The Atmosphere in Balance The Development of Earths

The Atmosphere in Balance

The Development of Earth’s Atmosphere 4. 6 billion years ago • During it’s formation Earth was bombarded by many meteorites and collisions creating a lot of heat and gases • Earth had no oceans it was so hot all of the water was in the atmosphere • As Earth cooled it formed the lithosphere

The Development of Earth’s Atmosphere Early Atmosphere 4. 0 to 3. 3 billion years ago • Volcanic activity released gases forming the early atmosphere • H 2 O, CO 2, and N 2 dominant. • SO 2 and CH 4 also present • Cooling of the atmosphere causes precipitation and the development of the oceans • By 3. 0 billion years ago O 2 begins to accumulate.

The Development of Earth’s Atmosphere Oxygen: First: oxygen was probably produced by the splitting of water in the atmosphere Later: the development of bluegreen algae created O 2 as a byproduct of photosynthesis **As life continued to develop the atmosphere continued to change

The Development of Earth’s Atmosphere Living Atmosphere 3. 3 billion years to Present N 2: 78%, O 2: 21%, Argon: 0. 9% CO 2: 0. 036% Other. Gases: (CH 4, He, H, Kr, Ne) H 2 O: Varies

Today’s Atmosphere ** Create a vertical bar graph (on the bottom of the front page… next to your percentages) to illustrate the principle gases found in dry air. 3. 3 billion years to Present N 2: 78%, O 2: 21%, Argon: 0. 9% CO 2: 0. 036%

The Delicate Balance • The recycling of nutrients helps to keep the atmosphere stable – Important compounds and elements move between the atmosphere, biosphere, geosphere and hydrosphere keeping the balance – These are called biogeochemical cycles • Ex. – The Carbon/Oxygen Cycle – The Carbon Cycle – The Nitrogen Cycle

The Delicate Balance The Carbon/Oxygen Cycle (p 367) • Plants/algae consume CO 2 during photosynthesis and make O 2 • All living things consume O 2 during respiration and make CO 2 Draw a picture that illustrates this cycle: How could this cycle go out of balance?

The Delicate Balance The Carbon Cycle (p 15) • Carbon is stored in many ways moving between spheres through different processes Hydrosphere Atmosphere Biosphere Geosphere What do humans do to shift this cycle out of balance? What natural occurrences could shift this cycle out of balance?

The Delicate Balance The Nitrogen Cycle • Nitrogen is an important element in protein • Atmosphere>>Bacteria>>Plants >> Animals >> Bacteria >> Atmosphere

What do humans do to shift this cycle out of balance? What natural occurrences could shift this cycle out of balance?

The 4 spheres keep the delicate balance