The Age of Perpetual Drought - The Ripple Effect: The Fate of Freshwater in the Twenty-First Century - page 115

dropped, evaporation accelerated, and the remaining water began to accumulate silt
and salts. By early 2009, the lakes had sunk to a meter (3.2 feet) below sea level. Further
evaporation could expose mud on the lakes' bottoms to the air, which would release sul-
furic acid and a host of poisonous metals into the atmosphere. If this happens, the lakes
will turn into what experts have termed irrecoverable “toxic swamps.”
One option is to flood the dying lakes with seawater, to prevent acidification—a
drastic measure that would destroy the freshwater ecosystem, disrupt bird migrations,
and leave behind a salty residue. “It will end up being a dead sea,” said Dr. Paul Dalby ,
an independent Australian water consultant. “The options are toxic swamp, dead sea, or
pray for rain.”
In a 2009 speech in Atlanta, Georgia, Dalby warned the United States, “Australia is
where America could be in a few years…. Climate change is not necessarily a slow and
gradual process. There are valuable lessons to be learned from the Australian experi-
ence. You can be forewarned and forearmed about how to deal with [climate change]
before it arrives, and perhaps not go through so much of the pain that we had.”
One positive consequence of the Big Dry, he said, was that Australian farmers had
learned new tricks. They now cover their crops with mulch and use underground irrig-
ation systems to reduce evaporation. More significantly, farmers won the right to use
a certain amount of water free, and a trading system now allows them to sell or buy
those rights (called usufructuary rights) from each other. This market-based approach
allowed resources to go to the most productive use. Profitable growers could use more
water, while farmers with marginal yields could still make a living by selling their water.
The allotments shift, depending on the weather. In some areas, irrigators are restricted
to 18 percent of their allocation during the drought.
Australian vintners, who export some $1 billion worth of wine a year, have been es-
pecially innovative; as grape supplies drop, prices have risen overall. Water is reserved
for older vines, which produce more profitable grapes. Newer vines are shorn of all their
leaves, wrapped in bandages, and kept barely alive with minimal irrigation. When more
water is available, the newer vines are allowed to flourish.
Australia has yet to reconcile that while it is the driest continent, it remains one of the
world's biggest exporters of “ virtual water ,” or the water used to grow exportable crops.
Invented by Professor John Anthony Allan, of King's College, London, virtual water is a
way to assess how much water is used to produce commodities. The water used to grow
wheat, for example, is said to be “virtual” because once the wheat has been grown and
is shipped to market, it no longer contains the actual water used to raise it. Measuring
virtual water helps judge which crops are best suited to a given climate. Cotton, rice,
corn, and alfalfa are water-intensive crops and are not as well suited to arid regions as
are fruits and nuts.