Likewise. In fact, I was under the opposite impression because of the benefit that sulfur enriched shipping exhaust had for our climate [0]. It looks like these clouds are thinner and don't have the same impact as that, though. While I felt that the featured article linked to their favorite site aggressively (four links to contrails.org), it looks like the google site is legitimate [1]. I couldn't find a recent [2] paper on NoAA about contrails, but presumably others have studied it.

[0] https://cpo.noaa.gov/the-unintended-consequences-of-reducing...

[1] https://sites.research.google/gr/contrails/

[2] https://csl.noaa.gov/news/2011/101_0714.html

> The proposed detours typically result in a 1% shift (and again, this is only for a small percentage of flights). That means increasing fuel use and flight time by around 1%. So if your flight is three hours long, it’s only adding an extra two minutes. For a 10-hour flight, six minutes. This seems socially acceptable to me; most people would barely notice.

It links to this post which has a little more technical explanation: https://notebook.contrails.org/comparing-contrails-and-co2/

And also this paper which is a very in-depth technical explanation: https://www.sciencedirect.com/science/article/pii/S135223102...

I understand why you're reminded of chemtrails, but it is not crazy or conspiratorial to look at these giant lines in the sky and think "those things must be doing something". You can't then make the leap to "it's intentional and it's a biological weapon to control my mind and I don't need any evidence to believe this", but you can take the next step of looking into decades of research on the topic and deciding if the conclusions make sense to you.

There's some anecdata from 9/11

https://globalnews.ca/news/2934513/empty-skies-after-911-set...

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, its 2005 value was estimated at 12 mW/m2, based on the reanalysis data, climate models, and radiative transfer codes; with an uncertainty range of 5 to 26 mW/m2, and with a low level of scientific understanding. [...] 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.

What I can say is that even in a place with moderate air traffic, you get to see lots of contrails crisscrossing the sky on some days; in places near busy airports I hear that a sizable fraction of all cloud cover is due to lingering contrails.

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

Contrails observably suppress the Diurnal Temperature Range (i.e. they make it cooler during the day).

How could this be observed you might ask? It turns out there was a study done immediately after the grounding of airplanes during the September 11th, 2001 events to take advantage of this unique incidence of effectively halting all air transportation for a few days [0]

0. https://journals.ametsoc.org/view/journals/clim/17/5/1520-04...

Well some of us are doing things to eliminate contrails ... (Shameless self promotion of my employer)

It’s funny to me that those people are all essentially a pessimistic flavor of homeopath (in the small quantities can have an effect sense).

Now they're hiding the chemtrails. It's even worse!

The radiation on the way in has a different frequency than on the way out. For example, there is UV included in sunlight. But black body heat at Earth's temperature radiates in infrared. Clouds are very opaque to infrared, and more (though not completely) transparent to UV.

Because it comes in at a different frequency versus when it goes out. Light, including UV and visible light, hits the ground, then the ground gets warm and radiates in the IR, which can be blocked by clouds.

Greenhouse gases only interact with specific wavelengths of light. A lot of sunlight comes in as visible or ultraviolet light, mostly passing through those gases. It hits the surface of the Earth and is absorbed and then re-emitted as infrared light, and a lot of that is just the right wavelength for greenhouse gases to interfere. Here's a good article about the physics of this: https://www.quantamagazine.org/the-quantum-mechanics-of-gree...

Single particles of radiation coming from the sun have higher energy than single particles radiating from the earth. Even though the total energy entering and leaving earth is at a near equilibrium.

My mental model is that a bullet leaving the barrel of a gun has much more penetrative power than that same bullet once it has ricocheted off a concrete wall.

Basic greenhouse effect: Visible light (and ultraviolet light) comes in relatively unhindered. Gets absorbed by the earth and heats it up. The heat is emitted as infrared radiation. This gets absorbed by CO2 (and equivalents) and reemitted in a random direction. Takes a long time to reach space by chance, so the energy stays in the atmosphere for a while.

Less than 1% globally, so you're right.

You don’t understand conspiracy loon logic. By the very act of hiding the chemtrails you are demonstrating that you are doing something nefarious.