Climate and Environmental Protection - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 222

Chapter 15
Climate and Environmental Protection
The air of the Earth can be divided into different layers, which are defined through
clear temperature differences. The two lower layers are important when referring
to climate change:
1. The troposphere, the layer with weather events and
2. The stratosphere, the layer above the troposphere [ 1 ].
The upper limit of the troposphere varies daily and mostly depends upon the
season and geographical latitude. In the area of the equator it is at an altitude from
16 to 18 km (from 52,459 to 59,016 ft or 9.94 to 11.19 mi), at the poles it is from 8
to 12 km (from 26,230 to 39,344 ft or 4.97 to 7.46 mi). In the tropopause between
the troposphere and the stratosphere the temperature is approximately -60C
(-76F). The ozone O 3 layer is in the stratosphere at an altitude from 25 to 30 km
(from 81,967 to 98,361 ft or 15.5 to 18.6 mi) [ 2 ].
The climate has been rapidly changing because of the rise in the concentration
of CO 2 and other Green House Gases (GHG) in the atmosphere. Global warming
on the Earth is the result of emissions of CO 2 and other climate changing gases [ 3 ].
15.1 Transportation Emissions
CO 2 is the most important Green House Gas that originates from the burning of
hydrocarbons, decomposition of biomass, e.g., from plants as well as from the
respiration processes of humans and animals. The combustion of 1l (0.264 gal (US)
and 0.220 gal (UK)) of gasoline produces 2.33 kg (5.14 lb) of CO 2. The combus-
tion of 1 l of diesel or kerosene emits 2.64 kg (5.82 lb) of CO 2 . The concentration
of CO 2 in the air is currently 370 ppm and increasing. CO 2 remains in the atmo-
sphere for approximately 100-200 years, depending on the concentration [ 4 ].