Masters on “Unprecedented” Arctic Ozone Hole: Inaction Risks “Future Nasty Climate Change Surprises Far More Serious”

Dr. Jeff Masters:  An unprecedented ozone hole opened in the Arctic during 2011, researchers reported this week in the journal Nature….  We know that an 11% increase in UV-B light can cause a 24% decrease in winter wheat yield (Zheng et al., 2003), so this year’s Arctic ozone hole may have caused noticeable reductions in Europe’s winter wheat crop….

It is highly probable that we will see future nasty climate change surprises far more serious than the Arctic ozone hole if we continue on our present business-as-usual approach of emitting huge quantities of greenhouse gases. Humans would be wise to act forcefully to cut emissions of greenhouse gases, as the cost of inaction is highly likely to be far greater than the cost of action.

Left: Ozone in Earth’s stratosphere at an altitude of approximately 12 miles (20 kilometers) in mid-March 2011, near the peak of the 2011 Arctic ozone loss. Right: chlorine monoxide–the primary agent of chemical ozone destruction in the cold polar lower stratosphere–the same day and altitude. Image credit: NASA/JPL-Caltech.

JR:   This important finding almost qualifies as an “unknown unknown,” in that this impact was considered unlikely.  And if it harms Europe’s winter wheat crop, it could seriously add to the world’s growing food insecurity (see “Global Food Prices Stuck Near Record High Levels and links therein.   Meteorologist Dr. Jeff Masters has a great post on this, which I reprint below.

Unprecedented Arctic ozone hole in 2011

by Dr. Jeff Masters

An unprecedented ozone hole opened in the Arctic during 2011, researchers reported this week in the journal Nature. Holes in the Antarctic ozone layer have opened up each spring since the early 1980s, but the Arctic had only shown modest springtime ozone losses in the 5% – 30% range over the past twenty years. But this year, massive ozone destruction of 80% occurred at altitudes of 18 – 20 kilometers in the Arctic during spring, resulting in Earth’s first known case of twin ozone holes, one over each pole. During late March and portions of April, the Arctic ozone hole was positioned over heavily populated areas of Western Europe, allowing large levels of damaging ultraviolet rays to reach the surface. UV-B radiation causes skin damage that can lead to cancer, and has been observed to reduce crop yields in two-thirds of 300 important plant varieties studied (WMO, 2002.) The total loss of ozone in a column from the surface to the top of the atmosphere reached 40% during the peak of this year’s Arctic ozone hole. Since each 1% drop in ozone levels results in about 1% more UV-B reaching Earth’s surface (WMO, 2002), UV-B levels reaching the surface likely increased by 40% at the height of this year’s hole. We know that an 11% increase in UV-B light can cause a 24% decrease in winter wheat yield (Zheng et al., 2003), so this year’s Arctic ozone hole may have caused noticeable reductions in Europe’s winter wheat crop.

What caused this year’s unprecedented Arctic ozone hole?
Earth’s ozone holes are due to the presence of human-emitted CFC gases in the stratosphere. The ozone destruction process is greatly accelerated when the atmosphere is cold enough to make clouds in the stratosphere. These polar stratospheric clouds (PSCs) act like ozone destruction factories, by providing convenient surfaces for the reactions that destroy ozone to occur. PSCs only form in the 24-hour darkness of unusually cold winters near the poles; the atmosphere is too warm elsewhere to support PSCs. Stratospheric temperatures are warmer in the Arctic than the Antarctic, so PSCs and ozone destruction in the Arctic has, in the past, been much less than in the Antarctic. In order to get temperatures cold enough to allow formation of PSCs, a strong vortex of swirling winds around the pole needs to develop. Such a “polar vortex” isolates the cold air near the pole, keeping it from mixing with warmer air from the mid-latitudes. A strong polar vortex in winter and spring is common in the Antarctic, but less common in the Arctic, since there are more land masses that tend to cause large-scale disruptions to the winds of the polar vortex, allowing warm air from the south to mix northwards. However, as the authors of the Nature study wrote, “The persistence of a strong, cold vortex from December through to the end of March was unprecedented. In February – March 2011, the barrier to transport at the Arctic vortex edge was the strongest in either hemisphere in the last ~30 years. This unusual polar vortex, combined with very cold Arctic stratospheric temperatures typical of what we’ve seen in recent decades, led to the most favorable conditions ever observed for formation of Arctic PSCs. The reasons for this unusual vortex are unknown.

Figure 2. Global lower stratospheric departure of temperature from average since 1979, as measured by satellites. The large spikes in 1982 and 1991 are due to the eruptions of El Chicon and Mt. Pinatubo, respectively. These volcanoes ejected huge quantities of sulphuric acid dust into the stratosphere. This dust absorbed large quantities of solar radiation, heating the stratosphere. Stratospheric temperature has been generally decreasing in recent decades, due to the twin effects of ozone depletion and the accumulation of greenhouse gases in the lower atmosphere. During Jan – Aug 2011, Earth’s stratosphere had its 3rd coldest such period on record. Image credit: National Climatic Data Center.

Greenhouse gases cause stratospheric cooling
When ozone absorbs UV light, it heats the surrounding air. Thus, the loss of ozone in recent decades has helped cool the stratosphere, resulting in a feedback loop where colder temperatures create more PSCs, resulting in even more ozone destruction. However, in 1987, CFCs and other ozone-depleting substances were banned. As a result, CFC levels in the stratosphere peaked in 2000, and had fallen by 3.8% as of 2008, according to NASA. Unfortunately, despite the fact that CFCs are falling in concentration, the stratosphere is not warming up. The recovery of the ozone layer is being delayed by human emissions of greenhouse gases like carbon dioxide and methane. These gases trap heat near the surface, but cause cooling of the stratosphere and increased formation of the PSCs that help destroy ozone. We need only look as far as our sister planet, Venus, to see an example of how the greenhouse effect warms the surface but cools the upper atmosphere. Venus’s atmosphere is 96.5% carbon dioxide, which has triggered a hellish run-away greenhouse effect. The average surface temperature on Venus is a sizzling 894 °F, hot enough to melt lead. Venus’s upper atmosphere, though, is a startling 4 – 5 times colder than Earth’s upper atmosphere. The explanation of this greenhouse gas-caused surface heating and upper air cooling is not simple, but good discussions can be found at Max Planck Institute for Chemistry and, for those unafraid of radiative transfer theory. One way to think about the problem is that the amount of infrared heat energy radiated out to space by a planet is roughly equal to the amount of solar energy it receives from the sun. If the surface atmosphere warms, there must be compensating cooling elsewhere in the atmosphere in order to keep the amount of heat given off by the planet the same and balanced. As emissions of greenhouse gases continue to rise, their cooling effect on the stratosphere will increase. This will make recovery of the stratospheric ozone layer much slower.

Greenhouse gases cause cooling higher up, too
Greenhouse gases have also led to the cooling of the atmosphere at levels higher than the stratosphere. Over the past 30 years, the Earth’s surface temperature has increased 0.2 – 0.4 °C, while the temperature in the mesosphere, about 50 – 80 km above ground, has cooled 5 – 10 °C (Beig et al., 2006). There is no appreciable cooling due to ozone destruction at these altitudes, so nearly all of this dramatic cooling is due to the addition of greenhouse gases to the atmosphere. Even greater cooling of 17 °C per decade has been observed high in the ionosphere, at 350 km altitude. This has affected the orbits of orbiting satellites, due to decreased drag, since the upper atmosphere has shrunk and moved closer to the surface (Lastovicka et al., 2006). The density of the air has declined 2 – 3% per decade the past 30 years at 350 km altitude. So, in a sense, the sky IS falling due to the greenhouse effect!

Since any increase in solar energy would heat both the lower and upper atmosphere, the observed drop in upper atmospheric temperatures in the past 30 years argues against an increase in energy coming from the sun being responsible for global warming. The observed cooling of the upper atmosphere is strong evidence that the warming at Earth’s surface is due to human-emitted greenhouse gases that trap heat near the surface and cause compensating cooling aloft. It should also give us additional confidence in the climate models, since they predicted that this upper atmospheric cooling would occur. Keep in mind, also, that 2010 was tied for Earth’s hottest year on record, and the amount of energy coming from the sun during 2009 – 2010 was the lowest since satellite measurements began in the late 1970s. There has been no long-term increase in energy coming from the sun in recent decades, and the notion that global warming is due to an increase in energy coming from the sun simply doesn’t add up.

The development of an ozone hole in the Arctic is a discouraging reminder that humans are capable of causing harmful and unexpected planetary-scale changes to the environment. A 2002 assessment of the ozone layer by the World Meteorological Organization concluded that an Arctic ozone hole would be unlikely to occur, due to the lack of a strong Arctic vortex in winter, and the fact CFCs levels had started to decline. However, an Arctic ozone hole may now become a regular visitor in the future. “Day-to-day temperatures in the 2010 – 11 Arctic winter did not reach lower values than in previous cold Arctic winters,” said the lead author of this year’s Nature study, Gloria Manney, of NASA and the New Mexico Institute of Mining and Technology in Socorro. “The difference from previous winters is that temperatures were low enough to produce ozone-destroying forms of chlorine for a much longer time. This implies that if winter Arctic stratospheric temperatures drop just slightly in the future, for example as a result of climate change, then severe Arctic ozone loss may occur more frequently.” I might add that its a very good thing CFCs were banned in 1987, or else the Arctic ozone hole would have opened up much sooner and would have been far worse. It turned out that the costs of the CFC ban, while substantial, were far less than the dire cost predictions that the CFC industry warned of. It is highly probable that we will see future nasty climate change surprises far more serious than the Arctic ozone hole if we continue on our present business-as-usual approach of emitting huge quantities of greenhouse gases. Humans would be wise to act forcefully to cut emissions of greenhouse gases, as the cost of inaction is highly likely to be far greater than the cost of action.

Manney, G.L., et al., 2011, Unprecedented Arctic ozone loss in 2011, Nature (2011), doi:10.1038/nature10556

Weather Underground Ozone Hole FAQ

World Meteorological Organization (WMO), “Scientific Assessment of Ozone Depletion: 2002 Global Ozone Research and Monitoring Project – Report #47”, WMO, Nairobi, Kenya, 2002.

Zheng, Y., W. Gao, J.R. Slusser, R.H. Grant, C. Wang, “Yield and yield formation of field winter wheat in response to supplemental solar ultraviolet-B radiation,” Agricultural and Forest Meteorology, Volume 120, Issues 1-4, 24 December 2003.

40 Responses to Masters on “Unprecedented” Arctic Ozone Hole: Inaction Risks “Future Nasty Climate Change Surprises Far More Serious”

  1. dick smith says:

    thanks again for the science updates. I knew the stratosphere was cooling. I did not realize that “When ozone absorbs UV light, it heats the surrounding air. Thus, the loss of ozone in recent decades has helped cool the stratosphere, resulting in a feedback loop where colder temperatures create more PSCs, resulting in even more ozone destruction.”

  2. Tom Gray says:

    “One way to think about the problem is that the amount of infrared heat energy radiated out to space by a planet is roughly equal to the amount of solar energy it receives from the sun. If the surface atmosphere warms, there must be compensating cooling elsewhere in the atmosphere in order to keep the amount of heat given off by the planet the same and balanced.” –I find this quite a bit more difficult to follow than the notion that GHGs are trapping heat which would otherwise be reaching the stratosphere. Is that because I am a doofus? Just checking.

  3. Joan Savage says:

    Accumulation of moisture in the stratosphere is a factor in the formation of the ozone-damaging PSC clouds. Moisture from the troposphere has worked its way into the stratosphere over several decades. The references on tropospheric-stratospheric mixing go back to the 1960s. Someone who can do the quantitative analysis could say more (or less) about reaching a critical level.

  4. Leif says:

    Yet another example of present day farmers taking loses while CFC deniers and delayers reaped past profits. I dare say that CFC Deniers will not compensate Europe’s farmers for present day crop loss. Just why are CFC Deniers not held libel? The facts were known.

  5. Raul M. says:

    What’s the name of that atmospheric component that breaks down methane?

  6. Joan Savage says:

    Were you thinking of hydroxyl radicals?

  7. Anderlan says:

    Raul, a quick search isn’t yielding much information on that one for me. I had always just assumed that methane very slowly became water and CO2 (like burning it, but through more circuitous chemical routes) in the irradiated upper atmosphere. I could be totally wrong and methane-to-CO2 microbes may play a larger role than non-bio pathways. Please post back here if you find out!

  8. Robert In New Orleans says:

    Pass the sunblock and say hello to more skin cancer.

    Which leads to an interesting point, will the remanents of humankind be able to survive in the Polar regions while being exposed to increased amounts of UV radiation?

    I am thinking the prospect of long term human survival has just become more problematic.

  9. Rabid Doomsayer says:

    Eli Rabett has a relatively easy read. (Meaning I almost understood it)
    To be honest I had never heard of HONO

  10. Merrelyn Emery says:

    Here come the systemic effects that can’t be predicted by reductionist science or even by models populated with the most probably influential variables.

    This event should give us even more cause to prohibit geoengineering in the atmosphere or oceans that has been tested on only small sites on in the lab, or in current theory, ME

  11. prokaryotes says:

    How does they plan to deal with volcanic eruptions, earthquakes, landslides, tsunamis and methane clouds which are eventually ignitable? And then the question what you going to plan to feed to the remaining breeding pairs?

    Also you have to consider, radioactive fallout clouds, acid rain, radioactive rain, contaminated foodchain, tainted water sources, the list goes on.

  12. Joan Savage says:

    Thanks for the link reminder. I want to brush up on the chlorine chemistry part, because of the Gloria Manney quote, “The difference from previous winters is that temperatures were low enough to produce ozone-destroying forms of chlorine for a much longer time.”

  13. Joan Savage says:

    For a tough but condensed read that includes many more of the chlorine reactions:

    Climate Change and Atmospheric Chemistry: How Will the Stratospheric Ozone Layer Develop?
    Prof. Dr. Martin Dameris.
    [review]Angewandte Chemie International Edition Volume 49, Issue 44, pages 8092–8102, October 25, 2010

  14. wili says:

    Methane in the troposphere reacts with hydroxyl radicals. But iirc it reacts directly with ozone in the stratosphere to yield H2O and CO2. This is the largest single source of water vapor in the stratosphere (about a third of the total) which itself seems to be a particularly powerful driver of GW.

    I can’t help but assume that dramatic sea ice loss and seabed methane release are related causally to the ozone hole this year, but the exact dynamics are difficult to work out. Both the methane and the increased water vapor from low ice cover would provide rising gasses that could, I would think, increase the power of the vortex.

  15. Masters doesn’t mention it, but at least with respect to the Antarctic Polar Vortex, I remember reading that it has become stronger due to the temperature differential between the troposphere and the stratosphere, with the stratosphere cooling in part due to the increased levels of carbon dioxide making the upper stratosphere a better emitter/radiator of thermal energy, the troposphere a better absorber (“good absorbers are good emitters”), with the net effect of carbon dioxide being that of an emitter above the effective radiating altitude but absorber below. As such, while one year to the next is weather, with rising levels of carbon dioxide and the cumulative effect of higher levels on temperature over time, it would make sense if we saw a trend towards stronger polar vortexes in the Winter and Spring. As the vortex serves to isolate the polar atmosphere from the rest of the atmosphere a strengthened vortex will amplify the cooling effect of higher levels of carbon dioxide on the stratosphere, although I would presume that being largely driven by the temperature differential between the stratosphere and troposphere it will tend to cool the lower stratosphere more so than the high.

    Similarly, the warming effect on the stratosphere of ozone (due to the absorption of ultraviolet radiation and thermalization of the energy through collision) takes place primarily in the lower stratosphere, and thus the cooling effect of ozone depletion has been primarily in the lower stratosphere. However, the level of CFCs in the stratosphere has been gradually decreasing. As such, the CFCs alone do not explain the ozone loss during the Spring. Increased levels of ice clouds providing a surface for and activating CFCs does. But this is due to lower temperatures in the stratosphere. So if there is a trend towards greater ozone loss what is driving it in large part must be rising levels of carbon dioxide with the consequent lower temperatures in the stratosphere, higher temperatures in the troposphere, and with cooling due to a stronger polar vortex and ozone loss serving to amplify the cooling effect of rising levels of carbon dioxide on the stratosphere.

    As such, it seems to me at least that we are dealing with some sort of threshold behavior, that we can expect the Arctic hole to become more common, at least for as long as CFC levels remain high enough.

    The authors of the paper state:

    Although the Arctic polar vortex is smaller than its Antarctic counterpart, it is also much more mobile, often moving over densely populated lower latitudes, where UV radiation is more intense than near the pole. By mid-April 2011, the lower stratospheric vortex had shifted off the pole and sat over central Russia, remaining intact and enclosing total ozone values less than 275 DU through late April (Figure 5). Significant increases in surface UV radiation were associated with these low ozone levels. For example, under a lobe of the vortex extending south over Mongolia on 22 April, the clear sky UV index (UVI, a commonly used metric for gauging the impact of surface UV radiation on human skin) at 48°N, 98°E was 8.60, compared to the long-term average of 5.36, an anomaly roughly seven times the standard deviation. The 22 April value was close to the highest UVI at that location in mid-summer. On 17 April, a tongue of vortex air extended over the Alps. Even though this tongue had experienced some in-mixing of extra-vortex air, the UVI at Arosa (46.8°N, 9.7°E) increased to 7.4, about four standard deviations above the long-term mean. UVIs exceeding 7 can cause sunburn within minutes.

    Manney, G.L., et al., 2011, Unprecedented Arctic ozone loss in 2011, Nature (2011)(Subscription Required)

    The Antarctic ozone hole puts people in the southern most parts of South America at much greater rise for skin cancer and cataracts. I would assume that with more intense solar radiation at lower latitudes even a hole that isn’t as severe as that Antarctic will pose as great or a greater threat, particularly as the hole is capable of reaching more densely populated areas. This is directly relevant, even to people living in the US lower 48. For example, Seattle is at 47.62°N and the hole this year wandered as low as 46.8°N, resulting in dangerously high ultraviolet radiation levels at that latitude.

    Now I wouldn’t want to blow this up into any sort of end of the world scenario because it clearly isn’t. For this century I would expect drought and famine to be of greater consequence than all the other effects of global warming combined. But I believe this story underscores just how much we have altered our world, and for the worse, given our addiction to fossil fuels. I would like to think that the Arctic ozone hole could serve as a wake-up call, for some.

  16. Bill G says:

    Robert in New Orleans: You hit a vital point. This is very bad news for survival in northern regions. UV in strong doses affects crops and man himself.

    We seem to be entering a zone of no return. Climate destruction is so multifaceted and goes into areas previously unknown. Did the IPCC address any of this?

    It seems even our escape route may be cut off. Very worrying if one cares about man’s survival.

  17. I have been “clicking around” for an explanation, and I think I understood it this way. Carbon dioxide absorbs certain wavelengths. It transfers the energy to the other atmospheric components via collisions. Those other gasses radiate a range of wavelengths based on temperature. So the wavelengths that CO2 absorbs are greatly diminished in the upper atmosphere. The heat is not trapped permanently in the troposphere, but it reaches the stratosphere in a form that cannot be absorbed. If we increase CO2 in the troposphere, then in the stratosphere and above, the part absorbed by CO2 decreases more. Radiation from the stratosphere would continue unchanged at first but would diminish as the stratosphere cools to re-establish equilibrium between radiation and absorption.
    At least I think I understood it that way. See . I think this is consistent with the temperature gradient explanation, but I am still thinking about it. Anyway, it should establish a larger gradient.

  18. Lewis Cleverdon says:

    If news of the nasty surprise of a massive arctic ozone hole developing, this early in the curve of pipeline global warming, has the effect of ending the delusion that the far north offers an escape from climate destabilization, then it will have done some good. Awareness that we are fighting for our species’ survival might just energize more people to take action, rather than planning to hide away and leave the rest to starve.

    Humanity being reduced to “a few breeding pairs in the arctic” – as Lovelock put it – has been widely misinterpreted. He spoke with expert knowledge of ecology, apparently assuming that his audience would be equally aware that any species reduced to a few breeding pairs is close to its inevitable extinction.

    Perhaps it also needs saying that Lovelock is by no means defeatist – for instance he is a staunch proponent of Biochar as a means to cut airborne CO2 potentially back to the pre-industrial level. Hansen, who also strongly endorses this option (naturally as a complement to halting GHG outputs ASAP) is on record as reporting that a global program of biochar interrment could cut airborn CO2 by 8ppmv/yr.

    So we ain’t beaten yet, not by a long chalk. We just need to realize that we have nothing to lose by taking this fight to the promoters of the coming genocidal climate impacts.



  19. Colorado Bob says:

    I’m wondering what this extra shot of UV does to the bottom of the food chain .
    If it blinds people, and stunts wheat , it doesn’t look good for zooplankton .

  20. Colorado Bob says:

    Thailand is running out of sand bags …
    ” Efforts to protect Ayutthaya’s inner town and parts of its key industrial estate have failed and widespread evacuations have begun. This morning Nakorn Sawan’s embankment failed as well. ”

  21. Anne van der Bom says:

    I have understood it in a slightly diffent manner. CO2 radiates at the same wavelengths as it absorbs (this is a fundamental law). More CO2 means a net increase of absorption low in the atmosphere and a net increase of radiation high up in the atmosphere. A net increase in radiation means more energy lost to space means lower temperatures.

  22. Mike Roddy says:

    The Amazon drought was certainly bad news, but there is far more carbon in the boreal, especially in the soils. Dessication or fires there could mean game over. The best thing we could do is stop logging it, but that would mean less toilet paper. Not likely.

  23. Mike Roddy says:


    Please send me the biochar link. 8 ppm is a lot, and I’d like to see how we can do it.

    The public has no idea of the facts that we read every day here on CP. It’s about time we figured out a way to get the word out, starting with abandoning the mainstream media. Whatever new companies run with news such as this will find a ready readership.

  24. Raul M. says:

    So what happens to the methane when it runs out of ozone way up there?
    Such a silly question since we have not found a way of dealing with the truth except by changing our ways.

  25. Lionel A says:

    The best thing we could do is stop logging it, but that would mean less toilet paper.

    And then what would Pat Michaels use to cover his nakedness?

  26. Sasparilla says:

    Very good article Joe. Presumably as CO2 levels rise the temperatures in the Polar stratosphere will continue to trend in decline in the future setting the stage for increasing instances of these conditions as time goes on – god help us at 1000ppm and beyond.

    As others have noted, this does not bode well long term for far northern large scale food production if we end up losing this war (as we appear to be on a rampage towards doing) and whats left of humanity has had to retreat towards the poles by the end of this century and beyond.

  27. Joan Savage says:

    Good point. Also phytoplankton. It varies.
    Penetration of water by light, including UV-B and UV-A, varies a great deal with water clarity. Depending on the body of water, UV-B can attenuate within centimeters of a murky surface, or penetrate over twenty meters in clear water.

  28. Christine says:

    I would be interested in the biochar link(s) as well. Please post – thanks!

  29. prokaryotes says:

    Another “unknown, unknwon” In terms of how far reaching the emotional complex consequences are)


    Emotional disquiet about negative changes in one’s environment.

  30. prokaryotes says:

    Lovelock on Biochar

    I said in my recent book that perhaps the only tool we had to bring carbon dioxide back to pre-industrial levels was to let the biosphere pump it from the air for us. It currently removes 550bn tons a year, about 18 times more than we emit, but 99.9% of the carbon captured this way goes back to the air as CO2 when things are eaten.

    What we have to do is turn a portion of all the waste of agriculture into charcoal and bury it. Consider grain like wheat or rice; most of the plant mass is in the stems, stalks and roots and we only eat the seeds. So instead of just ploughing in the stalks or turning them into cardboard, make it into charcoal and bury it or sink it in the ocean. We don’t need plantations or crops planted for biochar, what we need is a charcoal maker on every farm so the farmer can turn his waste into carbon. Charcoal making might even work instead of landfill for waste paper and plastic.

    James Lovelock Video about Biochar

    Assesment of the Royal Society on Biochar Co2 removal potential

    It was pointed out in the IPCC Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC) as a key technology for reaching low carbon dioxide atmospheric concentration targets.[26] The negative emissions that can be produced by Bio-energy with carbon capture and storage (BECCS) has been estimated by the Royal Society to be equivalent to a 50 to 150 ppm decrease in global atmospheric carbon dioxide concentrations[2] and according to the International Energy Agency, the BLUE map climate change mitigation scenario calls for more than 2 gigatons of negative CO2 emissions per year with BECCS in 2050


    Everything Biochar @ my website

  31. prokaryotes says:

    Population bottleneck
    A population bottleneck (or genetic bottleneck) is an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing.

    Evolutionary biologist Richard Dawkins has postulated that human mitochondrial DNA (inherited only from one’s mother) and Y chromosome DNA (from one’s father) show coalescence at around 140,000 and 60,000 years ago, respectively. In other words, all living humans’ female line ancestry can be traced back to a single female (Mitochondrial Eve) at around 140,000 years ago. Via the male line, all humans can trace their ancestry back to a single male (Y-chromosomal Adam) at around 60,000 to 90,000 years ago.[3]

    This is consistent with the Toba catastrophe theory that suggests that a bottleneck of the human population occurred c. 70,000 years ago, proposing that the human population was reduced to perhaps 15,000 individuals[4] when the Toba supervolcano in Indonesia erupted and triggered a major environmental change. The theory is based on geological evidences of sudden climate change and on coalescence evidences of some genes (including mitochondrial DNA, Y-chromosome and some nuclear genes)[5] and the relatively low level of genetic variation with humans

  32. Mike#22 says:

    8 ppm in 50 years for biochar.

    Improved forestry and agricultural options, about 0.8 ppm/year.

    Looking forward to the post on why planting trees won’t help.

  33. Steve Rankin says:

    Canada is considering closing its ozone monitoring network in the high artic. Headline in the ONION? Sadly No. This removes any doubt about Stephen Harper’s push to destroy a livable client. Facts get in the way of the fantasy so get rid of the facts.

  34. CO2 would emit the same wavelengths it absorbs if it had a chance to radiate. However collisions with other atmospheric molecules are another way for the CO2 to lose energy, and the timing of collisions vs. the lifetime of the excited states allows collisions to be an important process. That’s how absorption by CO2 heats the rest of the atmosphere. As the process proceeds through the atmosphere, this process would drain the wavelengths absorbed by CO2 from the radiation leaving little to be absorbed in the stratosphere. At least that’s how I understand it. I am a retired physicist with little contact with others in the field, so I am posting this to test my own knowledge. If anyone has a different idea, I am ready to listen. “Sock it to me.”

  35. Lewis Cleverdon says:

    See the “International Biochar Initiative” site for general info on the prospect and on current RD&D. Most of the US firms’ tech looks over-complex and costly for global replication – poor IIIW villages particularly in forested areas are the real target producers. Very well worth looking at the international efforts also shown – very diverse and very widespread.

    The Hansen reference was on the IBI front page as part of the general presentation. Interesting focus on the need for stringent codes of ecological sustainability. – Like anything else from growing potatoes to running a bank, biochar could be done well or done badly, and it is crucial that the former outcome is supported by effective codes of conduct.



  36. Jay Alt says:

    Joe –
    The reports say ozone depletion was worsened by the strong polar vortex. In contrast, recall studies of severe winter weather in NA & EU during 10 & ’11. Those events correlated with an unusually negative Arctic Oscillation phase. And models suggest the warmer Arctic Ocean helps drive that pattern. But most importantly, the pattern produced fridge Arctic weather fronts bulging south and into the U.S.

    At first glance these seem to contradict. But the 1st happens in the stratosphere, while the 2nd is in the troposphere. Is the polar vortex strictly a high altitude phenomena? Are there other differences? A clear explanation is needed or deniers will try to confuse on these two issues.

  37. Joe Bftsplk says:

    The Antarctic polar vortex is the wind that circles around the entire continent. In the winter especially, the effect is to isolate an air mass in the troposphere over Antarctica so it gets colder than any air anywhere else on Earth. The stratosphere sits up above winds generally, i.e. the troposphere is where weather is, but the Antarctic stratosphere gets colder than the stratosphere anywhere else as it is sitting on top of the isolated by the polar vortex, colder than anywhere else Antarctic troposphere. It was a surprise way back when, as scientists realized ice crystals could form in these conditions in the Antarctic stratosphere. Early Antarctic explorers had noted the very high unique ice clouds there, but the ozone scientists didn’t know. The fact that ice crystals are present accelerates the catalytic reactions where chlorine destroys ozone. At some levels almost all the ozone is gone. In the Antarctic spring the vortex tends to break up as new energy arrives in the area with the appearance of the Sun, which allows warmer air to mix in, and the ozone hole tends to disappear.

    So, in the Arctic, an unusual weather pattern must have isolated an air mass long enough to allow it to cool enough to freeze out some ice crystals in the stratosphere which allowed the chlorine which is still in excess everywhere in the stratosphere, to destroy enough ozone it could be called a “hole”. Because the Arctic is so different than the Antarctic, i.e. there isn’t an ocean all around a continent allowing winds to blow all around all winter, it seems unlikely this situation would be repeated very often. Like it hasn’t been seen until now, whereas an Antarctic hole has been around since the early 1980s.

  38. Joe Bftsplk says:

    PS The CFC and related chemicals ban under the Montreal Protocol is the most effective climate action yet taken by civilization. See:

    Another way to look at it: Hansen published a chart on page 36 of his Earth’s Energy Imbalance paper which shows the drastic decline in the amount of new climate forcing due to Montreal Protocol gases added each year, because they aren’t being added. These are long lived gases with very high global warming potential (>10,000 in some cases) and a lot of what went in prior to the Protocol is still there.

  39. Jay Alt says:

    Thanks for the replies but they don’t really address my question. A strong polar vortex associated w/ PSCs & ozone depletion seems somewhat at odds with weakened tropospheric circulation. The latter leads to a southerly bulge in Arctic weather conditions that chills the eastern U.S.