Monday was hottest day for global average temperature, as climate crisis bites | Hacker News Reader

Monday was hottest day for global average temperature, as climate crisis bites

theguardian.com

148 pointsrntn108 comments

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How does someone measure the average global temperature? And what does it means?

The Wikipedia[0] has one interesting source[1] but what they show there isn't an average.

My guess would be that somehow satellites can measure the surface temperature and use that to make an average?

I would be very happy if someone could some point me to some explanations about this process.

[0] - https://en.wikipedia.org/wiki/Global_surface_temperature

[1] - https://www.ncei.noaa.gov/access/monitoring/monthly-report/g...

Earth-observing satellites can measure surface temperature with so-called "thermal infrared" bands. I am unsure on the exact process typically used to go from that map to a global average, but that's a likely starting point.

The source of the data is https://climatereanalyzer.org/clim/t2_daily/ according to https://www.bloomberg.com/news/articles/2023-07-04/world-rec...

I wonder how a story like this gets picked up.

Quote from that page :

“ This page provides time series and map visualizations of daily mean 2-meter air temperature from the NCEP Climate Forecast System (CFS) version 2 (April 2011 – present) and CFS Reanalysis (January 1979 – March 2011). CFS/CFSR is a numerical climate/weather modeling framework that ingests surface, radiosonde, and satellite observations to estimate the state of the atmosphere at hourly time resolution onward from 1 January 1979. The horizontal gridcell resolution is 0.5°x0.5° (~ 55km at 45°N). Temperature anomalies are in reference to 1979–2000 climatology for each specific day of the year.”

Next I want to learn how they measure Earth's entropy.

There are tens (if not hundreds) of thousands of land based weather stations, bouys and floats, weather balloons, radiosondes, observatories, and satellites around the world that form a lot of different sensor networks like Argo, ASOS, AWOS, etc. operated by a bunch of government agencies around the world. The World Meteorological Organization at the UN coordinates the sharing of all this data and there are too many players to list but the most important global datasets produced by the US are the GHCN v4 for land and ERSST v5 for sea.

Each organization creates their own models and often compare with each other but most methods start by defining a grid that divides the planet, then use a model to estimate the average temperature for each cell given available sensor data. Many cells, especially in the middle of the ocean, don't have any direct measurements so have to be filled in using satellite based estimates or kriging (interpolation). They average over all of the grid cells in each hemisphere separately then apply some sort of formula to account for the fact that the northern hemisphere has significantly better coverage.

It's not the most precise calculation and what most people are looking for is the rate of change over time using the same model and dataset (which are also versioned based on changes in methodology).

The same way you take any temperature... by sampling and then averaging over the samples. Obviously you need to have enough well distributed samples to get a reasonable accuracy, but this is all an old hat.

Btw., I suspect you get that "I don't know what average temperature even means" from some nonsense Ivar Giaever spouted at a presentation that's on YouTube. The simple answer to that is that average temperature means the same thing as temperature, because temperature is always an average that we can only arrive at by sampling (since it represents the average kinetic energy of a volume of particles and you can't meassure each particle's energy individually). Ivar Giavever knows that, but he also knows that people will believe almost anything that comes from him because he has a Nobel Price. After all, his autobiography is titled "I'm the smartest man I know".

There are two sets of satellites that measure the temperature of the global troposphere, and have been doing so for over forty years. The data from one of them, UAH, is analyzed here.[0] It is increasing at 0.13C per decade, averaged over 44 years.

[0] https://www.drroyspencer.com/2023/06/uah-global-temperature-...

Interesting that until Remote Sensing Systems revised their historical data six years ago, no warming trend was evident. How could they have been so wrong for such a long time?

https://www.carbonbrief.org/major-correction-to-satellite-da...

https://www.drroyspencer.com/2017/07/comments-on-the-new-rss...

RSSv3 showed warming, it's there on the graph.

RSSv4 corrected against ground data (calibration) and normalised for time drift and incident angle also showed warming .. more warming as prior post processing results had an incorrect transfer function.

As a point of order, their raw historic data has not been altered - instruments rarely directly produce values of interest, they must be calibrated against other sources to provide a transfer function between raw instrument product and final values of interest.

Bimetallic strips don't measure "tempreture" - they show the expansion of metals in tension.

They must be calibrated to show a "tempreture" relative to amount of bend.

Traditional aircraft altimeters don't directly measure height above ground, they are aneroid barometers that reflect the atmospheric pressure from a static port outside the aircraft. Calibration and barometric pressure on the ground are required to form a transfer function for height.

It's so damn weird that Dr. Spencer -- whose job is producing the data that shows climate change -- is a climate denialist. The link in the grandparent comment, showing .12C/decade, is the very same site with the denialist claim you link to.

It's not just him, either. His colleague John Christy is also responsible for the UAH lab, and also a climate denialist.

They are different kinds of denialist. Spencer is in the "It's real but it's not our fault" camp, while Christy is in the "It's real and our fault but not important" camp. They are, however, very popular with the camp of "it's not real", and I've never seen them reject those claims, even though they are the ones responsible for the data that prove it is real.

Spencer is a "lukewarmer". He believes that warming is real, and it's partially caused by human emissions. So, not different from the IPCC in kind, just in degree.

It's not correct to call him a "denialist", given the above. But, he is quite skeptical of the computer models and the general state of climate science.

His point is the actual temperature record of the global troposphere over the last forty years takes precedence over a number of computer models, given that many of the inputs to the models are variables which are not well-characterized. Those models are failing to predict actual events.

He thinks that the 1.3C/century trend shown in the actual data is not a reason to panic and mangle the economy. He thinks that the overall benefit of global warming and greening due to CO2 may be net positive. His book is pretty even-handed.

The climate denialism on this site is ridiculous, considering the average education and pay rates of the users on this site.

You should also consider the field and expertise of the users. Also, I am not specialized in data science but even I know that at some point, it is just so easy to cook up whatever conclusions you want if you have a big enough dataset. So I imagine that those who works with data analysis all the time eventually get jaded whenever they heard someone demanding drastic, even unreasonable, changes based on data they found.

The idea that the data in this case is ambiguous is laughable and has been for 20 plus years.

It isn't data science. It is earth science.

Someone once commented "HN is a reactionary site" and (while I don't 100% agree with that) I keep thinking about it from time to time.

average education and pay have nothing to do with it. a lot of hn users are bazingapilled techno-opportunists.

climate breakdown confronts two axioms for what is probably a sizable userbase of this site:

- nothing (bad) ever (really) happens

- advancement of technology and industry solves all problems

they have no incentive to be any other way. because of the high pay and education, most of these people will be able to live comfortably within the confines of the global north and presumably wealthy nation-state for the rest of their lives.

Calling into question optimism and entrepreneurship can be a very existential question, I admit that believing the phenomenon is overblown and of the data dubious is very tempting given the mental weight it clears. But the irony for this population (me included) is that it’s the same as believing in afterlife to alleviate the existential dread of death, it’s religious thinking. People do great things without being death denialists, it should be the same without climate denialism.

Most people on here (generalisation) spend more time on a computer than in nature. If you spend time in Nature it is very obvious what is happening. Look at the world from whence it came and where it is going.

Heating of our climate is but one thing.

I don't think its outright denial as much as a general question on whether or not humans are contributing to it as much as "authorities" say (especially when the climate change conventions are traveled to by jets that contribute more to global warming in one flight that a person can reduce in a year, iirc the stats), and the resistance to all the restrictions placed on middle class when upper class and government gets a pass.

The other thing is that there were predictions made about some things like Miami being underwater in early 2020s that never came true, and the same type of predictions that are being made.

So tbf, its not really that unwarranted to be skeptical.

Who made those predictions?

Well the US Supreme Court said last year that any new Environmental Protection Agency regulation is invalid on creation, so there's that.

It’s supposed to be Congress’ job to do something, but unfortunately they appear to be useless.

Open your eyes to the possibility that maybe, just maybe, SCOTUS kicked it back to Congress purely because Congress is useless and won't do anything.

We have considered that possibility, assessed it, and determined that was not the case. Onto the next thing.

Congress has been doing climate and environmental regulation since Nixon. However in 1998 the Senate killed the Kyoto protocol (even though it was signed by the Clinton administration) and in 2001 the Bush administration became increasingly hostile towards any climate regulation. This supreme court case is simply yet another governing body standing in the way of congress to write and maintain climate and environmental regulation.

Don't blame this on the congress. Doing so is an ahistorical timeline.

Except in this instance, the conservative justices completely abandoned their "textualism" argument given the law in question was written by Congress to do precisely what they disallowed. And no, I don't want to hear that "well clearly not since they ruled against it."

To be clear: I'm talking about their redefinition of the word "adjacent". Forgive me if I'm not following the thread correctly here. Justice Alito seems to think adjacent means "navigable waters" instead of "these waters are literally connected to each other even if not above ground".

Almost all waters are “literally connected to each other” in a manner that’s clearly beyond anything Congress intended to regulate when they revised the CWA.

It’s just a matter of how intimately connected.

I think it should be clear by now that the textualists are only interested in text that suits their interests (e.g. the first clause of the second amendment is just flavor text since 2013).

Funny how this claim can be made when they pull shit like this but not when they legislate from the bench for the right.

If we pretend the Supreme Court is partisan, which it is not but let's entertain that thought here, then the decision was bipartisan. Both the Left and the Right judged that the EPA was overstepping its authority.[1]

>The court voted unanimously to reverse the Ninth Circuit, but split 5–4 on the rationale. The majority opinion, by Alito, introduced a new test to define wetlands, which reversed five decades of EPA rule-making and limited the scope of the Clean Water Act's authority to regulate waters of the United States. Justice Brett Kavanaugh joined the three liberal justices in agreeing that the CWA did not apply to the Sacketts' property, but argued that the majority's new definition was incorrect and will have significant effects on regulated waters.

[1]: https://en.wikipedia.org/wiki/Sackett_v._Environmental_Prote...

> If we pretend the Supreme Court is partisan, which it is not but let's entertain that thought here.. I mean, that’s laughable, I don’t know how anyone can call the current Court non-partisan with a straight face. That doesn’t mean every decision is necessarily partisan, but multiple decisions over the past few years have been blatantly partisan, with Thomas and Alito especially making very little effort, if any, to hide it. I used to feel that the Supreme Court was the one of the few non-partisan institutions in our government, but the way this Court has run roughshod over stare decisis to effect change in the interests of its majority was more than enough to disabuse me of that notion. Everyone loves when decisions are going their way, consequences be damned, but the way those decisions get made matters, and nobody should be happy with the way the current court is choosing to act. It has set a really bad precedent for future courts, and has already done immense damage to its reputation in the eyes of many.

Well, half are.

>unfortunately they appear to be useless

Being nice aren't we :)

They are useless unless the regulation lines their pockets along with it seems the Court System. The US will bring down the world with it based upon how the Supreme Court Legalized bribing.

I say this as a US citizen.

It bears repeating, the carbon dioxide/methane doesn't have any impact on global warming (troposphere warming?) until it reaches sufficient height.

It takes 2-3 years for the methane to reach those heights, and 20+ for the carbon dioxide. The average increase in temperature we have now is caused by 2003's emissions.

Other informations about how all this work (basic, incomplete, but better than what I usually hear):

Greenhouse effect doesn't really work like a greenhouse.

  Basically, to be in a balanced system, earth has to re-radiate all the energy it gets from the sun. The energy a body radiate depends on its temperature (plank's law). Earth need to reach 255K (-18 basically) to radiate all it gets from the sun. The nitrogen, dioxygen and argon in the atmosphere do not prevent that radiation, but water (especially) and Co2 do.


 This basically make that earth cannot radiate the energy it gets at ground level (that's the greenhouse effect) and has to radiate the energy where the atmosphere is thinner, a few kilometers up, where the concentration of both Co2 and h2o is lower (concentration here as particle per m3). So the earth has to heat all the atmosphere until that altitude (where GHGs do not block radiation anymore) reach 255K.


  So, when the Co2 concentration above that point rises, the altitude the radiation occurs rises too. But that altitude is colder, it cannot radiate as much energy as it gets from the sun. So the atmosphere heat up a bit, until that new altitude reach 255k.

Obviously it's a lot more complex, with reflection, absorption spectrum of molecules... There is also more than one GHG, there is stratosphere effect, but this explain way better than 'we live in a big greenhouse'.

Does that make sense? First time I do this in writing and in English?

I'll take every correction that will not make the explanation too hard (unless I'm flatly wrong and lying instead of vulgarising).

Very interesting. Please can you suggest a reference?

In French (I don't know if the English words I used were correct, so I can't search English sources):

Article from a vulgarisation paper: https://www.futura-sciences.com/planete/dossiers/climatologi...

And a pdf from my previous university (way drier, lot of math and inference, nice graphs though): https://web.lmd.jussieu.fr/~jldufres/IUFM_Creteil/Dufresne_b...

I can't find a date on either of these, but they look a bit dated. The newest reference in the presenetation is from 2007 and uses graphs from 2001.

I know that I heard something aout CO2 taking 20 years to get to the upper atmosphere around then, too, but not since, and I remember being curious about that and researching it a bit about a decade ago and finding that this is not what most atmospheric scientists believed (anymore?).

I stopped learning physics circa 2011, so I might be dated too tbh.

I'll look into it tomorrow.

Im don't have enough knowledge to know how accurate that is, but if true that is both fascinating and worrying.

I say this simply because I figured warming at any level would be an issue but what you say sounds plausible.

I have some reading to do.

Carbon dioxide takes 20+ years to reach the stratosphere? Gases with higher molecular weights like halogenated ozone depleting substances reach the stratosphere in no more than 5 years:

https://www.epa.gov/ozone-layer-protection/basic-ozone-layer...

Ozone depleting substances that release chlorine include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), carbon tetrachloride, and methyl chloroform. ODS that release bromine include halons and methyl bromide. Although ODS are emitted at the Earth’s surface, they are eventually carried into the stratosphere in a process that can take as long as two to five years.

I would expect gases with a lower molecular weight to blend into the homosphere even faster.

Probably depends on the % threshold you set, as it asymptotically approaches some equilibrium.

About that negative 18 degrees for equilibrium, does that take into account the heat radiating from within the earth as well? Radioactive decay, the core is quite hot.

Global average temperature is not a well-defined statistical measure and can be surprisingly difficult to measure given large regional random and systemic variation in the measurement, including sampling effects.

But, if you live near some mountains, you can look at them and compare to pictures taken 50 years ago and draw some conclusions about precipitation and temperature trends at the top of your local mountain range over the last 50 years. When I don't know what and who to believe anymore, that's what I usually do.

Also, nothing is preventing anyone from getting a thermometer and measuring + charting daily local temperatures themselves.

Does anyone want to write an app with me, where you can record and chart your daily ground level local temperature where you live, and discuss it with others?

what more do you need than a spreadsheet?

more generally, why would someone spend their time charting local temperatures manually… do you not trust the national weather service?

Humans evolved to work in tribe as a unit. They hunted and raised families in tribes. Then agricultural and industrial revolution happened in last few 100 years changing the game. We discovered fossil fuels, heat engines, electromagnetic forces and amplified the shit out of resources found in nature. Quite amazing.

However we are really bad at coordinating at a global scale on what to do about problems we're causing now that will hit generations later. Worse if those problems are negative feedback problems that self-amplify with time.

However what does make me sad is how we're so divided on whether this is even a problem. Like a frog being slowly cooked.

I'm optimistic since we got a handle on banning CFC gasses, getting a handle of tabacco causing cancer, or lead additives causing toxicity.

Rise of solar and how fast it came down in price has also been amazing to witness. Although still <10% of global energy supply.

Sometimes I do wonder if the evidence of lack of any intelligent life out in the universe is because any species that naturally evolves in intelligence ends up eventually destroying itself due to not being able to solve for long term negative feedback loops.

Told you so!

Svante Arrhenius (1896)

https://en.wikipedia.org/wiki/Svante_Arrhenius#Greenhouse_ef...

I believe Temperature is now a politicized measure, therefore it forever impossible to know it's true value.

Does it mean that if my thermometer shows 10C it might be lying because of its political bias? Or did you miss an “/s” and I the sarcasm?

it depends whether you re rounding up or down

that is a useful stance for someone who argues for the status quo. label anything you don't like "fake news" or "fake science" and go on whistling past the graveyard.

Similarly useful for everyone opposing change. Today everything contradicting ones view of the world is labeled as "anti-[whatever]", "[whatever]-denialism" and "fake news". Everything is so ridiculously polarized that constructive discourse is impossible.

I agree in the sense that global warming is about the temperature of the oceans, not the atmosphere. The oceans are essentially a very large thermal battery.

I immediately know the article is trash the moment they start blaming global warming for how hot or cold it is today rather than broader weather patterns. The upper and lower bounds for temperature at a given time of year are far more dependent on geography. It's trivially easy to see that all this "record breaking" is just recency bias, not global warming.

It's trivially easy to see that all this "record breaking" is just recency bias, not global warming.

This makes no sense. Are they not just comparing numbers? Or do you suggest that when they compare numbers to see which number is bigger, they add a bit to the number from this year because they have a recency bias?

Data from the past is less accurate and incomplete.

That creates a bias for recent data even if the real atmospheric temperatures have not changed. We're forced to treat the data as the source of truth only because it's all we have, but we shouldn't assume the data is perfect. In statistics, picking out individual data points is about as silly as it gets.

That's not "recency bias". Rather than "recency bias", I suspect you meant that data from the past is less accurate and less complete, due to measurement technology, measurement techniques and record-keeping.

I think this is more insightful, or at least interesting, than replies are giving credit. Sure, you know your temperature from the thermometer at your house, but how do you measure the world's temperature? What is included and excluded in the calculation? Scientific facts don't exist in isolation - they are created in people processes in a political environment. New and existing metrics can be cited or withheld to support an agenda. Anyhow, given this specific case is from a single source, it seems to be at least self-consistent.

I think it's unwise to constantly associate normal temperature fluctuations with any threat to civilization. If anything, it might be a leading indicator of mass migration. But we shouldn't ignore evidence to the contrary, mass influx of population towards warm areas, like the Sun Belt. If anything, humanity has increased in its capabilities to live in hot temperatures.

Did you not read the part where it's the hottest day recorded? That is, by definition, not a normal temperature fluctuation.

Hottest day recorded, likely since 1871 (1), but actually we don't know because the article doesn't offer that information. The Earth has been around much longer though.

(1): https://data.noaa.gov/onestop/collections/details/55bedd68-b...

> Hottest day recorded, likely since 1871 (1), but actually we don't know because the article doesn't offer that information. The Earth has been around much longer though.

Why does it matter how long the earth has been around? We're not talking about the hottest day of all time (remember that for a long time the earth had a molten crust), we're specifically talking about the hottest recorded day. It sounds like you're putting it as a gotcha when it's just the topic.

Such records are going to get broken pretty much every year. Shouldn't really be "news".

It should be news everywhere each and every day until we do enough about it so it isn't any more IMHO

the boy who cried wolf is about that

You're mistaken there: "The boy who cried wolf" is about lying about there being a wolf while it isn't, not about speaking the truth but nobody wanting to listen.

Edit: check for yourself if you like: https://en.wikipedia.org/wiki/The_Boy_Who_Cried_Wolf

I'm half wondering if commenter implies that the wolf doesn't exist indeed...

I didn't think about the inverse parable, but I suppose that's Cassandra (and I've heard the database name was also a playful jab at Oracle, since Cassandra herself was an oracle).

Cassandra foresaw the future but nobody listened.

i think you misjudged this as a climate denialist comment. it's not.

the boy who cried wolf was about someone stirring hysteria so much it desensitized people beyond the point of caring when the threat was actually existential. it's not a perfect analogy but basically we've been crying wolf for decades (focusing on the wrong things: denuclearization, air quality, ozone layer, full-electric cars; vs. energy density, dense land uses, hybrids, democratic economies, etc.) and now that the wolf is starting to eat us, crying more won't help

Climate change is such a slow-moving massive-scale issue of course there's going to be decades and decades of observational reporting on its myriad effects.

The boy who cried wolf is about telling fibs ruining one's credibility, it's entirely different.

Our news sources shouldn't suppress reporting slow-moving disasters just because humans have a short attention span.

So all the climate scientists in the 1980s who said that the sea levels would be a meter higher today did not ruin their credibility?

I think if you asked the average person about that they would not think they are very credible.

> So all the climate scientists in the 1980s who said that the sea levels would be a meter higher today did not ruin their credibility?

I don't know what specific claims you're referring to. I was a child in the 1980s and you should provide citations when making such historical claims. For all I know these purported scientific predictions were qualified with murky probabilities. Publications having error bars +- 50 years, and we're just playing some kind of 40+ year game of telephone hearsay.

But you are speaking as if sea levels went down since the 1980s which is obviously not the case.

Claims like this.

https://people.com/archive/co2-could-change-our-climate-and-...

https://i.stack.imgur.com/K3g5l.jpg

"could"

All the people decades ago saying that the sea levels would be way higher today certainly didn't help instill confidence in their prediction abilities however.

One could see how that could be seen as crying wolf.

That's a great way to make everyone ignore it. Calling it a "crisis" does the same thing, the first time you hear crisis you get worried, then you realize it's a very very slow moving thing and you start ignoring them.

Being alarmist helps no one.

Just be factual about it, it's not the news media's job to rile people up or get them to take some kind of action.

It has been the warmest day in the history since anyone starting measuring, and the summer days haven't started globally yet is a pretty factual way to put it in my book

I agree. But don't call it "Climate Crisis", that just sounds silly, and will make people ignore you (it's also not factual since a crisis is something that happens quickly). "Global Warming", or "Climate Change" work perfectly fine.

It very much is a crisis. Merriam-webster is literally using "the environmental crisis" as an example of proper use of the word "crisis".

https://www.merriam-webster.com/dictionary/crisis

There are mountains of people doing what you do and complaining about alarmism and fear mongering and chiding people for apocalyptic predictions any time this subject comes up. I think that's worse than unhelpful, and is a disservice to everyone that lives after us. People are sounding the alarms and making dire predictions because there is so far 0 indication that as a global society we can cooperate well enough to prevent serious and irreparable harm to Earth's ecosystems and a great deal of consequent human suffering. We just barely, as a species, managed to contain ourselves well enough to not blow up in a nuclear light show. Peace is a fragile stalemate, not a lack of desire to destroy each other. If you ask me, there's no hope of an adequate change of inertia to prevent unprecedented human suffering stemming from AGW, and that's in large part because people would rather ignore it and stay comfortable. Toning down the alarmism does nothing to fix that.

So what do you suggest? Be scared everyday of the impending doom that awaits us inevitably (or maybe not in the end)? Is that a good way to live life?

You can for example figure out how you can help the situation? Sticking your head in the sand is probably not the most helpful thing you can do. Even if YOU can't stop global warming (none of us can alone), you can atleast help spread willingness to action by telling the sober truth. Not exaggerate, but also not trivialise it.

On the flip side if we overreact and destroy our food and logistics systems over it the suffering will be worse than climate change. If the right people gain power I could see them doing something totally misguided like banning fertilizer or destroying electricity grids.

The effects of Global Warming should've been featured in sciency publications like Times Magazine at least three decades ago.

https://www.google.co.uk/search?q=time+magazine+1990s+global...

The Guardian hears you: https://www.theguardian.com/environment/2023/jul/05/tuesday-...

And this one will be broken again today

Indeed: https://www.theguardian.com/environment/2023/jul/05/tuesday-... For your next trick can you give us tomorrow's lottery numbers?

Should they stop reporting on it then? Hey maybe when an athlete next breaks a speed/distance record they won't report on that either.

A lot of things that happen more then once, repeatably and predictably are still news.

according to Webster news is just: 1a: a report of recent events

source: https://www.merriam-webster.com/dictionary/news

Happy Birthday my dude.

As long as we keep not doing any meaningful to stop those records to be broken, is good to be reminded that we are getting closer to hit a wall.

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