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Which one of the following is related to global dimming? (a) Fall of atmospheric pressure due to increased particulates (b) Raise of atmospheric pressure due to increased particulates (c) Raise of temperature due to increased particulates (d) Fall of temperature due to increased particulates
Explanation
Global dimming refers to the gradual reduction in the amount of global direct irradiance at the Earth's surface. This phenomenon is primarily caused by an increase in atmospheric particulates, such as aerosols (sulfates, black carbon, and dust), which result from human activities like burning fossil fuels. These particulates act as a 'planetary parasol' by reflecting and scattering incoming solar radiation back into space. Additionally, aerosols serve as cloud condensation nuclei, leading to the formation of brighter clouds with more droplets that further reflect sunlight. This reduction in net radiation flux at the surface leads to a cooling effect, effectively masking some of the warming caused by greenhouse gases [3]. Consequently, global dimming is characterized by a fall in surface temperature due to the increased concentration of these particulates.
Sources
- [3] https://www.nature.com/articles/s43247-024-01442-3