Contrails and Climate Change

Let’s start off with a few words about ConTrails. Some clear day you may look to the sky and see a long straight white line being drawn on the clear blue sky by a high-flying military aircraft. The aircraft of choice is most likely a B-52 bomber from an Air Force base on a training mission at high altitude. Some days there is one trail and some days there is a criss-cross panoply of several ConTrails. So what are they and how are they formed?

At the root, ConTrails are the “products of combustion.” As aircraft jet fuel is fed to a jet engine with a proportionate amount of oxygen (air) and ignited it is forced out of the jet engines’ tailpipe giving the push to move the aircraft forward. That exhaust is a mixture of hydrocarbon molecules and water vapor, commonly H2O. Two parts hydrogen and one part oxygen.

It’s that water vapor that hits the high altitude air at  -65 degrees Fahrenheit and instantly freezes to a white trailing cloud. This is the common ConTrail made of ice crystals.

Sometimes, depending on the temperature/pressure conditions that ConTrail can be a turned into a vapor (gas), a solid (ice crystals) or a liquid. You can see that happening in some ConTrails because they vanish soon after leaving the engine exhaust and disappear. If you’re observant you will see some begin to grow in width, becoming wide spread. This state is what is of interest because these ConTrails are now cloud-like and like a cloud  block out the sun on the earth’s surface below.  

Haven’t you been sitting in the sun at one time, nice and warn and a cloud passes over blocking the sun and suddenly you’re shivering with a chill? The cloud passes and you’re warm again. Then let’s look at the ConTrails effect in a similar way only it’s more widespread and stays for a longer time. At 65,000 feet where the ConTrail is  formed it grows in width maybe a mile and some times more. At that altitude it may look pencil thin but as air masses move this ConTrail will grow and grow it does. 

So what is the earthly effect of this ConTrail? It casts a shadow on the earth and that shadow is also about a mile wide and as long as the ConTrail is. So what happens then? Well, this cooled air mass then gets heavier than the surrounding air mass and a downward flow starts, a flow that wasn’t there earlier before the ConTrail affected it.  It’s like the butterfly flapping its wings creating the “butterfly effect.” This is described in Wikipedia as, “in chaos theory, the butterfly effect is the sensitive dependence on initial conditions in which a small change in one state of deterministic nonlinear system can result in large differences in a later state.”  Or, the butterfly flapping its wings in Brazil may cause a hurricane in Florida.

The monster air masses moving from west to east from the Pacific ocean over California are interrupted in their path. They hit this colder denser air dam from the ConTrail shadow and move upwards getting colder as they rise. This begets chaos and chaos begets climate change. But now this disturbed air keeps moving eastward over the plains; change in climate patterns as they go.

All of this is not instantaneous, it is subtle changes disturbing  the norm.  Maybe an increased number of tornados over the central states or more that usual snow on the eastern seaboard. The end result is a cry of ‘climate change.’

So the next time you’re glancing to the sky and see that ConTrail forming be aware, be very aware. But sleep soundly because your Air Force is doing what we pay them to do.

Richard Ruth

Milpitas Resident