This could've been a quick web search on your part, but here you go:
https://www.nature.com/articles/nclimate1068
Nevertheless, net radiative forcing due to contrail cirrus remains the largest single radiative-forcing component associated with aviation.
I will convolute this conversation further by stating that contrails (like all other clouds consisting of ice crystals) warm up the planet by letting shortwave radiation from the Sun through while being more reflective in longer infrared wavelenghts, thus trapping outgoing longwave radiation. Contrails themselves are also warming the planet up. It's a small contribution in the grand scheme, but far from a trivial one.
The fourth one of those is unfortunately an almost plausible theory. Plenty of people are seriously advocating for studies into Stratospheric Aerosol Injection (SAI) in order to mitigate climate change so that the almighty free market would have more time to fix the problem without any need for systemic change.
But that wouldn't be visible to the naked eye :D
Funnily enough, contrails like all other clouds composed of ice crystals actually warm the planet up by letting shortwave radiation from the sun through while reflecting longwave (infrared), effectively trapping heat. Thcker and lower clouds are more effective at reflecting shortwave radiation.
Every other human around you has almost the same genes as you. Just being kind to others is already a tiny contribution to the survival of the species and the genes we share. Pretty sure one would have to be actively suicidial or a Bond villain in order to not to help the genes that survive on with every breath anybody ever takes.
It's not limited to direct reproduction of one's own genes. Keep in mind that we live in a society. Contributing to that society means helping others of our species (with almost the same genes) pass their genes on. Just being kind to others is already great. You're valid.
Perhaps not with conscious intent. I suppose even staying alive and contributing to a society still means that you help your relatives pass their genes on. Even gay penguins do this when they adopt an orphaned egg.
The war is bound to happen at the latest when the Himalayan mountain glaciers melt away and a sufficiently bad drought hits the region. We'll see if they have the patience to wait that long though...
If you really boil it down, all that any species ever does is in some way an attempt to propagate its genes. We aren't any different either. The artistic spark that got Davinci to paint the Mona Lisa was there due to such behaviour being an evolutionarily beneficial trait (being good at art increases the social standing of a person and thus increases their chances of reproduction). I don't want to sound cynical about this because I'm not. That's just life. It really doesn't matter. The painting is still beautiful.
So was the video linked at the end. I knew I would regret clicking the link and I still did it. Morbid curiosity is a bitch.
Draw her maximizing shareholder value
I think someone is just utterly clueless about how any of this works, and decided to wipe the slate clean and try again.
No problem, it happens.