This is hysterical... "...The analysis found that vapor from airplanes may be altering the climate through accidental geoengineering..." The brilliant tarts at Harvard don't seem to understand that contrails are just...clouds. So we should now attempt to stop all clouds from forming? That won't be good for rainfall. Crops won't like that, no sir.
my understanding of that sentence is they accidentally realized that while individual con trails have minuscule effect, 'en-masse' could be used as a solar shade.
My understanding of the sentence is that the entire article is wrought with fear-mongering. En- masse contrails? So, the same as a layer of stratus clouds that causes an overcast day. Wow. Here4, just delete that article from your memory, it is the worst form of neo-hippy tripe. If folks want to stop the spread of pollution in the atmosphere, they can start by not intentionally dispersing pollutants into the atmosphere. The experiment is unneeded, and scientifically impotent. And if the world governments want to stop increased "sun-shade", they should stop with the silver iodide cloud-seeding stuff, if that still goes on. (and if it ever did.) LET NATURE TAKE IT'S COURSE!