Contrails Map • Hacker News Board

Re: Contrails Map

#11

Post by ejago53 » Sat, Dec 20, 2025, 10:04 AM UTC

ekunazanu wrote: post #8

extropy wrote: post #6

I'm not following the logic why contrails cause net warming. Why nuclear blasts - that also introduce lots of particles in atmosphere cause a cooling effect - "nuclear winter"?

The difference is that water vapour is a greenhouse gas. IIRC the net warming effect of clouds is a function of altitude.

Yes, also a mushroom cloud from a nuclear blast blocks light from passing through which reduces heating on the ground whereas contrails are thin which lets light through but still retains heat below them.

Re: Contrails Map

#12

Post by rkomorn » Sat, Dec 20, 2025, 10:07 AM UTC

msuniverse2026 wrote: post #10

Sieyk wrote: post #4

I was expecting this to be a gag about chemtrails. I am glad I was wrong.

[flagged]

> I am just so embarrassed on behalf of people who still think this doesn't exist and is all some conspiracy without any basis.

Downvoted for this, at the very least, and also downvoted for the fact you think you're entitled to an explanation even with your tone.

Re: Contrails Map

#13

Post by jibal » Sat, Dec 20, 2025, 10:12 AM UTC

msuniverse2026 wrote: post #10

Sieyk wrote: post #4

I was expecting this to be a gag about chemtrails. I am glad I was wrong.

[flagged]

> I am just so embarrassed on behalf of people who still think this doesn't exist and is all some conspiracy without any basis.

There's plenty of basis for thinking it's uninformed or intellectually dishonest conspiracy mongering.

And please don't rant at HN.

Re: Contrails Map

#14

Post by SequoiaHope » Sat, Dec 20, 2025, 10:32 AM UTC

rottencupcakes wrote: post #9

extropy wrote: post #6

I'm not following the logic why contrails cause net warming. Why nuclear blasts - that also introduce lots of particles in atmosphere cause a cooling effect - "nuclear winter"?

They don’t cause net warming, it’s transient. If we stopped flying tomorrow it would go away quickly. But we keep flying. But even with that the amount of warming this continuous effect creates is quite small and negligible compared to greenhouse gas warming and isn’t really worth talking about.

I think this link hit HN in part due to the new Simon Clark video on contrails which mentioned it. Simon discusses the claim that contrails can be avoided for a small fuel penalty, reducing the overall effect on climate change a given flight would have. Apparently some airlines are already exploring this and Google includes contrail impact estimates on their flight search. So maybe it is worth talking about.

https://youtu.be/QoOVqQ5sa08

Re: Contrails Map

#15

Post by andai » Sat, Dec 20, 2025, 10:51 AM UTC

jibal wrote: post #13

msuniverse2026 wrote: post #10

Earlier quoted context omitted.

[flagged]

> I am just so embarrassed on behalf of people who still think this doesn't exist and is all some conspiracy without any basis. There's plenty of basis for thinking it's uninformed or intellectually dishonest conspiracy mongering. And please don't rant at HN.

I'm out of the loop, didn't the government admit this stuff a few years ago?

I was at a presentation in Croatia recently about weather modification in Yugoslavia. This is considered public knowledge there. When Yugoslavia fell apart, Croatia was no longer permitted to engage in weather modification.

The main method discussed was the use of small rockets. It was used for agricultural purposes.

Re: Contrails Map

#16

Post by complex_pi » Sat, Dec 20, 2025, 11:07 AM UTC

extropy wrote: post #6

I'm not following the logic why contrails cause net warming. Why nuclear blasts - that also introduce lots of particles in atmosphere cause a cooling effect - "nuclear winter"?

It's not specifically about logic. It is possible to model and measure the radiative effect of contrails.

Re: Contrails Map

#17

Post by dns_snek » Sat, Dec 20, 2025, 11:14 AM UTC

andai wrote: post #15

jibal wrote: post #13

Earlier quoted context omitted.

> I am just so embarrassed on behalf of people who still think this doesn't exist and is all some conspiracy without any basis. There's plenty of basis for thinking it's uninformed or intellectually dishonest conspiracy mongering. And please don't rant at HN.

I'm out of the loop, didn't the government admit this stuff a few years ago? I was at a presentation in Croatia recently about weather modification in Yugoslavia. This is considered public knowledge there. When Yugoslavia fell apart, Croatia was no longer permitted to engage in weather modification. The main method discussed was the use of small rockets. It was used for agricultural purposes.

The problem is the unsubstantiated logical leap from "weather modification is possible" to "contrails behind commercial aircraft are secretly dispersing chemicals in order to control weather".

If I was an evil government figure trying to secretly control weather, there are better ways of doing that (e.g. drones, rockets) than orchestrating a conspiracy that requires hundreds of thousands of people to stay quiet for decades.

Re: Contrails Map

#18

Post by p-a_58213 » Sat, Dec 20, 2025, 11:57 AM UTC

The team behind this is world-class. Among other things, they have developed a python library that could be used to model contrails in your own projects.

https://py.contrails.org

Re: Contrails Map

#19

Post by nephihaha » Sat, Dec 20, 2025, 12:23 PM UTC

Sieyk wrote: post #4

I was expecting this to be a gag about chemtrails. I am glad I was wrong.

They definitely increase the cloud cover where I live. Very noticeable, you can often see which clouds were created by them... And that's without the conspiratorial stuff.

Re: Contrails Map

#20

Post by reactordev » Sat, Dec 20, 2025, 12:32 PM UTC

It states that half of aircraft pollution is from contrails made of aircraft soot.

I’d like to see the literature and discovery of aircraft soot.

As an engineer who has built aircraft, I find this fascinating. I would like to measure my amount of soot. How does one go about measuring how much soot I have?

Obviously if my exhaust ports are black that’s bad but I’m genuinely curious about this as I’ve always assumed “black smoke bad, white smoke ok”. As for contrails, disturbing the atmosphere is going to cause some freezing (clouds) at that altitude, at that temperature. How do you suggest we mitigate that? Fly lower and burn more fuel? Fly less and tell people to take the train or that their package will arrive next week?