mr cole crewdson known for his work on the ozone layer raised the possibility of spraying into the stratosphere to reflect a portion of solar radiation and cool down near. a particle suspended in the air in the lower part of the atmosphere the troposphere or the upper part of the stratosphere. that atmosphere in the stratosphere which begins around 10 kilometers above the earth particles move around horizontally rather than falling straight back down to earth. and one thick card that we do you know steve all the climate models. and this way we can simulate for example in the present climate that we can also simulate future . we cannot really test. in that way but it would be flawed because that would mean we would have to inject a large amount of gus's or air assault in the stratosphere but we don't know what it does and we don't know what the impacts are so best to really right now and use crime or large amounts to simulate the effect. this example shows the spread of a cloud of aerosols from a single source over a 2 year period the particles move around horizontally within the stratosphere an