Geoscience Reference
In-Depth Information
desertification, will inevitably result in in-
creased human conflict as populations
struggle for control of dwindling natural
resources. In an article in the
Atlantic
in
2007, Stephen Faris linked the conflict in
Darfur to desertification caused by climate
change. If this was one of the first climate
change-related wars, it will certainly not be
the last.
Up to the present day, human activi-
ties such as overgrazing and poor farming
practices have been largely responsible for
desertification in already arid regions. The
same is likely to be true in a time of global
change. Humans will play the major role in
causing desertification, but higher temper-
atures and perhaps other climate changes
will ease the way.
The saga of the Murray-Darling River
Basin of southeastern Australia, named
after its two main rivers, is likely a peek
into the future of a warming world in an
arid region. That much of the basin, which
is about the size of France and Spain com-
bined, was not prime agricultural land was
recognized early on. In 1865 a surveyor
on horseback, George Goyder, mapped a
line in the basin, now called the Goyder
line. It marked the boundary between ar-
able grassland and sparsely vegetated bush
country not suitable for farming.
About the time of the First World War,
settlers with government support began to
cross the Goyder line. Native vegetation was
essentially removed, crops that required
large amounts of water were grown, and
water from the rivers was over-allocated.
Soils became salinized as irrigation wa-
ter dissolved salts within and below the
soil layer; the salts then made their way
to the soil surface, leaving telltale white
soil patches. The most water-hungry crops
were cotton and rice. Livestock and dairy
cattle also consumed much water; a thou-
sand gallons of water are required to pro-
duce one gallon of milk. Nine years ago the
drought began—the worst in 120 years of
record keeping. Adding to the problem is a
rise in temperature of 1 degree Celsius (1.8
degrees Fahrenheit) over the last century,
which has increased the rate of evapora-
tion, especially in the summer. Farming
activities have been dramatically curtailed,
farm families are leaving their lands, and
the water wars have begun pitting states
against states, cities against rural residents,
and environmentalists against irrigation.
Desertification seemed to be well under
way in the Murray-Darling Basin. And then
came the deluge. In the first three months
of 2010 rains of a magnitude not seen for
decades filled the rivers, reservoirs, and
lakes all over New South Wales. Immedi-
ately politics came to the fore in the battle
between those who wished to go back to
the good old days of water for all and those
who recognized that this was likely a brief
respite in a long-term problem of control-
ling a vanishing resource. The
Economist
phrased the dilemma this way: Should Aus-
tralia save its rivers, or its farmers?
