Contrails can't change the weather

[faethor]

Weather and unjustifiable conspiracies

Of course, as the article notes - if someone's going to believe in a conspiracy no amount of accurate or correct science will sway them. (my 2 cents) They simply create a bigger conspiracy to hold on to their littler conspiracy. It's turtles all the way down.

 

[Glaucus]

It's like a religion. Those who believe can't be swayed with facts or logic. Arguing with them is a waste of time. Conspiracy theorists are the same if not worse because they think they have the facts and logic on their side but on close examination it's clear that their perception of everything is grossly distorted by preconceptions.

 

[FluffyMcDeath]

Weather and unjustifiable conspiracies

Should have gone with HAARP can't control the weather.
Contrails, as demonstrated by a nice little study when all air traffic was grounded for a few days after 911, produce significant daytime cooling. Contrails can also persist for a long time producing extensive but wispy high altitude cloud. The idea that chemicals could be added to aircraft fuel to enhance cooling, for example, has been mooted by researchers. In fact, carbon soot is already a "chemical" produced by jet engines and can act to nucleate ice crystals to form cloud. Other "chemicals" would include sulphur which is a normal contaminant in crude oil derived fuels and creates sulphate particles in the upper atmosphere that tend to reflect heat back into space and cool the planet. European and US air travel regulators have been looking at whether to mandate low sulphur fuels lately and, while they estimate that air quality improvements could mean a reduction of few thousand deaths globally, it could lead to more global warming.

So, yes. Contrails do effect the weather.

 

[Glaucus]

I seriously doubt it. And I'm not the only one.

9/11 research challenged: contrails aren't turning up the heat

The fact is that wasn't a proper experiment, there was no control and it's not repeatable. They did little to prove it wasn't a fluke and other scientists think it most likely was because those kinds of deviations are fairly common.

So no, we really don't know if contrails affect the weather but probably not.