Sections

Services

Information

UK United Kingdom

As emissions rise, we may be heading for an ice-free planet

Last December’s meeting of the American Geophysical Union featured three of the world’s leading climate scientists: James Hansen (NASA’s chief climate scientist), Elco Rohling (National Oceanography Centre…

An ice-free world isn’t impossible – even though it seems the stuff of science fiction. Alistair Knock

Last December’s meeting of the American Geophysical Union featured three of the world’s leading climate scientists: James Hansen (NASA’s chief climate scientist), Elco Rohling (National Oceanography Centre, Southampton) and Ken Caldeira (Stanford School of Earth Science). But it was Hansen who attracted the most attention when he stated:

“If you doubled CO₂, which practically all governments assume we’re going to do, that would eventually get us to the ice-free state” and “We would be sending our climate back to a state we haven’t adjusted to as a species".

Reaching ice-free-Earth conditions due to the addition of a few hundred parts per million CO₂ may sound like a science fiction story. But Hansen’s statement is consistent with the natural laws of physics (the Planck, Stefan-Boltzmann and Krichhoff laws of black body radiation), with atmospheric science and with the geological record.

A planet’s surface temperature is determined by the infrared absorption/emission characteristics of its atmosphere, determined by greenhouse molecules (CO₂, CH₄, N₂O, O₃). Earth’s surface conditions (including the atmospheric pressure, temperature and gases in its atmosphere) occupy an intermediate position between those of Mars and Venus. Advanced life on Earth is controlled by the presence of water and by the carbon and oxygen cycles.

Figure 1: CO2 with time. Andrew Glikson (with thanks to D Royer)

Studies of the evolution of the terrestrial atmosphere based on multiple proxies (carbon isotopes in phytoplankton and in fossil soils, plant leaf stomata pores, boron isotopes, boron/calcium ratios) confirm the upper stability boundary of the Antarctic ice sheet at about 500+/-50 ppm CO₂. Other estimates suggest 615 ppm CO₂ or near-800 ppm CO₂.

The original decline in temperature from the end-Eocene (~34 million years ago) and the onset of the Antarctic ice sheet occurred when CO₂ levels declined to below ~600 ppm (as shown in Figure 1). Greenhouse gases have increased by near 40% since 1750 (from ~280 to 392 ppm CO₂, at a rate increasing to ~2.6 ppm/year by 2010). At the current rate of increase, the climate could return to greenhouse Earth conditions within 50 to 200 years.

With current emissions growing by 5.9% in 2010 (see Figure 2) and a corresponding rise of temperature by 6.2% during the last decade (see Figure 3), Earth may be committed to an ice-free state.

Figure 2: Fossil fuel and cement CO2 emissions in billion tons carbon per year. Think Progress

Figure 3: Percentage change in global average temperature since the 1860s by decade. World Meteorological Organization

Climate change projections are complicated by the extreme rates of these processes. There is no precedent for such rates in the geological record, bar major greenhouse gas release triggered by methane eruptions, volcanic eruptions and asteroid impacts.

Further warming of the Greenland ice sheet and of the west and east Antarctic ice sheets may lead to pulses of ice-melt water which will cool adjacent ocean basins. Such pulsations occurred repeatedly in the North Atlantic Ocean around 8.2 thousand years ago (the Holocene Optimum), 12.9-11.7 thousand years ago (the “Youngest dryas” cold phase), and cold phases associated with the peak of earlier interglacials.

The bulk of the continents continue to heat, due to a rise in greenhouse gases, feedbacks from fires, methane release from permafrost and reduction of CO₂ intake by warming oceans.

The resultant ocean-land temperature polarity generates storms, reflected in the title of James Hansen’s book, “Storms of my grandchildren”. Similar conditions developed in November 2010 as north Siberia and Canada warmed to above 4°C relative to 1951-1980 while snow storms occurred in the North Atlantic.

Figure 4: Surface temperature Goddard Institute for Space Studies, NASA

The current consequences of polar temperature rises by 4°C and higher (see Figure 4) for the Greenland and the Antarctic ice sheets are shown in Figure 5. Between 2002 and 2008 a total of near-2500 billion tons of ice was lost while the projected rate of mass loss near-doubled over the period.

Figure 5: Ice mass changes http://forum.gloresis.com/2011/06/05/paleoclimate-implications-for-human-made-climate-c/

As atmospheric CO₂ is reaching a level unknown for the last three million years, the disconnection between science and the human response is growing. Despite warnings over the last 30 years, we are still developing global infrastructures to extract every economically accessible ton of coal, barrel of conventional or shale/sand oil and cubic meter of natural gas and coal-seam gas.

Contrarian claims by sceptics, misrepresenting direct observations in nature and ignoring the laws of physics, have been adopted by neo-conservative political parties. A corporate media maintains a “balance” between facts and fiction. The best that governments seem able to do is devise cosmetic solutions, or promise further discussions, while time is running out.

Good planets are hard to come by.

Join the conversation

124 Comments sorted by

Comments on this article are now closed.

  1. Tim Scanlon

    Author and Scientist

    Nicely said.

    Not only are we headed towards global average temperatures not seen for millions of years, we're going to make those changes in 100 years, as opposed to the 100,000s of years it would if it were a natural event.

    I look forward to the usual denial rhetoric in the comments to come.

    report
  2. Bruce Tabor

    Research Scientist at CSIRO

    I completely agree Andrew. We face a scary future, which we are rapidly losing he ability to control. I have one quibble and an observation.

    My quibble is that Figure 3 is awful. Percent changes in temperature can only meaningfully be made against absolute zero (-273C). I know the standard temperature chart shows only 0.7 C rise since the baseline (1950-1980 from memory) - and that doesn't sound impressive - but Figure 3 is woeful.

    As for an ice free planet and the 70 metre sea level rise to get there. The problem is that it is all happening too slowly to engage the public's attention beyond the all-too-regular extreme weather events. Once sea level rise get's going in earnest it will be very disruptive to civilisation, but hey, that won't happen until at least the second half of this century. (Unfortunately it may be unstoppable by then!)

    report
    1. Tim Scanlon

      Author and Scientist

      In reply to Bruce Tabor

      Kinda like the expontential growth analogy, isn't it Bruce. The pond has one lilly in it which then divides each day. Each plant created also does the same. At what day is the pond half-full? The day before it is full.

      Hard to make people think beyond themselves and their little piece of the world. Even harder to make them change now to avoid something in 50-100 years time.

      report
    2. Rick Baartman

      logged in via Facebook

      In reply to Bruce Tabor

      I agree with Bruce. Fig. 3 detracts from the article's credibility. A 6% rise is 18 degrees C; just wrong. And there are no error bars. The measured rise in the 2000's is barely statistically significant, something like 0.1 plus or minus 0.1 degree.

      report
  3. Dale Bloom

    Analyst

    And.

    What do you think should be done about it?

    report
    1. David Arthur

      resistance gnome

      In reply to Dale Bloom

      What should be done about it? Cease recycling geosequestered carbon to the atmosphere as rapidly as possible, and hope for the best.

      report
    2. Paul Richards

      logged in via Twitter

      In reply to Dale Bloom

      Dale, all we can do is as individuals who are out of the GCC circle is be informed and raise others awareness. This has proved invaluable at changing the political centre of gravity before. Civil rights here in Australia, civil rights in the US, Vietnam War, Apartheid in South Africa, if we choose not to be led by the nose, our disagreement is enough to make a difference.

      On the bright side, I have read a paper hypothesising a reversal of the Thermohaline circulation may actually make Southern…

      Read more
  4. Ben Heard

    Director, ThinkClimate Consulting

    Hard to come up with much to say about this.

    Yep. An honest look at the rate of warming, rate of emissions, response of the planet to warming, and the geological record, takes you to some raw and very confronting conclusions. I applaud Hansen for not shirking, and Glickson for then bringing it to us.

    @Dale Bloom, as for what should be done, why not go back to the source, James Hansen, and check in with him. His answer is rapid decarbonisation, cessation of new coal and elimination of current…

    Read more
  5. James Sexton

    Network administrator

    So, where is all the water going?

    report
    1. David Arthur

      resistance gnome

      In reply to James Sexton

      Sea level rise. Expect sea level rises of 1.5-2 m this century, 5-8 m rise from present by 2200 (I may not live to see if I'm right), unless we restore atmosphere to ~300-350 ppm CO2, plus decreases in other anthropogenic greenhouse gases (cessation of combustion and synthetic fertiliser use will eliminate atmospheric N2O, cessation of fossil fuel use will eliminate fugitive emissions of hydrocarbons).

      report
    2. James Sexton

      Network administrator

      In reply to David Arthur

      lol, that doesn't appear to be occurring. I really believe the weighting given GHG's aren't near what has been purported. But, as to the sea level... have you checked them lately? With all of the missing ice volume we should have expected a much more dramatic increase. Either the measurements are wrong or the theories are.

      report
    3. David Arthur

      resistance gnome

      In reply to James Sexton

      Missing ice volume? Loss of marine pack ice doesn't contribute to sea level rise, and terrestrial ice mass loss to date has only added a few mm to sea levels; my understanding is that the mass balance between terrestrial ice and oceans has been closed, ie missing ice volume and sea level rise are consistent with each other.

      Measurements and theories are consistent with each other.

      report
    4. James Sexton

      Network administrator

      In reply to David Arthur

      So, we haven't lost significant terrestrial ice mass? Is that what you're stating? Because if it is only going to rise < 1 mm/yr (Envisat and JasonII) then I think we'll be ok.

      report
    5. David Arthur

      resistance gnome

      In reply to James Sexton

      Although, long anticipated, terrestrial ice mass loss has only been underway for about 15-20 years. That's why it has only contributed a few mm to sea level to date.

      Now that the process has started, it will take a while to stop, especially as the driver of the process (heat retention near the earth's surface) is large and can only be slowly decreased.

      We need to get atmospheric CO2 back to ~300-350 ppm as rapidly as we can. For so long as CO2 is above that range, heat will continue to accumulate in the oceans rather than dissipate to space.

      After that, we've got to wait for the oceans to cool again.

      report
    6. James Sexton

      Network administrator

      In reply to David Arthur

      So, forget what the measurements are saying, just know that we're doomed unless we destroy our economy..... Ok.....

      I'll move on to a different topic because that's not rational. Notice the graph regarding CO2 emissions. Notice the dip on the right side of the graph. This was because of the global recession. Are you seriously advocating decreasing the CO2 more? That doesn't make any sense. Western society nearly collapsed and still has many difficult years ahead to financially fix the harm the recession caused. But, you're advocating more severe drop in economic activity than what we had in 2008-2009! Is that the position I'm seeing here?

      report
    7. David Arthur

      resistance gnome

      In reply to James Sexton

      James, I'm not advocating declining economic activity at all, and I must criticise the blinkeredness of any such suggestion.

      I encourage you to subscribe to "Climate Spectator" (climatespectator.com.au; it's free). You'll see that removing fossil fuel use from our economy will, if anything, be beneficial for the economy, even in the short term (this decade). In the longer term (several decades) the dependency of all economic activity on the environment will only strengthen this link.

      report
    8. James Sexton

      Network administrator

      In reply to David Arthur

      I appreciate the link, I'll check it out. Though, ignoring the 2008-2009 recession and its implications seems a bit of avoidance to me.

      report
    9. David Arthur

      resistance gnome

      In reply to James Sexton

      2008-9 recession was merely a slowdown in fossil fuel use, was not indicative of replacement of fossil fuel use with renewable energy.

      It's really of no relevance to what's required.

      report
  6. Peter Lang

    Retired geologist and engineer

    Dr Glikson,

    I have a few questions:

    So what if the planet heads to be ice free? Is that not its normal state? Hasn’t it been ice free for some 75% of the time since multi-cell life burst forth around 600 million years ago as it emerged from the last “snowball-Earth” event?

    Is it not true that life thrives when the planet is warmer and struggles when colder? It seems life likes it warmer.

    Is it not true that it will take thousands or millions of years to become ice free?

    Is it…

    Read more
    1. David Arthur

      resistance gnome

      In reply to Peter Lang

      Mr Lang asks, "is it not true that life thrives when the planet is warmer and struggles when colder?", adding that "it seems life likes it warmer".

      Life adapts to varying climate by processes of extinction and evolution. Are we really so wise as to threaten the ecosystems in which we have evolved?

      Mr Lang also ponders concerns about ice melting. The issue is sea level rise, which threatens all coastal infrastructure worldwide, as well as the low-lying lands of many millions of people.

      These concerns DO warrant cessation of fossil fuel use as rapidly as we can manage.

      report
    2. James Sexton

      Network administrator

      In reply to David Arthur

      This argument makes no sense to me. Most of the life today exists because of their adaptive capabilities. But, let's get to more specifics. In times past, grain crops were grown in Greenland. This suggests..... well, this mandates significantly less ice on Greenland than today. Still, humanity and the flora and fauna seemed to thrive quite nicely. How is it that today, we fear less ice on Greenland?

      report
    3. David Arthur

      resistance gnome

      In reply to James Sexton

      Crops could be grown in mediaeval Greenland because the Mediaeval Warm Period was a North Atlantic phenomenon - have a look for the remarks of Lennert Veerman after Barrie Pittock's Conversation article, "Responsible scientific advice about climate change is not scare mongering". That is, it was the result of a redistribution of warmth around the world's surface due to century-scale fluctuations in ocean currents.

      The present warming, however, is not the result of regional redistribution, but due to worldwide retardation of heat dissipation to space.

      report
    4. James Sexton

      Network administrator

      In reply to David Arthur

      I would differ with you on the regional posit, but it matters not to this discussion. The fact is there was far less terrestrial ice during the MWP than today. We seemed to have come through it just fine.

      report
    5. David Arthur

      resistance gnome

      In reply to James Sexton

      James, every aspect of your last remark is erroneous.

      You're wrong about what you call the "regional posit", and wrong about there being less terrestrial ice during the MWP - if anything, there would have been more ice in all locales (Himalayas, Andes, boreal tundra, certainly Antarctica) except southern coastal parts of Greenland closest to the Atlantic.

      report
    6. James Sexton

      Network administrator

      In reply to David Arthur

      And, we've evidence of that? Because my impression is that Antarctic terrestrial ice has been fairly steady up until recently. As to the Himalayas and Andes, I think in terms of magnitude, necessary for a significance in sea level, they are unimportant.

      report
    7. David Arthur

      resistance gnome

      In reply to James Sexton

      West Antarctic ice mass loss has been observed for several decades.

      For a couple of decades there, it was more than compensated for by increased ice accumulation on East Antarctica due to increased precipitation of snow that, in turn, came from increased evaporation off a warming Southern Ocean surface.

      I understand that East Antarctica fringing pack ice has extended somewhat as a consequence of increased East Antarctic glacial ice, as well as in situ formation about which I know less…

      Read more
    8. James Sexton

      Network administrator

      In reply to David Arthur

      David, this is what I don't get, and causes me to think something is amiss with the prognostications.

      If the Antarctic terrestrial ice volume is decreasing at an accelerating rate, and Greenland is as well, it should be manifested in sea level rise and its rate. But, that isn't occurring. The rate of sea level rise has decreased over the last decade or so, and in fact over the past few years sea level has dropped. (though I don't expect that to continue)

      As far as glacial retreat, that's been occurring well before CO2 hit 350ppm. Well, in fact, since the last ice age. Which, I generally look at it as a good thing. Water supplies not withstanding, it wasn't but a few thousand years ago place like Chicago were under mountains of ice.

      Given that we can never achieve a static climate, wouldn't we prefer less ice as opposed to more?

      report
    9. Andrew Glikson

      Earth and paleo-climate scientist at Australian National University

      In reply to James Sexton

      James

      For data regarding glacioer trends look at:
      http://www.skepticalscience.com/himalayan-glaciers-growing.htm

      "Most glaciers are retreating, posing a serious problem for millions who rely on glaciers for water. Although Glaciologists measure year-to-year changes in glacier activity, it is the long term changes which provide the basis for statements such as "Global Glacier Recession Continues". Some Skeptics confuse these issues by cherry picking individual glaciers or by ignoring long…

      Read more
    10. Ben Heard

      Director, ThinkClimate Consulting

      In reply to Peter Lang

      Peter Lang, I am quite sympathetic to critical approaches to viewing carbon pricing, which I maintain is not a solution but merely a (potential) enabler of solutions.

      Similarly, you raise sound points about the need for development. The simple fact is that it does not require climate change for a shanty town to be a very unsafe and risky place to live in terms of exposure to extreme weather. A big part of climate change protection is simply accelerated development for the very poor. Again, I agree…

      Read more
    11. David Arthur

      resistance gnome

      In reply to James Sexton

      The average depth of ice covering Antarctica is ~2 km, but if it all melted then sea levels would rise by only ~70m.

      This process is only just started (a couple-few decades), so it's not surprising that sea level rise has not been great so far.

      Regarding lower latitude glaciers, of course retreat would continue through a substantial portion of the trajectory of an interglacial period. We don't want too much glacier retreat, because glaciers are useful for storing water for subsequent use…

      Read more
    12. Andrew Glikson

      Earth and paleo-climate scientist at Australian National University

      In reply to James Sexton

      Regarding sea level rise:

      According to the CSIRO report "Climate change, sea level rise and Australia"

      http://indymedia.org.au/2011/10/04/climate-change-sea-level-rise-and-australia

      1. Global Sea level rise is happening with about 200mm rise from 1870 to 2009 already observed. During most of the 20th century global Sea levels rose at an average of 1.7mm per year, but from 1993 it has accelerated to 3.0mm per year.

      2. Sea levels at coastal locations do not rise at the same rate but vary…

      Read more
    13. Andrew Glikson

      Earth and paleo-climate scientist at Australian National University

      In reply to Peter Lang

      Regarding mass extinction of species.

      Whereas evolution hingest on gradual to fast changes to which some species adopt and others do not, inherent in geological mass extinctions are extreme rates of climate changes to which many or most species have not been able to adapt.

      Examples are the end-Devonian, P-T boundary, end-Triassic, end-Jurassic, K-T boundary where in every case global volcanic effects and/or asteroid impacts resulted in major extinctions, as in the following references:

      Asteroid/comet impact clusters, flood basalts and mass extinctions.
      www.somosbacteriasyvirus.com/basalts.pdf
      Mass Extinction of Species: The Role of External Forcing.
      http://journalofcosmology.com/Extinction103.html

      At >2 ppm CO2/year The current rise rate in radiative forcing due to greenhouse gases and land clearing is the fastest recorded in geological history except during global volcanic events, asteroid impacts and large methane eruptions.

      report
    14. James Sexton

      Network administrator

      In reply to Andrew Glikson

      Andrew, I would encourage you to look at the numbers instead of simply parroting what someone said.

      None of the current satellites are reporting a 3mm/year rise, and that's even if one includes all of the insipidly vapid adjustments. Sea level rise is decelerating, and has been for several years.

      We all know sea level doesn't rise evenly.

      My point is, if terrestrial ice volume is declining in an accelerated rate, it should be manifested in sea level rise. Again, sea level rise is decelerating.

      Yes, I agree, thermal expansion causes an increase in sea level. And perhaps the deceleration sea level rise is due to the cessation of warming temps over the last 15 years. But, if this is acknowledged, there are several more implications which turn much of this prognostication on its head.

      report
    15. David Arthur

      resistance gnome

      In reply to James Sexton

      James, I've already addressed the questions you now ask of Dr Glikson. Again:

      Ocean is BIGGER than ice caps. We can have relatively LARGE ice cap mass loss and yet have relatively SMALL sea level rise. Furthermore, the process has only been underway for a few decades, so we're yet to see major effects ...

      ... unless we live in the Ganges delta, or the Carteret Islands (most other coral islands, for that matter), or near one of many beaches in Australia.

      What part of this do you not understand?

      report
    16. James Sexton

      Network administrator

      In reply to David Arthur

      What I don't understand is what you haven't answered.

      If the volume loss is accelerating then the sea level should be as well, but it isn't. It is decelerating.

      None of the current satellites are reporting a 3mm/year rise.

      report
    17. Peter Lang

      Retired geologist and engineer

      In reply to Andrew Glikson

      What was the fastest rate of warming over periods of a decade in the Greenland ice cores? How did lfe respond to those rapid warmings?

      report
    18. David Arthur

      resistance gnome

      In reply to James Sexton

      Measurement uncertainty, plus multiple causes for sea level change.

      Even if it's real, decreasing rate of sea level rise is more likely than not due to isostatic rebound; continental plates are observed to be rising as their ice overburden decreases, so it is likely that ocean floors are undergoing commensurate sinking.

      report
    19. Peter Lang

      Retired geologist and engineer

      In reply to Ben Heard

      Ben Heard

      “When the warming becomes that great, the economic argument for adaptation over mitigation pretty quickly becomes a nonsense.”

      When no one can show persuasively that the consequences of warming are “that great” then it is not time to be damaging our economies with ideologically driven policies that will damage the economy - and that means it reduces people’s well-being and their ability to take the most appropriate actions to deal with whatever problems come up in the future.

      When…

      Read more
    20. Peter Lang

      Retired geologist and engineer

      In reply to Ben Heard

      Ben Heard

      “When the warming becomes that great, the economic argument for adaptation over mitigation pretty quickly becomes a nonsense.”

      When no one can show persuasively that the consequences of warming are “that great” then it is not time to be damaging our economies with ideologically driven policies that will damage the economy - and that means it reduces people’s well-being and their ability to take the most appropriate actions to deal with whatever problems come up in the future.

      When…

      Read more
    21. Andrew Glikson

      Earth and paleo-climate scientist at Australian National University

      In reply to James Sexton

      The rise in atmospheric GHG, the rise in temperature, increase ice melt and rising sea levels are intrinsically linked, in accord with the basic laws of physics, climate science and geological observations.

      It is decade-scale trends which tell which way the climate is heading. It would be a stawman argument to expect this rise, overprinted by the solar sunspot cycle, the ENSO cycle, volcanic events etc. - to constitute a simple linear trajectory.

      Those who do not accept the science will look…

      Read more
    22. David Arthur

      resistance gnome

      In reply to Peter Lang

      Mr Lang, I have previously set out some consequences of AGW for you on various pages in the past; are you demanding that Each and Every Person in the World explain the consequences to you before you will accept that there might be a problem?

      I suggest you have a look through the comments on this page for discussions James Sexton has had with myslef and with Dr Glikson.

      report
    23. David Arthur

      resistance gnome

      In reply to Peter Lang

      Interpolating a plot of ice core CO2 and global average T (proxy record) over 800 thousand years gives ~9 degrees C over a couple of millenia or so; ie ~0.045 to 0.09 deg C per decade for 100 to 200 such decades. That's about the same rate of temperature rise as has been experienced over the last century or so.

      If and when substantial areas of ice cover melts, expect much more rapid rates of temperature rise, particularly as rates of methane outgassing from melting permafrost and sublimating methane clathrates increase.

      How did life respond? I don't know, but there would have been substantial inundation of low-lying land (sea level rise ~120 metres, I believe.

      Terrestrial plant communities would have shifted uphill and towards higher latitudes, and would also have been massively altered by changed rainfall patterns (generally wetter, I believe).

      report
    24. David Arthur

      resistance gnome

      In reply to David Arthur

      Mention isostatic rebound, and the comment is marked by someone as "unconstructive"?

      The mention was only intended to clarify a point.

      report
    25. Ben Heard

      Director, ThinkClimate Consulting

      In reply to Peter Lang

      Peter, you've just gone all weird on me, which you seem to have the propensity of doing at the drop of a hat. Conversation closed, I don't have time for that kind of silliness.

      report
    26. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      I may as well wade in here, the result will be the same.

      Some general comments about Dr Glikson's end of the world scenario:

      1 CO2 and temperature do not correlate over any time scale; for a good exposition of the longer term see Frank Lansner's piece:

      http://icecap.us/images/uploads/CO2,Temperaturesandiceages-f.pdf

      I really would like a sensible comment about that article.

      2 The Antarctic is not melting, not even on the WAP as these papers show:

      http://www.agu.org/pubs/crossref/2008/2007GL032529.shtml

      Read more
    27. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony.

      Sea level increase: polar ice melt has only just started (ie last 1-2 decades), and seems to be accelerating (ref Rignot et al, "Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise:, Geophysical Research Letters, 2011).

      "Dr Glikson's article does not refer to the PETM which is probably the highest post dinosaur GAT and the fact that CO2 was not the cause of this event ..."

      PETM is thought most likely to have been caused by a pulse of methane to the atmosphere, most likely caused by disruption of a Tethys Sea methane clathrate deposit as India collided with Asia.

      This time, methane eveolution is due to sublimation of a methane clathrate deposit on the Arctic Ocean shelf of Siberia, as reported by U Alaska Fairbanks International Arctic Research Center researchers Natalia Shakhova and Igor Semiletov.

      report
    28. Peter Lang

      Retired geologist and engineer

      In reply to Ben Heard

      So why did you replying, other than to make the usual insults?

      You didn't manage to get the word "denier" into this latest comment, which is unusual.

      I don't have time for your type of silliness either - continual exaggeration, scaremongering, crying "catastrphe, catastrophe".

      report
    29. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      The PETM may have been initiated by methane hydrate release:

      http://www.nature.com/nature/journal/v450/n7173/full/nature06400.html

      But it probably was not caused by CO2 increase:

      http://igitur-archive.library.uu.nl/dissertations/2006-0906-200913/index.htm

      The crucial aspect of the PETM is that temperatures started to fall while CO2 levels were still increasing. This ties in with Lansner's analysis.

      As for the Shakhova paper arguing for a Siberian source for the recent slight increase…

      Read more
    30. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony.

      You're right about the PETM - the initial temperature rise was driven by the very powerful greenhouse gas methane; oxidation of methane to carbon dioxide resulted in a decrease in the effective greenhouse propensity of the atmosphere. Note, however, that temperatures remained elevated until CO2 content returned to pre-PETM levels.

      Thanks for your discussion of Shakhova's work. You've missed my point, which is that Shakhova et al report accelerating methane outgassing from…

      Read more
    31. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      "Note, however, that temperatures remained elevated until CO2 content returned to pre-PETM levels."

      That is problematic as this piece shows:

      http://wattsupwiththat.com/2009/10/16/searching-the-paleoclimate-record-for-estimated-correlations-temperature-co2-and-sea-level/#more-11753

      And note that the Eocene optimum occurred after the PETM with declining CO levels and a similar peak in temperature to the PETM:

      http://upload.wikimedia.org/wikipedia/commons/1/1b/65_Myr_Climate_Change.png

      It is also the case that the Antarctic thawed and reglaciated after the PETM with no apparent assistance from CO2 levels.

      report
    32. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Anthony Cox

      I forgot to mention that Shakhova's conclusions that there is an outgassing of methane from Siberia is contradicted by Rigby and Prinn's work; that was your point, that the methane levels are from a Siberian localised source?

      report
    33. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Shakhova did not conclude outgassing of methane from Siberia; her team observed it.

      My point is that it is occurring in the context of, and is consistent, a warming Arctic.

      report
    34. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony.

      Not only did the Antarctic undergo least some glaciation, then thaw, then reglaciate to the previous extent and then continue glaciation to its Pleistocene state after the PETM, but it did so after the Eocene Thermal "Optimum" (from the perspective of modern biota, that would be a poor choice of name).

      Atmospheric CO2 levels and temperature are related in a 'chicken-and-egg' manner, due to temperature-sensitive solubiity of CO2 in seawater, thus rendering references to correlations to attempt to Deny the atmospheric physics summarised above.

      report
    35. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      Shakhova observed this:

      "Here recent observational data obtained during summer (2005–2006) and winter (2007) expeditions indicate the ubiquitous presence of elevated dissolved CH4 and an elevated atmospheric CH4 mixing ratio."

      They concluded this elevated CH4 level was from a local source; what I am saying to you is that Rigby and Prinn showed the elevated source was global and therefore inconsistent with a local source.

      As for the 'warming Arctic' here is the trend for the last 7 years based on RSS, the most reliable temperature measurment:

      http://www.real-science.com/wp-content/uploads/2012/01/ScreenHunter_66-Jan.-04-07.27.gif

      The Arctic is NOT warming.

      report
    36. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony.

      You write: "The Arctic is NOT warming", and you can carefully select temperature measurements only from a short-enough period in which there is a minimum in sunlight intensity.

      However, you cannot refute observations of ice melt, observations of methane outgassing, observations of permafrost thaw, observations of vegetation changes, and observations of animal behaviour change.

      report
    37. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony.

      You write: "The Arctic is NOT warming", and the next day I find published Johnston DW, Bowers MT, Friedlaender AS, Lavigne DM. "The Effects of Climate Change on Harp Seals (Pagophilus groenlandicus)". PLoS ONE, 7(1): e29158 DOI: 10.1371/journal.pone.0029158 (available for Open Access download).

      It's reported at Reuters' Science Daily website sciencedaily.com as "Harp Seals On Thin Ice After 32 Years of Warming". This article quotes lead author David Johnston, research scientist…

      Read more
    38. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      I didn't carefully select anything; I presented RSS temperatures for the last 7 years; here is a graph based on HadCRUT3 and prepared by the lads at CRU for the last 110 years:

      http://users.tpg.com.au/johnsay1/Stuff/Arctic_1.jpg

      There is no doubt the rate of temperature increase in the Arctic was greater than today as leading researcher Chylek and his team show:

      http://www.lanl.gov/source/orgs/ees/ees14/pdfs/09Chlylek.pdf

      And after the polar bear scams I take any 'paper' about the plight of some designated animal suffering under the yoke of AGW with a grain of salt; and so should you if you want to be taken seriously; I mean, if there is NO evidence that AGW is occuring how can the Harp Seals be suffering because of it.

      report
    39. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony. There are other consequences of warming than rising atmospheric temperatures.

      What happens is, heat is transferred into the Arctic, and the temperature rises. Eventually, the temperature is warm enough for the ice to start melting, which it does.

      It is one of those curious things that melting ice requires energy - energy that would otherwise be available to drive further temperature rise.

      The thing is, during the time it takes for the ice to melt, the rate of temperature…

      Read more
    40. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      "There are other consequences of warming than rising atmospheric temperatures."

      Which is why I asked whether Dr Glikson, or anyone else promoting the AGW line, was aware of the difference between GAT and ERB or EEB [Earth radiation or energy balance]since it is the ERB/EEB which is the true measure of AGW.

      Your observation about energy required to melt ice which otherwise would be raising the temperature is getting a bit wearisome because it is both irrelevant and incorrect; ice has an albedo…

      Read more
    41. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony.

      1. Ice reflects much incoming sunlight, that's true. What it absorbs and is melted by is the heat contained in warming ocean currents from lower latitudes. After all, in order for ice to melt, it must be getting heat from somewhere.

      That deals with all your objections.

      2. The well-known physics I mention is that which I contributed to the general refutation of your claims in your ABC Unleashed articles.
      7 Oct 2010 "Warming to misanthropy", http://www.abc.net.au/unleashed/39750.html, (with Joanne Nova)
      21 April 2011 "The carbon tax that ate Australia"
      http://www.abc.net.au/unleashed/113676.html, (with David Stockwell)

      report
    42. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      Well, I'm bemused; "general refutation" of my claims; I missed that.

      "What it absorbs and is melted by is the heat contained in warming ocean currents from lower latitudes"

      IR, as directed back to the surface through backradiation, is the deus ex machina of AGW; unfortunately IR does not heat the ocean: IR is only capable of penetrating the ocean surface a few microns with all energy lost to the phase change of evaporation with no net heating of the ocean.

      That well known bit of physics really dispells AGW by itself.

      As for the Arctic warming, which it isn't, whatever is happening in the Arctic is explained by the Arctic Oscillation, an entirely natural process.

      report
    43. David Arthur

      resistance gnome

      In reply to Anthony Cox

      "general refutation" of your claims?

      In the fury, you may have missed the following posting in response to your creative contribution "Warming to misanthropy"
      ________________________
      tabatha 8 Oct 2010 11:38:20am
      Cox - 'CO2 has only increased linearly during the 20thC.'

      Blatently lying about something is very belittling and even if it was true it wouldn't add anything to your argument. CO2 has been rising since the industrial revolution, most learn this in primary school.
      At 591 parts…

      Read more
    44. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      "Unfortunately IR does not heat the ocean"; why does the word 'unfortunately' appear in this concoction (which is falsified every time some water is 'boiled' for a pot of tea)? This use of 'unfortunately' is reminescent of a defence barrister defending a client he knows is guilty."

      When said "unfortunately" I was just being polite; a quality absent from the, quite frankly,incoherent quotes you posted.

      And seriously, are you equating the heating of a pot of tea with the alleged heating of the…

      Read more
    45. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Anonymous bloggers tabatha and kaz havde done us the service of revealing the extent of your sophistry. Your contributions are of no value beyond indicating your resentment of those who actually understand a little physics.

      You see, Mr Cox, here's what you can't get around:

      Earth is warmed by absorbtion of short wave sunlight. Because of this, Earth's temperature can remain unchanged by returning the same amount of energy to space. That is, solar shortwave energy is balanced by the…

      Read more
    46. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony. You mention a blogger you identify as "Tamino". Nothing to do with me mate.

      I'm relieved to see that you don't Deny your assertion of increased evaporation rates as being proof of climate change. There we have it: Anthony Cox, Climate Sceptics secretary, acknowledges the reality of warming-driven climate change.

      report
    47. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      No need to get upset, it's not as though the fate of the world hinges on this conversation.

      But, rather than have this degenerate into a case of "he said that, he said this" maybe if the site hosts would allow me to present my case against AGW, perhaps by reviewing a few recent, peer reviewed papers in a post, what I really think about AGW can looked at without filtering it through the comments of others.

      So David, why don't you use your good offices to support my offer?

      report
    48. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Thanks Anthony for the kind offer.

      Our dialogue on this page provides sufficient evidence that general understanding of climate science would not be advanced by my supporting your proposal.

      I suggest that you continue submitting material to the Good People who run ABC's The Drum Unleashed (abc.net.au/unleashed/). That is already more than adequate.

      report
    49. Matthew Albrecht

      Postdoctoral Researcher at Curtin University

      In reply to Anthony Cox

      If by linear you mean in the linear regression coefficient sense (see http://stats.stackexchange.com/questions/8689/what-does-linear-stand-for-in-linear-regression/8706#8706) then yes. But if you're thinking linear as total amount, then your calculus is off and you've missed the point of the post. The 1st order differentiation of the total CO2 amount is linear and the 2nd order differentiation is constant. Which means the total CO2 amount is increasing as a second order polynomial.

      So the statement: "He, Tamino, is agreeing that the CO2 increase is linear" is incorrect, he's saying the *rate* of increase is linear.

      report
    50. Matthew Albrecht

      Postdoctoral Researcher at Curtin University

      In reply to Anthony Cox

      One would be inclined to think by the URL that the paper has been published in Nature. But it hasn't, in fact it hasn't been published anywhere since it was put out on the internet in 2010. Is my Google Scholar out? Or is this another unfair review process (conspiracy) for something opposing AGW?

      report
    51. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Peter Lang

      Peter Lang: "They are displaying religious like behaviours."

      That's what you're doing.

      report
    52. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Matthew Albrecht

      Do you want to discuss the ideas in the paper or go down the usual path of irrelevance, peer review and status based science validity? Just for the record Beenstock says:

      “If instead of a permanent increase in its level, the change in rfCO2 were to
      increase permanently by 1 w/m2, global temperature would eventually increase by 0.54C. If the level of solar irradiance were to rise permanently by 1 w/m2, global
      temperature would increase by 1.47 C.”

      CO2 heats indirectly, solar directly; the…

      Read more
    53. David Arthur

      resistance gnome

      In reply to Matthew Albrecht

      Relax Matthew. The reference Mr Cox gives is to a draft paper "Polynomial Cointegration Tests of the Anthropogenic Theory of Global Warming", by Michael Beenstock and Yaniv Reingewertz of the Department of Economics, The Hebrew University, Mount Scopus, Israel.

      In the paper, the authors have used time series in global average temperature, solar irradiance, CO2, CH4 and N2O to show that variation in global average air temperature does not correlate with variation in other variables. No surprises there, they disregard heat transfer to oceans, ice cap melting, atmospheric aerosols - and they persist with the ludicrous assumption that surface atmospheric global average temperature is a linear indication of heat accumulation.

      To be fair to Beenstock and Reingewertz, they're economists. Their job is to make ludicrous assumptions every day of the week.

      report
    54. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      Oh please David, apply that blowtorch of intellect to the other economists infesting AGW; start with Garnaut.

      As for Beenstock, now that you have confirmed their shame of 'only' being a "draft paper", could you also elaborate on the phrase "surface atmospheric global average temperature is a linear indication of heat accumulation", given this is what AGW assumes and is indeed the paradigm of the theory, bearing in mind what I have already requested, namely, would you or anyone address the difference between GAT and ERB/EEB.

      report
    55. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Just for the record Beenstock says: “If instead of a permanent increase in its level, the change in rfCO2 were to increase permanently by 1 W/m2, global temperature would eventually increase by 0.54C. ...”

      If global average temperature increases by 0.54 deg C, evaporation rates of water increase, as does the atmosphere's water vapour content. In turn, this further increases greenhouse warming. That is, if change if rfCO2 were to increase permanently by 1 W/m2, global average temperature would…

      Read more
    56. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      "If global average temperature increases by 0.54 deg C, evaporation rates of water increase, as does the atmosphere's water vapour content. In turn, this further increases greenhouse warming."

      This is in fact the "enhanced greenhouse effect" which AGW theory relies on:

      http://climateaudit.org/2008/01/07/ipcc-explains-the-greenhouse-effect/

      There are several problematic aspects to this; firstly it is not clear that evaporation is increasing, or that water vapor levels are increasing, particularly…

      Read more
    57. Matthew Albrecht

      Postdoctoral Researcher at Curtin University

      In reply to Anthony Cox

      No, I don't.
      1. My main point was that you had misunderstood Tamino's post; either the terminology or the calculus.
      2. If they can't make it through the most basic level of science quality control, one begins to wonder why and I'm not going to waste my time reading it.
      3. Your dismissal of peer review as "status based science validity" is, for the most part, sour grapes. Get over it, redraft it and resubmit it.

      report
    58. David Arthur

      resistance gnome

      In reply to Anthony Cox

      "It is not clear that evaporation is increasing" Really? That's what Richard Lindzen relies on to dismiss concerns about climate change.

      "It is not clear that upper tropospheric water vapour levels are increasing" - atmospheric water vapour content is increasing - how else do you explain increased precipitation onto East Antarctica?

      "it is clear clouds have a negative feedback on global energy balance" Actually, the effect of clouds is not well known at all. Indeed, clouds often hold heat…

      Read more
    59. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      "This may save your life when the witch-hunts begin."

      I'm not a witch.

      1 Evaporation is NOT increasing:

      http://www.blackwell-compass.com/subject/geography/article_view?article_id=geco_articles_bpl213

      2 Upper atmospheric water vapor levels are declining:

      http://www.sciencemag.org/content/327/5970/1219.abstract

      3 Clouds have a negative feedback:

      http://journals.ametsoc.org/doi/abs/10.1175/1520-0442%282001%29014%3C2976%3APBOTES%3E2.0.CO%3B2

      http://centaur.reading.ac.uk/21857/

      The oceans are irrelevant to CO2 because CO2 doesn't heat the oceans.

      report
    60. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Upper atmospheric water levels are declining? No, after large increases in the 1980's and 1990's, they've declined only over the last decade.

      Stratospheric Water Vapor Is a Global Warming Wild Card
      ScienceDaily (Jan. 31, 2010) — A 10 percent drop in water vapor ten miles above Earth's surface has had a big impact on global warming, say researchers in a study published online January 28 in the journal Science. The findings might help explain why global surface temperatures have not risen as…

      Read more
    61. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      "decadal fluctuation"; ok I showed the 00's, now the 1990's; from the 2005 16th AMS Symposium on Global Change and Climate Variations titled “Water vapor trends and variability from the global NVAP dataset” [extended abstract] by Thomas. H. Vonder Haar, John M. Forsythe, Johnny Luo, David L. Randel and Shannon Woo.

      “By examining the 12 year record [1988-1999], a decrease of TPW [Total Precipitable Water] at a rate of -0.29 mm / decade is observed. This relationship is significant at the 95 % but…

      Read more
    62. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Another thing you don't understand about gases, Anthony, is that they mix.

      This means that methane can be emitted from some areas, and will rapidly disperse throughout the atmosphere. Anyway, methane is generated from more sources than just the Arctic. Landfills, factory farms, CSG operations, hydrocarbon processing operations such as oil refineries, natural (and artificial eg rice padis) wetlands.

      The result is, of course methane is going to be widely dispersed through the atmosphere. There is no contradiction between Richard & Prinn's, and Semiletov and Shakhova's, work.

      What the latter have OBSERVED is that a new and rapidly increasing methane source has appeared.

      report
    63. David Arthur

      resistance gnome

      In reply to Anthony Cox

      In news just in, Trenberths' "missing heat" has been found, exactly where we all said it would be found: in the oceans.

      Loeb et al, "Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty", Nature Geoscience (2012) doi:10.1038/ngeo1375, published online 22 January 2012

      Abstract

      "Global climate change results from a small yet persistent imbalance between the amount of sunlight absorbed by Earth and the thermal radiation emitted back to…

      Read more
    64. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      This paper of Loeb et al is to the point, which is that the GAT, as used by AGW advocates as THE metric of AGW, is at best useless and at worse misleading; the EEB is indeed the proper measure of whether the Earth is 'warming'; and the Loeb et al paper is correct when it says:

      "We find that the difference between the heat balance at the top of the atmosphere and upper-ocean heat content change is not statistically significant when accounting for observational uncertainties in ocean measurements3…

      Read more
    65. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Anthony Cox

      Anthony Cox:

      "CO2 and temperature do not correlate over any time scale"

      This is complete garbage. The correlation between CO2 as measured from the Law Dome ice core for the years 1880 to 1978 and GISTEMP over the same period is 0.71.

      Anthony Cox demonstrates that fake skeptics such as himself cannot be trusted to tell the truth.

      report
    66. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Chris O'Neill

      "Anthony Cox demonstrates that fake skeptics such as himself cannot be trusted to tell the truth"

      Coming from you I'll take that as a compliment.

      In respect of the lack of correlation between CO2 and temperature see this which I have posted before:

      http://icecap.us/images/uploads/CO2,Temperaturesandiceages-f.pdf

      And this is always fun:

      http://notrickszone.com/wp-content/uploads/2011/08/Bastardi-CO2Temp.gif

      And this:

      http://www.freerepublic.com/focus/f-news/1644060/posts

      And so forth.

      report
    67. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Paul Richards

      Thank you, same to you; I must find one of those little lists which does the same for AGW alarmists.

      report
    68. Chris O'Neill

      Victim of Tony Abbotts Great Big New Tax

      In reply to Anthony Cox

      Anthony Cox:

      "In respect of the lack of correlation between CO2 and temperature see this which I have posted before"

      Typical fake skeptic response. Ignore the actual facts and respond with red herrings, only one of which (the correlation between US temperature over the 20th century and CO2) comes anywhere responding to the fact that was pointed out. Two points you have ignored:

      1. The US is not the world

      2. A correlation of 0.44 is not zero, even if it was the right figure.

      I'll let you get back to denying the facts now.

      report
    69. David Arthur

      resistance gnome

      In reply to Anthony Cox

      "... global average temperature is a linear indication of heat accumulation", given this is what AGW assumes ..."

      Anthony, I think I've identified our problem.

      I'm discussing the real world, you're banging on about some straw man you've created by which you demand that global average air temperature, measured at the surface, increases in a linear manner with atmospheric CO2 content.

      Regarding your assurance that you're not a witch, that'll be irrelevant to the people who'll be looking who to blame for the ongoing damage to the world.

      Elsewhere, you've found a reference to say that evaporation is not increasing. If that's the case, how can total precipitation (rain, snow, &c) have increased over the last few decades? You might want to have a look at Santer et al, "Identification of human-induced changes in atmospheric moisture content", 2007.

      report
    70. David Arthur

      resistance gnome

      In reply to Anthony Cox

      Gday Anthony, you write that evaporation is not increasing, and cite Roderick Hobbins and Farquhar's work on Pan Evaporation Trends and Terrestrial Water Balance.

      The last paragraph of the cited article reads as follows: "What does a decline in pan evaporation mean? In short, it means a decline in evaporative demand. However, there is no simple universal
      translation of the observed pan evaporation trend into a trend in the actual evapotranspiration, that is, the evaporation and transpiration…

      Read more
    71. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to David Arthur

      "In other words, all your references to published observations are either misrepresentations of the data, or as I've mentioned above, the observations are incomplete (as in finding the purportedly missing heat)."

      Well, it's really good you're around to catch me out.

      Actually the paper on pan evaporation, which is the most reliable way of measuring evaporation trends, says this:

      “Analyses of the pan evaporation data averaged over many pans from many different countries has revealed declines…

      Read more
    72. Paul Richards

      logged in via Twitter

      In reply to Anthony Cox

      It won't matter either way. Subscribing to what loosely is called the Gaia hypothesis as a critical thinker. Having accepted a lack of general cause and effect explanation is an inevitable phase of thought and appropriate for discussion, like a means to an end.

      Overall however some self-regulating phenomena may not be explainable at all mathematically. So find the arrogance of comment and belief finding the “truth”, most of the time hilarious. We really know so little about the life on earth and this forum highlights the issue.

      Richard Feynman felt like this, his explanation carries more weight than any here, before you say it he debated it also. After all Scott, Shackleton and most of the Antarctic explorers early last century were funded to start this research on GCC, it’s not a new debate or field of study.

      report
    73. Paul Richards

      logged in via Twitter

      In reply to Paul Richards

      Just went over the "Risk Management Issues" again for a friend. Not everyone gets it, there is a lot to grasp as Climate Change disinformation abounds.
      As we see in this forum.

      I challenge anyone to refute this logical argument on Climate Change; http://youtu.be/mF_anaVcCXg

      report
  7. Jim Wright

    Retired Civil/Structural Engineer, IT Consultant/Contractor

    There is something about the fossil fuel linkage with CO2 emissions which baffles me. What research, other than for geosequestration, is being done to design an industrial process to extract the CO2 from the waste gases before they are allowed into the atmosphere and return it to a solid carbon-based substance ? No doubt the power companies will argue that a substantial amount of the power expended on the process would result in higher energy prices, but wouldn't this be a truer evaluation of the…

    Read more
    1. David Arthur

      resistance gnome

      In reply to Jim Wright

      Power companies haven't stumped up for sequestration research, perhaps because they doubt its feasibility on either or both of technological and economic grounds.

      What is really remarkable is that mining companies have likewise not made such investment. In their case, perhaps they're just hoping to make as much money as possible before the penny drops.

      report
    2. Ben Heard

      Director, ThinkClimate Consulting

      In reply to Jim Wright

      We should be thinking about it Jim. We will need to draw down from current levels. Whether that is engineered, or a better more efficient use of land to allow greater afforestation, or likely a mix, remains to be seen. But don't feel silly for thinking about it, it's a great question. Hopefully IFR nuclear will provide the sort of plentiful energy that it makes it easier to consider energy intensive solutions in the mix.

      report
  8. Jim Wright

    Retired Civil/Structural Engineer, IT Consultant/Contractor

    Being a practical sort of guy who has spent his career designing and constructing things, I find this conversation between people whose job is obviously to study phenomena and numbers to reach some sort of conclusion quite fascinating. I have one small difficulty whit it, though. Nearly every remark zeroes in on one phenomenon or one series of numbers in order to make a point. Back in the 1980s, I was a great fan of James Lovelock and, whatever you think of the Gaia hypothesis, I think the root…

    Read more
  9. Timothy Curtin

    Economic adviser

    Andrew: what would be the costs and benefits of an ice-free planet? Apart from my scotch on the rocks, I am unable to see any benefits from ice. What is the biodiversity in the100% icy world that you advocate? None, but I know from observation of your efforts at ANU that you are totally against all forms of life - except your own.

    report
    1. David Arthur

      resistance gnome

      In reply to Timothy Curtin

      Sea level rise, hence loss of much built infrastructure (refer discussion with James Sexton on this page).

      No problem if you're sipping you Scotch in Canberra, unless Laphroaig is your tipple; their site will be inundated within a few centuries.

      report
  10. Matt Stevens

    Senior Research Fellow/Statistician/PhD

    One thing that troubles me with much of the climate change arguments presented is the lack of multivariate statistical models that have the ability to identify which of the variable have independent effects with the outcome (temperature change). A series of bivariate analyses, such as what is presented would not make it through a statistical review I was doing. The arguments are about what are the factors contributing to climate change and until we have data sets that allow for robust multivariate modelling, we will not have an accurate point of view on what the main causative factors are. Happy to be pointed in the direction of some solid empirical research that reflects multiple correlations, but identifies independent effects amongst factors. Only then will we get closer to understanding what causes climate change.

    report
    1. David Arthur

      resistance gnome

      In reply to Matt Stevens

      Thanks Matt. I haven't a multi-variate analysis to contribute, but what I can provide is a summary of the physics that, a priori, force the conclusion that Anthropogenic Global Warming is a real phenomenon (warning: requires competence in physics)

      Earth is warmed by absorbtion of short wave sunlight. Because of this, Earth's temperature can remain unchanged by returning the same amount of energy to space. That is, solar shortwave energy is balanced by the earth re-radiating to space as a 'black…

      Read more
    2. Anthony Cox

      logged in via email @optusnet.com.au

      In reply to Matt Stevens

      One of the best multivariate studies is by McKitrick's team's analysis of the Tropical Hot Spot and its lack thereof:

      http://www.rossmckitrick.com/uploads/4/8/0/8/4808045/mmh_asl2010.pdf

      This paper had 2 follow-ups:

      http://www.rossmckitrick.com/uploads/4/8/0/8/4808045/2011-09.pdf

      And most interestingly this which notes the slight tropical warming, while being much less than predicted by modelling, is explained by the climate shift of 1976:

      http://onlinelibrary.wiley.com/doi/10.1002/asl.290/abstract

      Koutsoyiannis also uses multvariate analysis in his various hindcasting papers.

      report
    3. Matt Stevens

      Senior Research Fellow/Statistician/PhD

      In reply to Anthony Cox

      Interesting stuff. It would appear that most statistical models ran in these papers found that predictions from climate change models over-estimated (significantly), increases in temperature. I suspect this is because the mathematical/physics based models do not account for covariation in variables and to not produce independent effects for the predictive variables in them. As most people who have done some multivariate modelling would know, you often have a number of variables correlated with each other and the outcome, but my putting these variables in a model together, you notice that many of the previously significant correlations between the outcome and other variables, become non-significant. My guess is that many maths based models use a cumulative effect of multiple predictor variables, and the models ignore this important fact.

      report
    4. David Arthur

      resistance gnome

      In reply to Anthony Cox

      None of which says anything at all about the physics that I've set out above.

      report
    5. Ben Heard

      Director, ThinkClimate Consulting

      In reply to Matt Stevens

      Hi Matt,

      McKitrick and co are part of a small number of credible scientists who do inhabit the more contrarian end of the spectrum, and they tend to work on isolating areas where model performance does not appear to be strong. Which is fine, it all matters, and that type of work does highlight where models need improvement. Climate is complex God only knows, we are a long way from perfectly reproducing the real world in a computer. But I would not want you to think the findings they report are…

      Read more
    6. Ben Heard

      Director, ThinkClimate Consulting

      In reply to Matt Stevens

      Matt, please also refer to my previous comment. The IPCC AR4 concluded with 9/10 certainty that the predominate cause of warming since the mid-20th century is anthropogenic greenhouse gas emissions. This suggest we do indeed have a good understanding of what is causing the climate change we are currently experiencing. I suggest you are not giving these people anywhere near enough credit in terms of the sophistication of the efforts that make this finding possible.

      report
    7. Matt Stevens

      Senior Research Fellow/Statistician/PhD

      In reply to Ben Heard

      Hi Ben

      Apologies, as I did not intend to belittle the efforts of many scientists. Thanks for the suggested readings also.

      report
  11. Timothy Curtin

    Economic adviser

    Surface snowmelt is widespread in coastal Antarctica.
    Satellite-based microwave sensors have been observing melt
    area and duration for over three decades. However, these
    observations do not reveal the total volume of meltwater
    produced on the ice sheet. Here we present an Antarctic melt
    volume climatology for the period 1979–2010, obtained
    using a regional climate model equipped with realistic
    snow physics. We find that mean continent-wide meltwater
    volume (1979–2010) amounts to 89 Gt y!1…

    Read more
  12. Timothy Curtin

    Economic adviser

    Matt Stevens: you said - "Happy to be pointed in the direction of some solid empirical research that reflects multiple correlations, but identifies independent effects amongst factors. Only then will we get closer to understanding what causes climate change." I am not sure if my works counts as solid! - but my paper "Econometrics and the Science of Climate Change" was accepted for presentation at ACE2011 (Conference of Ec Soc Australia) in July 2011, and is at the ACE2011 website, as well as at mine (www.timcurtin.com). A revised version has been accepted for publication after 4X peer review by an international Science journal (not E&E) and should be out shortly. Email me at tcurtin at bigblue.net.au for an advance copy but not for circulation or attribution until it actually appears.

    report
    1. Matt Stevens

      Senior Research Fellow/Statistician/PhD

      In reply to Timothy Curtin

      Thanks for the link to your article Tim. The most sensible article critiquing the "science" behind climate change and what are the causative factors involved I have accessed to date. It took a few hours, a few beers. a few ...., but it was a great read. Explaining complex phenomena and the statistics to explain it, is no easy task. I do not deny that humans may contribute to increasing temperature, but I would like to see strong evidence to prove it. But all the same I would like to see a reduction in pollution (i.e. an improvement in the air quality that all species on this plant are reliant on), less clearing of areas of environmental significance (i.e. high diversity or rare diversity), and of course peace, love and harmony. ;-)

      report
    2. David Arthur

      resistance gnome

      In reply to Matt Stevens

      Tim, you are a statistician, which I must respect.

      Your contributions show no understanding of atmospheric physics. Please search through my comments on this page for my summary description of the simple physics that implies that there is no way that Anthropogenic Global Warming is NOT occurring.

      You will also find the same description posted under my name in the discussion following Terry Kreig's recent Ockham's Razor talk ("Nuclear power - exploding the myths", 15 January 2012, http://www.abc.net.au/radionational/programs/ockhamsrazor/ockham27s-razor-15-january-2012/3732664#comments), in which Terry dismantles some myths around nuclear power.

      People who dispute the physics generally don't understand it.
      People who understand the physics generally don't dispute it.

      report
    3. Paul Richards

      logged in via Twitter

      In reply to David Arthur

      Terry Kreig's - dismantled nothing.
      All he did was outline his ignorance of the nuclear industry. Even current specialist engineers in the industry who are pro nuclear could drive holes through everything he said.

      Thankfully the old utopian dream we were sold in the 1950s of nuclear being our friend has is dying, the internet and freedom of information has seen to that. The power to shut down SOPA in the US, could easily deal it a death blow sooner than people think.

      I challenge you to sit through one video on the subject and come back with a re-buttle.

      Just one video;
      http://youtu.be/QEbjYr8rubA

      If you want to make yourself aware this playlist is a start;
      http://goo.gl/BLaQO

      report
    4. David Arthur

      resistance gnome

      In reply to Paul Richards

      Sorry I hadn't replied to you earlier.

      My comments are not intended to be rabidly pro-nuclear, and I see that you invited me to watch the same video in the comments after Terry Kreig's Ockham's Razor talk. I haven't bothered with the video because I assiduously avoid youtube, but I see you describe it as pertaining to nuclear waste.

      With all due respect, so what? Store the waste, then use it to backfill spent workings at Roxby Downs - better than Muckaty. Anyway, alternative nuclear technology…

      Read more
    5. Paul Richards

      integral operating system

      In reply to David Arthur

      David - due diligence is just that, if you feel you understand both sides of the "story" fully, fine.
      You are the best judge, it is your interior.

      Thorium, although promising is just that, unproven in practice, undeveloped and under consideration.

      The world actually can not wait for the metrics to prove if the theoretical thorium reactor can stand up un-assisted. Given gen III has a 40 - 50 year cycle and is yet to prove actually cost effective, all we ever can ever do is listen and have…

      Read more
  13. Timothy Curtin

    Economic adviser

    Matt: Many thanks indeed, I have been climbing a very rocky mountain for some years now, so great to have some encouragement.

    You also said: "I do not deny that humans may contribute to increasing temperature, but I would like to see strong evidence to prove it."

    Absolutely. My 74 years constitute only anecdotal evidence, but I am not conscious of climate "change" in any of the dozen countries I have lived in. Only last week Canberra had its coldest ever January night (1oC), while my son and…

    Read more
  14. Tim Benham

    Student of Statistics

    The figures two through four would be good textbook examples of misleading displays. Figure 2 cuts off the zero to exaggerate the size of the increase, figure 3 cannot possibly be percentage changes in Earth's absolute temperature or the present temperature would exceed 1900's by about 60K, and figure 4 uses a Mercator projection which is not area preserving. It grossly exaggerates areas close to the poles (such as Siberia and northern Canada).

    Figure 5 and the accompanying text seem to confuse…

    Read more
    1. Peter Lang

      Retired geologist and engineer

      In reply to Tim Benham

      Excellent points. I wonder why no one responded. Where are the scientists? Is this catastrophic climate change stuff just advocacy of an ideology?

      report
  15. James Szabadics

    BSc

    Sea level rise appears to be quite linear

    http://www.cmar.csiro.au/sealevel/images/alt_gmsl_seas_rem.jpg

    If anything the rate of change of sea level has been decellerating in the last few years and is quite a way below the trend line at the moment which is curious because more rapidly melting greenland and antarctic icecaps should result in an increasing rate of change of sea level?

    report