Summary: Biogeochemical Cycles And Cc Mitigation

Read the summary and the most important questions on Biogeochemical cycles and CC mitigation

• 1 Week 1

  This is a preview. There are 11 more flashcards available for chapter 1
  Show more cards here

• What are the natural cycles driven by?

  >>99% energy from the sun
  <<1% energy from radioactive decay from the earth's interior

• What are some of the features that are only made possible because of life on earth?

  Co-existence of organic matter and O2
  N2-rich atmosphere
  climate

• Is the on-going current decline in O2 a problem for human life?

  No; the concentration of O2 in the atmosphere is much higher than the concentration of CO2

• How has atmospheric CO2 changed in the past 800.000 years?

  Oscillation between 180-280 ppm
  
  increase to current value of 421.20 ppm(07/2024)
  - occured very rapidly
  - is far out of range of past 800.000 years

• What is the time scale of the carbonate-silicate cycle?

  Entire cycle takes about 100-200 million years

• What is the feedback loop of the carbonate-silicate cycle?

  Negative feedback loop
  
  E.g. High rates of volcanic and tectonic activity result in temporary increased atmospheric co2, and global warming, this increases weathering and eventually steady-state is restored.

• What is the effect of life on the carbonate-silicate cycle?

  It does not affect the cycle rate but it does affect the amount of material through increased weathering and/or carbonate precipitation

• What are the two organising principles of biogeochemistry?

  Thermodanynamics 
  Stoichiometry

• What are the two laws of thermodynamics you know?

  1st law: energy can be converted from one form to another
  
  2nd law: chemical reactions should proceed spontaneously in direction of lower free energy until reaching equilibrium

• What is the role of organisms in regard to thermodynamics?

  Living organisms must continually process energy to counteract basic laws of thermodynamics