13 ms·

What's Really Warming the World?

180 points by awjr 10y ago

StClaire 10y ago
I like to remind people that Joseph Fourier figured out the Greenhouse effect about 200 years ago, well before there was any good indication we were turning the Earth into Venus
Spooky23 10y ago
I was actually at a political event yesterday where some derp derp conservative was going on about how this stuff is all hoax. Meanwhile, we are in upstate NY, in late February, sitting outside enjoying the 80 degree weather which is warmer than Los Angeles.
- grzm 10y ago
  I understand where you're coming from. That said, including "some derp derp conservative" in your comment makes it easy for anyone who disagrees with you to dismiss anything else you say as partisan. Similarly, the issue is climate change. Looking at a single day, no matter how extreme, is an anecdote. The debate around the science supporting climate change is difficult enough without pointing to anecdotes in support of the theory. Given you chose to comment on this, I believe climate change is something you care about. One of the ways to be more effective in getting something done is to not leave yourself open to easy dismissal by those who disagree with you.
- SamReidHughes 10y ago
  Los Angeles is right by the ocean so it has much less temperature variation.
- akvadrako 10y ago
  You mean because it's 80° instead of 79° global warming must be real?
  - Spooky23 10y ago
    Meaning that in the nearly 40 years that I have been on earth, most of which within a 100 mile radius of where I live now, the average temperature at this time of year is around 20F. I never recall a day that was that warm in February, in Albany, NY.
vivekd 10y ago
What makes me mad about these kinds of data based climate change arguments is that they don't engage with the data in an honest way. The huge problem is 1880 was one of the coldest years in history. That cold period was caused by volcanism, several volcanos erupted causing a cold period that lasted from the 1600s to the late 1800s. This period is known as the little ice age. The worst of this period was in 1816 which was known as the "year without a summer." The Earth has gradually been warming since then. https://en.wikipedia.org/wiki/Little_Ice_Age https://en.wikipedia.org/wiki/Little_Ice_Age So when we track from the little ice age to now and say the world as gotten warmer and present this as unusual or surprising findings, you know that they are not being honest with you. I'm not saying that climate change isn't happening, I'm not saying it isn't man made. All I'm pointing out here is that proponents of global warming aren't engaging with the facts in an honest and forthright way.
- corradio 10y ago
  You're right. However, it's hard to argue with the speed at which this warming occurs. It's never seen before if you look at all the records we have. That's what's worrying.
  - karl11 10y ago
    The sample size of our records is incredibly small when stacked against the history of the earth and all the records we're missing.
    - euyyn 10y ago
      What makes you think so? There's plenty of ways to indirectly know past temperatures, even if there wasn't a human writing it down.
      - Udik 10y ago
        Not with the accuracy and resolution of the data we have since last century. When you compare the current time series with the reconstructed ones from the past, you're comparing a day by day thermometric reading with the assembled averages of multiple, very noisy and extremely low frequency samples. Very tricky to say from those what might have been the actual speed of change in the past.
ams6110 10y ago
What is magical about 1880-1910 as the implied "normal" average baseline? Why not 1600? 1400? 2500 BC?
- corradio 10y ago
  You shouldn't care about what reference is taken. The point is that compared to any reference, the curve is increasing.
  - sageikosa 10y ago
    800 million years ago is my reference point
  - karl11 10y ago
    That doesn't make sense. What if the reference is 5 minutes ago?
    - euyyn 10y ago
      If we're talking about annual average temperature, what doesn't make sense is thinking about 5min ago.
    - corradio 10y ago
      Take the reference that is 5min ago, call it T0. You will still observe that temperatures (i.e the sequence of measured temperatures minus T0) are increasing. Changing the reference changes the y-scale of a graph, but does not change the derivative (the speed at which it changes, i.e. increases or decreases).
      - joatmon-snoo 10y ago
        Did you look at the graph? The local derivative is most definitely not indicative of a general trend. For comparison, I throw a ball down at the ground, and for the first 0.1 seconds it's moving down - can I conclude that the ball is going to keep moving down, even when it hits the ground? That's your logic.
lend000 10y ago
Can someone explain why aerosols are decreasing in their graph? A definition of what they consider an aerosol would be a good start, which I didn't see on there. Apparently the term can cover a large number of natural and unnatural compositions of matter: https://en.wikipedia.org/wiki/Aerosol https://en.wikipedia.org/wiki/Aerosol
- emodendroket 10y ago
  Weren't they regulated after acid rain and ozone layer concerns in the 90s?
  - mirimir 10y ago
    Yes, SOX were regulated to mitigate acid rain, and particulates for health reasons. But then China starting burning massive amounts of dirty coal, with virtually no emissions controls. And that reduced global warming.
- TazeTSchnitzel 10y ago
  Aerosols aren't decreasing, the line shows the effect on the average temperature. Aerosols have a negative effect.
- stale2002 10y ago
  Aerosols are not decreasing. They are increasing. But increasing amounts of Aerosols causes Global Cooling, not warming, which is why the graph angles downwards.
- mirimir 10y ago
  Aerosols are not decreasing, but rather increasing. They reduce insolation, both directly and by increasing cloudiness. So they counteract greenhouse forcing. The main anthropogenic aerosols are sulfur oxides and particulates from fuel combustion. And potentially, crap from nuclear explosions ("nuclear winter"). Main natural sources are deserts, sea salt and volcanoes. So anyway, if China manages to reduce its aerosol emissions faster than its CO2 emissions, mean global temperature will likely increase even faster.
rectang 10y ago
> The only real question is: What are we going to do about it? Zilch, so long as politicians corrupted by the fossil fuel industry are in power. "It is difficult to get a man to understand something, when his salary depends upon his not understanding it!" -- Upton Sinclair
- curtis 10y ago
  There is a substantial percentage of the electorate who are ideologically opposed to the very notion of climate change. They're ideologically opposed to conservation, they're ideologically opposed to large scale government interventions for any purpose, they are specifically opposed to any sort of tax so a carbon tax is right out, and they are even ideologically opposed not simply to environmentalism, but to (it seems) environmentalists. Now in this environment, all the fossil fuel industry has to do is encourage that section of the electorate to continue to believe things they already believe. The fundamental problem here is (in my own humble opinion) the large number of voters with ideological blinders on, and that's the problem that's ultimately got to be addressed.
  - bunderbunder 10y ago
    Calling it ideological blinders is an easy dismissal, and also one that, IMO, isn't terribly useful. I think what you're really dealing with is cognitive dissonance: Accepting what the science says on climate probably means accepting that you yourself could be be contributing to a situation that could be a serious problem for your children and grandchildren. It probably also implies making some lifestyle modifications that may feel severe, such as cutting way back on high-carbon activities like driving and meat consumption. In a situation like that, which option is less daunting: Accepting the consensus opinion of climate scientists and all the worry that implies, or going with the denialists so that you can get back to business as usual?
    - curtis 10y ago
      > Calling it ideological blinders is an easy dismissal, and also one that, IMO, isn't terribly useful. No it's not an easy dismissal. It's the exact opposite of an easy dismissal. It's a really hard problem.
patricklorio 10y ago
That was really cool but it bothers me that they don't show the y axis for the effecting factors. Does anyone know if it's normalized or completely arbitrary?
- svantana 10y ago
  As I understood it they all showed (modeled) contribution to temperature change at the same scale as the data graph, that's why they could all sum up at the end.
- imh 10y ago
  >The colored temperature lines are the modeled estimates that each climate factor contributes to the overall temperature. There's only one y axis, and it's degrees F for both lines.
- nom 10y ago
  They share the same Y axis, the values are taken from simulations. From the article: "The colored temperature lines are the modeled estimates that each climate factor contributes to the overall temperature. Each factor was simulated five times, with different initial conditions; each slide here shows the average of five runs. GISS researchers laid out their historical simulations in detail last year in this [0] article." [0] http://pubs.giss.nasa.gov/abs/mi08910y.html http://pubs.giss.nasa.gov/abs/mi08910y.html
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zakk 10y ago
I can accept that in an infographic meant for a wide audience very strong correlation may imply causation. The aim of the infographic is, indeed, praiseworthy. However the missing y axis for the second factor really upsets me! What's the normalization? How has data been rescaled? That can affect __a lot__ how visually correlated two datasets appear.
- tgb 10y ago
  The problem you're thinking of is when you display two different kinds of data on the same axis and so there's two degrees of freedom in how you choose their relative scaling and offset. This makes it very easy to show "obvious" relationships. But the data here all has a very natural sense in which they share the same axis: they're all temperatures of the world, or simulated values thereof. So the choice in scaling and offset makes little to no difference in how the data is perceived.
  - deleted 10y ago
    [deleted]
emodendroket 10y ago
True, but the facts almost seem beside the point to climate change deniers.
joatmon-snoo 10y ago
Maybe it's just me, but I don't think the argument we need is that global warming is happening - yes, there are deniers - I think we need better proof that we're actually fucked if temperatures keep going this way. That's what I see people pushing back against now, not so much the reality that climate change is now happening.
- emodendroket 10y ago
  It's like playing whack-a-mole. You'll never convince them.
  - ikeyany 10y ago
    Who is "them"? There are many smart people who acknowledge that climate change is happening, but also acknowledge that there's no proof that there's a clear urgent action we need to do.
    - emodendroket 10y ago
      Case in point.
      - ikeyany 10y ago
        You didn't actually make a point.
        emodendroket 10y ago
        Global warming isn't real. OK, it's real, but it's not manmade. OK, it's manmade, but there isn't anything we can do about it. OK, there is something we can do about it, but we can't afford it. And so on like this forever.
cjensen 10y ago
That was a terrible use of graphs. The biggest error in this presentation is that author-chose a scale to ensure that the carbon scale was amplified just right to appear to be the same as the temperature scale. In all other cases, he chose small amplifications so that the other factors would appear to be unchanged. The second error in this presentation is that the graphs plainly show that aerosols do have a negative correlation with temperature. The third error is that correlation is not causation. Lack of correlation can prove non-causation, which is what the author was mostly going for. So this is a minor point.
- nom 10y ago
  No it wasn't. All values share the same Y axis and are calculated by simulating climate models. As I understand it, the graphs show how temperature would have evolved if there was only one of the influencing factors present. They also tell you right in the the graph title that some aerosols have the adverse effect and can cool the atmosphere.
  - cjensen 10y ago
    Okay, I am wrong about the Y-Scale between graphs. Nevertheless the author did make the incomparable y-scales between temperature and causes intentionally similar.
- 37 10y ago
  What even is the scale for these comparisons? I don't know how one can measure orbital changes, land use, or solar or volcanic activity in degrees Fahrenheit.
  - scatters 10y ago
    The graph shows predicted global temperature from climate models, with 90% confidence intervals, varying only that factor and keeping other factors unchanged. So the scale is exactly the same unit - Kelvin.
    - 10y ago
kuldeepk 10y ago
Correct me if i'm wrong but this data seem to put deforestation as benign. Wouldn't continued trend of deforestation make effect of GHS emissions worse? More that temperature changes shouldn't we worried about oxygen health of the planet?
- scatters 10y ago
  I think they're just including the albedo effect of deforestation in that graph, not the GHG effect of burning and decaying trees. (Cropland is usually lighter coloured than forest, so reflects more light and heat, giving a cooling effect.) Oxygen is not a worry in any realistic scenario. Crops still photosynthesize, and in any case most of our oxygen comes from marine phytoplankton. CO2 is measured in parts per million (currently around 400ppm), oxygen is around 20%, so CO2 would reach toxic levels (1%) long before any oxygen shortage became a problem.
  - kuldeepk 10y ago
    ha! thanks for clarifying, then I presume they are also not counting the decrease in CO2 absorption due to deforestation. I think that that bit of their section is dangerous by labeling it "is it deforestation? No!". Interpretation for avg readers: Let's continue with it! Taking this from - https://www.nytimes.com/2017/02/24/business/energy-environment/deforestation-brazil-bolivia-south-america.html?_r=0 https://www.nytimes.com/2017/02/24/business/energy-environme... > Forest loss is detrimental to the earth’s climate. The clearing of woodlands and the fires that accompany it generate one-tenth of all global warming emissions, according to the Union of Concerned Scientists, making the loss of forests one of the biggest single contributors to climate change.
Homunculiheaded 10y ago
For a more rigorous, scientific and yet still thoroughly digestible talk I strongly recommend watching Dr. Richard Alley's talk "The Biggest Control Knob: Carbon Dioxide in Earth's Climate History" [0] As a Bayesian I particularly enjoy Alley's running theme that: while there certainly could be alternative explanations for what is happening, we simply cannot find anything that explains the data better than CO2. I see many skeptics pointing out tiny holes in the main AGW hypotheses, but the real Bayesian test is "how much better does one hypothesis explain the observed data than then other?". When you put all the pieces of the atmospheric CO2 argument together it seem to explain what we're observing dramatically better than a thousand "...but what about?" that don't fit together into a coherent counter hypothesis. As an example: Suppose I come home and see my front window broken, my door open and my laptop missing. I assume I have been robbed based on this evidence. You could say "but couldn't the window have been broken by some kid throwing rocks?", "maybe you left the door unlocked and the wind blew it open", "are you absolutely sure you didn't leave your laptop at work?" While individually each of these counter hypotheses may explain a single event just as well, together they don't work: P(window broke, door open, laptop missing | robbed) x P(robbed) >> P(window broke, door open, laptop missing | neighbor threw rock, left door unlocked and left laptop at work) x P(neighbor threw rock & left door unlocked & left laptop at work). [0] https://www.youtube.com/watch?v=RffPSrRpq_g https://www.youtube.com/watch?v=RffPSrRpq_g edit: forgot to add my priors in that last section
- ABCLAW 10y ago
  Thank you for the link. This is a fantastic lecture that presents a very accessible synthesis of geologic and atmospheric science. Starts off a bit slow, but I suggest sticking with it. It addresses a number of the arguments presented in this thread.
  - graycat 10y ago
    I just watched it: It has a lot of interesting stuff on time scales of some millions or billions of years. Yup, in particular, there have been some huge swings in temperature and CO2 concentrations and big effects in weathering rocks, the pH of the oceans, what plants have to do differently in their breathing in response to big CO2 concentration changes, etc. He wants to claim "The Biggest Control Knob: Carbon Dioxide in Earth's Climate History". It does appear that he argued that CO2 is a big indicator of temperature changes. He brings in some surprising ideas that with big changes in temperature from whatever cause, CO2 turns out to be nearly necessarily an indicator. Okay. But, I'm not seeing that his interesting stuff says that CO2 is a control. He discusses two big causes of big temperature changes, and neither is CO2: His first cause is that some many millions of years ago, the sun gave the Earth about 30% less solar energy because the sun was cooler because it was burning more hydrogen, thus, converting it to helium and later got warmer because it had more helium. He does confess that we have poor data on how much cooler the sun was. But he goes on to say that it was clear that then the Earth had liquid water, and for this it needed to have the greenhouse effect of CO2 to keep the water from freezing. So, if believe that some many millions (some billions) of years ago the sun was significantly cooler, then maybe a CO2 greenhouse effect kept some of the water from freezing. Other ways to keep the water from freezing? Maybe volcanoes, radioactive decay of rocks, asteroid strikes, dust, water vapor, methane in the atmosphere, maybe more? But, okay, maybe in an extreme situation of a few billion years ago with an Earth atmosphere with a lot of CO2 (didn't yet have plants converting CO2 to O2), maybe also methane and water vapor, maybe clouds of dust, etc. the CO2 did help warm the Earth. But here the control was the cooler sun, not the CO2. His second cause was some effects of the Earth's orbit or some such. So, that effect caused several periods of global cooling that can be seen in the ice core samples going back 800,000 years. He states clearly that CO2 did not cause that cooling, that as he mentioned the orbit did. But then he goes on to explain how with the cooling there got to be more CO2 and, then, some warming he attributes to the extra CO2. But, again, the control was the orbit, not the CO2. His arguments are interesting, but his case is big swings in temperature and CO2 concentrations over millions of years with lots of big effects from the sun, the Earth's orbit, volcanoes, geology (weathering of rocks), pH of the oceans, huge changes in the oceans (e.g., lots of hydrogen sulfide), etc. He's not really talking about some significant effect of Joe's gasoline powered lawnmower on the temperature in NYC in year 2050 thus justifying carbon taxes on Joe's gasoline.
firefoxd 10y ago
It's interesting that we still try to scare people with the effect of global warming by saying: Average World temperature has risen by 1.8 degrees Fahrenheit. This may scientifically be a huge concern. But for the average person? When I open my window the temperature drops by more than 5 degrees and i don't even feel it. However, the first day i went to cairo egypt, i immediately understood the problem of pollution. I smelled it right out of the plane. And for the years that followed I had to deal with the health consequences on a daily basis. Climate change is boring, you still have to argue to convince people. But breathing in that thick grey smog shows you the consequences immediately.
- euyyn 10y ago
  This is a very good point. Once the science is clear and solid, those who want to effect political change based on it still have to do the work of presenting it in a way that makes "common sense" by being relatable. Otherwise it'll never be persuasive enough.
beefman 10y ago
These series are the outputs of models fit to the data, so no surprises. The "confidence intervals" describe the tightness of the fit (if we're lucky), not the uncertainty in a measurement.
37 10y ago
Discussion from 2015: https://news.ycombinator.com/item?id=9771493 https://news.ycombinator.com/item?id=9771493
id122015 10y ago
The sheep. Really. There was a documentary on TV claiming that when sheep digest food they eliminate some substances that make the world warmer and they invented a device to catch that gas they eliminate through their mouths.
- grzm 10y ago
  Cattle as well: http://www.npr.org/sections/thesalt/2014/04/11/301794415/gassy-cows-are-warming-the-planet-and-theyre-here-to-stay http://www.npr.org/sections/thesalt/2014/04/11/301794415/gas... There's even been action to reduce global warming from dairy cattle in California: https://phys.org/news/2016-11-california-dairy-cows-combat-global.html https://phys.org/news/2016-11-california-dairy-cows-combat-g... According to that last article: Livestock are responsible for 14.5 percent of human-induced greenhouse gas emissions, with beef and dairy production accounting for the bulk of it, according to a 2013 United Nations report. To imply that it's only livestock (or only sheep, for that matter), is not accurate.
Faaak 10y ago
If someone hasn't seen it yet, xkcd made a very good representation of global warming, at scale: https://xkcd.com/1732/ https://xkcd.com/1732/
command_codes 10y ago
Regrettably at the moment cannot parse through this entire thread but surely proponents are aware that global temperature seems to have fluctuated within historical record, and not just the Little Ice Age Extending further, we know that paleoclimates could be radically different and have oscillated. I knew this even in elementary school Is Earth's climate changing? Of course; and that is because of course it will. Should we tax ourselves to feel good about it? I think a dubious prospect, in light that climate already changes in absence of anthropogenic activity, therefore there must be certainty; furthermore, a tax won't even help, as massive noncompliant countries such as China industrialize Then there is always curiously left out the consideration, now forgotten depending on your birthyear, that scientists of a recent generation were up in arms about global cooling instead I think there is danger of a curious autism and naivete re: the trustworthiness of certain scientists - remember they are people - coupled with a kind of religious fanaticism
- conistonwater 10y ago
  > Should we tax ourselves to feel good about it? Respectfully, I think you might be entirely missing the point of why people want to do something about climate change. > Then there is always curiously left out the consideration, now forgotten depending on your birthyear, that scientists of a recent generation were up in arms about global cooling instead It is not forgotten, but it is untrue: see for example the discussion in The Myth of the 1970s Global Cooling Scientific Consensus (http://journals.ametsoc.org/doi/pdf/10.1175/2008BAMS2370.1 http://journals.ametsoc.org/doi/pdf/10.1175/2008BAMS2370.1).
  - command_codes 10y ago
    Climate change destroyed civilizations. Any student of history knows this, and that, without even to tease apart the mysterious circumstances of, say the Bronze Age - it is as simple as Greenland getting too cold. The impulse just "to do" something is a religious impulse. Global cooling is an ancillary matter; it doesn't change the point. After all, the globe really will cool sometime in the future
- pg314 10y ago
command_codes 10y ago
Regrettably cannot at the moment parse through this entire thread but surely proponents are aware that global temperature seems to have fluctuated within historical record, and not just the Little Ice Age Extending further, we know that paleoclimates could be radically different and have oscillated Is Earth's climate changing? Of course. Should we tax ourselves to feel good about it? I think a dubious prospect, in light that climate already changes in absence of anthropogenic activity, therefore there must be certainty; furthermore, a tax won't even help, as noncompliant countries such as China industrialize Then there is always curiously left out the consideration, now forgotten depending on your birthyear, that scientists of a recent generation were up in arms about global cooling instead
ChuckMcM 10y ago
A far more interesting question for me is the system response. Let's stipulate, for the purposes of the next bit of discussion, that it a fact that human activity is changing the balance of gases in the atmosphere and causing a net increase in warmth. So the planet is warming up and up and up. Our planet is a system, and by that I mean it has a number of dynamic processes that all run along that are being influenced by other processes. The basis of a climate model is to capture all of those processes and include them in the model so that given changes to a particular part of the system you can predict how the other parts will respond. To Vivek's point, the "best" model would let you take all of the data you can get and put that in for the various modeled parameters at any given time and get back an answer. But we don't have one of those models. For example, none of the IPC's models allow for an ice age even though we know we have had ice ages. I haven't looked recently but the literature on what might be the factor behind the cycle of warm and cold cycles is still unknown. Second, we have ice cores which suggest that with much lower CO2 levels the planet was warmer than it is now, and which much higher CO2 levels it was cooler than it is now. As a result, the research we've done, the models we've produced, are accurate for a small set of conditions which we have been observing for a very short period of time (even giving credit for the first Sumerian tablets). We also know that there have been periods of time where this planet was unable to support human life. Not that we hadn't evolved or emerged yet, completely unable to exist. Once, like Mars today, our atmosphere was nearly all CO2! And the really important bit, we don't know how to control climate change, it is pretty clear we can dump a lot of CO2 into the air and affect it but we don't have the necessary understanding, and models, needed to drive it in one direction or another. As a result, if we cut our carbon foot print to zero, we are still 100% at risk of extinction from climate change. Only then it will be due to one of the other things that we're not in control of doing it instead of us. There isn't a climate scientist out there who has ever gone on the record to say "do this and it will 'end' global warming." They can't because we don't know enough to know what would drive the climate to stay in it's current state forever.
- acqq 10y ago
  > As a result, if we cut our carbon foot print to zero, we are still 100% at risk of extinction from climate change. No, not in the comparable time frames. Please do see that https://xkcd.com/1732/ https://xkcd.com/1732/ if you haven't. > we don't have the necessary understanding, and models, needed to drive it in one direction or another. No. We know that we drive it to very fast warming with filling the atmosphere with CO2. https://www.youtube.com/watch?v=ujkcTZZlikg&t=4m24s https://www.youtube.com/watch?v=ujkcTZZlikg&t=4m24s > we don't have one of those models. We do. See above. See the bloomberg article to which we comment -- the effects are confirmed with the models. > I haven't looked recently but the literature on what might be the factor behind the cycle of warm and cold cycles is still unknown. Or maybe you haven't looked carefully enough? The cycles are, unsurprisingly, connected to how much the Sun warms the Earth (that's not a constant): https://www.youtube.com/watch?v=ujkcTZZlikg&t=18m05s https://www.youtube.com/watch?v=ujkcTZZlikg&t=18m05s Milankovitch was aware and slowly calculated the periods at the times when the computers didn't exist (he started some 100 years ago) knowing the exact astronomical behavior of the Earth. Now we can do it much easier. https://en.wikipedia.org/wiki/Milankovitch_cycles https://en.wikipedia.org/wiki/Milankovitch_cycles We have less exact models the further we move in the past, but that's irrelevant. It's like complaining that you don't know who was the wife of Socrates' second uncle, and that therefore we can't talk about the son-in-law of Donald Trump. You know less the more you move in the past, but it's not the argument to ignore what's going up now. > there isn't a climate scientist out there who has ever gone on the record to say "do this and it will 'end' global warming." It's completely the opposite. All the IPCC messages of all the world scientists were always "cut the CO2 emissions if you don't want huge increase in the average Earth temperature so fast like it never happened in the history of Earth, you are not going to like the effects." If anything IPCC reports are made to sound less "alarming" than they should be, given what we know. The most recent: http://www.ipcc.ch/report/ar5/wg3/ http://www.ipcc.ch/report/ar5/wg3/ Specifically: http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/WGIIIAR5_SPM_TS_Volume.pdf http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/WGIIIAR5_SP...
linkregister 10y ago
(2015)
jordigh 10y ago
Anyone in Montréal or Edinburgh who's interested in working on a company that does greenhouse gas and land use assessments, this company is hiring for Django and ReactJS: http://stackoverflow.com/jobs/companies/ecometrica http://stackoverflow.com/jobs/companies/ecometrica
christkv 10y ago
Here is something I've always wondered about. Coal, oil and gas is originally organic matter. By the creation of coal, oil and over millions of years the overall level of free carbon was reduced and probably lower temperatures. However by starting to burn oil, coal and gas we are increasing the freed carbon again back to some earlier historic level. I seems we would just be setting us up to a return to a even lusher greener planet like during the Jurassic period. Of course it would be a disaster for our current civilization but it does not seem world-ending.
- graeme 10y ago
  >Of course it would be a disaster for our current civilization but it does not seem world-ending. That's the point. We probably can't destroy all life on earth. But we can destroy the conditions that created our civilization and sustained it.
- euyyn 10y ago
  I mean, not even the Oxygen Holocaust was world-ending. Not sure that's the bar we want to measure our actions against :)
- akvadrako 10y ago
  This really needs to be given more attention, because the natural alternative to global warming is probably significant global cooling. Looking at the long-term trend we've been in a geological ice age for the past 2M years, due to the poles being permanently frozen. During this ice age we've had a few interglacial periods lasting about 10K years, but the current one is still dragging on. Either we are due for a return to glacialization or we've broken the trend; human caused warming is a likely factor.
- stillsut 10y ago
  The Anabaena Event is something you'd be interested in. Also, the decrease in atmospheric CO2 below 200ppm would be catastrophic to almost all photosynthesizing crop-type plants. For reference the natural cycle has had us oscillating between 220 and 280 ppm for the past 4M years.
otto_ortega 10y ago
I just want to say one thing: What a beautiful interactive chart!
shmerl 10y ago
They should've used Celsius in the article.
sebringj 10y ago
It is so very pathetic that we have to see these types of diagrams spelling things out so elementary about global warming, now. At the heart of this, I still believe strongly there needs to be some type of mandatory subject, as core as reading and math, about reasoning and classifying types of information, taught in grade school, given the recent turn of events in the American election. If kids were shown the different ways information is generated and how the quality of the information directly correlates to the ways in which it was obtained, they would have some sort of toolset to understand the world to the point of it eventually being culturally unacceptable to be ardantly ignorant. This would radically dismantle strongly held beliefs of the past that are baseless in reason, bringing forth a brighter future. Of course this would be completely opposed and blocked by organizations that thrive on disinformation till their dying breath.
woodandsteel 10y ago
What the global climate change skeptics won't acknowledge is that, in practical, political, and economic terms, they have already lost the argument. What the skeptics want, or at least most of them, is for the human race to stay on fossil fuels forever. Perhaps 20 years ago they might have persuaded the world that this is the right path. But instead the world went down the path of developing renewable energy, and it is now getting so cheap that it is going to replace fossil fuels over the coming decades. And there is nothing the skeptics can do to stop this from happening.
heyworld 10y ago
"Humans have cut, plowed, and paved more than half the Earth's land surface." Calling bullshit on that claim.

180 points by awjr 10y ago

I like to remind people that Joseph Fourier figured out the Greenhouse effect about 200 years ago, well before there was any good indication we were turning the Earth into Venus

Spooky23 10y ago

I was actually at a political event yesterday where some derp derp conservative was going on about how this stuff is all hoax. Meanwhile, we are in upstate NY, in late February, sitting outside enjoying the 80 degree weather which is warmer than Los Angeles.

grzm 10y ago
I understand where you're coming from. That said, including "some derp derp conservative" in your comment makes it easy for anyone who disagrees with you to dismiss anything else you say as partisan. Similarly, the issue is climate change. Looking at a single day, no matter how extreme, is an anecdote. The debate around the science supporting climate change is difficult enough without pointing to anecdotes in support of the theory. Given you chose to comment on this, I believe climate change is something you care about. One of the ways to be more effective in getting something done is to not leave yourself open to easy dismissal by those who disagree with you.
SamReidHughes 10y ago
Los Angeles is right by the ocean so it has much less temperature variation.
akvadrako 10y ago
You mean because it's 80° instead of 79° global warming must be real?
- Spooky23 10y ago
  Meaning that in the nearly 40 years that I have been on earth, most of which within a 100 mile radius of where I live now, the average temperature at this time of year is around 20F. I never recall a day that was that warm in February, in Albany, NY.

vivekd 10y ago

What makes me mad about these kinds of data based climate change arguments is that they don't engage with the data in an honest way. The huge problem is 1880 was one of the coldest years in history. That cold period was caused by volcanism, several volcanos erupted causing a cold period that lasted from the 1600s to the late 1800s. This period is known as the little ice age. The worst of this period was in 1816 which was known as the "year without a summer." The Earth has gradually been warming since then. https://en.wikipedia.org/wiki/Little_Ice_Age https://en.wikipedia.org/wiki/Little_Ice_Age So when we track from the little ice age to now and say the world as gotten warmer and present this as unusual or surprising findings, you know that they are not being honest with you. I'm not saying that climate change isn't happening, I'm not saying it isn't man made. All I'm pointing out here is that proponents of global warming aren't engaging with the facts in an honest and forthright way.

corradio 10y ago
You're right. However, it's hard to argue with the speed at which this warming occurs. It's never seen before if you look at all the records we have. That's what's worrying.
- karl11 10y ago
  The sample size of our records is incredibly small when stacked against the history of the earth and all the records we're missing.
  - euyyn 10y ago
    What makes you think so? There's plenty of ways to indirectly know past temperatures, even if there wasn't a human writing it down.
    - Udik 10y ago
      Not with the accuracy and resolution of the data we have since last century. When you compare the current time series with the reconstructed ones from the past, you're comparing a day by day thermometric reading with the assembled averages of multiple, very noisy and extremely low frequency samples. Very tricky to say from those what might have been the actual speed of change in the past.

ams6110 10y ago

What is magical about 1880-1910 as the implied "normal" average baseline? Why not 1600? 1400? 2500 BC?

corradio 10y ago
You shouldn't care about what reference is taken. The point is that compared to any reference, the curve is increasing.
- sageikosa 10y ago
  800 million years ago is my reference point
- karl11 10y ago
  That doesn't make sense. What if the reference is 5 minutes ago?
  - euyyn 10y ago
    If we're talking about annual average temperature, what doesn't make sense is thinking about 5min ago.
  - corradio 10y ago
    Take the reference that is 5min ago, call it T0. You will still observe that temperatures (i.e the sequence of measured temperatures minus T0) are increasing. Changing the reference changes the y-scale of a graph, but does not change the derivative (the speed at which it changes, i.e. increases or decreases).
    - joatmon-snoo 10y ago
      Did you look at the graph? The local derivative is most definitely not indicative of a general trend. For comparison, I throw a ball down at the ground, and for the first 0.1 seconds it's moving down - can I conclude that the ball is going to keep moving down, even when it hits the ground? That's your logic.

lend000 10y ago

Can someone explain why aerosols are decreasing in their graph? A definition of what they consider an aerosol would be a good start, which I didn't see on there. Apparently the term can cover a large number of natural and unnatural compositions of matter: https://en.wikipedia.org/wiki/Aerosol https://en.wikipedia.org/wiki/Aerosol

emodendroket 10y ago
Weren't they regulated after acid rain and ozone layer concerns in the 90s?
- mirimir 10y ago
  Yes, SOX were regulated to mitigate acid rain, and particulates for health reasons. But then China starting burning massive amounts of dirty coal, with virtually no emissions controls. And that reduced global warming.
TazeTSchnitzel 10y ago
Aerosols aren't decreasing, the line shows the effect on the average temperature. Aerosols have a negative effect.
stale2002 10y ago
Aerosols are not decreasing. They are increasing. But increasing amounts of Aerosols causes Global Cooling, not warming, which is why the graph angles downwards.
mirimir 10y ago
Aerosols are not decreasing, but rather increasing. They reduce insolation, both directly and by increasing cloudiness. So they counteract greenhouse forcing. The main anthropogenic aerosols are sulfur oxides and particulates from fuel combustion. And potentially, crap from nuclear explosions ("nuclear winter"). Main natural sources are deserts, sea salt and volcanoes. So anyway, if China manages to reduce its aerosol emissions faster than its CO2 emissions, mean global temperature will likely increase even faster.

rectang 10y ago

> The only real question is: What are we going to do about it? Zilch, so long as politicians corrupted by the fossil fuel industry are in power. "It is difficult to get a man to understand something, when his salary depends upon his not understanding it!" -- Upton Sinclair

curtis 10y ago
There is a substantial percentage of the electorate who are ideologically opposed to the very notion of climate change. They're ideologically opposed to conservation, they're ideologically opposed to large scale government interventions for any purpose, they are specifically opposed to any sort of tax so a carbon tax is right out, and they are even ideologically opposed not simply to environmentalism, but to (it seems) environmentalists. Now in this environment, all the fossil fuel industry has to do is encourage that section of the electorate to continue to believe things they already believe. The fundamental problem here is (in my own humble opinion) the large number of voters with ideological blinders on, and that's the problem that's ultimately got to be addressed.
- bunderbunder 10y ago
  Calling it ideological blinders is an easy dismissal, and also one that, IMO, isn't terribly useful. I think what you're really dealing with is cognitive dissonance: Accepting what the science says on climate probably means accepting that you yourself could be be contributing to a situation that could be a serious problem for your children and grandchildren. It probably also implies making some lifestyle modifications that may feel severe, such as cutting way back on high-carbon activities like driving and meat consumption. In a situation like that, which option is less daunting: Accepting the consensus opinion of climate scientists and all the worry that implies, or going with the denialists so that you can get back to business as usual?
  - curtis 10y ago
    > Calling it ideological blinders is an easy dismissal, and also one that, IMO, isn't terribly useful. No it's not an easy dismissal. It's the exact opposite of an easy dismissal. It's a really hard problem.

patricklorio 10y ago

That was really cool but it bothers me that they don't show the y axis for the effecting factors. Does anyone know if it's normalized or completely arbitrary?

svantana 10y ago
As I understood it they all showed (modeled) contribution to temperature change at the same scale as the data graph, that's why they could all sum up at the end.
imh 10y ago
>The colored temperature lines are the modeled estimates that each climate factor contributes to the overall temperature. There's only one y axis, and it's degrees F for both lines.
nom 10y ago
They share the same Y axis, the values are taken from simulations. From the article: "The colored temperature lines are the modeled estimates that each climate factor contributes to the overall temperature. Each factor was simulated five times, with different initial conditions; each slide here shows the average of five runs. GISS researchers laid out their historical simulations in detail last year in this [0] article." [0] http://pubs.giss.nasa.gov/abs/mi08910y.html http://pubs.giss.nasa.gov/abs/mi08910y.html

deleted 10y ago

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zakk 10y ago

I can accept that in an infographic meant for a wide audience very strong correlation may imply causation. The aim of the infographic is, indeed, praiseworthy. However the missing y axis for the second factor really upsets me! What's the normalization? How has data been rescaled? That can affect __a lot__ how visually correlated two datasets appear.

tgb 10y ago
The problem you're thinking of is when you display two different kinds of data on the same axis and so there's two degrees of freedom in how you choose their relative scaling and offset. This makes it very easy to show "obvious" relationships. But the data here all has a very natural sense in which they share the same axis: they're all temperatures of the world, or simulated values thereof. So the choice in scaling and offset makes little to no difference in how the data is perceived.
- deleted 10y ago
  [deleted]

emodendroket 10y ago

True, but the facts almost seem beside the point to climate change deniers.

joatmon-snoo 10y ago

Maybe it's just me, but I don't think the argument we need is that global warming is happening - yes, there are deniers - I think we need better proof that we're actually fucked if temperatures keep going this way. That's what I see people pushing back against now, not so much the reality that climate change is now happening.

emodendroket 10y ago
It's like playing whack-a-mole. You'll never convince them.
- ikeyany 10y ago
  Who is "them"? There are many smart people who acknowledge that climate change is happening, but also acknowledge that there's no proof that there's a clear urgent action we need to do.
  - emodendroket 10y ago
    Case in point.
    - ikeyany 10y ago
      You didn't actually make a point.
      - emodendroket 10y ago
        Global warming isn't real. OK, it's real, but it's not manmade. OK, it's manmade, but there isn't anything we can do about it. OK, there is something we can do about it, but we can't afford it. And so on like this forever.

cjensen 10y ago

That was a terrible use of graphs. The biggest error in this presentation is that author-chose a scale to ensure that the carbon scale was amplified just right to appear to be the same as the temperature scale. In all other cases, he chose small amplifications so that the other factors would appear to be unchanged. The second error in this presentation is that the graphs plainly show that aerosols do have a negative correlation with temperature. The third error is that correlation is not causation. Lack of correlation can prove non-causation, which is what the author was mostly going for. So this is a minor point.

nom 10y ago
No it wasn't. All values share the same Y axis and are calculated by simulating climate models. As I understand it, the graphs show how temperature would have evolved if there was only one of the influencing factors present. They also tell you right in the the graph title that some aerosols have the adverse effect and can cool the atmosphere.
- cjensen 10y ago
  Okay, I am wrong about the Y-Scale between graphs. Nevertheless the author did make the incomparable y-scales between temperature and causes intentionally similar.
37 10y ago
What even is the scale for these comparisons? I don't know how one can measure orbital changes, land use, or solar or volcanic activity in degrees Fahrenheit.
- scatters 10y ago
  The graph shows predicted global temperature from climate models, with 90% confidence intervals, varying only that factor and keeping other factors unchanged. So the scale is exactly the same unit - Kelvin.
  - 10y ago

kuldeepk 10y ago

Correct me if i'm wrong but this data seem to put deforestation as benign. Wouldn't continued trend of deforestation make effect of GHS emissions worse? More that temperature changes shouldn't we worried about oxygen health of the planet?

scatters 10y ago
I think they're just including the albedo effect of deforestation in that graph, not the GHG effect of burning and decaying trees. (Cropland is usually lighter coloured than forest, so reflects more light and heat, giving a cooling effect.) Oxygen is not a worry in any realistic scenario. Crops still photosynthesize, and in any case most of our oxygen comes from marine phytoplankton. CO2 is measured in parts per million (currently around 400ppm), oxygen is around 20%, so CO2 would reach toxic levels (1%) long before any oxygen shortage became a problem.
- kuldeepk 10y ago
  ha! thanks for clarifying, then I presume they are also not counting the decrease in CO2 absorption due to deforestation. I think that that bit of their section is dangerous by labeling it "is it deforestation? No!". Interpretation for avg readers: Let's continue with it! Taking this from - https://www.nytimes.com/2017/02/24/business/energy-environment/deforestation-brazil-bolivia-south-america.html?_r=0 https://www.nytimes.com/2017/02/24/business/energy-environme... > Forest loss is detrimental to the earth’s climate. The clearing of woodlands and the fires that accompany it generate one-tenth of all global warming emissions, according to the Union of Concerned Scientists, making the loss of forests one of the biggest single contributors to climate change.

Homunculiheaded 10y ago

For a more rigorous, scientific and yet still thoroughly digestible talk I strongly recommend watching Dr. Richard Alley's talk "The Biggest Control Knob: Carbon Dioxide in Earth's Climate History" [0] As a Bayesian I particularly enjoy Alley's running theme that: while there certainly could be alternative explanations for what is happening, we simply cannot find anything that explains the data better than CO2. I see many skeptics pointing out tiny holes in the main AGW hypotheses, but the real Bayesian test is "how much better does one hypothesis explain the observed data than then other?". When you put all the pieces of the atmospheric CO2 argument together it seem to explain what we're observing dramatically better than a thousand "...but what about?" that don't fit together into a coherent counter hypothesis. As an example: Suppose I come home and see my front window broken, my door open and my laptop missing. I assume I have been robbed based on this evidence. You could say "but couldn't the window have been broken by some kid throwing rocks?", "maybe you left the door unlocked and the wind blew it open", "are you absolutely sure you didn't leave your laptop at work?" While individually each of these counter hypotheses may explain a single event just as well, together they don't work: P(window broke, door open, laptop missing | robbed) x P(robbed) >> P(window broke, door open, laptop missing | neighbor threw rock, left door unlocked and left laptop at work) x P(neighbor threw rock & left door unlocked & left laptop at work). [0] https://www.youtube.com/watch?v=RffPSrRpq_g https://www.youtube.com/watch?v=RffPSrRpq_g edit: forgot to add my priors in that last section

ABCLAW 10y ago
Thank you for the link. This is a fantastic lecture that presents a very accessible synthesis of geologic and atmospheric science. Starts off a bit slow, but I suggest sticking with it. It addresses a number of the arguments presented in this thread.
- graycat 10y ago
  I just watched it: It has a lot of interesting stuff on time scales of some millions or billions of years. Yup, in particular, there have been some huge swings in temperature and CO2 concentrations and big effects in weathering rocks, the pH of the oceans, what plants have to do differently in their breathing in response to big CO2 concentration changes, etc. He wants to claim "The Biggest Control Knob: Carbon Dioxide in Earth's Climate History". It does appear that he argued that CO2 is a big indicator of temperature changes. He brings in some surprising ideas that with big changes in temperature from whatever cause, CO2 turns out to be nearly necessarily an indicator. Okay. But, I'm not seeing that his interesting stuff says that CO2 is a control. He discusses two big causes of big temperature changes, and neither is CO2: His first cause is that some many millions of years ago, the sun gave the Earth about 30% less solar energy because the sun was cooler because it was burning more hydrogen, thus, converting it to helium and later got warmer because it had more helium. He does confess that we have poor data on how much cooler the sun was. But he goes on to say that it was clear that then the Earth had liquid water, and for this it needed to have the greenhouse effect of CO2 to keep the water from freezing. So, if believe that some many millions (some billions) of years ago the sun was significantly cooler, then maybe a CO2 greenhouse effect kept some of the water from freezing. Other ways to keep the water from freezing? Maybe volcanoes, radioactive decay of rocks, asteroid strikes, dust, water vapor, methane in the atmosphere, maybe more? But, okay, maybe in an extreme situation of a few billion years ago with an Earth atmosphere with a lot of CO2 (didn't yet have plants converting CO2 to O2), maybe also methane and water vapor, maybe clouds of dust, etc. the CO2 did help warm the Earth. But here the control was the cooler sun, not the CO2. His second cause was some effects of the Earth's orbit or some such. So, that effect caused several periods of global cooling that can be seen in the ice core samples going back 800,000 years. He states clearly that CO2 did not cause that cooling, that as he mentioned the orbit did. But then he goes on to explain how with the cooling there got to be more CO2 and, then, some warming he attributes to the extra CO2. But, again, the control was the orbit, not the CO2. His arguments are interesting, but his case is big swings in temperature and CO2 concentrations over millions of years with lots of big effects from the sun, the Earth's orbit, volcanoes, geology (weathering of rocks), pH of the oceans, huge changes in the oceans (e.g., lots of hydrogen sulfide), etc. He's not really talking about some significant effect of Joe's gasoline powered lawnmower on the temperature in NYC in year 2050 thus justifying carbon taxes on Joe's gasoline.

firefoxd 10y ago

It's interesting that we still try to scare people with the effect of global warming by saying: Average World temperature has risen by 1.8 degrees Fahrenheit. This may scientifically be a huge concern. But for the average person? When I open my window the temperature drops by more than 5 degrees and i don't even feel it. However, the first day i went to cairo egypt, i immediately understood the problem of pollution. I smelled it right out of the plane. And for the years that followed I had to deal with the health consequences on a daily basis. Climate change is boring, you still have to argue to convince people. But breathing in that thick grey smog shows you the consequences immediately.

euyyn 10y ago
This is a very good point. Once the science is clear and solid, those who want to effect political change based on it still have to do the work of presenting it in a way that makes "common sense" by being relatable. Otherwise it'll never be persuasive enough.

beefman 10y ago

These series are the outputs of models fit to the data, so no surprises. The "confidence intervals" describe the tightness of the fit (if we're lucky), not the uncertainty in a measurement.

37 10y ago

Discussion from 2015: https://news.ycombinator.com/item?id=9771493 https://news.ycombinator.com/item?id=9771493

id122015 10y ago

The sheep. Really. There was a documentary on TV claiming that when sheep digest food they eliminate some substances that make the world warmer and they invented a device to catch that gas they eliminate through their mouths.

grzm 10y ago
Cattle as well: http://www.npr.org/sections/thesalt/2014/04/11/301794415/gassy-cows-are-warming-the-planet-and-theyre-here-to-stay http://www.npr.org/sections/thesalt/2014/04/11/301794415/gas... There's even been action to reduce global warming from dairy cattle in California: https://phys.org/news/2016-11-california-dairy-cows-combat-global.html https://phys.org/news/2016-11-california-dairy-cows-combat-g... According to that last article: Livestock are responsible for 14.5 percent of human-induced greenhouse gas emissions, with beef and dairy production accounting for the bulk of it, according to a 2013 United Nations report. To imply that it's only livestock (or only sheep, for that matter), is not accurate.

Faaak 10y ago

If someone hasn't seen it yet, xkcd made a very good representation of global warming, at scale: https://xkcd.com/1732/ https://xkcd.com/1732/

command_codes 10y ago

Regrettably at the moment cannot parse through this entire thread but surely proponents are aware that global temperature seems to have fluctuated within historical record, and not just the Little Ice Age Extending further, we know that paleoclimates could be radically different and have oscillated. I knew this even in elementary school Is Earth's climate changing? Of course; and that is because of course it will. Should we tax ourselves to feel good about it? I think a dubious prospect, in light that climate already changes in absence of anthropogenic activity, therefore there must be certainty; furthermore, a tax won't even help, as massive noncompliant countries such as China industrialize Then there is always curiously left out the consideration, now forgotten depending on your birthyear, that scientists of a recent generation were up in arms about global cooling instead I think there is danger of a curious autism and naivete re: the trustworthiness of certain scientists - remember they are people - coupled with a kind of religious fanaticism

conistonwater 10y ago
> Should we tax ourselves to feel good about it? Respectfully, I think you might be entirely missing the point of why people want to do something about climate change. > Then there is always curiously left out the consideration, now forgotten depending on your birthyear, that scientists of a recent generation were up in arms about global cooling instead It is not forgotten, but it is untrue: see for example the discussion in The Myth of the 1970s Global Cooling Scientific Consensus (http://journals.ametsoc.org/doi/pdf/10.1175/2008BAMS2370.1 http://journals.ametsoc.org/doi/pdf/10.1175/2008BAMS2370.1).
- command_codes 10y ago
  Climate change destroyed civilizations. Any student of history knows this, and that, without even to tease apart the mysterious circumstances of, say the Bronze Age - it is as simple as Greenland getting too cold. The impulse just "to do" something is a religious impulse. Global cooling is an ancillary matter; it doesn't change the point. After all, the globe really will cool sometime in the future
pg314 10y ago

command_codes 10y ago

Regrettably cannot at the moment parse through this entire thread but surely proponents are aware that global temperature seems to have fluctuated within historical record, and not just the Little Ice Age Extending further, we know that paleoclimates could be radically different and have oscillated Is Earth's climate changing? Of course. Should we tax ourselves to feel good about it? I think a dubious prospect, in light that climate already changes in absence of anthropogenic activity, therefore there must be certainty; furthermore, a tax won't even help, as noncompliant countries such as China industrialize Then there is always curiously left out the consideration, now forgotten depending on your birthyear, that scientists of a recent generation were up in arms about global cooling instead

ChuckMcM 10y ago

A far more interesting question for me is the system response. Let's stipulate, for the purposes of the next bit of discussion, that it a fact that human activity is changing the balance of gases in the atmosphere and causing a net increase in warmth. So the planet is warming up and up and up. Our planet is a system, and by that I mean it has a number of dynamic processes that all run along that are being influenced by other processes. The basis of a climate model is to capture all of those processes and include them in the model so that given changes to a particular part of the system you can predict how the other parts will respond. To Vivek's point, the "best" model would let you take all of the data you can get and put that in for the various modeled parameters at any given time and get back an answer. But we don't have one of those models. For example, none of the IPC's models allow for an ice age even though we know we have had ice ages. I haven't looked recently but the literature on what might be the factor behind the cycle of warm and cold cycles is still unknown. Second, we have ice cores which suggest that with much lower CO2 levels the planet was warmer than it is now, and which much higher CO2 levels it was cooler than it is now. As a result, the research we've done, the models we've produced, are accurate for a small set of conditions which we have been observing for a very short period of time (even giving credit for the first Sumerian tablets). We also know that there have been periods of time where this planet was unable to support human life. Not that we hadn't evolved or emerged yet, completely unable to exist. Once, like Mars today, our atmosphere was nearly all CO2! And the really important bit, we don't know how to control climate change, it is pretty clear we can dump a lot of CO2 into the air and affect it but we don't have the necessary understanding, and models, needed to drive it in one direction or another. As a result, if we cut our carbon foot print to zero, we are still 100% at risk of extinction from climate change. Only then it will be due to one of the other things that we're not in control of doing it instead of us. There isn't a climate scientist out there who has ever gone on the record to say "do this and it will 'end' global warming." They can't because we don't know enough to know what would drive the climate to stay in it's current state forever.

acqq 10y ago
> As a result, if we cut our carbon foot print to zero, we are still 100% at risk of extinction from climate change. No, not in the comparable time frames. Please do see that https://xkcd.com/1732/ https://xkcd.com/1732/ if you haven't. > we don't have the necessary understanding, and models, needed to drive it in one direction or another. No. We know that we drive it to very fast warming with filling the atmosphere with CO2. https://www.youtube.com/watch?v=ujkcTZZlikg&t=4m24s https://www.youtube.com/watch?v=ujkcTZZlikg&t=4m24s > we don't have one of those models. We do. See above. See the bloomberg article to which we comment -- the effects are confirmed with the models. > I haven't looked recently but the literature on what might be the factor behind the cycle of warm and cold cycles is still unknown. Or maybe you haven't looked carefully enough? The cycles are, unsurprisingly, connected to how much the Sun warms the Earth (that's not a constant): https://www.youtube.com/watch?v=ujkcTZZlikg&t=18m05s https://www.youtube.com/watch?v=ujkcTZZlikg&t=18m05s Milankovitch was aware and slowly calculated the periods at the times when the computers didn't exist (he started some 100 years ago) knowing the exact astronomical behavior of the Earth. Now we can do it much easier. https://en.wikipedia.org/wiki/Milankovitch_cycles https://en.wikipedia.org/wiki/Milankovitch_cycles We have less exact models the further we move in the past, but that's irrelevant. It's like complaining that you don't know who was the wife of Socrates' second uncle, and that therefore we can't talk about the son-in-law of Donald Trump. You know less the more you move in the past, but it's not the argument to ignore what's going up now. > there isn't a climate scientist out there who has ever gone on the record to say "do this and it will 'end' global warming." It's completely the opposite. All the IPCC messages of all the world scientists were always "cut the CO2 emissions if you don't want huge increase in the average Earth temperature so fast like it never happened in the history of Earth, you are not going to like the effects." If anything IPCC reports are made to sound less "alarming" than they should be, given what we know. The most recent: http://www.ipcc.ch/report/ar5/wg3/ http://www.ipcc.ch/report/ar5/wg3/ Specifically: http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/WGIIIAR5_SPM_TS_Volume.pdf http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/WGIIIAR5_SP...

linkregister 10y ago

(2015)

jordigh 10y ago

Anyone in Montréal or Edinburgh who's interested in working on a company that does greenhouse gas and land use assessments, this company is hiring for Django and ReactJS: http://stackoverflow.com/jobs/companies/ecometrica http://stackoverflow.com/jobs/companies/ecometrica

christkv 10y ago

Here is something I've always wondered about. Coal, oil and gas is originally organic matter. By the creation of coal, oil and over millions of years the overall level of free carbon was reduced and probably lower temperatures. However by starting to burn oil, coal and gas we are increasing the freed carbon again back to some earlier historic level. I seems we would just be setting us up to a return to a even lusher greener planet like during the Jurassic period. Of course it would be a disaster for our current civilization but it does not seem world-ending.

graeme 10y ago
>Of course it would be a disaster for our current civilization but it does not seem world-ending. That's the point. We probably can't destroy all life on earth. But we can destroy the conditions that created our civilization and sustained it.
euyyn 10y ago
I mean, not even the Oxygen Holocaust was world-ending. Not sure that's the bar we want to measure our actions against :)
akvadrako 10y ago
This really needs to be given more attention, because the natural alternative to global warming is probably significant global cooling. Looking at the long-term trend we've been in a geological ice age for the past 2M years, due to the poles being permanently frozen. During this ice age we've had a few interglacial periods lasting about 10K years, but the current one is still dragging on. Either we are due for a return to glacialization or we've broken the trend; human caused warming is a likely factor.
stillsut 10y ago
The Anabaena Event is something you'd be interested in. Also, the decrease in atmospheric CO2 below 200ppm would be catastrophic to almost all photosynthesizing crop-type plants. For reference the natural cycle has had us oscillating between 220 and 280 ppm for the past 4M years.

otto_ortega 10y ago

I just want to say one thing: What a beautiful interactive chart!

shmerl 10y ago

They should've used Celsius in the article.

sebringj 10y ago

It is so very pathetic that we have to see these types of diagrams spelling things out so elementary about global warming, now. At the heart of this, I still believe strongly there needs to be some type of mandatory subject, as core as reading and math, about reasoning and classifying types of information, taught in grade school, given the recent turn of events in the American election. If kids were shown the different ways information is generated and how the quality of the information directly correlates to the ways in which it was obtained, they would have some sort of toolset to understand the world to the point of it eventually being culturally unacceptable to be ardantly ignorant. This would radically dismantle strongly held beliefs of the past that are baseless in reason, bringing forth a brighter future. Of course this would be completely opposed and blocked by organizations that thrive on disinformation till their dying breath.

woodandsteel 10y ago

What the global climate change skeptics won't acknowledge is that, in practical, political, and economic terms, they have already lost the argument. What the skeptics want, or at least most of them, is for the human race to stay on fossil fuels forever. Perhaps 20 years ago they might have persuaded the world that this is the right path. But instead the world went down the path of developing renewable energy, and it is now getting so cheap that it is going to replace fossil fuels over the coming decades. And there is nothing the skeptics can do to stop this from happening.

heyworld 10y ago

"Humans have cut, plowed, and paved more than half the Earth's land surface." Calling bullshit on that claim.