We’re not looking for the name of the clouds in the picture. If we were, we might mistake them for cirrus clouds, whose quantity is probably affected by our mystery.
In fact, the bluish clouds are noctilucent clouds composed of ice particles that crystallise around meteoric dust. In the late 1800s, the astronomer Otto Jesse examined simultaneous pictures that were taken 35 km apart, and by comparing the clouds to the position of a star, he obtained a parallax angle. Using a tangent ratio, he calculated that they were 82 000 metres above us, at about 13 times the altitude of cirrus. For a while it was believed that an increasing number of noctilucent clouds had been forming, serving as a canary for a problem caused by our mystery. But with more data it turns out that the frequency of the formation of this cloud-type oscillates.
We are looking for something that combines with water to convert mica and feldspar into salt, sand and clay. An 18th century Scottish doctor described it as a diamond dissolved in vital air. Both its physical and chemical properties make it essential to life. Until the middle of the 20th century, it was also believed to be the source of that vital air, but that belief turned out to be mistaken.
It is part of a great cycle. Rain, oceans and the most common protein on earth remove it from the air. Volcanoes, mitochondria, and certain human activities return it to the atmosphere. Our mystery absorbs part of the electromagnetic spectrum by stretching asymmetrically and bending in two different ways, so if found in excess, it disturbs the planet far more profoundly and objectively than the way the rock band INXS perturbs my peace of mind.
I was offended by a Fraser Institute brochure that was once once distributed to Canadian schools. It claimed that because the percentage of the mystery is so small relative to the rest of its constituents, it could not possibly be harmful—an odd argument to make, given, for example, the lethal does of botulism toxin. Others such as Bjorn Lomborg do not dispute that its increasing quantity is significant but pretend that the consequences are exaggerated. I wish he knew what he was talking about. Scholar Howard Friel’s The Lomborg Deception systematically tears apart Lomborg’s thesis; it had gained credibility only because most readers had not dug into the book’s sources. Others feel so threatened by the social and political solutions being proposed to reduce the amount of the mystery that they fund all sorts of organizations to misrepresent the truth. Here is a list of those receiving such funds:
The German word for our mystery has 17 letters, and it is derived from their word for coal, kohlen. When burnt, coal produces more of the answer to our puzzle than any other fossil fuel.
Cirrus Clouds and Climate Change http://www.nature.com/nclimate/journal/v1/n1/full/nclimate1068.html
Lectures on the Elements of Chemistry: Delivered in the University of Edingburg …, Volume 1
By Joseph Black
Noctilucent clouds—not a canary for climate change http://onlinelibrary.wiley.com/doi/10.1029/2003EO280001/epdf