Science, technology and the environment (sc nats 1840a) - tuesday. Carbon is backbone of all life on earth. Organic molecules provide structure, food, etc. for living things. Hydrosphere (dissolved co2 gas in oceans and lakes) Co2 gas is only 0. 03% of the atmosphere, but the exchange between air and the biosphere is at the root of the carbon cycle. Water cycle driven by solar energy, causing evaporation of surface water. Water vapour carries this energy in thermal form. Vaporization of 1kg of water requires 2260 kj. Flowing water shapes of the earth over long time scales. Other macronutrients also from cycle through the ecosphere. In all cases the biosphere plays a crucial role in the cycle. Matter is continuously recycled in the ecosphere via. Matter can neither be created nor destroyed and earth is a closed system with respect to matter. The ecosphere must make do with the limited resources that are already here.