What percentage of the clouds are man-made?

[petew83]

I’m located on the Jersey shore, but I’m interested in more general statistics as well.

[Richard_Pearse]

What do you mean by man made? Can you give an example of one that you consider to be man made?

[panache45]

Man-made? Do you mean they’re the result of evaporation from man-made bodies of water?

[Askance]

Here are aircraft contrails forming clouds.

One site says

If there were no other clouds in the sky, contrail cirrus clouds would cover up to 10 percent of European skies and about 6 percent over the east coast of North America

and ships can do it too.

I’ve been unable yet to find anything that gives it as a proportion of all cloud. One reason is you quickly get into the Contrail CT nut websites and all hope of actual information is lost.

[Xema]

This could be considered an example of a man-made cloud (at least the cloud looks to have been meaningfully augmented by the power station).

Here’s another example of contrails.

But the overall answer to the OP’s question has to be “A very low percentage.”

[petew83]

Thanks a lot for the feedback. I found a related link on the NASA website: Every Cloud Has a Filthy Lining No exact statistics are offered, but the general idea of man-made cloud formation is articulated.

Testing theories of man-made cloud formation has been a difficult task. In most urban areas, scientists are unable to discern exactly how pollutants contribute to forming clouds because the atmosphere over the land is too tumultuous. As an alternative, researchers from NASA’s Goddard Space Flight Center and a number of universities around the country have turned to studying “ship tracks” — clouds formed from the aerosols coming from large ships… What they have found is that the sulfur dioxide released from ships’ smokestacks could be forming sulfate aerosol particles in the atmosphere, which cause the clouds to be more reflective, carry more water and possibly stop precipitating. This is proof that humans have been creating and modifying clouds for generations through the burning of fossil fuels.

and from page 2:

A majority of cloud-creating aerosols arise from natural sources, ranging from volcanoes to microscopic ocean plants. Yet, scientists speculate that an ever growing number originate from our need for electricity and transportation. Each time we burn fossil fuels, sulfur dioxide, a gas that leads to the formation of sulfate aerosols, is released. The particles often rise into the atmosphere and create more and brighter clouds.

[Machine_Elf]

@petew83

Testing theories of man-made cloud formation has been a difficult task.

The ground of planes in the US for three days after 9/11 provided a unique opportunity to study just how much aircraft contrails were influencing cloud formation and local climate:

Contrail