Any doubts about industrial activity changing the atmosphere ought to be answered by this image (below) of ship tracks off the west coast of the US captured by NASA’s Terra satellite on October 5.
These are different in composition, and larger and more enduring than jet contrails.
Although first recognised as being formed by the exhaust plumes of ships in 1965, when they were detected by early cloud cover monitoring satellites, they are now being seen by some researchers as answering one of the many puzzles about the causes of anthropogenic global warming.
And with a twist. Ship tracks cool the atmosphere by blocking incoming solar radiation … good … and inhibit rainfall … bad, very bad.
The theory advanced by the GISS and other atmospheric researchers is that the northern hemisphere, being populated by more shipping and more sulphate emitting industry, shows a lesser rate of warming than the southern hemisphere because of a differential caused by these larger sized reflective particles, which fall out of the atmosphere more rapidly than carbon dioxide.
In short, something new, and sinister, in north/south divides when it comes to the causes and disproportionate effects of global warming.
Ships burn heavy-grade marine diesel fuels that emit sulphur dioxide and have in studies been seen as adding to the load of industrially released sulphate aerosols that characterise the skies over China, India and other areas of major metal smelting and manufacturing activity.
They also liberate fossilised carbon adding to the thermal opacity of the atmosphere, which retards heat radiation back into space through the greenhouse gas affect, and drives global warming.
Jet contrails differ from ship tracks by forming where water vapour traces in the air are able to condense on fine particles of soot ejected from engines after the combustion of kerosene.
These contrails also deflect incoming solar radiation but contaminate the atmosphere with nitrous oxides, which are potent greenhouse gases, as well as liberating fossilised carbon.
This story is a variation on the 4 Corners doco via UK from about 4 years ago regarding “Global dimming” from particulates, which is running parallel to AGW, ie global warming, and potentially opposite directions.
I like to think of it as foot on the brake and the accelerator …. at the same time. The brake is particulate reflectors reducing global heating. The accelerator is increased greenhouse gases. My guess the oft argued plateau of rising temperatures may relate to the massive increase in economic driven particulates this last 10 years – China, India etc etc. Thus it masks an intrinsic increase in heat capturing physical reality, if and when that pollution is resolved – say for lung disease imperatives.
Like a car you expect something to break with brake on and accelerator revving, smoking the engine of intricate machinery and instrumentation. I would expect everything to wear out quicker. Which in out context probably means compacting of historical ages into much shorter horizon. Sadly.