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Scientists caught off-guard by record temperatures linked to climate change

146 points by fspear 10y ago

dev1n 10y ago
climate change is one of those few issues where an alarmist attitude is actually needed. Still need to get more media outlets to change from saying "save the planet" to "save humanity".
- ars 10y ago
  Why? Humanity will be fine. At worst some people will have to move a bit inland.
  - soundwave106 10y ago
    Under some predictions, parts of the Middle East and North Africa might become, if not uninhabitable, very uncomfortable (50C+ summer averages) by the end of the century, with all the consequences that arise from this. http://link.springer.com/article/10.1007/s10584-016-1665-6 http://link.springer.com/article/10.1007/s10584-016-1665-6 Present experience proves that people, especially the impoverished, can't just easily uproot and leave one country for another, with no political or sociological consequences whatsoever.
kodroid 10y ago
So, what can be done? I posted this question on Reddit ages ago with no replys, would be interesting to hear anyone on heres opinion on it... > Hi all, Im sure there are many reasons why this would not work but thought would be good to get some input. I came across this article about creating carbon fibre from atmospheric carbon https://www.technologyreview.com/s/540706/researcher-demonstrates-how-to-suck-carbon-from-the-air-make-stuff-from-it/ https://www.technologyreview.com/s/540706/researcher-demonst... and as carbon fibre utilising 3d printers now exist like https://markforged.com/product/mark-one-composite-3d-printer/ https://markforged.com/product/mark-one-composite-3d-printer... this seems like something with amazing potential. Of course one of the main challenges is the energy needed to operated such a machine - but in the right places (which im guessing is windy as the carbon pulling machine needs high air exposure anyway) renewable forms of energy could maybe be used? In a daydream I thought it would be amazing to replace steels and plastics with atmospheric carbon. Reduce oil dependency, lower carbon footprint (even thought its not putting it back in the ground it seems like a good second), created a fantastic building element. Anyhow - would be great to hear why this wont (or would!) work from someone who knows more than me about this stuff. :)
- pjc50 10y ago
  Money? There isn't currently a market for this product, there may never be, and it requires a big upfront investment. Scaling? "given an area less than 10 percent of the size of the Sahara Desert" does nobody have any idea how large that is? If he'd said "an area the size of Texas and California combined" it might look less feasible. But really it needs millions in altruistic funding to even get a pilot plant going. It's a lot like Tesla's plan to get everyone driving electric cars: no technical barrier, but the financial one is huge and it takes a while to scale even if it's successful.
- the8472 10y ago
  It takes a lot of energy. If we built enough clean energy to have some to spare for pulling carbon out of the atmosphere then we would already have met the goals of decarbonizing the economy. This would merely be going the extra mile on top of that. And we already have self-replicating zero-emission carbon extraction machines. They're called trees. You could just plant trees, wait a few decades and then drop them with some weights into the ocean if you wanted to get rid of carbon. Of course you would have to do that at industrial scale and somehow find a way to replace all the nutrient minerals you're also sinking into the ocean. And we're talking about gigatons per year. The only thing that's comparable in human production is concrete. We would have to build all our roads, cities and megastructures out of carbon to reverse current emissions.
blondie9x 10y ago
We all know by now CO2 and CH4 leads to a warmer planet. We also know what's driving greenhouse gas levels to rise across Earth. Contributors are deforestation, intensive animal farming, and primarily the combustion of carbon fossil fuels like coal, tar sands, oil, natural gas etc. But here is the underlying problem, despite us knowing how bad things are, (97+% of scientists who study this field agree we are causing the planet's climate to shift away from the temperate climate we thrived in) not enough is being done at present to truly solve the problem. What really is disheartening and what no one in the media and government is talking about is how in 2015 CO2 levels rose by the largest amount in human recorded history. 3.05 PPM http://www.esrl.noaa.gov/gmd/ccgg/trends/gr.html http://www.esrl.noaa.gov/gmd/ccgg/trends/gr.html We are being lied to and mislead by our governments that uniform actions are being performed to save the planet for the future of man. Vested interests in the fossil fuel industry continue to drive climate change. Yes, solar and wind energy is starting to become incredibly efficient and cheap but not enough of it is coming online in proportion to fossil fuel burning that persists and is also installed annually. If we do not rally against it, our ability to live on this planet is at stake. The lives of our posterity are also at risk because of the burning. It will not be until we take extreme actions not on a country level but as humanity together that we will slow the burning and save ourselves. What are these actions you might ask that will actually be effective? These can range from banning fossil fuels entirely, global carbon pricing system, banning deforestation, changing human diets, extreme uniform investment in renewable energy and potentially fourth generation nuclear reactors, more funding for developing nations to install alternative energy sources, and to shift the transportation grid towards sustainability.
- redwood 10y ago
  One more key contributor (since CH4 aka natural gas is so much worse as a green house gas compared with CO2 when released than burned or kept in the ground): Human activity, ranging from fossil fuel extraction, to natural gas usage, has massively led to a large amount of natural gas leakage across the network. All this leaking adds up and is an "unseen" but incremental accelerant on these problems (https://www.washingtonpost.com/news/energy-environment/wp/2016/02/25/california-gas-leak-was-the-worst-man-made-greenhouse-gas-disaster-in-u-s-history-study-says/ https://www.washingtonpost.com/news/energy-environment/wp/20...)
redwood 10y ago
It's all about batteries. An order of magnitude more efficient electric battery technology is the key missing piece to get us away from a fossil based economy.
awt 10y ago
Buy some of these from your local government: https://en.m.wikipedia.org/wiki/Indulgence https://en.m.wikipedia.org/wiki/Indulgence
pluma 10y ago
IOW climate change is even worse than scientists anticipated.
- yiyus 10y ago
  While this is true, I think that what the article is trying to point out is not that climate change is worse, but that the models we have do not work in the current conditions. This is scary, because scientists have been anticipating climate change for decades, but now we know that what they anticipated was not as accurate as we thought. If predictions from 10 years ago, let's say, had been replaced by worse predictions one or two years ago, we would still know with some certainty what will happen next. But what the article says is that everything we know is that things are getting worse than expected and we have no way to know how worse. Scary.
  - NumberCruncher 10y ago
    >> scientists have been anticipating climate change for decades, but now we know that what they anticipated was not as accurate as we thought. It's tough to make predictions, especially about the future
    - chx 10y ago
      Aye but predictions are necessary. If there's a 4C global temperature rise that displaces 760M people. To put this into perspective, about 1M migrants in a year almost collapsed Europe's political system. We need to know how quick that happens so we can begin to do something. Dam, evacuate etc.
      - vkou 10y ago
        More likely, we will cover the borders with barbed wire, and machineguns.
        chx 10y ago
        The borders of what? Omaha? New York, DC, Los Angeles, Seattle and 'Frisco are (at least partially) gone.
conistonwater 10y ago
How much of it is due to El Niño, and how much due to global warming proper? Is it difficult to figure out? The article doesn't say.
- tehmaco 10y ago
  From Bad Astronomy, El Niño accounts for around 0.1C globally: http://www.slate.com/blogs/bad_astronomy/2016/07/20/june_2016_was_the_hottest_june_on_record.html http://www.slate.com/blogs/bad_astronomy/2016/07/20/june_201...
cconcepts 10y ago
I have no doubt that climate change is a problem. I have kids, I dont want to give them a hospital pass. I've tried to stop living such a carbon dependant lifestyle but I look outside and my efforts feel futile. How do I REALLY do something about this other than a few pretentious yet barely discomforting lifestyle changes and the odd empassioned few sentences at dinner parties? Start pushing for a carbon tax? Start an electric car company? Begin development of technology to get us to Ma.....oh wait Plant heaps of trees? Buy drones and start my own version of operation sunscreen? Seriously. The mild excitement that comes with media alarmism has transitioned into "I really need to start doing something drastic or I'll regret it"
- s917 10y ago
  How much stuff do we in the west consume that originates in China, where they don't seem to give a damn about environmental controls? And exactly how much CO2 and other chemicals are belched out by these giant container ships we use to get it all to us? We can buy all the solar panels, wind turbines, electric cars and energy efficient washing machines we want, but until China (and probably others) starts playing ball AND we find a way to move vast quantities of stuff around without container ships we're probably fighting a losing battle. Would it be possible to manufacture goods in the regions they're to be sold in? edit: wordings.
  - malka 10y ago
    well, we could have nuclear container ships, I guess. May not be the best idea ever though.
  - vkou 10y ago
    Almost all of it. We used to make it with little regard for the environment - now China does. If you want to fix that problem, institute a carbon tax, and import tarrifs on countries that don't have carbon taxes. Practically, with things like the TPP, that's not the way the world is going.
- nathan_f77 10y ago
  I like your thinking. I don't there's much a regular person can do, even if you become an activist. You really have to become a salesman for climate change, you need to build up your voice and try to get CEOs and politicians to listen to you. I feel the same way about vegetarians and vegans. You're not saving the world by eating salads or sharing the occasional thing on Facebook. You might feel better about yourself and your choices, which is great. But it's only a drop in the ocean, and won't have any effect unless you try to do something bigger. And it's actually going to help with global warming, if the world can start eating less (or no) cows and chickens. It's certainly too big for one person to solve, but that's why people start organizations. I know it's not much, but you can start by signing this petition: http://www.stopwarming.eu/?petition=signup http://www.stopwarming.eu/?petition=signup
threeseed 10y ago
It seems pretty clear to me what is going to happen over the coming century. The world has turned a blind eye to the millions dying from starvation and preventable disease. And will do so again when tens to hundreds of millions die from the effects of climate change e.g. starvation, flooding, heat waves etc. And as the disaffected and left behind turn to terrorist acts to vent their frustration the rest of humanity will close borders, become more xenophobic and intolerant. Governments will be polarised to the extent that they will be largely ineffectual. Ultimately it is going to be the likes of Tesla and hopefully Apple to make electric cars a lust item, scientists to finally get nuclear fusion, carbon storage and renewable battery technology working and entrepreneurs to glue it all together.
- zamalek 10y ago
  At times I hope that climate change deniers in positions of power are held accountable for crimes against the human race; however, in the face of what I would anticipate to be the global living conditions justice would seem pointless. We can only hope that it becomes just bad enough to scare everyone[1], but no worse (i.e. methane pockets). If it's already "worse" geoengineering is the only thing that can save us because it's a runaway process, cutting carbon emissions would only delay the inevitable. We're not seeing much in the way of investment into that final pocket ace, though, at least Alphabet had a shot at it. [1]: http://traveller24.news24.com/News/Alerts/watch-another-tornado-hits-joburg-in-peak-traffic-20160726 http://traveller24.news24.com/News/Alerts/watch-another-torn...
Shivetya 10y ago
except that temperatures dropped in June by a large amount after El Nino started to wane. The La Nina that is coming could once again stall the "warming". Let alone, the warmest title is for years since 1979, its not like we have satellite data that is accurate and going back that long. We do however have drought data including some good numbers out of China that shows clear cycles in weather for centuries. So long story short, we don't know why and we need to quit acting other wise and put more effort into correcting models so that they are least close to predicting what has occurred over the last few decades of known data. If a model cannot reproduce what has happened it cannot be reliable in predicting what will. How can we not fix them?
- Brakenshire 10y ago
  The temperature dropped in June in the sense that the rather than being 0.3 degrees warmer than the warmest equivalent month, now it's only 0.2 warmer than the warmest equivalent month ever recorded. That is an odd sort of progress. Also, the records don't go back to 1979, most go back to the start of the instrumental record in the 1880's. And satellite data isn't a panacea, the process of getting from the direct measurements to a temperature distribution involves a significant amount of processing based on theoretical models, and corrections for factors like orbital decay, and different satellites and processing methodologies have historically shown a lot of disagreement. It's all useful data, but it's not as if satellites are perfect and everything that comes before is worthless.
danieltillett 10y ago
When are we going to stop f*ing around and start doing something serious? Let's just buy off the carbon lobby (oil/coal/gas owners) and get on with a crash program of energy decarbonisation.
- umanwizard 10y ago
  We are never going to, because of the tragedy of the commons problem. Humanity is doomed. We had a good run.
- pif 10y ago
  I think that many people agree with you in principle, but when they start considering the cost in terms of lifestyle, than the followers start to vanish.
  - pietrofmaggi 10y ago
    "Cost in terms of lifestyle" compared to what? there're studies (e.g. this report from citybank[0]) that shows that inaction is actually more expensive, taking into account the cost of the climate change disasters... Seems to me that people believe that doing nothing we will keep living in the same way. Sorry to have to wake you up. Doing nothing will screw up the planet and your (and mine) "lifestyle". The article referenced in this discussion[1] have other nice data/information about this topic. I have kids and this is not the future I want for them. [0] https://ir.citi.com/hsq32Jl1m4aIzicMqH8sBkPnbsqfnwy4Jgb1J2kIPYWIw5eM8yD3FY9VbGpK%2Baax https://ir.citi.com/hsq32Jl1m4aIzicMqH8sBkPnbsqfnwy4Jgb1J2kI... [1] https://news.ycombinator.com/item?id=10622615 https://news.ycombinator.com/item?id=10622615
    - pif 10y ago
      > "Cost in terms of lifestyle" compared to what? there're studies (that shows that inaction is actually more expensive Please, keep in mind that renouncing to your car will not prevent you from breathing smoke, unless many people around you do the same. Reducing to the bare minimum your electricity consumption will not lower the slice of your taxes devoted to dealing with global warming, unless many people around you do the same. Et cetera...
barney54 10y ago
What is frustrating about this article is that no climate scientists were caught off-guard by 2016 bring hot so far. There was a strong El Niño. Everyone saw serious heat coming months in advance.
- Diederich 10y ago
  The amount of heating is what's surprising, not the heating itself.
knowThySelfx 10y ago
CO2 is the only culprit? This one says Ozone layer is recovering: http://research.noaa.gov/News/NewsArchive/LatestNews/TabId/684/ArtMID/1768/ArticleID/10741/Report-telltale-signs-that-ozone-layer-is-recovering-.aspx http://research.noaa.gov/News/NewsArchive/LatestNews/TabId/6... This one says increased CO2 has helped the speedy recovery of Ozone: http://classroom.synonym.com/co2-deplete-ozone-layer-4828.html http://classroom.synonym.com/co2-deplete-ozone-layer-4828.ht... I understand the topic is climate change. Probably there are other factors contributing to it. Its been said Methane and NOx are more potent. Is there an increase in those emissions? We are only looking at CO2 it seems.
secult 10y ago
It's hot in summer, who would expect that?
- ceejayoz 10y ago
  Ah yes, climate scientists just forgot to account for summer. I'm sure that's it.
- Scarblac 10y ago
  14 consecutive, global hottest months ever (1) So june last year, which was as much summer as this one was, was hotter than all previous junes, all of which were in summer. And this june was hotter. 1: in modern times, I assume
- ocschwar 10y ago
  Ever heard of the southern hemisphere?
cpncrunch 10y ago
What is this data based on? From my own experience, living on Vancouver Island, temperatures this summer have been much cooler than in recent years. This summer has been almost exactly average in temp, compared to above average for the last few years. Looking at accuweather's data (www.accuweather.com, search for a city, then click 'month'), virtually everywhere in the US has been pretty much bang on the average temps for June and July.
- radiorental 10y ago
  What drought? it rained in my town today.
  - cpncrunch 10y ago
    I didn't mention drought. And why am I getting downvoted for asking a valid question?
  - cpncrunch 10y ago
    Ok, I see you were being sarcastic, saying that what happens in my hometown has no relevance. I guess you didn't read the rest of my comment...as well as my personal anecdote (which was probably bad to put on HN), I put actual science. If you look at the data for New York, Miami, Los Angeles, and various other cities across the US, you'll see that temperatures have been exactly average for June and July. So, I'm just wondering where this data came from, and why it is difference from the actual recorded temperatures. Is it because it is satellite data? If so, why does it differ? In typical HN fashion this is a press release rather than an actual scientific article. Just to clarify, I'm not a climate change denier. However scare articles with no science behind them do more harm than good (if that is what this is). EDIT here is where the data comes from: http://www.ncdc.noaa.gov/sotc/global/201606 http://www.ncdc.noaa.gov/sotc/global/201606 I guess a small amount above average temperatures just isn't noticeable in the average temperature graphs.
    - Oletros 10y ago
      >I guess a small amount above average temperatures just isn't noticeable in the average temperature graphs. From your link > The worldwide ocean surface temperature during June 2016 was 0.77°C (1.39°F) above the 20th century average, the highest global ocean temperature for June in the 137-year record. 0.77C is not a small amount
merpnderp 10y ago
I see articles like this that are pure fear mongering and weep. It didn't mention El Nino even once. Yet a massive El Nino event caused the increase in world temperature and higher rainfall around the world in 2016. This isn't even a debatable fact, yet apparently not worth mentioning in an article about weather and temperature events in 2016.
graycat 10y ago
Some points: (1) Does the climate change? Apparently. E.g., we had glaciations, most recently IIRC, about 12,000 years. (2) What is a greenhouse gas: Leading examples are water vapor, CO2, and methane. Each of these is transparent to visible light, e.g., if water vapor or CO2 were not transparent to visible light, then we could see our breath as we exhale. So, since greenhouse gasses are transparent to visible light, visible light from the sun passes through greenhouse gasses in the atmosphere, strikes the surface of the earth, and gets absorbed by and warms the surface. That warmer surface then radiates as in Planck black body radiation. That radiation is mostly out in the infrared we cannot see with our eyes. But here is what a greenhouse gas does: It absorbs the Planck black body infrared radiation from the surface of the earth, gets warmer, and warms the atmosphere. Without a greenhouse gas, that infrared radiation might just continue and escape into outer space. The glass in the ceiling of a greenhouse works similarly -- it lets visible light from the sun in but blocks infrared light from the warm interior surfaces of the greenhouse from getting out (there is some controversy in how a greenhouse works, but a greenhouse is still the source of the term greenhouse gas). (3) Since CO2 is a greenhouse gas, CO2 in the atmosphere warms it? Yup. (4) What are the sources of CO2 in the atmosphere? I don't have good data on all the sources and how much each contributes (it's not clear that anyone does). Supposedly one of the largest sources is volcanoes, and there we have to count the ones under the oceans, too. Supposedly rotting vegetation is a source. All animals exhale CO2. Burning fossil fuels, wood, etc. releases CO2. Baking calcium carbonate to make lime for cement, etc., releases CO2. Supposedly a large source of CO2 is the oceans: Supposedly warmer water can absorb less CO2. So, as ocean water warms, from circulation, volcanoes, the seasons, warmer climate, etc., CO2 can be emitted. A guess is that the oceans are an overwhelmingly large store of CO2 and a major source/sink of CO2 (as a source emits CO2, a sink absorbs it). Yes, rotting vegetation emits CO2, but, then, sure, as that vegetation originally grew, it was a sink of CO2. (5) Does CO2 absorb all the infrared light? Nope, not even close. CO2 absorbs in just three narrow frequency bands, one for each of bending, twisting, and stretching of the molecule. More generally, say, for other gasses, the subject is molecular spectroscopy, based on, e.g., quantum mechanics, some group theory, etc. (6) Okay, CO2 is a greenhouse gas and, thus, warms the atmosphere. If someone lights a match, then that, too, will warm the atmosphere. A question is, how much? In particular, how much CO2 warms the atmosphere how much? So, we believe that what CO2 does follows only from well understood principles of physics and chemistry. For large changes in CO2 concentrations over long terms, say, centuries, maybe we would have carefully to consider biology, that is, how plants, the oceans, etc., respond to the extra CO2. But, already just for small changes in CO2 over just a few decades, apparently the calculations from principles in physics and chemistry are quite challenging. E.g., for flows in the atmosphere and oceans we would have to use the equations of fluid flow, the Navier-Stokes equations, for the whole planet, including the oceans. Of course, for such a calculation, we would need boundary conditions, e.g., what all the CO2 concentrations, temperatures, and flow rates are now. For the oceans, our best data for the boundary conditions is often crude. Still there have been efforts to do the calculations. The efforts resulted in predictions of temperature for a few decades. The results of some dozens of efforts to do these calculations have been summarized in, e.g., http://www.energyadvocate.com/gc1.jpg http://www.energyadvocate.com/gc1.jpg By now we have been able to compare the predicted temperatures with the observed ones. The result is that in nearly all cases of the calculations, the predicted temperatures were way above the observed temperatures. In simple terms, as science, the calculations flopped. So, for the question of how much CO2 warms the planet how much, we don't have solid scientific information. (7) Apparently a common Claim is that essentially the only cause of changes of the temperature of the planet is greenhouse gasses, essentially just CO2, from human or other sources. So, with more CO2, the temperature will go up; with less CO2, the temperature will go down; the times the temperature went up was due to more CO2; the times the temperature went down was due to less CO2. Well, we can test this Claim. We have three tests, A-C: Test A. As at https://en.wikipedia.org/wiki/Little_Ice_Age https://en.wikipedia.org/wiki/Little_Ice_Age there was the Little Ice Age: "The NASA Earth Observatory notes three particularly cold intervals: one beginning about 1650, another about 1770, and the last in 1850, each separated by intervals of slight warming." It was significantly colder, certainly in both Europe and the US. Some of the effects are famous: E.g., in the famous painting of General Washington crossing the Delaware River, there was ice in the river. IIRC, usually there isn't. There was winter ice skating on the Thames River in London; IIRC usually there isn't. Was this cooling caused by lower CO2 concentrations? Apparently there is no such evidence. So, the cause was something else. So, the Little Ice Age serves as a counterexample to the Claim above. So, there can be causes of significant changes in temperature that have little or nothing to do with CO2. Test B. Can say the same for the Medieval Warm Period, as at https://en.wikipedia.org/wiki/Medieval_Warm_Period https://en.wikipedia.org/wiki/Medieval_Warm_Period from "lasting from about 950 to 1250". Test C. For more, at Vostok Station in Antarctica, the Russians took some ice cores and from them measured CO2 concentrations and temperature back ballpark 1 million years. They found several times when temperature went up and CO2 concentrations went up. Al Gore's movie An Inconvenient Truth showed a graph of those two over several hundred thousand years. E.g., as at Web page http://www.globalchange.umich.edu/globalchange1/current/labs/Lab10_Vostok/Vostok.htm http://www.globalchange.umich.edu/globalchange1/current/labs... can see graph http://www.globalchange.umich.edu/globalchange1/current/labs/Lab10_Vostok/Vostok_files/untitled2.jpg http://www.globalchange.umich.edu/globalchange1/current/labs... Gore claimed that the higher CO2 caused the higher temperatures. Well, due to the long time interval of the horizontal axis of the graph, not easy to see on the graph was that the CO2 peaks occurred about 800 years after the temperature peaks. So, really, just by common sense, the higher temperatures were not caused by higher CO2. Instead, something caused the higher temperatures; they caused more biological activity, and in 800 years that activity caused higher CO2. So, here we have three failed tests of the Claim, three counterexamples of the Claim above. For anything scientific, those counterexamples are an overwhelmingly serious problem for the Claim about CO2. === The Current Scientific Situation === If we get a case when CO2 went up and soon temperature went up, that still is poor evidence that the higher CO2 caused the higher temperature, that is, the several counterexamples to the Claim remain. That is, from the data, we already know, e.g., the end of The Little Ice Age, the Medieval Warm Period, and the Vostok data, that there are causes of significant warming that have nothing to do with CO2. Indeed, it is not at all clear that at realistic concentrations CO2 has anything at all significant to do with the temperature of the earth; to the Claim from climate data we have several overwhelmingly serious counterexamples, and otherwise we just don't have any solid scientific evidence: We tried with calculations from principles of physics and chemistry, and they flopped. Net, from the calculations and from the historical record, we have no solid evidence that, at anything like realistic levels, more CO2 in the atmosphere will cause significant increases in the temperature of the earth. Yes, CO2 is a greenhouse gas, but we just don't have any solid evidence, from either calculations or observations, that CO2 will be causing any significant warming of the earth. So, can we use science to urge reductions in burning fossil fuels, subsidize wind and solar sources of electric power, impose carbon taxes, etc.? IMHO, my view is that such steps would be extremely irresponsible, would shoot our economy in the gut for reasons that are little more solid than some ancient religion, e.g., when the Mayans killed people to pour their blood on a rock "to keep the sun moving across the sky" -- e.g., as at http://books.google.com/books?id=DgqLplWtGPgC&pg=PA76&lpg=PA76&dq=Mayan+blood+sun+moving+sacrifice&source=web&ots=Do6njWN5M9&sig=FxTeclIiqggqIH5Ws_oENCek1uI&hl=en&sa=X&oi=book_result&resnum=1&ct=result#PPA76,M1 http://books.google.com/books?id=DgqLplWtGPgC&pg=PA76&lpg=PA... on page 76 of Susan Milbrath, 'Star Gods of the Maya: Astronomy in Art, Folklore, and Calendars (The Linda Schele Series in Maya and Pre-Columbian Studies)', ISBN-13 978-0292752269, University of Texas Press, 2000. with "Indeed, blood sacrifice is required for the sun to move, according to Aztec cosmology (Durian 1971:179; Sahaguin 1950 - 1982, 7:8)."

146 points by fspear 10y ago

dev1n 10y ago

climate change is one of those few issues where an alarmist attitude is actually needed. Still need to get more media outlets to change from saying "save the planet" to "save humanity".

ars 10y ago
Why? Humanity will be fine. At worst some people will have to move a bit inland.
- soundwave106 10y ago
  Under some predictions, parts of the Middle East and North Africa might become, if not uninhabitable, very uncomfortable (50C+ summer averages) by the end of the century, with all the consequences that arise from this. http://link.springer.com/article/10.1007/s10584-016-1665-6 http://link.springer.com/article/10.1007/s10584-016-1665-6 Present experience proves that people, especially the impoverished, can't just easily uproot and leave one country for another, with no political or sociological consequences whatsoever.

kodroid 10y ago

So, what can be done? I posted this question on Reddit ages ago with no replys, would be interesting to hear anyone on heres opinion on it... > Hi all, Im sure there are many reasons why this would not work but thought would be good to get some input. I came across this article about creating carbon fibre from atmospheric carbon https://www.technologyreview.com/s/540706/researcher-demonstrates-how-to-suck-carbon-from-the-air-make-stuff-from-it/ https://www.technologyreview.com/s/540706/researcher-demonst... and as carbon fibre utilising 3d printers now exist like https://markforged.com/product/mark-one-composite-3d-printer/ https://markforged.com/product/mark-one-composite-3d-printer... this seems like something with amazing potential. Of course one of the main challenges is the energy needed to operated such a machine - but in the right places (which im guessing is windy as the carbon pulling machine needs high air exposure anyway) renewable forms of energy could maybe be used? In a daydream I thought it would be amazing to replace steels and plastics with atmospheric carbon. Reduce oil dependency, lower carbon footprint (even thought its not putting it back in the ground it seems like a good second), created a fantastic building element. Anyhow - would be great to hear why this wont (or would!) work from someone who knows more than me about this stuff. :)

pjc50 10y ago
Money? There isn't currently a market for this product, there may never be, and it requires a big upfront investment. Scaling? "given an area less than 10 percent of the size of the Sahara Desert" does nobody have any idea how large that is? If he'd said "an area the size of Texas and California combined" it might look less feasible. But really it needs millions in altruistic funding to even get a pilot plant going. It's a lot like Tesla's plan to get everyone driving electric cars: no technical barrier, but the financial one is huge and it takes a while to scale even if it's successful.
the8472 10y ago
It takes a lot of energy. If we built enough clean energy to have some to spare for pulling carbon out of the atmosphere then we would already have met the goals of decarbonizing the economy. This would merely be going the extra mile on top of that. And we already have self-replicating zero-emission carbon extraction machines. They're called trees. You could just plant trees, wait a few decades and then drop them with some weights into the ocean if you wanted to get rid of carbon. Of course you would have to do that at industrial scale and somehow find a way to replace all the nutrient minerals you're also sinking into the ocean. And we're talking about gigatons per year. The only thing that's comparable in human production is concrete. We would have to build all our roads, cities and megastructures out of carbon to reverse current emissions.

blondie9x 10y ago

We all know by now CO2 and CH4 leads to a warmer planet. We also know what's driving greenhouse gas levels to rise across Earth. Contributors are deforestation, intensive animal farming, and primarily the combustion of carbon fossil fuels like coal, tar sands, oil, natural gas etc. But here is the underlying problem, despite us knowing how bad things are, (97+% of scientists who study this field agree we are causing the planet's climate to shift away from the temperate climate we thrived in) not enough is being done at present to truly solve the problem. What really is disheartening and what no one in the media and government is talking about is how in 2015 CO2 levels rose by the largest amount in human recorded history. 3.05 PPM http://www.esrl.noaa.gov/gmd/ccgg/trends/gr.html http://www.esrl.noaa.gov/gmd/ccgg/trends/gr.html We are being lied to and mislead by our governments that uniform actions are being performed to save the planet for the future of man. Vested interests in the fossil fuel industry continue to drive climate change. Yes, solar and wind energy is starting to become incredibly efficient and cheap but not enough of it is coming online in proportion to fossil fuel burning that persists and is also installed annually. If we do not rally against it, our ability to live on this planet is at stake. The lives of our posterity are also at risk because of the burning. It will not be until we take extreme actions not on a country level but as humanity together that we will slow the burning and save ourselves. What are these actions you might ask that will actually be effective? These can range from banning fossil fuels entirely, global carbon pricing system, banning deforestation, changing human diets, extreme uniform investment in renewable energy and potentially fourth generation nuclear reactors, more funding for developing nations to install alternative energy sources, and to shift the transportation grid towards sustainability.

redwood 10y ago
One more key contributor (since CH4 aka natural gas is so much worse as a green house gas compared with CO2 when released than burned or kept in the ground): Human activity, ranging from fossil fuel extraction, to natural gas usage, has massively led to a large amount of natural gas leakage across the network. All this leaking adds up and is an "unseen" but incremental accelerant on these problems (https://www.washingtonpost.com/news/energy-environment/wp/2016/02/25/california-gas-leak-was-the-worst-man-made-greenhouse-gas-disaster-in-u-s-history-study-says/ https://www.washingtonpost.com/news/energy-environment/wp/20...)

redwood 10y ago

It's all about batteries. An order of magnitude more efficient electric battery technology is the key missing piece to get us away from a fossil based economy.

awt 10y ago

Buy some of these from your local government: https://en.m.wikipedia.org/wiki/Indulgence https://en.m.wikipedia.org/wiki/Indulgence

pluma 10y ago

IOW climate change is even worse than scientists anticipated.

yiyus 10y ago
While this is true, I think that what the article is trying to point out is not that climate change is worse, but that the models we have do not work in the current conditions. This is scary, because scientists have been anticipating climate change for decades, but now we know that what they anticipated was not as accurate as we thought. If predictions from 10 years ago, let's say, had been replaced by worse predictions one or two years ago, we would still know with some certainty what will happen next. But what the article says is that everything we know is that things are getting worse than expected and we have no way to know how worse. Scary.
- NumberCruncher 10y ago
  >> scientists have been anticipating climate change for decades, but now we know that what they anticipated was not as accurate as we thought. It's tough to make predictions, especially about the future
  - chx 10y ago
    Aye but predictions are necessary. If there's a 4C global temperature rise that displaces 760M people. To put this into perspective, about 1M migrants in a year almost collapsed Europe's political system. We need to know how quick that happens so we can begin to do something. Dam, evacuate etc.
    - vkou 10y ago
      More likely, we will cover the borders with barbed wire, and machineguns.
      - chx 10y ago
        The borders of what? Omaha? New York, DC, Los Angeles, Seattle and 'Frisco are (at least partially) gone.

conistonwater 10y ago

How much of it is due to El Niño, and how much due to global warming proper? Is it difficult to figure out? The article doesn't say.

tehmaco 10y ago
From Bad Astronomy, El Niño accounts for around 0.1C globally: http://www.slate.com/blogs/bad_astronomy/2016/07/20/june_2016_was_the_hottest_june_on_record.html http://www.slate.com/blogs/bad_astronomy/2016/07/20/june_201...

cconcepts 10y ago

I have no doubt that climate change is a problem. I have kids, I dont want to give them a hospital pass. I've tried to stop living such a carbon dependant lifestyle but I look outside and my efforts feel futile. How do I REALLY do something about this other than a few pretentious yet barely discomforting lifestyle changes and the odd empassioned few sentences at dinner parties? Start pushing for a carbon tax? Start an electric car company? Begin development of technology to get us to Ma.....oh wait Plant heaps of trees? Buy drones and start my own version of operation sunscreen? Seriously. The mild excitement that comes with media alarmism has transitioned into "I really need to start doing something drastic or I'll regret it"

s917 10y ago
How much stuff do we in the west consume that originates in China, where they don't seem to give a damn about environmental controls? And exactly how much CO2 and other chemicals are belched out by these giant container ships we use to get it all to us? We can buy all the solar panels, wind turbines, electric cars and energy efficient washing machines we want, but until China (and probably others) starts playing ball AND we find a way to move vast quantities of stuff around without container ships we're probably fighting a losing battle. Would it be possible to manufacture goods in the regions they're to be sold in? edit: wordings.
- malka 10y ago
  well, we could have nuclear container ships, I guess. May not be the best idea ever though.
- vkou 10y ago
  Almost all of it. We used to make it with little regard for the environment - now China does. If you want to fix that problem, institute a carbon tax, and import tarrifs on countries that don't have carbon taxes. Practically, with things like the TPP, that's not the way the world is going.
nathan_f77 10y ago
I like your thinking. I don't there's much a regular person can do, even if you become an activist. You really have to become a salesman for climate change, you need to build up your voice and try to get CEOs and politicians to listen to you. I feel the same way about vegetarians and vegans. You're not saving the world by eating salads or sharing the occasional thing on Facebook. You might feel better about yourself and your choices, which is great. But it's only a drop in the ocean, and won't have any effect unless you try to do something bigger. And it's actually going to help with global warming, if the world can start eating less (or no) cows and chickens. It's certainly too big for one person to solve, but that's why people start organizations. I know it's not much, but you can start by signing this petition: http://www.stopwarming.eu/?petition=signup http://www.stopwarming.eu/?petition=signup

threeseed 10y ago

It seems pretty clear to me what is going to happen over the coming century. The world has turned a blind eye to the millions dying from starvation and preventable disease. And will do so again when tens to hundreds of millions die from the effects of climate change e.g. starvation, flooding, heat waves etc. And as the disaffected and left behind turn to terrorist acts to vent their frustration the rest of humanity will close borders, become more xenophobic and intolerant. Governments will be polarised to the extent that they will be largely ineffectual. Ultimately it is going to be the likes of Tesla and hopefully Apple to make electric cars a lust item, scientists to finally get nuclear fusion, carbon storage and renewable battery technology working and entrepreneurs to glue it all together.

zamalek 10y ago
At times I hope that climate change deniers in positions of power are held accountable for crimes against the human race; however, in the face of what I would anticipate to be the global living conditions justice would seem pointless. We can only hope that it becomes just bad enough to scare everyone[1], but no worse (i.e. methane pockets). If it's already "worse" geoengineering is the only thing that can save us because it's a runaway process, cutting carbon emissions would only delay the inevitable. We're not seeing much in the way of investment into that final pocket ace, though, at least Alphabet had a shot at it. [1]: http://traveller24.news24.com/News/Alerts/watch-another-tornado-hits-joburg-in-peak-traffic-20160726 http://traveller24.news24.com/News/Alerts/watch-another-torn...

Shivetya 10y ago

except that temperatures dropped in June by a large amount after El Nino started to wane. The La Nina that is coming could once again stall the "warming". Let alone, the warmest title is for years since 1979, its not like we have satellite data that is accurate and going back that long. We do however have drought data including some good numbers out of China that shows clear cycles in weather for centuries. So long story short, we don't know why and we need to quit acting other wise and put more effort into correcting models so that they are least close to predicting what has occurred over the last few decades of known data. If a model cannot reproduce what has happened it cannot be reliable in predicting what will. How can we not fix them?

Brakenshire 10y ago
The temperature dropped in June in the sense that the rather than being 0.3 degrees warmer than the warmest equivalent month, now it's only 0.2 warmer than the warmest equivalent month ever recorded. That is an odd sort of progress. Also, the records don't go back to 1979, most go back to the start of the instrumental record in the 1880's. And satellite data isn't a panacea, the process of getting from the direct measurements to a temperature distribution involves a significant amount of processing based on theoretical models, and corrections for factors like orbital decay, and different satellites and processing methodologies have historically shown a lot of disagreement. It's all useful data, but it's not as if satellites are perfect and everything that comes before is worthless.

danieltillett 10y ago

When are we going to stop f*ing around and start doing something serious? Let's just buy off the carbon lobby (oil/coal/gas owners) and get on with a crash program of energy decarbonisation.

umanwizard 10y ago
We are never going to, because of the tragedy of the commons problem. Humanity is doomed. We had a good run.
pif 10y ago
I think that many people agree with you in principle, but when they start considering the cost in terms of lifestyle, than the followers start to vanish.
- pietrofmaggi 10y ago
  "Cost in terms of lifestyle" compared to what? there're studies (e.g. this report from citybank[0]) that shows that inaction is actually more expensive, taking into account the cost of the climate change disasters... Seems to me that people believe that doing nothing we will keep living in the same way. Sorry to have to wake you up. Doing nothing will screw up the planet and your (and mine) "lifestyle". The article referenced in this discussion[1] have other nice data/information about this topic. I have kids and this is not the future I want for them. [0] https://ir.citi.com/hsq32Jl1m4aIzicMqH8sBkPnbsqfnwy4Jgb1J2kIPYWIw5eM8yD3FY9VbGpK%2Baax https://ir.citi.com/hsq32Jl1m4aIzicMqH8sBkPnbsqfnwy4Jgb1J2kI... [1] https://news.ycombinator.com/item?id=10622615 https://news.ycombinator.com/item?id=10622615
  - pif 10y ago
    > "Cost in terms of lifestyle" compared to what? there're studies (that shows that inaction is actually more expensive Please, keep in mind that renouncing to your car will not prevent you from breathing smoke, unless many people around you do the same. Reducing to the bare minimum your electricity consumption will not lower the slice of your taxes devoted to dealing with global warming, unless many people around you do the same. Et cetera...

barney54 10y ago

What is frustrating about this article is that no climate scientists were caught off-guard by 2016 bring hot so far. There was a strong El Niño. Everyone saw serious heat coming months in advance.

Diederich 10y ago
The amount of heating is what's surprising, not the heating itself.

knowThySelfx 10y ago

CO2 is the only culprit? This one says Ozone layer is recovering: http://research.noaa.gov/News/NewsArchive/LatestNews/TabId/684/ArtMID/1768/ArticleID/10741/Report-telltale-signs-that-ozone-layer-is-recovering-.aspx http://research.noaa.gov/News/NewsArchive/LatestNews/TabId/6... This one says increased CO2 has helped the speedy recovery of Ozone: http://classroom.synonym.com/co2-deplete-ozone-layer-4828.html http://classroom.synonym.com/co2-deplete-ozone-layer-4828.ht... I understand the topic is climate change. Probably there are other factors contributing to it. Its been said Methane and NOx are more potent. Is there an increase in those emissions? We are only looking at CO2 it seems.

secult 10y ago

It's hot in summer, who would expect that?

ceejayoz 10y ago
Ah yes, climate scientists just forgot to account for summer. I'm sure that's it.
Scarblac 10y ago
14 consecutive, global hottest months ever (1) So june last year, which was as much summer as this one was, was hotter than all previous junes, all of which were in summer. And this june was hotter. 1: in modern times, I assume
ocschwar 10y ago
Ever heard of the southern hemisphere?

cpncrunch 10y ago

What is this data based on? From my own experience, living on Vancouver Island, temperatures this summer have been much cooler than in recent years. This summer has been almost exactly average in temp, compared to above average for the last few years. Looking at accuweather's data (www.accuweather.com, search for a city, then click 'month'), virtually everywhere in the US has been pretty much bang on the average temps for June and July.

radiorental 10y ago
What drought? it rained in my town today.
- cpncrunch 10y ago
  I didn't mention drought. And why am I getting downvoted for asking a valid question?
- cpncrunch 10y ago
  Ok, I see you were being sarcastic, saying that what happens in my hometown has no relevance. I guess you didn't read the rest of my comment...as well as my personal anecdote (which was probably bad to put on HN), I put actual science. If you look at the data for New York, Miami, Los Angeles, and various other cities across the US, you'll see that temperatures have been exactly average for June and July. So, I'm just wondering where this data came from, and why it is difference from the actual recorded temperatures. Is it because it is satellite data? If so, why does it differ? In typical HN fashion this is a press release rather than an actual scientific article. Just to clarify, I'm not a climate change denier. However scare articles with no science behind them do more harm than good (if that is what this is). EDIT here is where the data comes from: http://www.ncdc.noaa.gov/sotc/global/201606 http://www.ncdc.noaa.gov/sotc/global/201606 I guess a small amount above average temperatures just isn't noticeable in the average temperature graphs.
  - Oletros 10y ago
    >I guess a small amount above average temperatures just isn't noticeable in the average temperature graphs. From your link > The worldwide ocean surface temperature during June 2016 was 0.77°C (1.39°F) above the 20th century average, the highest global ocean temperature for June in the 137-year record. 0.77C is not a small amount

merpnderp 10y ago

I see articles like this that are pure fear mongering and weep. It didn't mention El Nino even once. Yet a massive El Nino event caused the increase in world temperature and higher rainfall around the world in 2016. This isn't even a debatable fact, yet apparently not worth mentioning in an article about weather and temperature events in 2016.

graycat 10y ago

Some points: (1) Does the climate change? Apparently. E.g., we had glaciations, most recently IIRC, about 12,000 years. (2) What is a greenhouse gas: Leading examples are water vapor, CO2, and methane. Each of these is transparent to visible light, e.g., if water vapor or CO2 were not transparent to visible light, then we could see our breath as we exhale. So, since greenhouse gasses are transparent to visible light, visible light from the sun passes through greenhouse gasses in the atmosphere, strikes the surface of the earth, and gets absorbed by and warms the surface. That warmer surface then radiates as in Planck black body radiation. That radiation is mostly out in the infrared we cannot see with our eyes. But here is what a greenhouse gas does: It absorbs the Planck black body infrared radiation from the surface of the earth, gets warmer, and warms the atmosphere. Without a greenhouse gas, that infrared radiation might just continue and escape into outer space. The glass in the ceiling of a greenhouse works similarly -- it lets visible light from the sun in but blocks infrared light from the warm interior surfaces of the greenhouse from getting out (there is some controversy in how a greenhouse works, but a greenhouse is still the source of the term greenhouse gas). (3) Since CO2 is a greenhouse gas, CO2 in the atmosphere warms it? Yup. (4) What are the sources of CO2 in the atmosphere? I don't have good data on all the sources and how much each contributes (it's not clear that anyone does). Supposedly one of the largest sources is volcanoes, and there we have to count the ones under the oceans, too. Supposedly rotting vegetation is a source. All animals exhale CO2. Burning fossil fuels, wood, etc. releases CO2. Baking calcium carbonate to make lime for cement, etc., releases CO2. Supposedly a large source of CO2 is the oceans: Supposedly warmer water can absorb less CO2. So, as ocean water warms, from circulation, volcanoes, the seasons, warmer climate, etc., CO2 can be emitted. A guess is that the oceans are an overwhelmingly large store of CO2 and a major source/sink of CO2 (as a source emits CO2, a sink absorbs it). Yes, rotting vegetation emits CO2, but, then, sure, as that vegetation originally grew, it was a sink of CO2. (5) Does CO2 absorb all the infrared light? Nope, not even close. CO2 absorbs in just three narrow frequency bands, one for each of bending, twisting, and stretching of the molecule. More generally, say, for other gasses, the subject is molecular spectroscopy, based on, e.g., quantum mechanics, some group theory, etc. (6) Okay, CO2 is a greenhouse gas and, thus, warms the atmosphere. If someone lights a match, then that, too, will warm the atmosphere. A question is, how much? In particular, how much CO2 warms the atmosphere how much? So, we believe that what CO2 does follows only from well understood principles of physics and chemistry. For large changes in CO2 concentrations over long terms, say, centuries, maybe we would have carefully to consider biology, that is, how plants, the oceans, etc., respond to the extra CO2. But, already just for small changes in CO2 over just a few decades, apparently the calculations from principles in physics and chemistry are quite challenging. E.g., for flows in the atmosphere and oceans we would have to use the equations of fluid flow, the Navier-Stokes equations, for the whole planet, including the oceans. Of course, for such a calculation, we would need boundary conditions, e.g., what all the CO2 concentrations, temperatures, and flow rates are now. For the oceans, our best data for the boundary conditions is often crude. Still there have been efforts to do the calculations. The efforts resulted in predictions of temperature for a few decades. The results of some dozens of efforts to do these calculations have been summarized in, e.g., http://www.energyadvocate.com/gc1.jpg http://www.energyadvocate.com/gc1.jpg By now we have been able to compare the predicted temperatures with the observed ones. The result is that in nearly all cases of the calculations, the predicted temperatures were way above the observed temperatures. In simple terms, as science, the calculations flopped. So, for the question of how much CO2 warms the planet how much, we don't have solid scientific information. (7) Apparently a common Claim is that essentially the only cause of changes of the temperature of the planet is greenhouse gasses, essentially just CO2, from human or other sources. So, with more CO2, the temperature will go up; with less CO2, the temperature will go down; the times the temperature went up was due to more CO2; the times the temperature went down was due to less CO2. Well, we can test this Claim. We have three tests, A-C: Test A. As at https://en.wikipedia.org/wiki/Little_Ice_Age https://en.wikipedia.org/wiki/Little_Ice_Age there was the Little Ice Age: "The NASA Earth Observatory notes three particularly cold intervals: one beginning about 1650, another about 1770, and the last in 1850, each separated by intervals of slight warming." It was significantly colder, certainly in both Europe and the US. Some of the effects are famous: E.g., in the famous painting of General Washington crossing the Delaware River, there was ice in the river. IIRC, usually there isn't. There was winter ice skating on the Thames River in London; IIRC usually there isn't. Was this cooling caused by lower CO2 concentrations? Apparently there is no such evidence. So, the cause was something else. So, the Little Ice Age serves as a counterexample to the Claim above. So, there can be causes of significant changes in temperature that have little or nothing to do with CO2. Test B. Can say the same for the Medieval Warm Period, as at https://en.wikipedia.org/wiki/Medieval_Warm_Period https://en.wikipedia.org/wiki/Medieval_Warm_Period from "lasting from about 950 to 1250". Test C. For more, at Vostok Station in Antarctica, the Russians took some ice cores and from them measured CO2 concentrations and temperature back ballpark 1 million years. They found several times when temperature went up and CO2 concentrations went up. Al Gore's movie An Inconvenient Truth showed a graph of those two over several hundred thousand years. E.g., as at Web page http://www.globalchange.umich.edu/globalchange1/current/labs/Lab10_Vostok/Vostok.htm http://www.globalchange.umich.edu/globalchange1/current/labs... can see graph http://www.globalchange.umich.edu/globalchange1/current/labs/Lab10_Vostok/Vostok_files/untitled2.jpg http://www.globalchange.umich.edu/globalchange1/current/labs... Gore claimed that the higher CO2 caused the higher temperatures. Well, due to the long time interval of the horizontal axis of the graph, not easy to see on the graph was that the CO2 peaks occurred about 800 years after the temperature peaks. So, really, just by common sense, the higher temperatures were not caused by higher CO2. Instead, something caused the higher temperatures; they caused more biological activity, and in 800 years that activity caused higher CO2. So, here we have three failed tests of the Claim, three counterexamples of the Claim above. For anything scientific, those counterexamples are an overwhelmingly serious problem for the Claim about CO2. === The Current Scientific Situation === If we get a case when CO2 went up and soon temperature went up, that still is poor evidence that the higher CO2 caused the higher temperature, that is, the several counterexamples to the Claim remain. That is, from the data, we already know, e.g., the end of The Little Ice Age, the Medieval Warm Period, and the Vostok data, that there are causes of significant warming that have nothing to do with CO2. Indeed, it is not at all clear that at realistic concentrations CO2 has anything at all significant to do with the temperature of the earth; to the Claim from climate data we have several overwhelmingly serious counterexamples, and otherwise we just don't have any solid scientific evidence: We tried with calculations from principles of physics and chemistry, and they flopped. Net, from the calculations and from the historical record, we have no solid evidence that, at anything like realistic levels, more CO2 in the atmosphere will cause significant increases in the temperature of the earth. Yes, CO2 is a greenhouse gas, but we just don't have any solid evidence, from either calculations or observations, that CO2 will be causing any significant warming of the earth. So, can we use science to urge reductions in burning fossil fuels, subsidize wind and solar sources of electric power, impose carbon taxes, etc.? IMHO, my view is that such steps would be extremely irresponsible, would shoot our economy in the gut for reasons that are little more solid than some ancient religion, e.g., when the Mayans killed people to pour their blood on a rock "to keep the sun moving across the sky" -- e.g., as at http://books.google.com/books?id=DgqLplWtGPgC&pg=PA76&lpg=PA76&dq=Mayan+blood+sun+moving+sacrifice&source=web&ots=Do6njWN5M9&sig=FxTeclIiqggqIH5Ws_oENCek1uI&hl=en&sa=X&oi=book_result&resnum=1&ct=result#PPA76,M1 http://books.google.com/books?id=DgqLplWtGPgC&pg=PA76&lpg=PA... on page 76 of Susan Milbrath, 'Star Gods of the Maya: Astronomy in Art, Folklore, and Calendars (The Linda Schele Series in Maya and Pre-Columbian Studies)', ISBN-13 978-0292752269, University of Texas Press, 2000. with "Indeed, blood sacrifice is required for the sun to move, according to Aztec cosmology (Durian 1971:179; Sahaguin 1950 - 1982, 7:8)."