Vapor de Água na Atmosfera: do efeito estufa às mudanças climáticas

Abstract

A water molecule interacts with both solar and longwave radiation emitted by Earth’s surface. Were it not for such absorption, which accounts for 2/3 of the natural greenhouse effect and keeps the atmosphere and surface warm, climate would not be as we know it today and possible life would not be possible on Earth. The presence of water vapor in the climate system also allows for an efficient vertical transport of energy from the surface to the troposphere, modifying the vertical profile of temperature through the heat exchanges involved in the phase changes of water to form a cloud. On their turn, clouds cover 2/3 of the sky – and their interaction with solar radiation increases the planetary albedo from 15 to 30% − whereas they also trap infrared radiation that would otherwise be lost to space. In this article we will show that if we are to keep advancing our understanding of climate and climate change, we have to keep advancing our understanding of the roles water vapor and clouds play in our atmosphere.