"Dissipating haze from plane exhaust alters how sunlight reaches the Earth and may be unintentionally affecting our climate"
These headlines are from a recent article in the Smithsonian Magazine. The article is rather lean on facts, and it seems the scientists who were quoted below are rather puzzled at what they are seeing in the sky.
For example, Charles Long of NOAA’s Earth System Research Laboratory in Boulder, Colorado said at a press conference last week at the American Geophysical Union Fall Meeting in San Francisco, “This haze is caused by airplanes, and it is gradually whitening blue skies. We might be actually conducting some unintentional geoengineering here."
I find it rather funny the words that he had chosen such as in the last sentence, "We might be actually conducting some unintentional geoengineering here."
My commentary: I think this might be unintentional disclosure with a bit of added ignorance for humor...
The article further states, Long and his colleagues don’t yet have enough data to know how much of an effect the icy haze left by airplanes may be having on the climate or whether it is contributing to warming or cooling. But its existence demonstrates yet another way that humans might be altering the climate system, Long says, and “you can see this with your own eyes.”
“We’ve got a mystery here,” Long said. There must be something in the atmosphere scattering the sun’s light. “Small ice particles fit the bill,” he said.
Long thinks air traffic is the most likely source of those particles. Exhaust from an airplane engine contains aerosols and water vapor. High in the atmosphere, where it is extremely cold, the particles serve as nuclei for ice crystals, which form the bright contrails seen in a plane’s wake. Some of these contrails, scientists have found, can contribute to climate change.
As a contrail dissipates, it leaves behind a thin, icy haze. The sky may appear cloud free, but the particles are there until they fall out of the atmosphere. And while in the sky, they scatter the sun’s light in a similar way as in the proposed geoengineering projects.
“It seems quite possible that [Long is] seeing something that’s real,” says Kevin Trenberth of the National Center for Atmospheric Research. But there’s a lot more work that needs to be done to verify the find and make a connection to the climate.
Skies aren’t clear all the time, and why they are clear one day and not the next could matter. “The reason for the clear sky is a factor [Long] needs to explore more,” Trenbeth says.