The Hot 15 Million Year Time Machine — 415 Parts Per Million CO2

The clanking, wheezing, gasping, choking engines of fossil fuel burning are propelling us backwards toward hotter and hotter geological contexts. And with new atmospheric CO2 records shattered this week, it is, once again, time to take stock.

Jonathan Overpeck, dean of the School for Environment and Sustainability yesterday noted:

“We keep breaking records, but what makes the current levels of CO2 in the atmosphere most troubling is that we are now well into the ‘danger zone’ where large tipping points in the Earth’s climate could be crossed.”

One way we can get a sense of how far we’ve crossed into Overpeck’s ‘danger zone’ is by looking at how present atmospheric heat trapping gas levels compare to past climate ages. Taking measure, we find that over the last few days, carbon dioxide levels have spiked to over 415 parts per million. An ominous new record driven by fossil fuel burning that spells more warming and climate disruption for a planet already in crisis.

As a report in LiveScience yesterday noted — the present spike in atmospheric CO2 is unprecedented in the past 800,000 years. A span of time when we are able to directly measure historic atmospheric carbon dioxide due to air bubbles trapped in the ice of ancient glaciers in Antarctica and Greenland.

But as we can see in the above image, 415 parts per million is not only the highest atmospheric CO2 level in the last 800,000 years, it significantly exceeds all historic measures in this time period. The 2nd highest reading came in about 320,000 years ago at around 300 parts per million. 415 parts per million is nearly 40 percent higher than this peak value. It’s more than double the heat-trapping atmospheric CO2 averages seen during ice ages.

We have to go far, far back, much further back, to find a time when atmospheric CO2 values were likely similar to those experienced today. Indirect proxy readings indicate that the last time levels of this heat trapping gas were so high extend not hundreds of thousands, but millions of years.

(Atmospheric CO2 levels are now the highest since the Middle Miocene of 15 to 17 million years ago. Image source: Skeptical Science.)

In fact, we have to push into a period of time about 15 million years ago to see similar atmospheric CO2 readings. In other words, present CO2 levels are comparable to the Middle Miocene climate epoch when global temperatures were 3-4 degrees Celsius hotter than late 19th Century levels. And if we keep burning fossil fuels at present rates over the coming decade, we will keep elevating CO2 by around 3 parts per million each year. This continued activity would put us near the 450 part per million mark in just one decade further solidifying a Middle Miocene to early Ogliocene climate context.

Dr Michael Mann yesterday noted to Livescience:

“If you do the math, well, it’s pretty sobering. We’ll cross 450 ppm in just over a decade. [Such high levels of CO2] are likely to lock in dangerous and irreversible changes in our climate.”

What this means is that our continued fossil fuel burning brings with it heightening climate disruption. More heatwaves, wildfires, powerful storms, blows to ocean health, sea level rise, and harm to those living on Earth. The only way to significantly blunt that disruption is to rapidly reduce the fossil fuel based emission and transition to clean energy.

(CO2 hitting 415 ppm in the Mauna Loa Observatory puts us far out on a global warming limb.)

Present energy forecasts show a leveling off of fossil fuel burning over the ten year horizon. But clean energy substitution will have to ramp up considerably to prevent rapidly hitting new major and dangerous climate thresholds — driving not just a leveling off, but a decline in fossil fuel burning.

It is worth noting that adding in other greenhouse gasses such as methane puts us even further over the mark — at around 495 parts per million CO2 equivalent in 2019 and near 550 ppm CO2e within about 15 years if projected fossil fuel burning and extraction continue. However, since methane is a short lived gas, fossil fuel extraction reductions and changes to agriculture could tamp down a portion of the CO2e overshoot.

It’s time to get very, very serious about reducing fossil fuel burning and rapidly building out clean energy. The climate disruption that is coming won’t hold back. We need to pull out all the reasonable stops to prevent it. This is why everything from individual action to climate change focused policies like the Green New Deal are so important.

(Want to help fight climate change by transitioning to a clean energy vehicle? Get 1,000 to 5,000 free supercharger miles at this link.)


Leave a comment


  1. redskylite

     /  May 15, 2019

    Thanks once again to R.S for keeping us tuned to the undeniable facts and dangerous situation it is leading us into.

    From RollingSTone’s JEFF GOODELL

    415: The Most Dangerous Number
    There’s only one metric that really matters — and it’s telling us we’ve done less than zero to combat climate change.

    Last week, an exquisitely sensitive instrument located in a metal shack on the top of Mauna Loa, a 13,679-foot-high volcano in Hawaii, recorded a terrifying human achievement: Thanks to our ever-increasing addiction to burning fossil fuels, the level of carbon dioxide in the Earth’s atmosphere has risen to 415 parts per million. This is the highest level it has been since human beings have lived on Earth. And it is further evidence (as if further evidence were needed) of just how hell-bent we are on cooking the planet we live on.

    Liked by 2 people

    • Bentley

       /  May 15, 2019

      C02 will reach 450 in the next decade iff we continue with business as usual. Don’t you think that is increasingly less likely to happen? Don’t you suspect that the (money) wealth built by all that fossil fuel will vanish in a coming storm? Don’t you believe that one earth system or another will undermine the economic system that drives this gas producing engine we call civilization? I suspect that emissions will slow, but not for the reasons we’d like.

      I found this an interesting read, maybe you will too:

      Click to access IAIS_and_SIF_Issues_Paper_on_Climate_Change_Risks_to_the_Insurance_Sector_-1.pdf


      • I believe that we can make the choices that facilitate the above response. I also believe that we can make the wrong choices. The future is up to us.

        Liked by 1 person

        • Abel Adamski

           /  July 15, 2020

          Hi Robert, you put your money where your mouth is buying that M3 , hope you bought some shares as well


  2. redskylite

     /  May 15, 2019

    Part 3 from Weather Underground’s Dr. Jeff Masters

    If the Old River Control Structure Fails: A Catastrophe With Global Impact

    “As I wrote in my 2016 post, Food System Shock: Climate Change’s Greatest Threat to Civilization, the greatest threat of climate change to civilization over the next 40 years is likely to be climate change-amplified extreme droughts and floods hitting multiple major global grain-producing “breadbaskets” simultaneously. An interruption in U.S. grain exports due to failure of the ORCS, if it occurs during the same year that another major grain-producing nation experiences a serious drought or flood, could cause a frightening global food emergency. The impact might be similar to what was outlined in a “Food System Shock” report issued in 2015 by insurance giant Lloyds of London, with rioting, terrorist attacks, civil war, mass starvation and severe losses to the global economy.”

    Liked by 1 person

  3. mlp in nc

     /  May 15, 2019

    An update on chronic kidney disease of agricultural workers in hot climes. It has now hit the US – California, Florida and Colorado (Colorado?).
    As one of the authors put it, “Those impacted are mostly agricultural workers, the people who grow and harvest the world’s food.”They are the people who feed the planet,” Johnson said. “If climate change continues like this who is going to feed us?”

    Chronic kidney disease epidemic in agricultural workers: High heat, toxins. May 8, 201 U, of Colorado Anschutz Medical Campus.

    Liked by 2 people

  4. redskylite

     /  May 15, 2019

    Siberian Times reports wildfires in the Taiga regions and this report in the Moscow Time

    A camera set up by scientists in Russia’s Amur region has captured a rare video in which an endangered white stork remains in its nest while forest fires ravage the surrounding landscape.


  5. eleggua

     /  May 15, 2019

    Tonight in Melbourne; in 45 minutes, actually.

    art of Climarte’s ART+CLIMATE=CHANGE 2019 event, a huge, near month-long arts festival going on there through the 19th. Highly interesting and inspiring interspecies interactivity: the future is now!

    Wander the heritage rooms of the Royal Society of Victoria, discovering new ideas, hypotheses, and research findings presented through 19th century salon-style discussions, exhibits and performances.

    Our inaugural Science Gossip event, Woodland Rumours and Thinking Trees, plants artists and philosophers in common ground with scientists working to unravel the secrets of forest communication, connection and community. Through discussions, musical performance, and art installation we invite you to consider the inner lives of trees, and re-examine your relationship with them.

    Science Gossip: Woodland Rumours and Thinking Trees is part of ART+CLIMATE=CHANGE 2019 presented by CLIMARTE.


    Short presentations and interactive activities will be presented by a selection of scientists, artists, and philosophers.

    Keynote introduction by Dr Monica Gagliano

    Monica Gagliano is Research Associate Professor of Evolutionary Ecology. She is currently based at the University of Sydney as a Research Affiliate at the Sydney Environment Institute and a Senior Research Fellow at the School of Life and Environmental Sciences, opening the doors of the brand-new BI Lab – Biological Intelligence Lab. She is the author of the new book Thus Spoke the Plant, numerous scientific articles in the fields of animal and plant behavioural and evolutionary ecology, and is the co-editor of The Green Thread: Dialogues with the Vegetal World (Lexington Books, 2015) and The Language of Plants: Science, Philosophy and Literature (Minnesota University Press, 2017). Her work has extended the concept of cognition (including perception, learning processes, memory and consciousness) in plants. Gagliano has pioneered the brand-new research field of plant bioacoustics, for the first time experimentally demonstrating that plants emit their own ‘voices’ and, moreover, detect and respond to the sounds of their environments. We are offering discounted presale copies of Monica’s book, to be signed by the author on the night. For more information about her work, visit:

    Anna Madeleine

    Anna Madeleine is an artist working with AR, VR, drawing, animation and installation, to explore intersections between art and science. She has a PhD in Media Arts from UNSW Art & Design (2014) and is a Lecturer in Printmedia & Drawing at ANU School of Art & Design. She has had solo exhibitions in New York, Melbourne, Sydney, Canberra, Montreal and Bandung, and participated in residencies with Cité Internationale des Arts, Paris, Bundanon Trust, Asialink Arts, and the School of Cinematic Arts, University of Southern California, Los Angeles.

    Vicki Hallett

    Vicki Hallett is a clarinetist, composer and sound artist who graduated from the Victorian College of the Arts and the University of Melbourne. She has composed, produced and performed in live concerts, solo recordings ranging from chamber music to sound art and acoustic ecology. Through a unique approach, combining acoustic ecology, scientific analysis and innovative performance practices, Vicki reshapes the role of interdisciplinary research. This exploration has led her to develop a collaborative concept with Cornell University’s Elephant Listening Project. In 2017, Vicki attended the international residency, Sonic Mmabolela, where she performed on Mabolel Rock with a pod of Hippopotami.

    Dr Sapphire McMullan-Fisher

    Sapphire is an ecologist who has special interest in the conservation of biodiversity, particularly the macrofungi and mosses. She did her doctorate at the University of Tasmania and has been actively involved with Fungimap* since 1999. She is the regional representative for Australasia for the International Society for Fungal Conservation, and is active with community groups including field naturalist clubs and Landcare groups. Having lived in four states and travelled across Australia’s landscapes she has worked with many fungal community groups to raise the profile of local fungi and the important roles fungi play in our environment.

    Adjunct Professor Freya Mathews

    Freya Mathews is Adjunct Professor of Environmental Philosophy at Latrobe University and a fellow of the Australian Academy of the Humanities. Her books include The Ecological Self (1991), Ecology and Democracy (editor) (1996), For Love of Matter: a Contemporary Panpsychism (2003), Journey to the Source of the Merri (2003), Reinhabiting Reality: towards a Recovery of Culture (2005), Ardea: a philosophical novella (2015) and Without Animals Life is not Worth Living (2015). She is the author of over eighty articles in the area of ecological philosophy and panpsychism. In addition to her research activities she co-manages a private conservation estate in northern Victoria.


  6. mlp in nc

     /  May 15, 2019

    Unprecedented weakening of Asian summer monsoon
    Models implicate sulfate aerosol emissions as the culprit behind widespread drought cycle
    May 15, 2019. American Geophysical Union.

    Rainfall from the Asian summer monsoon has been decreasing over the past 80 years, a decline unprecedented in the last 448 years, according to a new study.
    The new research used tree ring records to reconstruct the Asian summer monsoon back to 1566. The study, published in the AGU journal Geophysical Research Letters, found the monsoon has been weakening since the 1940s, resulting in regional droughts and hardships.

    The new research finds human-made atmospheric pollutants are likely the reason for the decline. The 80-year decline in the monsoon coincides with the ongoing boom in industrial development and aerosol emissions in China and the northern hemisphere that began around the end of World War II, according to the study’s authors.

    Liked by 1 person

  7. DJ LX

     /  May 16, 2019

    Modest actions to take to combat climate change:

    – support a tax on CO2 emissions
    – if possible, bicycle or walk to work and shopping trips, or at the very least take public transport or join a carpool
    – go vegetarian or, short of that, limit consumption of meat products
    – limit reproduction to no more that 2 children (replacement level) and consider having one or none
    – avoid air travel
    – start a garden to grow your own food to supplement what otherwise needs to be shipped
    – minimize use of air conditioning in the summer and heating in the winter
    – proselytize – raise the issue of climate change whenever possible, carefully explaining why it’s in our long term interest to take actions – painful though they may be – to radically reduce CO2 emissions.

    I don’t know if we can turn this thing around in time, but we have to try.

    Liked by 1 person

  8. Abel Adamski

     /  May 16, 2019

    Back to good old faithful, the rather large canary of the polar ice sheets, ohh sheet
    Extraordinary thinning’ of ice sheets revealed deep inside Antarctica
    Ice losses are rapidly spreading deep into the interior of the Antarctic, new analysis of satellite data shows.

    The warming of the Southern Ocean is resulting in glaciers sliding into the sea increasingly rapidly, with ice now being lost five times faster than in the 1990s. The West Antarctic ice sheet was stable in 1992 but up to a quarter of its expanse is now thinning. More than 100 metres of ice thickness has been lost in the worst-hit places.

    A complete loss of the West Antarctic ice sheet would drive global sea levels up by about five metres, drowning coastal cities around the world. The current losses are doubling every decade, the scientists said, and sea level rise are now running at the extreme end of projections made just a few years ago.

    He said the thinning of some ice streams had extended 300 miles inland along their 600-mile length. “More than 50% of the Pine Island and Thwaites glacier basins have been affected by thinning in the past 25 years. We are past halfway and that is a worry.”

    Liked by 2 people

    • Abel Adamski

       /  May 16, 2019

      On the theme from March
      Australian researchers find huge lakes beneath largest east Antarctic glacier
      The Totten glacier is 30km wide and up to two kilometres thick, and has the potential to raise sea levels by seven metres.


    • mlp in nc

       /  May 17, 2019

      Here is what Fred Pearce had to say about West Antarctica in With Speed and Violence, 2007, Ch. 9 The Mercer Legacy, pg 48 and 49.
      “In 1978, in Nature, he (John Mercer) published a paper declaring: “I contend that a major disaster – a rapid deglaciation of West Antartica – may be in progress. . . within about 50 years”. . .
      “The heart of the West Antarctic ice sheet has some protection from the ocean. On two sides it is buttressed by mountains, and on the other two sides it is held in place by the Ronne and Ross ice shelves. But Mercer warned that if the ice shelves gave way, the entire sheet could lift off and float away . . . Once under way, the disintegration would “probably be rapid, perhaps catastrophically so.” Most of the ice sheet would be gone within a century. He reckoned that a warming of 9 degrees (I think Pearce is using F here) would be enough to set the process in train. . . “


  9. wharf rat

     /  May 16, 2019

    In the warming Arctic, a promising solution to climate change

    For the last three years in Utqiagvik, Leslie Field and the research team at her Silicon Valley nonprofit Ice 911 have been testing an unusual solution to restore Arctic ice. Her novel approach is on track to stop one of the largest effects and influences on climate change, becoming part of a global Climate Restoration solution that could return the climate to something like the one our grandparents knew….

    Field’s “inconvenient hobby,” as she describes it, which has now turned into full-time-plus work for her and the Ice911 team, began with experiments carried out with buckets of water set out on her sunny, Bay Area deck. She tried spreading reflective sheets on Lake Tahoe and on lake ice in the Sierras. Then she began experimenting with tiny, hollow microbeads made mostly of silica, a type of sand made of quartz rock. (Unlike the plastic nanobeads found in cosmetics, which have become a scourge on the world’s waterways, the silica microbeads are safe for animals, aquatic life, and ecosystems.)

    When spread across ice, these beads become a reflective shield against the sun, enhancing the ice’s natural albedo. They’re buoyant, so they float on melt ponds and slushier patches of sea ice. Spread these beads across strategic areas of Arctic ice, Field thought, and more of it might survive through the summers, keeping reflectivity high and short-circuiting that vicious ice-albedo feedback loop.

    Field and her team have tested the microbeads across more than three football fields’ worth of lake ice at the Barrow Arctic Research Center/Environmental Observatory since 2016. Buoys designed and placed by the Ice911 team since 2010 send data wirelessly from various test sites back to the organization’s labs in Sunnyvale and Redwood City, California, so that researchers can measure ice growth, reflectivity, weather, and water currents. They use satellite imagery and aerial photos taken by Maverick, their line-of-sight drone, to compare the reflectivity of treated ice to untreated ice.

    Their findings so far: Ice treated with silica microbeads grows thicker and more reflective with each application. Ice911 modeling suggests that spreading the beads in only a few strategic areas, like the Beaufort Gyre or the Fram Strait, could reverse melting across the Arctic.

    “By using just a tiny amount of material, you end up making young ice seem more like multiyear ice, and that changes the radiative balance in the Arctic back to where it was,” Field said. “You think, those are pretty humble goals — is it going to be enough? As it turns out, it’s enough. This material makes a very large impact on regrowing ice and preventing further temperature rise in the Arctic.”

    Liked by 1 person


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