The Intergovernmental Panel on Climate Change (IPCC) claims that carbon dioxide (CO_{2}) production from industrial activity (such as fossil fuel burning and other human activities) has increased the (CO_{2}) concentrations in the atmosphere. Because it is a greenhouse gas, elevated (CO_{2}) levels will increase global mean (average) temperature. In this section, we will examine the increasing rate of carbon emissions on Earth.
In 1955, there were (globally) 2 billion tons of carbon emitted per year. In 2005, the carbon emissions more than tripled to reach approximately 7 billion tons of carbon emitted per year. Currently, we are on the path to doubling our current carbon emissions in the next 50 years.
1) Label the vertical axis C, where C represents the number of gigatons (billions of tons) of carbon emitted, and label the horizontal axis t, where t is the number of years. Let t=0 correspond to 2005.
(A “wedge” is a strategy to reduce carbon emissions over a 50year time period from zero to 1.0 GtC/yr (gigatons of carbon per year).
2) Find the equations of the flat path and the seven lines corresponding to the seven wedges.
a) Flat path (no increase) over 50 years (2005 to 2005) 
b) Increase of 1 GtC over 50 years (2005 to 2055) 
c) Increase of 2 GtC over 50 years (2005 to 2055) 
d) Increase of 3 GtC over 50 years (2005 to 2055) 
e) Increase of 4 GtC over 50 years (2005 to 2055) 
f) Increase of 5 GtC over 50 years (2005 to 2055) 
g) Increase of 6 GtC over 50 years (2005 to 2055) 
h) Increase of 7 GtC over 50 years (2005 to 2055) [projected path] 
3) For each of the seven wedges and the flat path, determine how many total gigatons of carbon will be reduced over a 50year period. In other words, how many gigatons of carbon would the world have to reduce in each of the eight cases?
a) Flat path 
b) Increase of 1 GtC over 50 years 
c) Increase of 2 GtC over 50 years 
d) Increase of 3 GtC over 50 years 
e) Increase of 4 GtC over 50 years 
f) Increase of 5 GtC over 50 years 
g) Increase of 6 GtC over 50 years 
h) Increase of 7 GtC over 50 years [projected path] 
4) Research the “climate carbon wedge” concept and discuss the types of changes (transportation efficiency, transportation conservation, building efficiency, efficiency in electricity production, alternate energies, etc.) the world would have to make that would correspond to each of the seven wedges and the flat path
a) Flat Path 
b) Wedge 1 
c) Wedge 2 
d) Wedge 3 
e) Wedge 4 
f) Wedge 5 
g) Wedge 6 
