An increase inthe amount of particulate matter(dust and Smoke) in the atmosphere result in cooler world temper

Question

because

the dust refalects solar radiation or more ir is emitted inti space or more sunlight is absorbed by Earth

Answer 1

the dust reflects thermal radiation

Answer 2

They reflect the sun's rays higher up in the atmosphere and don't get reflected back because there isn't so much CO2 between the dust and space