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Eliminating contrails from flying could be cheap

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Re: Eliminating contrails from flying could be cheap

#71

Post by evnp »

DominikPeters wrote: post #41

Given that the warming impacts of contrails are short-lived (roughly a day), I think it is a good idea to do research now on the weather forecasting needed to avoid producing contrails. But I don't really see a reason to actually start avoiding them now, with the associated costs in terms of fuel, CO2 emissions, and time. We can start avoiding them in a few decades when it might have become urgent to have cooling.

Aren't the impacts perpetual if we're creating new contrails every single day?

Taken from another comment, this seems pretty clear:

> Contrail cirrus may be air traffic's largest radiative forcing component, larger than all CO2 accumulated from aviation, and could triple from a 2006 baseline to 160–180 mW/m2 by 2050 without intervention.

[1] https://en.wikipedia.org/wiki/Contrail#Impacts_on_climate

The original article describes associated costs in time and fuel usage in the realm of 1% increase.

Re: Eliminating contrails from flying could be cheap

#72

Post by Agree2468 »

Den_VR wrote: post #69
aerostable_slug wrote: post #47

Earlier quoted context omitted.

Fun fact: the B-2 bomber has a LIDAR-based contrail detection sensor, called the Pilot Alert System. https://tridsys.com/our-divisions/optical-precision-sensors/

There’s always been something disturbing about public internet advertisements of military equipment. I suppose it’s dual use, but it seems like baiting a malicious actor to play with it in detail.

If you're ever in DC, you should check out the ads in the metro stops near the Pentagon. Seeing those kinds of ads in real life is even more shocking.

Re: Eliminating contrails from flying could be cheap

#76

Post by Retric »

Agree2468 wrote: post #72
Den_VR wrote: post #69

Earlier quoted context omitted.

There’s always been something disturbing about public internet advertisements of military equipment. I suppose it’s dual use, but it seems like baiting a malicious actor to play with it in detail.

If you're ever in DC, you should check out the ads in the metro stops near the Pentagon. Seeing those kinds of ads in real life is even more shocking.

Walked into a weapons show a few decades ago that had a full scale Abrams tank + demo camera providing good 360 degree visibility.

It was odd because I was like yea this is obviously a good idea, but also I’m not the person you need to convince here so WTF.

Re: Eliminating contrails from flying could be cheap

#77

Post by DemocracyFTW2 »

bityard wrote: post #56
DemocracyFTW2 wrote: post #27

Earlier quoted context omitted.

Wikipedia[1] states it very clearly: > It is considered that the largest contribution of aviation to climate change comes from contrails. In general, aircraft contrails trap outgoing longwave radiation emitted by the Earth and atmosphere more than they reflect incoming solar radiation, resulting in a net increase in radiative forcing. In 1992, this warming effect was estimated between 3.5 mW/m2 and 17 mW/m2. In 2009,…

> in places near busy airports I hear that a sizable fraction of all cloud cover is due to lingering contrails Hmm. I don't know about that. My understanding is that contrails only (or mainly?) form at higher altitudes. Most of the traffic around a busy airport is low-altitude take-offs and landings. I live practically next door to a busy international airport and can't say I ever notice contrails, except for a few o…

Do you ever see this kind of sky https://www.spiegel.de/wissenschaft/technik/kondensstreifen-... ? That's over Frankfurt, Germany's busiest airport. Also from the 2020 article (v. G. tr.):

> Researchers believe that the ice clouds created by contrails have contributed more to the rise in global temperatures in recent years than all the CO2 released into the atmosphere since the beginning of aviation. The annual increase in air traffic and flight routes at ever higher altitudes are particularly contributing to the formation of ice clouds. At high altitudes, contrails can combine with icy cirrus clouds and thus remain in the sky for up to 18 hours.

Re: Eliminating contrails from flying could be cheap

#79

Post by stevage »

DominikPeters wrote: post #41

Given that the warming impacts of contrails are short-lived (roughly a day), I think it is a good idea to do research now on the weather forecasting needed to avoid producing contrails. But I don't really see a reason to actually start avoiding them now, with the associated costs in terms of fuel, CO2 emissions, and time. We can start avoiding them in a few decades when it might have become urgent to have cooling.

It is already urgent.

Re: Eliminating contrails from flying could be cheap

#80

Post by stevage »

SyzygyRhythm wrote: post #44

The article mentions that some flights produce a net cooling effect. I wonder if it could be cost effective to divert flights toward contrail formation when it's predicted that they'll produce cooling (I also wonder what the actual circumstances are when they produce cooling--low surface temperatures, maybe?).

Perhaps also early morning flights where most of the contrail's lifespan will be in sun.
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