Homework 2 (I need your written answers for questions 2-4, due at the next class)

1. Review all the slides: concepts and facts

2. Ask questions
3. Guesstimate on human impact, carbon footprint, and ecological footprint
4. William Ruddiman proposed the 'early Anthropocene' hypothesis in which he claims that at the dawn of civilization, deforestation by early humans for agriculture released a large amount of carbon into the atmosphere, and the resulting greenhouse effect prevented the onset of an ice age that would have already taken place by now.
    Do you think this hypothesis is plausible? Discuss your reasons briefly. We will discuss/debate this in-depth in a later class.

Homework #1
Review of course material and questions to ponder on
   Please finish before the next class. You don't need to turn in anything, but I will ask about Question 4 in class later


1. Please review all slides we covered in class 

2. Review  carefully some basic numbers/units/concepts that will be very useful for the remainder of the class (Slide 'Some basic stuff')

ppmv: parts per million by volume

What's the atmospheric CO2 concentration now, in ppmv and percentage?

What's the atmospheric CO2 concentration before the industrial time?

What is the greenhouse effect?

What is the so-called climate sensitivity?

CO2 concentration vs. total mass of carbon in the atmosphere?

1 ppmv of atmospheric CO2 concentration corresponds to about 2 PgC of carbon in the whole Earth's atmosphere

1 tC (tonne of carbon) is contained in 44/12 (=3.7 or about 4; molecular weight ratio of CO2:C) tonne of CO2 (you can remember it simply as: 1 tC = 3.7 tCO2)

1 PgC (Peta gram or 10^15 gram) = 1 GtC (Giga-tonne of carbon)


3. Study carefully the slide "The disturbed carbon cycle' by

1) Compare the magnitude of the carbon pools

2) Compare the magnitude of the carbon fluxes

3) Try to remember these numbers, at least the relative magnitude of these pools and fluxes

Things to discover

4. Carbon footprint (answers to the questions below were Not clearly stated in class; tell me how you got the numbers):
   How much carbon an average American emits every year? An average person in the world?


5. Read the book 'CO2 Rising' in the next two weeks