We all see trails growing in clear blue skies, and we know the importance of the saturation point.
We know highly supersaturated, 125% – 140%, air allows for clouds to form, and subsaturation results in clear blue skies.
We have learned that jet engines are flying water-making machines.
We know that the word “chemtrails” has been socially stigmatised with conspiracies that make it an impossible subject to investigate or talk about.
We have learned that “trace” amounts are actually astronomically large numbers. We know the metallic elements and the high sulfur content of the fuel make the trails grow logarithmically, directly behind the engines. The hygroscopic ice nuclei are able to scavenge the water in the supersaturated exhaust and hold it to resist dissipation in subsaturated areas, and also accelerate trail growth in saturated areas.
Now we will consider the effects of these trails on the climate.
The earlier NASA study recoded trails rising at 10 centimeters per second, and a 2021 study by Gao confirms how the heat from the sun can be used to make the particles left by ordinary plane exhaust rise and stay aloft for many days.
Simulations have found that only 10 micrograms per meter of black carbon in the exhaust plume is enough to raise material well into the stratosphere.
Once in the stratosphere they are able to travel far from where they were made.
A 2008 study by Meehl found the effect of atmospheric black carbon changed the Asian monsoon season.
It was found that the rainfall over parts of India, Bangladesh, Burma, and Thailand decreased while they increased over Southern China.
These findings were confirmed in his 2009 study.
These changes in world climate were noted in a 2020 study by Xie which reports distinct responses of Asian summer monsoon, and atmosheric temperature to black carbon aerosols and greenhouse gases, but black carbon aerosols had a greater influence than greenhouse gases.
The impact of black carbon aerosols on monsoon circulation is far greater than previously understood, challenging assumptions that low-level thermal feedbacks were the main driver of monsoon changes. Trails are a far greater influence than is CO2.
A 1997 study by Sassen reports “The evidence indicates that the direct radiative effects of contrails display the potential for regional climate change at many midlatitude locations.”
This was also confirmed in a 2009 study by Haywood in which the radiative forcing of a single trail was measured as being 10 w/m2 during the day and 30 w/m2 at night.
A 2010 report by MIT for the IPCC estimated the radiative forcing of CO2 as 1.6 w/m2.
A study by Gettelman found considerable changes in weather during the lockdown of 2020.
COVID lockdowns were a natural experiment. This confirms the understanding of the dramatic effects on climate from trails.
Trails are thin, high clouds that cool the surface by reflecting sunlight in summer but warm it by trapping heat in winter. The COVID-19 lockdown revealed this seasonal tug-of-war by temporarily removing contrails and exposing their hidden influence on regional weather patterns.
This article by Zelenski (2015) for Smithsonian Magazine explains that airplane contrails are causing “accidental geoengineering” by whitening the blue sky. Charles Long from NOAA confirmed this idea, saying, “We might be actually conducting some unintentional geoengineering here.”
The issue of “Global Dimming” was first noticed when scientists observed a decrease in sunlight reaching the Earth.
After confirming the Sun’s output hadn’t changed, they concluded that aviation aerosols from regular airliner exhaust were altering the atmosphere, and blocking sunlight.
These aerosol particles, which act as ice nuclei, stay in the sky long after the trail disappears and scatter sunlight, sometimes creating visible halos around the Sun.
This confusion over intentional and unintentional geoengineering is the reason none of the recent US Bills have succedded in preventing chemtrails.
The bills are written to exclude unintentional geoengineering, Even though trails from ordinary commercial airliners are very effective at altering the climate, they are not done with that intention. The intention of the flights is to carry passengers from one place to another, so trails are not geoengineering.
We can see that trails are responsible for major changes in the climate. Locally, we often see them change our days from sunshine to cloudy, but they can also rise high into the stratosphere and cause major climate changes far from where they were made.
They cause increase in surface temperatures and have a far greater local raditive forcing effect than does CO2. During lockdown a decrease in temperature was noted and the changes trails cause in climate patterns were exposed.