[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)