Feel free to browse the whole report as I only made some highlights regarding "chemtrails" scientifically referred to as: aerosol injection, aerosol trails or Solar Radiation Management. Again, aerosol injection is only one method to geoengineering, and if you have any critical thinking skills it is very apparent what is occurring. Once again, this is "their side of the story" thus being "toned down" and it is clear they are uncertain of anything regarding geoengineering, only the risks they state, which are definitely occurring.
http://fas.org/sgp/crs/misc/R41371.pdf
"Aerosol injection is the dispersal of aerosols, such as hydrogen sulfide (H2S) or sulfur dioxide(SO2), into the stratosphere to direct solar radiation back toward space or absorb heat, thuscooling the Earth. Military aircraft, artillery shells, or stratospheric balloons could be employed to inject the aerosols. The annual cost for sulfur particle injection using airplanes is calculated to be several billion dollars, depending on the amount, location, and type of sulfur particle injected into the stratosphere. However, there has not been any testing to determine whether the theoretical predictions will match reality.Aerosol injection seeks to imitate large volcanic eruptions. Indeed, many studies have based aerosol injection simulations on data gathered and analyzed from the Mount Pinatubo volcanic eruption in the Philippines in 1991, which led to a reduction in global temperatures, though not distributed evenly across regions.
Sulfur releases from volcanic eruptions are random, with cooling impacts that have lasted no more than a few years. Aerosol injection would probably have to occur several times over decades or centuries to offset radiative forcing caused by greenhouse
gases due to the short effectiveness time frame of aerosol injection.
The benefits and risks of aerosol injection would not be evenly distributed around the globe. Apotential benefit, in addition to cooling of the planet, could be reduced or reversed sea and land ice melting (as long as the aerosols don’t settle on and darken snow and ice).
Some risks could be drought in Africa and Asia leading to a loss in agricultural productivity, the GHG impact that would accumulate from transporting the aerosol to the site of injection, stratospheric ozone depletion, weakening of sunlight for solar power,
a less blue sky, and obstruction of Earth-based optical astronomy."
"•Changes in regional and seasonal climates. SRM techniques may alter
precipitation patterns, which could have consequences for ecosystems and
affected societies.
•Ozone depletion. Under certain circumstances, use of SRM techniques such as
sulfate aerosol injection may lead to ozone depletion which would allow harmful
UVB rays to reach the Earth.
•Preservation of non-CO2 greenhouse gases. SRM techniques applied in the
stratosphere or space lessen the amount of ultraviolet radiation striking the
Earth’s atmosphere, which is likely to extend the atmospheric lifetime of non-CO2
greenhouse gases that are more potent than CO2.
•Diversion from more permanent solutions. If societies conclude that SRM
techniques can provide quick relief, they may invest less in developing and
deploying more permanent GHG emission reduction solutions.
•“Unknown unknowns.” The history of the Earth’s climate demonstrates that
small changes may result in abrupt changes, raising concerns about unknown
effects of large-scale geoengineering."
