Geography Reference
In-Depth Information
burn coal without polluting the air — such as by removing impurities before being burned or by de-
veloping smokestacks that are akin to giant filter cigarettes.
Second, coal is bulky and unwieldy. Although it can be crushed, mixed with water, and transported
short distances by pipeline as slurry, you can't send coal down a pipeline a long distance or pour it
into a gas tank — although it would be a much more convenient and widely applicable if you could.
Thus, considerable research has focused on coal
liquefaction
.
In any event, coal, like petroleum, is very unevenly spread across the planet (as shown in Figure
16-3). While substantial reserves are found in North America, Europe, and Asia, South America and
Africa are largely without any. Thus it has limited geographic prospects. In addition, and as discussed
in the sidebar, some coal reserves are much more valuable and useful than others.
Figure 16-3:
The
geography
of
coal.
Natural gas
Natural gas exists in abundance and, as far as fossil fuels go, has attractive qualities. It burns very
cleanly (producing only the most modest air pollution), requires little or no processing before use,
and can be transported cheaply and efficiently overland by pipeline. Its versatility is also a point in
its favor. In addition to heating a majority of the homes in the United States, natural gas is used to
generate electricity, provide energy for some kinds of light manufacturing, and power an increasing
number of motor vehicles.
On the downside, natural gas is not well-suited for transoceanic trade. Pipelines of that length are not
feasible. Shipping is possible when
liquefied natural gas
is involved, but that is not cost effective.
Also, natural gas is, after all, a non-renewable resource, so someday supplies will be exhausted.
That is not going to happen anytime soon, however. Given current data on reserves and annual pro-
duction, the world has about a 70-year supply of natural gas. But people who know the pertinent
