> 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 off in the distance around dusk.
I notice a lot more contrails when I'm out in rural "flyover country", but that might also just be because you typically get to see much more of the sky when you're out in the middle of nowhere.
> 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.
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 off in the distance around dusk.
I notice a lot more contrails when I'm out in rural "flyover country", but that might also just be because you typically get to see much more of the sky when you're out in the middle of nowhere.