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Comment by PaulDavisThe1st | Hacker News Reader

Just in case it saves one person the effort to research this themselves ... for some reason I find the measurement of climate change in units of temperature a bit problematic (though entirely rational). It tends to suggest the old bugbear of "global warming", which of course gets translated by deniers (& skeptics) into "well it's colder here so that's wrong".

I spent a while digging in to try to get some numbers on a different sense of what's happening. Global average temperature is changing because extra energy is being retained within the boundary of the planet's atmosphere [0]. So how much extra energy is being retained?

A best guess estimate from 2015 would appear to be that

> the earth is getting about 300 terawatt hours of energy per hour due to anthropogenic climate change, and humans use about 16 terawatt hours of energy per hour.

That is, the earth is gaining 18x more energy per hour than we use every hour, thanks to the changes in radiative forcing driven by climate change contributors.

[0] anyone familiar with complex physical systems will understand that when you add energy to such a system, the effects are often hard to predict. It is very likely that the temperature of the system will rise, but you may also see, for example, more movement as well (which is in some sense a related concept to "temperature" but not identical, and it adds uncertainty because it of the extra degrees of freedom).

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> anyone familiar with complex physical systems will understand that when you add energy to such a system, the effects are often hard to predict

This is something that is very underappreciated. It's entirely possible that the climate becomes chaotic (in a mathematical sense) and there are sudden, drastic changes that cause economic and social devastation.

It seems inevitable that people will be complacent until it's too late.

> It's entirely possible that the climate becomes chaotic

Ya think ? :)

(no insult intended)

On the other hand, this energy can also get converted into complexity. It's not like this hasn't happened before (organisms, trees, animals, cities, etc...). So it's possible with this fast increase in energy, we get the SciFi city we have all been dreaming of.

Of course, it's easier for this energy to dissipate as heat and kill us all.

It seems inevitable that [conservatives] will be complacent until it's too late.

Let's not white-wash the problem.

The problem looks pretty “white” to me already.

What does that mean?

Flipping that around, it seems inevitable that [leftists] will insist on mass collective action based on the predictions of unreliable academics, until the moment they realize those predictions were wrong. Again.

Example: the idea that global warming doesn't cause warming is new. 20 years ago climatologists were telling British people with absolute confidence that by now there'd be no more snow. In the 1960s they were telling people there was a new ice age on the way. Both predictions were dead wrong and have now been white-washed out of existence.

Why is it only conservatives who require that if people claim their understanding of the climate is good enough to predict it decades into the future, they actually be able to do that? Why is it only conservatives who recognize that academia's reputation should suffer if they constantly make aggressive predictions, get it wrong and then pretend it never happened?

> Example: the idea that global warming doesn't cause warming is new. 20 years ago climatologists were telling British people with absolute confidence that by now there'd be no more snow.

The idea that global warming causes local climate shifts, increases extremes, and breaks existing patterns in ways that will sometimes not cause local warming and may even cause local cooling has been a major theme of GW discussions at least as old as the 1980s.

The particular local predictions for Britain may be new, but that its hard to make specific local predictions of the effects is also not a new realization, so I doubt very much that climatologists (as opposed to, say, popular media) were predicting anything of the kind you describe with “absolute confidence”.

>> I doubt very much that climatologists (as opposed to, say, popular media) were predicting anything of the kind you describe with “absolute confidence”.

Here's proof but there's far more where it comes from.

Prediction, March 2000: According to Dr David Viner, a senior research scientist at the climatic research unit (CRU) of the University of East Anglia, within a few years winter snowfall will become "a very rare and exciting event". "Children just aren't going to know what snow is," he said.

https://realclimatescience.com/2023/03/the-end-of-snow-8/

Reality, March 2023: Met Office weather: Snow could return as fresh -4C blast to hit UK. A return of wintry weather has not been ruled out despite the country now being in spring

https://www.somersetlive.co.uk/news/uk-world-news/met-office...

Climatologists have a reputation for being always wrong not due to media mis-representation. The media by and large doesn't misrepresent what they're saying. They have that reputation because they keep making stupid predictions with absolute confidence that then don't come true, and they never admit that this has happened even though the archives are full of examples.

https://extinctionclock.org/

What do you think "a few years" means to a climate scientist?

Actually asking, this is not rhetorical.

It means the same as any other person who says it. "A few", as in, maybe 3 to 5 years. That's why he said children won't know what snow is. If they were small children in 2000 then by 2003 snow is gone, they won't remember it.

But yea, sure, if you want to argue that he wasn't speaking English and that "Children just aren't going to know what snow is" didn't happen then go for it, that'll be amusing to read.

As you wish. Enjoy the view as you pass the 12th floor.

I'm not sure what that idiom means, sorry.

Here's an experiment for you: take a two bar pendulum and set it at the bottom with no motion.

Now turn up the temperature in your house until it starts moving. You can put it in the oven and crank up the heat if you want

The thing that blew my mind was that they always report this in degrees Celsius.

I'm in America, even despite an engineering degree, I think in Fahrenheit.

1.5C sounds like a small number, until you remember that Fahrenheit is ~2x 1C.

So 1.5 degrees C is ~3 degrees F. Which, to me, just emotionally feels like a bigger number despite being the same empiraclly.

Similarly, it means when the IPCC is saying there might be a 7C change in 100 years, they mean a 15F change. 15F is emotionally terrifying to me. Its the difference between 85 degrees and 100. 7C is an abstract concept to me.

The US is basically the only country in the world that uses the Fahrenheit scale.

This is false. Fahrenheit is commonly used in Canada to this day. Awareness of the scale still exists in the UK as well. Any commonwealth country is likely to have awareness because metrication happened so late in those countries.

That's certainly not true for Australia and New Zealand, numbers in Fahrenheit are basically meaningless for me.

Australia and NZ had much more successful conversions to the metric system than Canada but there are people alive today who would have used the Fahrenheit scale early in their lives. Contrast this with non commonwealth countries who converted to the metric system 100 years earlier than the commonwealth.

UK Metrication: 1978 (partial)

Canadian Metrication: 1976 (partial)

Australian Metrication: 1988

NZ Metrication: 1976

French Metrication: 1858

German Metrication: 1872

Mexican Metrication: 1857

My friends in Canada talk in degrees Celsius by default. They have a basic understanding of Fahrenheit (more than Americans do of Celsius), but it's not their native temperature scale.

Yes, they use both. Celsius primarily, but still both. Ask them how hot their oven is, or the temperature of the pool.

Canadians don't know what 15f is going to look like though

275, 375, 400, 425, and hot are arbitrary settings to me, not particular temperatures. They're comparable only in that they're ordered. This is not an understanding of the scale, beyond knowing that it's talking about temperature. I definitely could not tell you how 100f relates to a standard room temperature of 18C

Sure. I was just pushing back on the “America doesn’t metric system, lol” cliche.

As a Canadian I never use Fahrenheit. The only people I know who do are at least 70.

Edit: For weather.

Honest question: what temperature scale is on your oven? My understanding is that it is likely to be Fahrenheit but I don't actually know.

The metric system is everywhere but the kitchen :)

Sorry, I meant in terms of weather. The oven is Fahrenheit (presumably because its product being sold in America too) but I don't have a mapping for that vs weather.

Ah, yeah, that's a fair confusion.

I don't think Canadian ovens feature the Fahrenheit scale because they are sold in the US. The SKUs are likely to be different and changing the display is easy. Consider cars which are similar. I assume Canadian cars feature speedometers in KPH and external thermometers in Celsius. I am curious what units your engine coolant temp uses though!

Canada is a commonwealth country and the commonwealth didn't begin converting to the metric system in earnest until the 1970s. This is over 100 years later than the rest of the world. Canada paused metrication in 1988. Cooking is likely to have been one of the last things to change because it is so common.

Pre-metrication Canada used the Imperial system and the US used the US Customary system. This means the definition of units like the gallon was inconsistent. Units in Canada seem to be influenced more by the commonwealth than they are by their southern neighbor.

Canadian cars use KPH because they’re required to by law. My Canadian Hyundai showed the temperature in F when it was new off the lot and every time I disconnect the battery, and there’s a crazy secret set of button pushes I have to do in a particular order to switch it back to C which I can never find.

A lot of things in Canada are imperial because of the influence of the US. The Ontario building code says when framing a house, wooden studs need to be on 406.4mm centers. That sounds like a really weird number, until you realize it’s actually 16”. It has to be metric, but it also has to evenly divide 4 feet, because drywall here is 4 feet wide so we can import/export from/to the US.

That sounds reasonable but I’m not certain. You could be right, especially with lumber export. Does Mexico have similar mixed units for cross border trade?

Seems more likely to me Canadian sizes are the way they are because of the Imperial system and commonwealth history.

The US never used the Imperial system so even when both countries used gallons they were different sizes.

As a Brit, I concur.

Awareness is not the same thing as familiarity.

If you give temperatures in Fahrenheit, most people outside the US (and Canada) are going to need to convert that to Celsius.

Yes, most people will. But that’s more than just America being familiar with Fahrenheit and allows for a disproportionately larger population of Fahrenheit-literate people in the commonwealth.

> disproportionately larger population of Fahrenheit-literate people in the commonwealth

Fahrenheit-literacy, at least in Australia, is practically zero for anyone under 60-70 that has lived outside the US.

Even folks who grew up with it. In Australia they have have spent the last 40 years using Celsius for everything. You tell them something in Fahrenheit and they're going to pause, have to think "How do I convert that".

But anyway, the point was that it's not false to say "The US is basically the only country in the world that uses the Fahrenheit scale."

Basically everywhere else DOES use Celsius.

For day to day understanding of weather and climate, using anything other than Celsius is going to confuse or frustrate more people than it's going to help. Regardless of whether they're in or out of the Commonwealth.

That is unfortunately not correct. I grew up in a commonwealth country, have travelled to many others, and now live in the UK. Not a single person I know in either country has even the faintest idea what Fahrenheit numbers mean for temperature. It is never used in any way in these countries.

It is used for cooking in Canada even today. Here’s a UK weather report from 1987 that uses both Celsius and Fahrenheit: https://youtu.be/NnxjZ-aFkjs. Celsius is the default but there are living people in the UK who recall using the Fahrenheit scale. This is much less common outside the commonwealth.

An example from 1987 isn't particularly a good example.

The BBC's weather reports are all in Celcius: https://www.bbc.com/weather/2643743

It’s a good example of “living memory”. You won’t find an example like this outside the commonwealth.

> This is false. Fahrenheit is commonly used in Canada to this day.

At least where I am, Celsius is the unit of choice, even among the older generation.

Even in the kitchen?

You're right, our oven and most recipes are in Fahrenheit. My kettle though is in Celsius :)

Hah, how strange. An exception to the exception. I find all this history very interesting. The US gets a lot of blame for delaying Canadian metrication but looking at the timelines the opposite seems equally plausible.

UK tabloids apparently choose to use Fahrenheit to sensationalize heat waves.

I wish warnings came with clear outlines of mass extinctions, of changes in resources, and most importantly, of cost to property owners in impacted areas.

That last one could finally cause some action because the current economy largely ignored anything else.

But if any of those outlines don't happen when expected or in a different way then people call it all bunk - same reason people discount it now because of previous dire warnings. The boy who cried wolf is the great fable for this, because ultimately there was a wolf.

"16 terawatt-hours of energy per hour" is simply "16 terawatts of power (continuously)". I want to see writers move away from the unit kWh and instead use joules, which is way less confusing and harder to misuse. Also we as a society need to respect the distinct concepts of energy (J) versus power (J/s = W).

Is that a problem of units or education?

Children sometimes confuse the units of speed and distance, but not when they get older.

In this place I'm citing from, the writer originally used Joules, but was critiqued by some anonymous commenters and switched. They noted:

> Note: Before anyone complains, I’ve deliberately conflated energy and power above, because the difference doesn’t really matter for my main point. Power is work per unit of time, and is measured in watts; Energy is better expressed in joules, calories, or kilowatt hours (kWh). To be technically correct, I should say that the earth is getting about 300 terawatt hours of energy per hour due to anthropogenic climate change, and humans use about 16 terawatt hours of energy per hour. The ratio is still approximately 18.

Out of interest, you can also convert it to calories. 1kWh is about 0.8 million calories. So, we’re force-feeding the earth about 2 x 1017 (200,000,000,000,000,000) calories every hour. Yikes.

https://www.easterbrook.ca/steve/2012/01/how-much-extra-ener...

The analogy I've seen which I like is to that of a boiling pot of water on a stove. As you increase the heat (energy) in the system, the water level fluctuates throughout. You have points where there's a higher water level, but you also have points where there's a lower water level.

Do you have a sense of what the % increase in total energy is? As in what is the denominator for the +300 terawatt hour figure?

Yeah this stat is a bit confusing to me.

Does this imply in preindustrial times the net energy was 0, or is this total energy and there’s some number not mentioned of loss?

My understanding (I'm not a climate scientist) is that yes, net energy was zero over the "right" period of time (i.e. incoming energy from the sun balanced energy lost by radiating to space).

The key technical term (IIUC) is "radiative forcing" https://en.wikipedia.org/wiki/Radiative_forcing

When we do hit whatever +1.5C or +2C, Q will be 0. The amount of energy input to the earth system isn't changing - that's defined by the temperature of the sun, it's the output that is decreasing.

What your energy look describes is dT/dt, how quickly we will reach the new equilibrium.

At the new equilibrium, the temperature is likely still to be the best descriptor of the new normal - we describe most processes and states in terms of temperatures they happen at, because it's and intensive property rather than an extensive one. You don't have to temper this 300 TW number by the mass or surface area of the earth to get a sense of what's happening when you use temperature

What's the energy number at which a glacier will melt? What's the temperature?

∆T is one of the most important numbers in thermodynamics for good reason

> What your energy look describes is dT/dt, how quickly we will reach the new equilibrium.

The rate is important, but so is the final result. A system whose new equilibrium is +10C is as useless to humanity and life and earth whether we reach it in 25 years or 200.

I agree with you that ∆T is more useful for thinking about actual effects (e.g as you noted glacial melt), but my interest in thinking about it in energy terms is (a) I think it highlights the cause more strongly (YMMV) (b) it better accomodates the possibility of the extra energy in the system having effects not so obviously correlated with ∆T

Yeah, those are interesting numbers. Another one I’m curious about is: how much faster are we burning fossil fuels than they are replenished naturally? The only number I found was a low estimate of 750x, and I think that was for oil. I assume “natural” gas is faster?

Not specific to fossil fuels, but there is Earth Overshoot Day[0]

> Earth Overshoot Day marks the date when humanity has used all the biological resources that Earth regenerates during the entire year.

[0]: https://www.overshootday.org/

Basically a few minutes into January 1st it's earth overshoot on oil and gas replenishment.

Given many fossil fuel deposits took millions of years to settle/decompose/compress, I don't think you get a proper X multiplier without an exponent greater than 6.

Yeah the time is interesting but it doesn’t directly imply anything about the flow. I’m curious about that. Ie how much new oil/gas etc is being produced by nature each year.

Found this[1] now, which gives a ballpark of 20-80k barrels/y which can vary quite a bit depending on the guesstimates of undiscovered reserves. Since we produce 80-100M barrels/y, we’re drinking from the basin about 1000x the rate that it replenishes. Or slightly worse, because we’re slurping up the yummy and easily accessible parts, whereas formation occurs everywhere. Still, the 1e6 estimate seems orders of magnitude too high (to my surprise as well).

Again, this is only for crude oil, and there are certainly more factors at play.

1: https://earthscience.stackexchange.com/questions/571/how-muc...

That answer makes a ton of assumptions, including if it is even an ongoing, continuous process with a useful enough replacement rate that can be used to compare on an annual basis. That's the more important reason to bring up timescales: if it takes millions of years to happen, estimates of "annual" production are a fun game, but just as likely to be statistical lies as actual useful on the ground facts.

(Also, as a reply points out, there's thoughts that time periods after the Jurassic epoch, if not some point earlier in the mid-to-late Cretaceous, may be much less "fertile" in petroleum and coal-producing raw elements and that for the most part new "production" by "nature" has been "stopped" and we've long just been mining further and further back in time. Which is to suggest there is no real, meaningful replacement rate at all with which to discuss.)

Given the timescales involved, I know I'm far more inclined towards pessimism that any discussion on replacement rate with respect to human lifetimes, especially on an "annual" basis rather than cumulative across the human epoch, is ignoring the forest for some statistically insignificant trees.

Oh yeah replenishment is beyond miniscule on any human timescales. Best case we use the amount of oil produced from ancient Egypt until now in ~3 days at current rate (see updated back-of-the-napkin estimate in sibling comment). This of course is based on averages and doesn’t factor in differences in “fertility”.

I was just curious about the numbers, mostly because media refuses to share anything more than the most simplistic data. For instance, if we can say that we drank 500k years or natural production in 1y, that is more meaningful (to me).

>80-100M barrels/y,

Per day...

>we’re drinking from the basin about 1000x the rate that it replenishes

Try half a million times faster.

> Per day...

Oh shit. You’re totally right.

> Try half a million times faster.

Yep. At least it’s better to have a number than nothing, even if it’s +-1 OOM. It’s pretty wild to imagine using up 500k years of fuel production in only a single year.

While googling around, found another interesting metric: ratio of proven reserves to production rate, ie how much longer can we sustain given current consumption and no new developments. That number has increased over the decades, and sits around ~50 years for both oil and nat gas and ~100+ years for coal.

https://en.m.wikipedia.org/wiki/Reserves-to-production_ratio

90% absorbed by the ocean thanks to a high specific heat it's an even more modest number in degrees

Complex systems usually tend to equilibrium otherwise they would be in constant oscillation (positive feedback theory).

As we look back in ice cores, there is variation, but not constant oscillations witch confirm a self stabilizing system.

A few negative feedback we don’t often hear:

increase of co2 have a huge effect on plant grow especially in hash deserted conditions.

Increase in temperature increase humidity: clouds that have a huge effect on reflecting radiation (much greater than co2) increase precipitation, increase plant growth in deserts.

Not to say that we should continue this experiment, but maybe not panic either and see this as the only problem: war, famine, poverty are much more important and real immediate problems instead of projected possible problems.

Im sure the IPCC authors didn't forget their climate science 101 material.

Moreover, we can tackle multiple problems concurrently, no need to make it appear we can only ever do one thing. And as it so happens, climate change tends to correlate extremely well with war and famine. It certainly appears a climate solution is going to help many other big problems along as well.

> climate change tends to correlate extremely well with war and famine

and migration.

Does it? We have fewer and fewer death because of climate (most death of climate is because of cold) We have a proxy war in Ukraine that has nothing to do with climate We have a famine in Sri Lanka that was caused by the green movement

The narrative of climate is the cause of all problems isn’t reasonable anymore.

Robust institutions disagree on whether heat or cold is more significant:

> Extreme heat and extreme cold both kill hundreds of people each year in the U.S., but determining a death toll for each is a process subject to large errors. In fact, two major U.S. government agencies that track heat and cold deaths--NOAA and the CDC--differ sharply in their answer to the question of which is the bigger killer.

https://www.wunderground.com/cat6/Which-Kills-More-People-Ex...

And while it may indeed be that cold is a more significant source of death, these numbers are hardly trivial:

2003 heatwave, Europe: 72,000 2022 heatwave, Europe: 20,000

and for the future:

> In the course of this century, the percentage of the European population dying from cold temperatures will steadily decrease, while the percentage of the population dying from heat will increase. The latter increase will start to exceed the reduction of cold-weather related mortality in the second half of this century, especially in the Mediterranean. As a result, mortality in Europe related to non-optimal temperatures will start to increase by the end of the century in a moderate scenario of climate change, and already by the middle of the century in the high-end scenario of climate change.

Derived from: Martínez-Solanas et al., 2021. Lancet Planetary Health 5: e446–54

There is no serious narrative that claims that climate change is the current cause of all problems. There is no serious narrative that can refute the obvious point that if climate chnage predictions play out, it will add greatly to all existing problems.

No it doesn't, that's just people trying to tie together two hobby-horses. Nobody is migrating to Europe or America because of climate change, they're migrating because of wealth and war.

If you live in an agricultural area and can't get sufficient water for irrigation anymore, the distinction between climate change, wealth and war is pretty immaterial.

Do you seriously think that if, in say 30 years, substantial chunks of the tropics-to-tropics range of latitude have become too hot/dry for mass agriculture, that people will not be trying to migrate?

I haven't seen anyone claiming that there is currently mass migration due to climate change. But I haven't seen anyone claiming that previous climate change events (anthropogenic or not) were not accompanied by mass migration (even if the absolute numbers of people were smaller due to total population)

You used the present tense in the post I replied to. But as you say, currently it's not true and there is no correlation between climate change and migration, because the climate hasn't actually changed anywhere near enough in any location to cause people to move.

> I haven't seen anyone claiming that previous climate change events (anthropogenic or not) were not accompanied by mass migration

What climate change events were you thinking of? Medieval warm period? I don't think there's any record of anything that we'd call a mass migration, any time in history beyond the past few hundred years. Not unless you count migrations that took place over tens of thousands of years as mass migration.

> the climate hasn't actually changed anywhere near enough in any location to cause people to move.

Where I live (near Santa Fe, NM), human civilization has moved in and out several times over the last, say, 5000 years, always correlated with the arrival of long term drought conditions. The last big movement was during the megadrought of the late 1300's, and apparently involved migrations of between 300 and 1000 miles.

Similar patterns are well known to archaeologists and anthropologists across the planet.

Also "and migration" doesn't have any tense or time context and even the GP's wording ("X tends to correlate with Y") is also largely free of any implied time period.

The Syrian conflict started after 4 or so successive years of crop failures, which have been linked to desertification and climate change.

You don't think that had more to do with ISIS than climate change?

ISIS came after the breakdown of society due to crop failure after crop failure.

Migration started end masse after Russia was invited over to kill every civilian in sight. But that is also after Assad lost the ability to control and feed the population, something he wasn't doing very well anyway, granted, but without climate change related failed harvests its hard to imagine it had spiralled out of control.

Yes we can, but what are those problems, what is the cost involved, what are we willing to sacrifice?

There is many other goals that are largely ignored because "climate" is very very popular.

I like the work of Bjorn Lomborg on that front. When we rank the problems and solution climate is not at the top.

> clouds that have a huge effect on reflecting radiation

My understanding is that clouds are inside that part of the atmosphere in which radiative forcing has decreased. This means that while they may reflect radiation so that it does not reach the ground, they do not stop (all) the energy from being trapped within the atmosphere.

> war, famine, poverty

All actual problems that will result from significant climate change, not distinct from climate change (even though they may exist for other reasons too).

> Increase in temperature increase humidity

Water vapor amplifies the effect of other greenhouse gases.

https://climate.nasa.gov/ask-nasa-climate/3143/steamy-relati...

Yes, but also with clouds that prevent radiation from reaching the ground.

> increase of co2 have a huge effect on plant grow especially in hash deserted conditions.

Which might sound good for crops but of itself can destabilise ecosystems, African savannahs are already becoming scrubbier with brush and shrubs due to more CO2 enrichment for at least ~1 million and possibly several million years. That will definitely have implications for populations of animals adapted for grassland

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