A. Unrelated species in distant regions often show striking similarities. The distribution of species is related to climate, topography, and species interactions. The biosphere is the sum total of all the earth regions where organisms live. The atmosphere has mediating effects on the earth's climate.
Ultraviolet radiation is absorbed by ozone and oxygen in the upper atmosphere.
Clouds, dust, and water vapor in the atmosphere absorb and reflect solar radiation. Radiation warms the earth's surface and generates heat that drives the earth's weather systems. B. Air currents are the result of heating from the sun. The sun differentially heats equatorial and polar regions creating the world's major temperature zones. Oceans, Land Forms, and Regional Climates A. Ocean Currents and Their Effects 1.