Energy and Electricity - Introduction to Carbon Capture and Sequestration - page 40

Table 1.5.5 Gas efficiency and CO 2 footprint by car type

Limestone
required for
calcination (kg)

Type of
Car

Miles per
gallon

Lifetime gas
consumed (gal)

Lifetime CO 2
produced (g)

Hummer 14 13,214 114 million 259,000

Prius 50 3,700 31 million 72,500

New York. In order to maintain his 1k Flyer Status, he must make this trip
roughly 16 times (8 round trips) per year.
According to the International Civil Aviation Organization (ICAO) car-
bon emissions calculator, a passenger making a round trip from San
Francisco (SFO) to Amsterdam (AMS) in Economy class is responsible for
a carbon footprint of approximately 1.472 metric tonnes of CO 2 . Per year,
this equates to 11.78 metric tonnes of CO 2 from flights for our professor,
twice the amount of CO 2 saved annually by switching from an SUV to a
Prius. Furthermore, due to other pollutants and the altitude at which they
are released, the environmental impact of an aircraft is larger than just the
net carbon dioxide released. According to the IPCC, we should apply an
empirical multiplier of 2.7, called the radiative forcing index (RFI), to find
the actual net greenhouse effect of flying. This brings our professor's
flight-based carbon footprint up to a staggering 32 effective metric
tonnes of CO 2 annually, dwarfing the 5 tonnes saved by switching to a
Prius.
When it comes to reducing carbon emissions, it is very important to
understand the scope of the savings. In the example of the traveling pro-
fessor, a seemingly large cutback in one area may actually be insignifi-
cant compared to another. In order to combat global warming, it is
important to know how to significantly reduce emissions by targeting the
greatest contributors. There has been much debate over which is better
for the environment: car or air travel. These factors are variable depend-
ing on the flying and driving habits, aircraft, and vehicle type for the
traveler in question. In the end, both are significant contributors to our
carbon footprints and need to be reexamined as a whole.