[HN Gopher] Climate change and the 1991-2020 U.S. Climate Normals ___________________________________________________________________ Climate change and the 1991-2020 U.S. Climate Normals Author : ctk_brian Score : 102 points Date : 2021-04-26 17:02 UTC (5 hours ago) (HTM) web link (climate.gov) (TXT) w3m dump (climate.gov) | Hammershaft wrote: | Interesting... judging from this pic the 1960s seemed to be | unusually cool. I wonder why. | | https://www.climate.gov/sites/default/files/30yrNormal_Temp_... | Diederich wrote: | Only slightly educated guess forthcoming. | | Air pollution was pretty bad in the United States from the | 1950s through the late 1980s, and we know that | https://en.wikipedia.org/wiki/Global_dimming has kept | temperatures down a bit. | | So basically from the early 1970s through the 1990s in the | United States, the amount of 'global dimming' type air | pollution decreased tremendously, because of a number of | factors, including all sorts of clean air mandates and | regulation. | kossTKR wrote: | The dimming factor seems a bit frightening. | | I don't know how sound the theory is, but i remember | listening to the climate podcast Radio Ecoshock where a | scientist talked about aerosols in general and that there | could be a negative feedback loop that would disappear if we | stop polluting heavily, ironically then raising temperatures | significantly - this could mean that an extremely agressive | decrease towards 2030 could increase temperature weirdly | enough. | | The effect was seen over the US after 9/11 as far as i | remember. | | A damned if you do and don't situation. | ip26 wrote: | Well, we can always spray sulphur aerosols in the | stratosphere without all the CO2 and acid rain. | pedrocr wrote: | > The effect was seen over the US after 9/11 as far as i | remember. | | There was a study that claimed that but there's a second | study that claims general cloud cover was a confounding | factor not controlled for that explains the actual result: | | https://en.wikipedia.org/wiki/Global_dimming#Contrails_and_ | c... | | Even with a full set of airplanes in the air contrails are | a tiny minority of the cloud cover. Seems pretty hard for | them to have any visible impact. Aerosols in general are | another matter all together. Those are all over the | atmosphere and it wouldn't be surprising if they had a | large effect as they accumulate. | kossTKR wrote: | Thanks for the clarification. Always seemed a bit too | quick and neat a causation. | | But as you say the bigger picture is still worrying - and | i am not sure that disregarding cloud formation there | isn't still certain aerosols hanging around changing | things for the worse after heavy air traffic - it's hard | to gauge from the Abstracts of papers i just skimmed, but | something seems to be happening : | https://link.springer.com/article/10.1023/A:1006600107117 | https://www.researchgate.net/publication/279155481_Impact | _of... | kobieyc wrote: | Related to cloud cover: one of the biggest uncertainties | in climate models is how to cater for the albedo effect | also known as cloud feedback. It goes something like | this: | | 1) The most potent greenhouse gas is water vapor (not | CO2) 2) Increased temperatures result in more water vapor | (simple evaporation) 3) Water vapor forms clouds 4) | Clouds are white and reflect incoming solar radiation | | A lot of models have to make big assumptions about the | strength of this negative feedback loop, and the | assumptions have a big impact on the output of the | models. | | https://en.wikipedia.org/wiki/Cloud_feedback | Retric wrote: | Conversely, further increased evaporation > even more | water vapor > increased precipitation > fewer clouds. | | Also, clouds reflect sunlight > less warming, but clouds | reflect IR > less cooling. | | It's a really complex interaction that doesn't have a | clear global maximum as each region has a slightly | different impact and they all interact. Atmosphere dust | is one of the biggest impacts here and dust alone | involves a lot of non linear feedback loops. | btilly wrote: | My best guess is some natural cycle tied to the | https://en.wikipedia.org/wiki/Atlantic_multidecadal_oscillat... | is involved. You'll note that the 1960s correspond to the point | where the Atlantic was cooling most rapidly, which would be | suggestive that the air above the Atlantic was relatively cold | at that time. | | That said I'm not a climatologist, nor do I play on on TV. | counters wrote: | It's worth pointing out that there likely is no such thing as | the AMO. The scientist who coined the term in some pioneering | work in 2000 has, over the past few years, been extremely | outspoken that it was probably an errant interpretation of | the data available at the time (e.g. | https://michaelmann.net/content/rise-and-fall-atlantic- | multi...) and even just a year ago published an article in | Nature which more or less thoroughly eliminates the | possibility of such a mode of multi-decadal variability | actually existing | (https://www.nature.com/articles/s41467-019-13823-w). | btilly wrote: | Whether or not the variation is a predictable cycle | notwithstanding, there is a substantial natural variation, | and the 1960s coincided with a drop in Atlantic sea | temperatures of the right order of magnitude. Which | suggests that natural variation could have caused the 1960s | to be unusually cool relative to overall warming trends. | nanis wrote: | > 1960s seemed to be unusually cool | | Note that the set of thermometers and temperatures that make it | into the GHCN comprise repeated convenience samples. The | techniques used to smear individual observations over vast | swathes of territory tend to leave much to be desired. | | Here's an animation[1] I made way back when I thought maybe | thinking scientifically about how to evaluate the existing | climate record for the recent past was acceptable. | | I have not touched the GHCN recently nor have I updated the | analyses, but it did not take much time to produce the videos | many years ago. Anyone curious should be able to repeat the | same thing of plotting coordinates of temperature stations with | fresh data with no trouble. | | So, for the original question, the answer is we do not know. | However, data are subject to selection bias and that affects | what kind of inferences you can make. | | But do compare the distribution of observation sources in the | 60s to periods before and after. | | [1]: https://www.youtube.com/watch?v=h95uvT67bNg GHCNv3 | (20141118 qca) Temperature Station Locations 1702-2014 | at-fates-hands wrote: | Interesting to note that in the 1970's the talk of another ice | age was really more of a conversation about a rapidly changing | planet. The real anxiety was over pollution and its effect on | the climate - not that the planet was cooling naturally or | going through a cooling phase: | | 1974 TIME "Another Ice Age?" | https://www.sott.net/article/271592-Time-magazine-1974-Anoth... | | _As they review the bizarre and unpredictable weather pattern | of the past several years, a growing number of scientists are | beginning to suspect that many seemingly contradictory | meteorological fluctuations are actually part of a global | climatic upheaval._ | | They thought it was due to pollution (man made) even back then: | | _Man, too, may be somewhat responsible for the cooling trend. | The University of Wisconsin 's Reid A. Bryson and other | climatologists suggest that dust and other particles released | into the atmosphere as a result of farming and fuel burning may | be blocking more and more sunlight from reaching and heating | the surface of the earth._ | | Interesting to note they speculate the trend might be temporary | - which makes sense because as we've reduced pollution by leaps | and bounds since then, you've started to see more of a warming | trend: | | _Climatic Balance. Some scientists like Donald Oilman, chief | of the National Weather Service 's long-range-prediction group, | think that the cooling trend may be only temporary. But all | agree that vastly more information is needed about the major | influences on the earth's climate._ | | This article was never an indictment on the scientists | believing we were heading for another ice age. Quite the | opposite. They started seeing rapid changes in the planet's | climate and wanted to try and explain what the consequences | were. They even say they need more data and more research to | figure out exactly what's going on. | tryonenow wrote: | In my day to day work, if you showed me a noisy graph of a | periodic signal measured over some 1/10th to 1/10000th of a | typical cycle period, I would tell you that you don't have nearly | enough data to establish a trend. Especially when the underlying | phenomena are chaotic, complex, impossible to model accurately, | and incompletely understood. | | I also believe that the orthodoxy is overly negative. Who's to | say that earth won't be better off with the newly arable northern | latitudes? The OP seems to indicate a trend toward increasing | rainfall as well - and plants thrive in increased CO2 | environments. | | Then there is the supposed looming socioeconomic catastrophy as | sea levels rise and displace coastal inhabitants. That also | sounds like positive economic churn to me, especially if you go | by the metric of GDP. This will be a gradual migration over | 50-100 years and potentially a boon for various economies - jobs | for infrastructure and construction. | | I'm just not sold on the idea that the world is ending (literally | or figuratively) if we don't act. | nerdponx wrote: | _This will be a gradual migration over 50-100 years_ | | This is wishful thinking. | | _potentially a boon for various economies - jobs for | infrastructure and construction._ | | This is the broken window fallacy. | betwixthewires wrote: | Is it wishful thinking though? How exactly? | | Also how is the idea that this _may_ be good for some | economies a broken window fallacy? | allturtles wrote: | You seem to be imagining that the sea level will smoothly | rise mm by mm over a century and that people will gradually | and peacefully abandon the shoreline and move inland. | | It seems to me that a more likely outcome is that people | will build defenses to protect existing cities (which are | after all massive investments) and and that those defenses | will work well right up until they catastrophically fail in | a major storm (e.g. see Katrina). | xienze wrote: | > It seems to me that a more likely outcome is that | people will build defenses to protect existing cities | | Honestly, this part right here is what makes me very | skeptical about the magnitude of the problem as it's | communicated to the proles. We've heard countless times | how Manhattan will essentially be underwater in XX years, | a foregone conclusion, yet no one has made a serious | proposal to build sea walls around it or other valuable | coastal areas. | | That and the fact that the US is obsessed with importing | countless numbers of foreign citizens who doubtless would | produce far lower carbon footprints in their home | countries than they would in the US. I mean it would only | make sense to limit third world immigration to first | world countries as long as possible if we're concerned | about carbon footprint, wouldn't it? The population | decrease in first world countries would be an added bonus | as far as climate change goes. Yet we do the complete | opposite. Curious! | exporectomy wrote: | How is it that you can predict the defenses are likely to | fail catastrophically but the people building them won't? | Is your concern really that other people don't know as | much as you about how to build sea walls? | allturtles wrote: | I didn't actually say it was likely, just more likely | than a gradual upslope migration in advance of any | danger, which seems contrary to all human social behavior | that I've ever witnessed. When major storms come through | and wreck places that are bound to be wrecked every time | the water rises, the political drumbeat is to rebuild. To | give up on those places would be to show weakness (See | "Jersey Strong / Stronger than the Storm" slogan after | Hurricane Sandy). | | If we could somehow build strong enough defenses to | protect all the major coastal population centers from | rising waters indefinitely, that would be great, though | obviously very expensive. I'm doubtful though. Lots of | money and effort was poured into protecting New Orleans, | and, in the long run, it didn't work. | betwixthewires wrote: | I'm not imagining anything, I'm only asking questions. | Which you have not answered BTW. | twiddling wrote: | Sealioning... | allturtles wrote: | Surely when you say "This will be a gradual migration | over 50-100 years" you are imagining a process by which | this will happen. | | You didn't ask me any questions, you asked nerdponx, and | I chose to join the conversation. What I posted above was | my answer to "Is it wishful thinking though? How | exactly?" | | But given the way are responding, I'm not sure you're | interested in having an honest conversation. | randomopining wrote: | Throws stuff out of equilibrium that our fragile human world | depends on. Could stack with unleashing the trapped methane | gases in Siberia, to form a positive feedback loop. | | Your response is so sophomoric, but not funny. You clearly | don't understand the tight relations of human systems to the | environmental ecosystems. | porb121 wrote: | Have you read a single page of any IPCC report or any major | climate science publication? | | The rhetoric you're spewing is uninformed and dangerous. Even | if you are exactly right (and well-founded scientific arguments | would suggest you are definitely not), you are speaking | completely out of turn without any evidentiary basis. | | Like, "plants like CO2 so more CO2 might be good" is naive, | elementary school reasoning. You might as well say "cardio | exercise is good for the heart, so maybe medically inducing | tachycardia is good for me". It's a complete non-sequitur with | no empirical grounding. | alea_iacta_est wrote: | > The rhetoric you're spewing is uninformed and dangerous. | | The self righteous people like you are way more dangerous in | my humble opinion... | tjr225 wrote: | Unfortunately for you we don't have time to care about your | feelings. I've got a daughter who is going to have to live | in this mess. | sintaxi wrote: | The IPCC doesn't produce scientific research as you are | implying. The purpose of the IPCC is to justify the basis of | "global climate action" so their opinion has no relevancy | when it comes to debating the scientific upsides and | downsides of rising CO2. | | What few people seem to realize is that during the last ice | age CO2 levels @180ppm was so low life on earth for mankind | nearly collapsed - and we know CO2 levels on earth have | reached 8000ppm in the past - so there is significant reason | to be at ease with a rising CO2 considering how close to | extinction level CO2 was a short while ago. | tryonenow wrote: | >Have you read a single page of any IPCC report or any major | climate science publication? | | As a matter of fact I have, though not in a few years. The | papers and the commentary are both far less certain in their | assertions than you would ever guess judging by the common | fervor against "denialists". | | >Like, "plants like CO2 so more CO2 might be good" is naive, | elementary school reasoning. You might as well say "cardio | exercise is good for the heart, so maybe medically inducing | tachycardia is good for me". It's a complete non-sequitur | with no empirical grounding. | | No, it's based on studies of modern [0] and prehistoric | plants. The Carboniferous period for example had CO2 levels | comparable to today's and an explosion of coal forming plant | growth. | | >The rhetoric you're spewing is uninformed and dangerous. | Even if you are exactly right (and well-founded scientific | arguments would suggest you are definitely not), you are | speaking completely out of turn without any evidentiary | basis. | | The rhetoric I'm spewing is scientifically rational | skepticism. The current science _as practiced_ is one sided, | primarily because of reactions like yours, which equate | differing opinions with heresy. Climate science is far from | settled and so called denialism is nowhere near the same | level as flat earth /chemtrails/antivax skepticism to which | it is dismissively compared. | | Also you haven't made a single argument against my point that | we are looking at a tiny fraction of a periodic signal and | presuming a trend - and that's because there fundamentally is | no argument against it. | | 0. https://www.noaa.gov/news/study-global-plant-growth- | surging-... | potatoman22 wrote: | Is 0.16 F increase in average temperature per decade a legitimate | cause for concern? From my (unlearned) perspective, It seems | barely statistically significant. | gameswithgo wrote: | It is enough to change weather patterns, raise sea levels | significantly, its a pace of temperature change that causes | extinction events, when it has happened this fast in the past. | schemescape wrote: | It probably is, yes. This link (which is _not_ directly related | to NOAA 's article) has more information: | | https://skepticalscience.com/few-degrees-global-warming.htm | | > A few degrees of global warming has a huge impact on ice | sheets, sea levels and other aspects of climate. | potatoman22 wrote: | I wish that article had citations, but thanks; that helps | clear up some avenues in which this can have other impacts. | rhodozelia wrote: | Since precipitation that falls as snow is released much later | in the spring but precipitation that falls as rain causes | additional melting and immediate runoff exactly where the | freezing level is can have a dramatic effect on glacial melt | And how dry forests get in the summer, with the ensuing forest | fires. | ArkanExplorer wrote: | CO2 also has an impact on human cognitive function, and | acidifies the ocean. | | Air pollution - usually linked to CO2 emissions - has a whole | slew of other problems. | | We absolutely have the technology to get rid of coal and oil | for transport and electricity production - we need to start | banning the production of new ICE cars and new coal power | plants now, and tariffing any nations who don't follow. | nerdponx wrote: | OK, but the question was about temperatures, not about CO2. | | Has there _ever_ been a concern that we could put so much CO2 | into the atmosphere as to impair cognitive function? | [deleted] | Afforess wrote: | > _average temperature_ | | It's not the average temperature change that is significant, | its the effect of the temperature that is significant. For | example, 33F vs 32F is very significant... If there are more | days above freezing, which leads to extra ice melt, it doesn't | matter if the average is up only a tiny bit. | potatoman22 wrote: | That makes a lot of sense, thanks. | zosima wrote: | I think some kind of error bars would have been very | enlightening, yes. | | I find it quite hard to evaluate what is being shown, when the | total change in temperature over a century is smaller than the | temperature difference between different parts of the room I'm | currently sitting in. | melling wrote: | When there were only 22 American Coronavirus deaths on March 9, | 2020, was there a cause for concern? | | Many people said no. | Pyramus wrote: | Your comment may sound unrelated - but it's exactly at the | heart of the problem. | | Both climate change and viral growth increase exponentially. | Not only do we release more CO2 into the atmosphere every | year, but also the growth rate accelerates. | potatoman22 wrote: | Why does climate change increase exponentially? For reasons | other than our collective output increasing exponentially? | MarkLowenstein wrote: | This is an excellent question. It is a very popular idea | that there is some "tipping point", plus positive | feedback loops, that are definitely going to make this | problem worse, someday. That they are popularly imagined | by non-scientists, and that the effects are always | promised for the future rather than identified in the | past, are cause for skepticism. | | Judging by the fact that for the billion years after life | has dominated, Earth climate has always stayed decidedly | non-Martian and non-Venusian, the evidence is strong that | negative feedback loops are more powerful than the | positive ones that people may publicize. I would like to | see more substantiation behind such assertions. | addison-lee wrote: | From what I understand it is feedback loops that cause | concern for exponential climate change. For example, snow | reflects a large amount of the sun's energy back into | space. As you lose the snow cover you absorb more heat | causing more snow to melt, leading to snow melting | faster, etc. etc. | | Another example is in the Arctic tundra. The top layer of | the ground was always frozen, i.e. a permafrost. However | now that layer is melting and it releases a ton of | methane. Methane causes the temperatures to rise, leading | to the permafrost melting faster and more methane being | released. | [deleted] | SAI_Peregrinus wrote: | Positive feedback loops. | | For example, warming the climate tends to melt ice. Ice | reflects sunlight back to space better than liquid water | or dirt. So the reduced ice cover makes more sunlight get | absorbed by the Earth. Absorbed sunlight becomes heat, | which raises the temperature. The increased temperature | melts more ice. | | Technically all of these loops can only result in a | sigmoid curve, not an exponential. The temperature won't | become arbitrarily large. Trivially it can't get any | hotter than the input (the sun). But in the ranges we | care about (temperatures suitable for human habitation | without massive adaptation and migration needed) it's | effectively exponential. | Pyramus wrote: | _Technically_ logistic growth is locally exponential | until it isn 't. | Diederich wrote: | > Why does climate change increase exponentially? For | reasons other than our collective output increasing | exponentially? | | I'm a decades long 'climate change alarmist'. | | We really don't know if the temperature is _really_ | increasing exponentially, considering the proper | definition of exponential: "a value increases in | proportion to its current value". Also consider that | "exponential growth" doesn't necessarily mean "extremely | fast"...at least in reasonable time horizons. | | I and many others think that the amount of energy in our | planet's atmosphere is increasing, and we also believe | the rate of increase is increasing. This _might_ be | technically 'exponential', but it very well might not. | It could 'just' be quadratic...which, given the 'right' | constants, could be even worse. | | > For reasons other than our collective output increasing | exponentially? | | Humanity's greenhouse gas output was growing (something | like) exponentially (ie, 'very fast') for a good while, | but it's probably no longer: | https://ourworldindata.org/grapher/annual-co-emissions- | by-re... | | To your underlying, fundamental question: why is the rate | of increase probably increasing? Feedback effects. To | seriously get into the weeds, look here: | https://en.wikipedia.org/wiki/Climate_change_feedback | | In short, all chaotic but meta-stable systems, such as | our planet's climate, have built in many 'tipping | points', where a small change in input can have a very | large change in behaviour. Under ideal circumstances, | such tipping points are quite hard to identify with any | precision, and virtually impossible with the most complex | system in the world: earth's climate. | | Even shorter: we don't know for certain, but there's a | large and ever growing pile of data that shows _here and | now_ impacts of a warming climate. Per my other comment, | for example: the rate at which 100, 500 and 1000 year | extreme weather events are occurring. | | In summary: us not knowing with certainty does NOT mean | we should not make it a top priority to start reversing | the things we _do know_ are causing damage: enormous | releases of CO2 and CH4. | potatoman22 wrote: | Thanks! | [deleted] | zosima wrote: | No, the effect of a linear increase of CO2 on temperature | is logarithmic. Though the speculation is the there will be | catastrophic exponential feedback mechanisms. | | I guess CO2 is increasing exponentially, so maybe | CO2-dependent temperature change is a somewhat linear with | respect to time. | Kenji wrote: | Many still say no. | potatoman22 wrote: | I understand the potential gravity of the situation, but this | example doesn't help to explain the significance of these | numbers. | jfengel wrote: | Yes, because we're talking about a time frame of 200 years. | That amounts to 3.2F, and yeah, that's a lot. | | It's enough to make a lot of marginally-livable places | completely unlivable. It's enough to throw off growing seasons, | costing a significant amount of agriculture. It will require | more water, already a tough squeeze in a lot of places. It will | melt a lot of ice, causing disruptions to sea level that will | make expensive storms more frequent. It will throw off rain | patterns, meaning that some places will become arable that | weren't, but forcing some existing farms to stop. That will be | hugely disruptive and expensive. | | The real problem is that it likely won't just be 3.2F. That's | actually pretty much what the IPCC's target is: they want it to | be _just_ 3.2F (2C). But even that much involves drastically | cutting CO2 output: CO2 is very stable and will last for many | centuries. We will continue to get warmer for decades even if | we stopped burning fossil fuels utterly, right this instant. | | Instead, the world as a whole has continued to increase its | CO2. (The US has actually gone back down to 1990 levels, | largely because of a shift from coal to natural gas, but partly | due to renewables.) That means we're on a track for more like | 6F to 8F by 2100, and that is pretty clearly a lot. | porb121 wrote: | Yes. The effects of increasing average temperature are highly | localized. It's not that at every place in the world, every day | is 0.16 F hotter, but that in some places, some days are much, | much hotter. | comte7092 wrote: | Effect size isn't what statistical significance refers to. It's | only in reference to whether or not the measured effect appears | to differ from zero. The effect itself may be minuscule to the | point where it's practically inconsequential in real life. | notafraudster wrote: | Right, the comment surely should have said "substantively | significant" and not statistically significant, since | statistical significance is a product of not just effect size | but also sample size and estimator efficiency (and, indeed, | chosen alpha -- anything can be significant if you make the | alpha large enough) | comte7092 wrote: | Yeah, one of my major frustrations is how poorly framed | statistical significance is in popular media. | potatoman22 wrote: | Thanks for clearing things up. How would we know if measured | climate change is statistically significant? It seems | difficult to measure these sorts of cyclical long-term | events. | comte7092 wrote: | There are a couple of ways to interpret your question, one | is purely statistical "is the climate/temperature actually | changing?" And the other is "does it matter?". I'm not | really equipped to answer the second one properly. | | Re the first question, statistical hypothesis testing | requires a null state of the world that you want to test, | in this case "is the global temperature changing". What | that requires, more rigorously, is some sort of assumed | probability distribution that generates the data we | observe. We would probably assume a normal | distribution/bell curve with mean equal to the long term | average temperature during the last few thousand years, or | whatever period is relevant (again, im not a climate | scientist), and variance deduced the same way. | | To test that null hypothesis: "the temperature over the | last decade isn't meaningfully different from the long term | average", you then take your recent data, say the last and | ask "what is the probability we'd see this data, assuming | the state of the world we assume given our null | hypothesis". If the observed data is sufficiently unlikely | to be generated by that null distribution, you say there is | a statistically significant difference. | | Now, That's not the only way to analyze the data (putting | it into two buckets and asking if they differ). But I don't | want to get too into the weeds without better understanding | what your wondering about/where the disconnect is. | | Edit: looking back on this answer, there are some glaring | issues that need to be addressed, because they're both bad | analysis and you hinted at it in your question. | | Obviously the issue here is that cyclical data clumps | together so to speak. Sot he temporal binning i outlined | here is a big issue, because you are going to get data with | lower variance that you would expect. | | This could conceivably be adjusted for by raising your | significance threshold, though off the top of my head I'm | not 100% sure how I would approach it personally. | potatoman22 wrote: | Thanks for the reply. It seems like a pretty complicated | subject, and I'm sure I'd need to learn more of climate | science if I want to feel good about interpreting data | like this. | chrisco255 wrote: | No. In fact in the grand scheme of earth's climate history it's | a normal cyclical perturbation. | crispyporkbites wrote: | You missed a key point here- this data is USA only- which is | not a very big part of the world. | | The poles are heating up much faster! Eg the North Pole rose | 2-4c in the last 50 years: | | https://en.m.wikipedia.org/wiki/Climate_change#/media/File%3... | | The change is accelerating. Projections that held true in the | 80s and 90s are being revised. We're talking about 6-12 degrees | Celsius warmer on Average globally in 100 years. | https://en.m.wikipedia.org/wiki/Climate_change#/media/File%3... | That means some days/months will be significantly warmer and | our crops, food supply, water supplies and other industries | won't have adapted quickly enough to survive. | | The worst case scenarios are the breakdown of civilisation and | human extinction. | esalman wrote: | It seems significant if you live in a coastal area prone to | tidal flooding. | | https://www.virginiamercury.com/2020/07/17/virginias-coast-s... | gilbetron wrote: | It's misleading, since it sounds like everywhere is just going | to be a tiny bit warmer, basically unnoticeable. However, it's | really about the massive amount of energy required to warm the | atmosphere up by that much, and how that energy isn't equally | distributed. | | One analogy I use is: imagine sitting in a pool with friends, | and one person starts pushing one of those floating lounge | chairs up and down. They might only increase the average height | of the water by a millimeter or so, but the whole pool starts | getting more wavy and chaotic. That's how it is with our | atmosphere - more extreme events (both "hot" and "cold") occur | and in general more chaotic weather as that energy is spread in | waves and troughs throughout the world. | mdiesel wrote: | Great way I had it explained to me was that if we imagine | weather follows some kind of normal distribution called | climate, then a shift of of the distribution makes those | extreme weather events far more likely much quicker than it | affects the mean weather. | Diederich wrote: | However much temperature is increasing, I find the frequency of | extreme weather events far more problematic. How many | 100/500/1000 year storms has the United States dealt with over | the past few years? | | Even more to the point, is it possible that the rate at which | these extreme weather events is increasing is also increasing? | | Without getting into the weeds about particular numbers, it's | known that given a global temperature increase, the poles | experience the majority of that change. One reason the United | States has experienced so much extreme weather of late is | because the northern hemisphere polar jet stream has gotten a | lot more erratic, in large part because of a declining | temperature delta between the north pole and its adjacent | temperature bands. | learn_more wrote: | I wonder how much warming and change in precipitation is related | to greening of the country from additional CO2 in the atmosphere | and resulting changes in the albedo. | thanatos519 wrote: | I'm happy to see unmuzzled reporting from US government funded | scientists again. Welcome back! | betwixthewires wrote: | So one thing to keep in mind, showing 20 year averages every 10 | years and comparing them to century long averages for the same | time period is a really good idea, it shows that there is a trend | and it can show shorter temporal anomalies. | | One thing I found very interesting is the information on | precipitation. I've heard it said "a warmer world is a wetter | world" and that would appear to be supported by this data. | chrisco255 wrote: | We don't have a century of homogenous temperature data. We | didn't have weather satellites until the late 70s, early 80s. | And temps were only recorded in some cities and some towns, | with uneven coverage, with inconsistent global quality | practices. Sea temps were also inconsistently recorded. | shoto_io wrote: | This should be the top comment. The images suggest a level of | detail and accuracy that can't be correct. | newacct583 wrote: | So... we have a half century of homogenous high quality | temperature then. Does the good data we do have not support | the same conclusion? Seems like it does to me. | [deleted] | NotChina wrote: | The universal constant of climate is what? | crispyporkbites wrote: | This is a bit misleading as the data is US only but the climate | and weather doesn't care about our made up borders. So to get a | real picture of climate change you need to look at global weather | patterns and temperature changes. | exporectomy wrote: | So? Isn't its purpose it to show American farmers what the | climate is like to help them plan their planting? | [deleted] ___________________________________________________________________ (page generated 2021-04-26 23:01 UTC)