Economic adviser

    RL asks (19 June 2011) (1): “What is your statement of affairs? Do you deny that CO2 is a greenhouse gas?” No, John Tyndall showed it was back in 1861.
    And (2) “Do you deny that CO2 has increased since 1750?” No.
    And (3) “Do you assert that the climate sensitivity of CO2 is lower than the generally accepted value of 3*+ or - 1.5*C?” YES
    Observations show that global mean temperature has increased by only 0.75 oC since 1900 (or 1960 allowing for the actual declines from 1940 to 1960), or just 0.0125…

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    1. Richard Lawson

      logged in via Twitter

      In reply to Timothy Curtin

      Thanks Tim. You calculate zero climate sensitivity for CO2. This confirms my growing conviction that the debate should focus on climate sensitivity, since that is the central thesis of the sceptic lobby.

      As a separate q, do you also calculate zero climate sensitivity for the other factors? I guess not, since you mention methane and H2O. Is CO2 therefore the only factor which has zero climate sensitivity in your view?

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    2. John Dodds

      Retired Engineer

      In reply to Richard Lawson

      I also claim zero climate sensitivity for CO2 & methane etc. I claim that it is the number of energy photons, not the number of GHGs that cause the changes in temperature. If you add CO2 you will ONLY get more warming, IF and ONLY IF you add more energy photons to the added or already excess GHGs in the air. When you reduce the number of photons you reduce the GHE every night, every winter, every 60 years, every 900-1000 years etc. in spite of adding more GHGs/CO2
      If there is no change in the number…

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  15. Rowan Steele

    logged in via Facebook

    It is fantastic to see such a clear and succinct explanation of the basic reasons scientists know we are causing climate change. This information is available on multiple platforms, but I have found this article the most useful for one-on-one rebuttal of climate denial.

    Well done to the scientific community for starting to really holding up there end of the stick and putting the basic scientific debate to rest, so we, the community campaigners, can fight in our local community for stronger action to address this issue.

    We stand united. If we continue to do so, there is hope. For just one example to raise your hopes, check out the work of the Australian Youth Climate Coalition.

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    1. John Dodds

      Retired Engineer

      In reply to Rowan Steele

      What happened to the laws of physics? Conservation of Energy says you can NOT get warming unless you add more energy. SO just how do you get positive (or negative) FEEDBACK? YOU MUST add the energy for feedback from somewhere OR it ain't gonna happen. If the world is at an energy equilibrium and the daily cycles above and below equilibrium and the operation of the Stefan-Boltzmann law's action of increasing or decreasing energy radiated out at the speed of light, means that we are AT EQUILIBRIAM…

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    2. Ian Orchard

      logged in via Facebook

      In reply to John Dodds

      Oh for crissake, John! Put three extra eiderdown duvees (dooners?) on your bed. Are you hotter? Undoubtedly! Have you added any extra energy? No!! How does the atmosphere differ?

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    3. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Ian Orchard

      Don't keep us in suspense Ian, you're obviously privy to inside knowledge about the peer review; peel back the eiderdown and give us the warmed facts.

      While you're at it perhaps you'd care to comment about Lu's finding of CO2 saturation as well:

      http://journalofcosmology.com/QingBinLu.pdf

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    4. John Dodds

      Retired Engineer

      In reply to Ian Orchard

      The analogy does NOT work.The blanket analogy starts with a heat source UNDER the blankets, & an increase in a resistance to heat transfer for a local change in the temperature. It means that if under the blanket is now warmer then above the blanket is now colder. There is a conservation of energy.
      The Earth has a heat source outside the blankets, and a trivial resistance that is only partially in use (there are more GHGs than photons.) The claim is that the GLOBAL, ie WHOLE, ENTIRE, WORLD has heated…

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    5. Ian Orchard

      logged in via Facebook

      In reply to John Dodds

      "The analogy does NOT work.The blanket analogy starts with a heat source UNDER the blankets, & an increase in a resistance to heat transfer for a local change in the temperature. It means that if under the blanket is now warmer then above the blanket is now colder. There is a conservation of energy. "
      Harking back to Climate Change 101, the incoming solar radiation is not absorbed or reflected by the atmosphere, but the longer wavelengths of IR emitted by the surface is. That's the whole basis of the so-called greenhouse effect. How did you miss that?

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    6. John Dodds

      Retired Engineer

      In reply to Ian Orchard

      Do the math. You are claiming tht the total mass in the cooler stratosphere balances the warmer troposphere plus the warmer ground plus the warmer ocean plus the warmer entire earth. It don't add up. I

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    7. Jimmy Green

      logged in via Facebook

      In reply to John Dodds

      John, CO2's property of restricting radiation in the infrared and transmitting it in the visible is very easy to verify and understand experimentally, regardless of your thought experiment. The earth will not always be in thermodynamic equilibrium, it takes time for it to warm up because it has thermal mass and only once it has warmed up will outgoing IR radiation be in equilibrium with incoming radiation, due to the Stefan Boltzmann law as you said. IR radiation is the only relevant energy out of the system, what mechanism could possibly make gravitational and magnetic field energy be related to the temperature? Friction from falling objects? Some kind of massive dynamo? I don't think any gravitation or magnetic field energy need be considered. Incoming and outgoing radiation has been measured by sattelites as you know and is the only relevant flow.

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    8. Jimmy Green

      logged in via Facebook

      In reply to John Dodds

      What are you talking about? The mass in the stratosphere doesn't need to balance the warmer anything. The earth just needs to get warmer so it can get the same amount of radiation that it used to radiate before out through all the CO2 that's in the way.

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    9. John Dodds

      Retired Engineer

      In reply to Jimmy Green

      Jimmy I think you underestimate the Earth's ability to come to equilibrium. In a single day we go above and below by 5-10 degrees. forcing equilibrium. It takes about 6-8 CO2 absorbtions (ie tens of microseconds) for the half up half down postulated scenario due to a photon absorption to come to equilibrium where Energy in equals energy out. Since this is a continuous process, We are essentially ALWAYS at equilibrium. The half up half down scenario gets energy from the previous 10 absorptions…

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    10. John Dodds

      Retired Engineer

      In reply to Jimmy Green

      You seem to be under the impression that adding CO2/GHGs adds warming (ie what IPCC says.) If the world is always at equilibrium, and it results in 33C of warming, AND this requires that all of the available photons are in use (continuously), then if you add CO2 (which we do!) it can NOT undergo the GHE because there iare NO More photons available to be used. for more GHE or for feedback The only way to get more warming is to add more photons to get more absorbtion and the added photons causes more…

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    11. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Nathan Stewart

      Quite simply that is wrong; the rate of warming from 1910 to 1945 was as great as the warming during the era of AGW, from 1976 onwards:

      http://www.woodfortrees.org/plot/hadcrut3vgl/from:1910/to:1945/trend/plot/hadcrut3vgl/from:1976/to:2012/trend

      The trend from 1910-1945 was 0.0162365 per year; from 1976 it has been 0.0162365 per year; that is essentially no difference.

      On a longer scale the Medieval Warm Period was at least as warm as today as the McShane and Wyner critique of Mann's hockeystick shows:

      http://noconsensus.files.wordpress.com/2010/08/aoas1001-014r2a0.pdf

      The Roman Warm Period was also warmer as was the Holocene:

      http://www.sciencedirect.com/science/article/pii/S0277379110000673

      As to rates of warming; if you want real speed of warming google Dansgaard–Oeschger event:

      http://icebubbles.ucsd.edu/Publications/Preboreal_EPSL_2008.pdf

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    12. Jimmy Green

      logged in via Facebook

      In reply to John Dodds

      Concerning your model of IR radiation through a GHG: This should be demonstrable in a lab, do you have any references for laboratory tests in support of this model?

      The proximity of Jupiter to the earth and any associated changes in gravitational potential energy have no effect on earth's temperature. I don't dispute that gravitational potential energy can be converted into heat, like when a space shuttle re-enters earth's atmosphere, but in the case of Jupiter there's no thermal interaction until…

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    13. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Anthony Cox

      That should be 0.0162448 per year from 1976, but the point holds that there is essentially no difference with the rate of increase in temperature from 1910-1945.

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    14. Nathan Stewart

      Mr

      In reply to Jimmy Green

      Can i just say thanks Jimmy - whilst you will never convince John Dodds otherwise, your responses have been very informative for myself and im sure a few others aswell, so it hasnt all been in vain! I too find it unfathomable that they are able to ignore the sheer weight of evidence backing up AGW and are so adamant about a crazy theory that somehow gravity is connected to the earth's temperature. I once worked with an old bloke who was a hydraulics engineer. He was adamant that a solar hot water panel he was trying to sell was so good it could produce heat from the light of a full moon. He said it at a meeting with potential clients, i had never been so embarrassed in my life. Absolutely impossible, of course he had never had it tested, but he swore he had seen it done on the internet.

      Anyway, thanks again for the wide ranging education in global warming and gravity's potential for heating, or lack thereof.

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    15. John Dodds

      Retired Engineer

      In reply to Jimmy Green

      Jimmy, Thank you for asking the questions, & letting me provide my answers. I think your contribution will provide some answers to people questioning the IPCC science. However as Gavin says (below) you will not convince me.

      Your last question first: There is a 250+page paper called "John Dodds Wobble Theory of Global Warming" available in www.scribd.com that calculates the forces of gravity of each of the sun and planets as a function of time & prioritizes them.. The reason it is not in the summary…

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    16. John Dodds

      Retired Engineer

      In reply to Nathan Stewart

      Gavin- your questiion is partly answered above to Jimmy, BUT, if you look at the figure on p7 of the free "Gravity causes Climate change" paper at www scribd.com) you will find a GISP2 ice core derived plot of temperature (not mine) with the current 150 years of measured temps grafted on by me. The history shows that now is not unique. It is not even the largest rise or fall . How does the temperature FALL if more CO2 keeps causing more warming?
      Anthony Cox's rate of rise is represented by the…

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    17. John Dodds

      Retired Engineer

      In reply to Nathan Stewart

      Gavin
      I'm going to turn your comment around on you.
      You are aware that it warms in the morning and cools at night due to changes in the amount of energy photons that comes in with the solar insolation changes on a daily basis. So why should you believe that a "Crazy theory" like IPCC's global warming or "More GHGs means more warming" when it is perfectly obvious that more energy photons causes warming and fewer energy photons causes cooling. It is the exact same energy photon that comes in and gets radiated out by the ground/ocean as what causes the GHE. They can NOT go in opposite diections. How can more GHGs at night cause more cooling, not warming. Maybe you should look for a theory like more gravity energy every 60 years like Doug Cottons theory means more warming instead of more GHGs or CO2.

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    18. Nathan Stewart

      Mr

      In reply to John Dodds

      There is no cooling. This past decade was the warmest ever. This upcoming decade will be the warmest ever again. Unless this upcoming decade shows a decrease in temperature then there is no evidence of cooling whatsoever.

      There are a lot of forces at play, not least of all La Nina and El Nino which im sure you know all about. Arent you concerned that even though we had La Nina conditions last year, 2010 was in the top three hottest years ever recorded?

      As im sure you have been told many…

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    19. Jimmy Green

      logged in via Facebook

      In reply to Nathan Stewart

      Thanks for your support and input Gavin! Energy and Thermodynamics do seem to be some of the most poorly understood conceptual structures in science as your prime example illustrates.

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    20. John Dodds

      Retired Engineer

      In reply to Nathan Stewart

      Gavin. responding to your post:
      G:"There is no cooling."
      J:There is cooling EVERY night, or don't you believe the weatherman.
      There is cooling every winter.or don't you believe the thermometer.
      IF more CO2 means more warming per IPCC, then how the hell do we get cooling? when the CO2 is continuously higher.
      G: There was cooling This past decade was the warmest ever.
      J: NO IT WASN'T. This last decade was the warmest in about a thousand years. It was half a degree warmer in the year 1000AD, It was…

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    21. Nathan Stewart

      Mr

      In reply to John Dodds

      Your response is bordering on a hysterical rant that makes no sense. I have a much firmer grasp on these scientific principles let me assure you. I cant believe you use night time as reasoning for global cooling. In case you werent aware, the earth always has the sun shining on it somewhere :)

      the fact is, we have X amount of energy hitting the earth which needs to escape back out to the atmosphere - finding equilibrium as you keep banging on about. Now if you make it harder for the heat to escape, the temperature goes up until it finds its new equilibrium. The more greenhouse gasses, the higher the temp has to be to find the happy balance of incoming vs outgoing energy. Take off your blinkers mate.

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    22. Nathan Stewart

      Mr

      In reply to John Dodds

      Let me explain to you as simply as i possibly can.

      At night there is no more incoming solar raditiation on that part of the earth, but there is still outgoing radiation, thus it cools down. Agree?

      GHG's slow the exit rate of IR radiation at night, thus it does not cool too rapidly as does occur on planets/moons without GHG's.

      If you add more GHG's, less heat gets out at night (and during the day as well of course), thus average temperatures start to rise. Simple physics. Enjoy

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    23. Peter Doidge

      Mr

      In reply to Anthony Cox

      Anthony Cox: with what commendable precision you calculate the average rate of surface temperature rise. But are you *really* sure that the rate is 0.01642448C/yr, and not, say, 0.01642449C/yr after 1976? You need to read up about significant figures.
      Your comparison with the rates of heating during Dansgaard-Oeschger (D-O) events is, like so much of your comment here and elsewhere, misleading. D-O events, though showing abrupt temperature rises, are spatially limited to the North Atlantic region. Globally, the averages would be much less, as can be seen clearly in Fig. 4(e) of the article “Climate Shock: Abrupt Changes Over Millennial Time Scales” by Edouard Bard in Physics Today (Dec. 2002). There, the maximum air temperature anomaly, around 6 C in Greenland, would be 1C or less, I suggest, when globally-averaged.
      Finally, where is the proof that the MWP was warmer than today? McShane and Wyner? I think not.

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    24. Peter Doidge

      Mr

      In reply to Anthony Cox

      Anthony Cox: Regarding the paper by Lu to which you provided a link, it is curious that Lu makes reference to a paper by Griggs and Harries, but that what those authors say about the interpretation of the difference spectra obtained from the IRIS (1970), IMG (1997) and AIRS (2003) data does not chime with what Lu claims. In the paper, Griggs and Harries note that “…[a] negative going brightness temperature difference is observed in the CO2 band around 700cm^-1 in the 1997-1970 and the 2003-1970 difference…

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    25. Scott Brown

      Mathematician turned Engineer

      In reply to Anthony Cox

      Anthony, did you bother to look at the item Gavin linked to before you replied? It says

      "Models predict that Earth will warm between 2 and 6 degrees Celsius in the next century. When global warming has happened at various times in the past two million years, it has taken the planet about 5,000 years to warm 5 degrees. The predicted rate of warming for the next century is at least 20 times faster. This rate of change is extremely unusual."

      Quite simply, comparing the rate of change for two periods of a few decades in the 20th century is completely irrelevant to the point.

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  16. John Dodds

    Retired Engineer

    With regard to the reliance of academics on PEER REVIEW, I ask WHY? Isn't it a basic tenet of Science that new evidence can always overturn an old theory?
    True, supposedly any review should weed out incorrect arguments, MOST of the time. The fact that it is by peers or the supposed experts coworkers etc in the field may mostly work in a highly technical complex subject area, BUT it also means that the "peers" are also likely to be predisposed to the same scientific argument, with its inherrant…

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  17. harrydhuffman

    logged in via Twitter

    That CO2 and other gases absorb (and emit) infrared radiation is fundamental (experimentally observed) physics, but the greenhouse effect as promulgated in climate science is not. The definitive evidence is the comparison of temperatures in the atmospheres of Venus (with 96.5% CO2) and Earth (with 0.04% CO2), as I have apparently been the first scientist to do properly at

    <a href="http://theendofthemystery.blogspot.com/2010/11/venus-no-greenhouse-effect.html">Venus: No Greenhouse Effect</a>

    I…

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    1. Nathan Stewart

      Mr

      In reply to harrydhuffman

      I feel truly sorry for you. Even the most extreme skeptics believe that earth is being kept warm by a greenhouse effect. After all, why is the moon so hot on the bright side and so cold on the dark side? Answer: No atmosphere.

      For goodness sake, nights are always warmer if there are clouds in the sky. water vapour is a very effective GHG.

      Thanks for putting a smile on my face Harry.

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    2. Ken Sekiya

      logged in via Twitter

      In reply to Nathan Stewart

      No one here is denying the Greenhouse effect of Vapour.

      This is basic science that was verified along with every other Greenhouse gas. including CO2.

      However the deciding factor that raises the capacity and the level of Water vapour in the Atmosphere is heat and temperature.

      And is not a factor that we can actively take control of, except by artificially raising atmospheric temperatures.

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    3. Nathan Stewart

      Mr

      In reply to Ken Sekiya

      Yes it is. Visible (shortwave) radiation hits the earth - passing through the greenhouse gasses quite freely. It is then transformed into IR (Longwave energy aka heat). The greenhouse gasses then keep this in. The more greenhouse gasses the more heat that is retained on earth. Its such a basic principle to understand.

      Do you not believe that GHG's are capable of allowing shortwave radiation to pass through but not longwave?

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    4. John Dodds

      Retired Engineer

      In reply to Nathan Stewart

      Gavin, the GHGs do NOT keep the energy in. The GHGs can only absorb IR & not incoming energy photons at the higher energy/frequency. The delay of the release to space by an absorption causes the very real greenhouse warming effect warming. You need to educate yourself on the real process. Learn the science, not the words quoted by the press etc. If you do not have the science bakground learn it. It is NOT hard. It does NOT require a degree.

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    5. Richard Lawson

      In reply to John Dodds

      John, your communications seem confused. You seem to be disagreeing with Gavin while restating what he has said. You have said "I ... claim zero climate sensitivity for CO2 & methane etc" You also say, "The delay of the release to space by an absorption causes the very real greenhouse warming effect".

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    6. Richard Lawson

      In reply to Richard Lawson

      Just to bring us back to Earth, Let us remember one of the key points in the original article: "Patterns of temperature change that are uniquely associated with the enhanced greenhouse effect, and which have been observed in the real world include:

      greater warming in polar regions than tropical regions
      greater warming over the continents than the oceans
      greater warming of night time temperatures than daytime temperatures
      greater warming in winter compared with summer
      a pattern of cooling in the high atmosphere (stratosphere) with simultaneous warming in the lower atmosphere (troposphere)."

      These are telling observations. It is up to skeptics to provide a full explanation for them.

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  18. simon neville

    logged in via email @yahoo.com.au

    Okay help me out here. I'm not educated I'm no climate scientist I am after reading very confused.
    My Understanding like many of my friends is the analogy of a Garden Green House. The Gases in the atmosphere act like the layer of a garden greenhouse trapping in energy from the sun. Yet I'm reading above that it's not the case that in order for my Garden greenhouse to be hotter than the outside ambient temp I need more energy input from the sun. So am I experiencing delusion when I walk into my garden greenhouse and it's warmer?
    Now if I'm not deluded and it is hotter due to the plastic I have trapping the heat energy am I now to attribute this extra heat from planetary gravity from Jupiter and the moon etc or even to the magnetic fields of the earth?
    OR ?? is the analogy an incorrect one
    Seriously please help are these gases incorrectly called greenhouse gasses?

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  19. simon neville

    logged in via email @yahoo.com.au

    Another point I'd like to question. None of the sceptics are climate scientists ! Am I to believe that there is a world wide problem with Environmental Education??? I see geologists and other disciplines but no climate scientist. So Either I'm to assume that every single climate scientist is wrong that every single climate scientist has an inferior knowledge of Climate than Geologists, Physicists and retired nuclear scientists and engineers. Was there this much opposition to the anti smoking science when it started?

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  20. John Nicol

    logged in via Facebook

    Having spent some considerable time discussing the basis for the assumptions made regarding warming by increased atmospheric carbon dioxide with members of the CSIRO Climate Group and attempting to learn more about the basis of the green house effect from people such as Andy Pitman and Will Steffen without being provided with any clear cut evidence and certainly no peer reviewed publication which substantiates the claims, I am very interested to see this article which seeks to point out why it…

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