Today, the following are known as effects caused by kosa, but it is not known clearly how kosa works completely: When being placed over forests or sea, kosa grains provide the so-called umbrella effect to prevent the penetration of the sunlight (cooling effect); When being placed on snow areas or glaciers, they provide the effect of warming the air through absorbing sunlight (heating); Being able to become nuclei of generating clouds, they provide the effect of controlling the distribution of clouds above the earth; Because substances included in kosa affect the growth of plants and planktons, kosa also provides the effect of affecting the carbon cycle.
黄砂の粒子が森林や海洋の上にあるときは太陽放射を遮蔽する日傘効果（冷却）、黄砂の粒子が雪や氷河の上にあるときは太陽光線を吸収して大気を暖める効果（加熱）、黄砂の粒子が雲核となって地球上の雲の分布を左右する効果（冷却・加熱）、黄砂に含まれる成分が植物やプランクトンに作用することで炭素循環に作用する効果などがあり、結果的にどう作用するかは現在はっきりと分かっていない。