NASA’s James Hansen explains why we should be concerned about human-made climate change when it’s changed so much in the past

Climate de-crocker Peter Sinclair has the video, “The 8 Minute Epoch: 65 Million Years with James Hansen“:

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39 Responses to NASA’s James Hansen explains why we should be concerned about human-made climate change when it’s changed so much in the past

  1. Matt says:

    I new that the Himalayas were a major reason for the draw down but I’ve never seen such a coherent explanation for the spike in CO2 before that. Great video!

  2. pete best says:

    Well its not really a case of losing all of west or east Antarctic ice sheet but some of it which we are doing presently along with Greenland.

    Just how much between now and 2100 is up for grabs.

  3. espiritwater says:

    New Report from AOL on Australia: “There’s Quite a Horrible Smell to it all”- poisonous snakes and spiders on the loose:

    With water receding in some parts, people are going in to assess damage,” she said. “But the worst is the heat — we’re in summer here –and the mud, the overall humidity and all the damage. There’s quite a horrible smell to it all.”

    Rule-Murphy said that floodwaters are expected to rise and fall over the coming weeks and that the cleanup could take months or even a year. “A lot of farming country’s been hit, and people can’t grow those lost crops until next year,” she said.

    Prime Minister Julia Gillard pledged government aid today “in the order of many hundreds of millions of dollars,” the Australian Associated Press quoted her as saying. The aid package includes low-interest loans to farmers, she said.

    Coal exports, one of the mainstays of Australia’s economy, have also been hit, with mines flooded and railways washed away. Eighteen ships are waiting at the port of Gladstone for loads of coal that may take 10 days to arrive, costing the $55 billion a year industry dearly, Reuters reported.

    And authorities say it could get worse before it gets better. The town of Rockhampton, on the edge of the rising Fitzroy River, is receiving food and supplies by military air drops north of the city because all major highways out of town have been cut off by flooding. The airport is also closed.

    Nathan Berry, who works at Rockhampton’s riverfront Criterion Hotel, said he spent the weekend preparing for the worst, as he watched the river slowly rise toward the hotel’s front steps.

    “The water is just up to our gutters today. But when it comes up another meter or so, which is likely to happen Tuesday or Wednesday, it’ll be at our doorstep,” Berry told AOL News in a telephone interview from the hotel, where he’s now trapped. “There’s not much we can do now. We have to just deal with it.”

    Supplies being dropped into Rockhampton also include batches of snake anti-venom, amid fears that poisonous snakes and spiders have been forced out of their hiding spots because of the flooding.

    “There’s heaps of them. We’ve had a plague of mice, a lot of frogs, and so we knew the snakes would come,” Barry Moessinger, who lives in a Rockhampton suburb, told The Australian newspaper. Six shots of brown snake anti-venom and 10 generic emergency snakebite injections were among the medical supplies flown into Rockhampton on Sunday, the paper said.

    Rockhampton Mayor Brad Carter said he’s received several reports of snakebites and is worried the floodwaters could bring crocodiles up into populated areas as well.

    Sponsored Links”Snakes have been swimming at people’s feet as they make their way through the waters,” Carter told the BBC. “I know one guy who killed four snakes this morning, one of which was a taipan — the more it bites, the more it injects venom that could easily kill.”

  4. Peter M says:

    The snakes are a real problem I am sure. That part of Australia has two of the most deadly species in the world; The Eastern Brown snake, and the coastal Taipan.

  5. espiritwater says:


  6. All the world and its leaders (especially Obama) should be paying much more attention to James Hansen. He knows what has happened to our planet’s climate; he knows what is happening now to our planet; and he knows all too well what will happen to our planet if we don’t stop burning fossil fuels now.

    It is almost too late. Why won’t we listen?

  7. Peter M says:

    #6 Phillip E.

    Obama I am sure is familiar with Dr. Hansen’s work, and the dire situation we are in. But he as little courage to tell the American public.


    He would be laughed at by half the people of this nation, who either do not understand the problem, or others who take for truth what they hear at Fox News.

    Sadly, we will have long passed the point of no return by 2020- this could change of course if during this decade we see more climate catastrophes occurring- especially in the USA- with a regularity that cannot be ignored.

    But Obama will likely pass the buck to the Next President. The cost for doing nothing however goes higher every year- exponentially.

  8. catman306 says:

    Philip Eisner, we’re (the human population) won’t listen now, because we didn’t listen 20 or 50 years ago either. Only some details have been added to our understanding of human caused climate change knowledge in those years. Jimmy Carter was trying to move us in the proper direction 30 years ago and look what happened to him: fossil fuel propaganda bad-mouthed him and he lost re-election. Cheney went back into the White House for Reagan and here we are today.

    Yes, all the world and its leaders should be paying attention to James Hansen. Put a tax on fossil carbon today!

  9. Barry says:

    When I talk to people about climate change I often offer to give them Hansen’s book if they are at all interested in reading about the climate science and what it means for our future. It is by far the best book I’ve read on the actual climate science.

    So far I haven’t given a single copy away. Amazing.

    This year, now that his book is in paperback, I’ll be carrying a copy with me most of the time and just hand it out if people I know show even the slightest flicker of interest.

    Hopefully the “Storms of Ourselves” that we are now suffering will be enough motivation to get at least some people to read a little bit about climate.

    I do think the title of Hansen’s book was a mistake. Not many people realize his “Grandchildren” are alive and in school already. It makes the threat seem to distant in time to many folks. I can see the wheels spinning in their heads along the lines of “Do I want to read about a problem I don’t want to face and that won’t happen for two more generations?”

    Hansen has a great quote about how extreme weather events today would very likely not be happening without our global warming pollution. That is brilliant messaging. His book title…not so much.

    Sadly people do judge a book by its cover, especially when they want to shove their head back into the sand as fast as they politely can.

    Bottom line: highly recommend Hansen’s book to anyone interested in climate science and where earth climate has been and is heading this time.

  10. Peter M says:

    Barry #9

    I gave Hansen’s book to a friend (he has a PhD- College administration & Psychology)- I saw him a few times over the holiday- his wife and others at cocktail and dinner parties.

    Also on my coffee table is Make Lynas’ book ‘6 Degrees’- which I highly recommend- and Diane Dumanoskis’ ‘End of the Long Summer’

    I try and educate as many people as possible– most listen-and realize we are facing deep deep problems. But to the ‘average’ person, they still seem to be in some kind of a ‘funk’ about the ramification of humans continuing to burn coal.

  11. Colorado Bob says:

    “We have three-quarters of our coal fields unable to operate and unable to supply markets,” Bligh told ABC Television. “There is likely to be a significant long-term effect from that and not only nationally but internationally,” she said.

    Coal is Australia’s biggest export earner, responsible for about A$55bn in annual revenue. The country’s booming resources sector has been largely responsible for the strength of the economy in the past two years.

  12. Colorado Bob says:

    Southern Queensland and northern New South Wales are Australia’s main growing areas for hard red winter wheat, the type used primarily to produce flour.

    “It’s the hard red winter wheat crop in Australia that has been damaged,” Gartman said. The world is short of the grain and “the premium that hard red winter has over soft red will widen even further.”

    ‘Unharvestable’ Grain

    Rainfall and flooding will damage the remaining uncollected wheat crop, Wayne Newton, grains president of farmers group Agforce, said last week from Dalby, Australia. A lot of the grain that has still to be collected will be “unharvestable,” he said

    World wheat output in the current season is forecast to lag behind demand by 20 million tons, according to the U.S. Department of Agriculture.

  13. Jenny says:

    I agree that this is a great video for people who understand science. But for the average non-scientist who needs to become informed about these issues — and, frankly, that is the audience to be targeted in a comprehensive manner if anything constructive is going to be done about climate change before it’s too late — this explanation is much too technical.

    Among other issues, I think the portions of the Hanson video relating to solar forcing and natural carbon sources and sinks are not understandable by the average non-scientist.

    By the way, can anyone give me a brief, very clear, very non-technical explanation of how rock weathering functions as a natural carbon sink? (Or perhaps someone can refer me to a brief, clear explanation online.) I would like to modify some of what Hanson presents in the video in updating my lecture/slideshow presentation about climate change issues. Also, are the graphics presented in the video available for use? Thanks in advance.

  14. Chris ODell says:

    For those of you who are interested, here is a link to the full lecture (one hour+ in length):–0A

  15. Rob Honeycutt says:

    As excellent a scientist as Hansen is, he’s just not a compelling lecturer (I’ve seen him say as much himself). But he really has so much that is important to say. Peter Sinclair’s video does a great job of making Hansen’s talk engaging.

    Personally, I can easily sit through an hour or more listening to Hansen speak. But this is a topic that I (and most reading here) maintain a strong interest in. It’s so important to get Hansen’s message out there to the general public who have a hard time maintaining their attention through a 60 second sound bite.

    So, once again, kudos to Peter for helping to make this complex issue more digestible for the general population.

  16. catman306 says:

    I was wondering how roundup ready crops fair in our changing climate, difficult growing condition world so I googled ’roundup ready crops’ hardiness. I got zero hits which means no one’s thinking about this possibility. So the hardiness of Roundup ready might be a story or a research project. How will roundup ready crops do in the coming years of extreme weather, droughts, floods and other bad growing conditions?

    They’ve altered genes to make the plants immune to Roundup but they’ve possibly weakened them in other ways. We’ll be finding out soon.

  17. Colorado Bob says:

    Jan. 3 (Bloomberg) — Palm oil rose to the highest level in more than 33 months on concern that global supplies of cooking oils will shrink after rains disrupted harvests in Indonesia and Malaysia, the biggest producers of the tropical commodity.

  18. Colorado Bob says:

    Meanwhile, Argentina’s agriculture industry faces a grim season.

    The heat wave is likely to break the country’s all-time records in soy and wheat exports. Argentina is one of the world’s top grain producers – and that explains why officials and experts very worried.

    Five provinces are on code orange alert for severe drought – not good news for a nation that depends so heavily on agriculture.

    And it’s not just Argentina that will be affected by this extreme weather. A loss of Argentina’s important crops is likely to affect international commodity prices.

  19. dbmetzger says:

    anyone else notice that various parts of the earth are having 100 year floods every 5 years or so?
    Queensland’s Rockhampton Now Completely Cut Off by Floods
    Huge swaths of the Outback have become a virtual lake, with more than 20 Australian communities either cut off or slipping beneath floodwaters. Military flights are rushing to restock the Australian city of Rockhampton as it is cut off by floodwaters.

  20. Colorado Bob says:

    Munich Re –

    Some 56,000 died in a combination of heatwaves and forest fires in Russia, it said.

  21. Steve Bloom says:

    Re #13: Jenny, I think Hansen is trying hard to simplify things as much as possible. If you have specific ideas on how to do that, email him with them. Bear in mind that a major criticism of Gore’s AIT is that he skipped over the too much of the science and so asked the audience to take too much on faith.

    Re rock weathering, the CO2 dissolved in rainwater makes it slightly acidic. The acid reacts with the rock to form carbonate compounds, which then crumble and wash away, mostly ending up as ocean sediments. The rainwater isn’t very acidic and can only work on the exposed rock face, so this is a *very* slow process on a human time scale.

  22. Steve Bloom says:

    Just to add, I think if a professional writer and editor worked with Hansen on this presentation it could be made much more clear and effective.

  23. Richard Brenne says:

    I’ve read and re-read Hansen’s “Storms of My Grandchildren” and taught from it, yet this talk was so clear and succinct that it brought new awareness to the issue for me.

    Hansen says that our increase of CO2 parts per million (ppm) to 389 (the talk was last October, I’ve been using 390 but I’d still like to know what others feel is the best annual average to use) has happened 10,000 times faster (and he doesn’t say this in this clip but I think he should consider it) THAN EVER BEFORE IN THE HISTORY OF EARTH.

  24. Leif says:

    Thanks for the link, Colorado Bob @ 20: I printed the article and a hand note to the local Editor on my walk.

  25. Colorado Bob says:

    “I was doing a plant survey to see how the wetlands had changed over the years, and I noticed a lot of the plants were blooming earlier than they had in the previous survey,” said Conover.

    The biologist pointed out that the mean annual temperature during the survey periods increased nearly 2 degrees from 53.38 degrees (11.88 C) to 55.27 degrees (12.93 C) in roughly a decade’s time.

    “This is a big change for such a short time period,” said Conover. “There is a lot of data coming from all over the world indicating that biological communities are being impacted by warmer temperatures.”

  26. espiritwater says:

    Jenny, #13, says:
    I agree that this is a great video for people who understand science. But for the average non-scientist who needs to become informed about these issues — and, frankly, that is the audience to be targeted in a comprehensive manner if anything constructive is going to be done about climate change before it’s too late — this explanation is much too technical.

    I know of some very highly educated individuals, who smirk and almost giggle when I mention global warming, pointing to all the snow as if it disproves GW. One woman, who has a child she keeps pointing out as “gifted” (as if she’s the only one with a gifted child) told me, “well, you know, there are scientists who are saying it’s not happening!” My mother, on the other hand, only has a 6 th grade education, and she “gets it” (as do many other poor, uneducated people)and tries to inform others about it. So it’s not a matter of education/ literacy. It’s a matter of WANTING to understand. And some people just do not.

  27. Mulga Mumblebrain says:

    catman306 #16-just try the Institute of Science in Society. They have a lot of good research on Roundup, glyphosphate, and why its use is yet another horrific disaster in the making. There are so many disasters, most hideously synergistic,all antithetical to human life, all hidden by corporate power and media complicity, that it is hard to avoid the feeling that someone or something wants us gone.

  28. Bruce Turton says:

    THe biggest concern about Round-Up is that there are now many noxious weeds that are not killed by this chemical concoction. The most hazardous of these weeds is ‘hog weed’, which can grow to huge proportions and cannot be touched because it inflicts serious chemical burns. It is spreading throughout your American agricultural regions!

  29. Prokaryotes says:

    Why is Hansen not mentioning the PETM?

    The most extreme change in Earth surface conditions during the Cenozoic Era began at the Paleocene/Eocene boundary, 55.8 million years ago. This event, the Paleocene–Eocene Thermal Maximum (PETM, alternatively “Eocene thermal maximum 1” (ETM1), and formerly known as the “Initial Eocene” or “Late Paleocene Thermal Maximum”,[1] (IETM/LPTM)), was associated with rapid (in geological terms) global warming, profound changes in marine and terrestrial ecosystems, and major perturbations in the carbon cycle.
    Global temperatures rose by about 6°C (11°F) at the start of the PETM, which appears to have occurred within 20,000 years. At nearly the same time, many deep-sea benthic foraminifera went extinct, and mammalian life on land experienced a major turnover, which marks the emergence of numerous modern mammalian orders. The event is linked to a prominent negative excursion in carbon stable isotope (δ13C) records from across the globe, and dissolution of carbonate deposited on the seafloor of all ocean basins. The latter observations strongly suggest that a massive input of 13C-depleted carbon entered the ocean or atmosphere at the start of the PETM. The event has become a focal point of geoscience investigations because it is perhaps the best past analog in which to understand the fate and consequences of current fossil fuel emissions on an intermediate time-scale (>1000 years).–Eocene_Thermal_Maximum

    Nevertheless great video!

  30. catman306 says:

    Mulga Mumblebrain and Bruce Turton, sorry, my miscommunication: I referring to genetically modified crops, specifically Roundup Ready Soybean and Corn seed. Can they endure the stress of our new changing climate and produce good crops yields in times of heat and drought as well as during saturating periods of rain better than conventional seeds?

    I’ve used the product Roundup and the Walmart imitation in ridding my yard of kudzu (this took years) and to limit the poison ivy. The secret is to apply a tiny spray spurt to each leave on the stem you want to remove. Don’t overspray.

  31. Wit's End says:


    This is not even close to communicating with the average enormously consuming American level of scientific understanding.

    So, what is the point?

  32. @Prokaryotes #29,

    Maybe he spent more time on the PETM at a different point in the lecture? His actual lecture was over 1 hour long. At any rate, he discusses the PETM clearly and at length in Storms of My Grandchildren.

    BTW, I believe Hansen’s book provides a *much* better overview of climate science than that 8-minute clip does. Of course, asking someone to watch an 8-minute video is much easier than asking them to read a book. But still, reading the book is *well* worth the extra time invested.

  33. Barry says:

    Jenny (#13): can anyone give me a brief, very clear, very non-technical explanation of how rock weathering functions as a natural carbon sink?

    Here is an explanation from pg 99 in Veron’s “A Reef In Time”:

    “Over very long time scales — millions of years — atmospheric CO2 levels are primarily controlled by a balance between the rate of volcanic release from the Earth’s interior and the rate of extraction through photosynthesis and the chemical weathering of rocks at the Earth’s surface, according to the equation CaSiO3 + CO2 -> CaCO3 + SiO2.”

    When India docked to Asia it started the Himalayas uplifting which exposed lots of fresh rock surfaces for weathering, thus drawing down CO2 a bit “faster” than normal.

    The other big extraction pump is the photosynthesis and calcification by phytoplankton. As these die and fall to the ocean floor some are turned into sediments and then to sedimentary rocks.

    The cycle completes itself when these sedimentary rocks are subducted. The immense heat and pressure reverse the equation above, reforming the silicate rocks and CO2. These escape back to the surface via volcanoes and traps. A super-long carbon cycle in and out of rocks.

    I recommend Veron’s book for anyone interested in coral reefs and climate changes, both the relatively slow ones of the past and the far-too-rapid one we are unleashing by burning fossil fuels now.

    Final point: if you are talking to people about climate change I very strongly recommend you do as Richard Brenne (#23) does and read Hansen’s book. I’m on my fourth reading and learning more each time. It is definitely the best book on the climate science of many I have read.

    Final final point: Hansen has all his papers, talks and graphs available online at

  34. Barry says:

    Richard Brenne (#23), I believe what Hansen is saying is that the current rate of CO2 change is a 10,000 times greater climate forcing than what was required to end the last ice age.

    In that case it was a very slow change in earth orbit resulting in increased solar forcing. The worrisome message is that such a smaller and slower forcing still managed to remove a mile thick slab of ice from much of the northern hemisphere.

    I think Hansen states that our current CO2 forcing is an order of magnitude more rapid than any forcing we know about in the past. That is 10 times greater than anything the planet has faced in the past. As he puts it, this is a hammer blow to the climate system.

    In addition the earth has never faced a rapid WARMING forcing of any kind. All the past WARMING forcings have been slow. All the rapid forcings in the past have been COOLING (ex: volcanoes, meteor impacts).

    We are locking ourselves into a cage with a proven nasty climate beast and hammering away at it with the biggest stick ever. We are unlikely to be happy with the results much longer.

    Meanwhile we have the entire GOP in lock-step attack formation to prevent humanity from doing anything to stop this insanity in time.

  35. Richard Brenne says:

    Wit’s End (#31) – You know how much I respect your work and how often I agree with you (and I’d love to hear your comments about Roundup and other plant issues in the above discussion), but I think both Hansen and this talk are very important.

    I heard most of the entire YouTube version of the talk as I was packing up for a day and night of biking and meetings, and because of Hansen’s monotone delivery hardly a word resonated with me. But with Peter Sinclair’s skillful editing, I liked the 8 minute clip a lot – for those of us with a pretty sophisticated understanding of climate change, like so many CP readers.

    Hansen is the gold standard of understanding the science of climate change (with Trenberth, Mann, Alley, Solomon, Santer, Romm, etc) – I think he’s the closest we have to a Robert (though Michael’s good too) Oppenheimer at tying all the various facets of climate science together, as Oppenheimer did during the Manhattan Project at Los Alamos.

    I think it’s our job – since you, Romm and so many here are such good communicators – to understand as much as we can of what Hansen knows and communicate it much better than he can.

    It’s the same with Hansen’s political understanding. It might be naive relative to Joe’s and other’s, but I think he’s fundamentally right about that as well, only very idealistic.

    That has value, as I’ve pointed out before. The former slave turned most ardent abolitionist Frederick Douglas stated the ideals, and Lincoln worked toward those ideals in the real world about as rapidly (and opportunistically) as anyone could have. Without Douglas, Lincoln might well have not had such ideals so firmly in mind.

    To me Hansen is our Frederick Douglas. I appreciate the tremendous amount he has to offer, then would love to partner with him and others to communicate what he knows better than anyone. . .well, better than he alone can.

    And Peter Sinclair’s editing helped the talk a great deal. I wouldn’t look at Hansen’s talk as the ultimate end product going out to the public, but the beginning of that process.

    Cheerio, or any other cereal of your choosing.

  36. Ed Hummel says:

    Richard Brenne #35, as usual you have given an answer to Gail that is very well thought out and really gets to the heart of the matter. Sinclair’s editing of Hansen’s talks is exactly what is needed, but as you said, it is just a start. I agree that Hansen is like our modern Frederick Douglas and his work should be disseminated as much as possible, especially in ways such as Sinclair has done. There are many gifted communicators out there, quite a few who have connections to big media, who should be approached to join Pete Sinclair in his work which must become much bigger than it presently is. We must overwhlem the denier machine and give the president the impetus to “make him do it” as both Lincoln and FDR finally did concerning civil rights. Climate change matters are the ultimate civil rights since they affect the very existence of billions of people.

    I too have read Hansen’s book a few times, and use it as a reference book to back me up when I give talks and presentations to different types of audiences. I agree that the biggest problem is not putting an audience to sleep with the minutiae of how the climate works and I always gleen these posts for ways to help myself make my presentations better. Because the deniers are so well funded and politically entrenched, I see the next two years in DC (and probably longer if I’m being realistic) as being a waste of time that we can’t afford to lose. So our only hope to get the president to finally do what he really has to do is to blitz all media outlets as much as we can and bypass the grid-locked Congress while going strait to the people. Sinclair’s clip is one way, though we need him and others with his talent to multiply their efforts a thousand fold.

    In my more optimistic moments (which tend to be very few these days), I actually have some hope that all the disasters happening around the world which are having an immediate impact on global food prices and supplies and which will probably continue to accelerate this year might actually be the magic elixer which could wake the majority of sleeping people up to what we face and to what we must do about it. Even the slickest denier machines can get blown off their tracks when a critical mass of the public finally realizes how they’ve been had. I only hope that the reaction doesn’t turn into another French Revolution. Anyway, for what it’s worth, Happy New Year everyone and keep those videos coming Pete Sinclair!

  37. LT says:

    Colorado Bob @ 11
    Video of Ann Bligh’s comments available here for a few days.

  38. Steve Meacher says:

    Thanks, this is a great excerpt (with improved graphics inserted).

    You might be interested that the full presentation given by Jim Hansen at the University of Oregon on 16th October 2010 is available here ––0A

  39. Jenny says:

    Thanks very much to everyone who provided info in response to my post.