In the context of which of the following do some scientists suggest the use of cirrus cloud thinning technique and the injection of sulphate aerosol into stratosphere?

The techniques of 'cirrus cloud thinning' and 'injection of sulphate aerosol into stratosphere' are both prominent concepts within geoengineering or climate engineering. These are proposed large-scale interventions in the Earth's climate system designed to counteract global warming. Cirrus cloud thinning aims to reduce the radiative forcing (warming effect) of cirrus clouds by making them less opaque, thus allowing more heat to escape from Earth. Injecting sulphate aerosols into the stratosphere aims to mimic the cooling effect observed after large volcanic eruptions by reflecting incoming solar radiation back into space, thereby reducing the amount of solar energy absorbed by the Earth's surface and atmosphere. Both methods are explored as potential ways to mitigate the adverse effects of climate change and reduce global temperatures.