4 Conditions For Life On Earth
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The document outlines 4 key conditions for life on Earth: 1) a constant temperature between -50 to 50 degrees Celsius maintained by the greenhouse effect, 2) the importance of water which makes up over 50% of living things and allows for metabolic processes, 3) the importance of gases like nitrogen, oxygen, and carbon dioxide which living things use to produce energy and build biomolecules, 4) the role of the atmosphere in shielding from radiation while trapping heat and maintaining oxygen at 21% levels required to support animal life.
4 Conditions For Life On Earth
- 1. The 4 Conditions for Life on Earth
- 2. 1. A Constant and Relatively Mild Temperature -50 to about +50 degrees Celsius Average temp. has been between 10-20 degrees C for 3.5 billion years The Greenhouse effect allows for heat in the atmosphere (carbon and water vapor) Without proper water and carbon, the earth would be -73 degrees C.
- 3. The Greenhouse Effect Plants play a significant role in creating a stable temperature through releasing water vapor and oxygen by the processes of photosynthesis and transpiration They also absorb heat from the sun’s rays and limit the albedo effect
- 4. The Real Greenhouse Effect
- 5. 2.The Importance of Water First water likely came from volcanic activity and the vapors released Biologists believe earth first began in the oceans – blue-green algae Oceans trap heat and distribute it around the world (2/3 of the earth) No living thing consists of less than 50% water Water is the metabolizing agent that allows plants and animals to dissolve minerals and nutrients to create energy
- 7. 3. The Importance of Gases 78% nitrogen, 21% oxygen, carbon dioxide 0.03% The plants have removed most of the carbon dioxide that originally existed and produced lots of oxygen Without life on earth, carbon dioxide would increase The production of carbohydrates, fats, and proteins require oxygen, carbon, and nitrogen atoms from the atmosphere, and hydrogen from water
- 8. 4. The Role of the Atmosphere Layer of gases about 80-100kms thick Helps maintain a consistent temp. Shields earth from collisions with cosmic particles (meteors) Oxygen levels at 21% allow for life, if they drop, animal life would not be possible, if it exceeds 25% most plants would be consumed by fire Oxygen is produced by plants and consumed by animals and the burning of plants and fossil fuels
- 9. The 4 Spheres Lithosphere – earth’s crust (soil, rocks, and minerals) Hydrosphere – earth’s water Atmosphere – the gases in the air Biosphere – all living things (plants, bacteria, animals)