The Physical Environment An integrated system of four spheres
What are the four spheres? Atmosphere –Trophosphere 0-10 miles Virtually all water here Ozone layer here 80-85% of mass of atmosphere –Stratosphere miles –Mesosphere miles –Thermosphere >50 miles Little known
Except for water and ozone, composition is fairly constant up to the thermosphere Density goes down as you go up
Lithosphere Geology Crust of earth
Hydrosphere Water layer on earth Carries heat, moves it pole-equator and vice versa Influenced by the Coriolis effect
Biosphere Layer where life is Deepest ocean - highest mountain tops Next week we’ll look at various biomes (specific divisions of biosphere) Ecology applies here
Cycles Between the Spheres Law of Conservation of Energy - matter cannot be created nor destroyed Matter and energy can be transformed into various forms Gas-liquid-solid Biogeochemical cycles
Abundances Life is very different from its environment
Carbon Cycle Looks complex; but it is all about withdrawals to and additions from atmosphere Withdrawls: –Photosynthesis –6CO2 + 6H20 + energy ---->C6H12O6 + 6O2 –Accumulation into tissues Fossil fuels Shells = limestone
Oceanic geological Terrestrial Atmosphere
Carbon Cycle Additions: –Cellular respiration –C6H12O6 + 6O2 ---> 6CO2 + 6H2O + energy –Literally exhalation –Combustion Of such fossil fuels Global warming = too much CO2 accumulating in atmosphere
Carbon cycles goes through all 4 spheres Atmosphere - CO2 gas Hydrosphere - CO2 gas, also in tissues Now in Biosphere When organisms die now tissues become fossilized; part of lithosphere Fossil fuels burned releases CO2 gas back to atmosphere