By David L. Brown
According to Wired magazine’s web site, the dust storm that engulfed Sydney, Australia three days ago was “apocalyptic.” In this image taken from space, that description doesn’t seem over-the-top. You can see this and another NASA image here. According to the Wired article, the source of at least some of the dust was farmland that has been dried out during several years of severe drought.
Australia has long had a reputation as a desert continent, but more so in recent years. The Murray-Darling river system that provides irrigation water for the nation’s major agricultural region has virtually dried up after three years of dry weather. And according to environmental journalist Fred Pearce, writing a few months ago in the UK newspaper The Guardian, “the drought has cut the country’s exports of thirsty crops such as rice, sugar and wheat by more than half. And the talk down under is that the drought is a near-permanent consequence of global warming.”
According to Pearce, Australia is the world’s largest exporter of “virtual water,” water that has been converted into food crops for sale abroad. He warns that “as the Murray and dozens of others rivers run dry across the planet, water is becoming the key constraint on food production. More than land, the availability of water now defines how full the world’s granaries are – and what price we pay for our daily bread.” You can read the rest of Pearce’s article, which originally appeared on April 17, at this link.
Water is one of the key elements in agricultural production, and like many other resources it is becoming scarce. The Colorado River, before it reaches the Gulf of California in Mexico, runs dry most of the time. The water is sucked out far upstream to supply growing cities such as Las Vegas and Phoenix, and to irrigate crops on land that would otherwise be unable to produce a crop.
The Colorado is not alone in this, for rivers around the world are running dry. One factor is the diminishing snow pack and glaciers on high mountain ranges, the Alps in Europe, Himalayas in Asia and Andes in South America. Without a steady flow of meltwater through the summer growing seasons, the rivers flood early and dry up later, creating havoc among farmers and threatening the world’s food supply.
And as the rivers disappear, the dust rises to fill the air. Few of us have been around long enough to remember the Dust Bowl days on the 1930s, but we have heard stories of air so thick with dirt that some farmers had to stretch ropes between their houses and barns to keep from becoming lost. On Wednesday the residents of Sydney had a taste of what that must have been like, with pictures such as this to provide evidence of Mother Nature in a nasty mood. This is a composite of several shots showing the Sydney Harbor Bridge in a very wide-angle view, shrouded in almost-Martian red dust.
For anyone who doubts that climate change is taking place, and that it poses a real threat to human civilization, events such as this provide a sharp reminder. In his article in The Guardian, Pearce wrote that as our planet grows dryer, it “is turning a series of local water shortages into a global food crunch.” He continued:
Britain is not immune. By my estimate, Britain imports each year about 40 cubic kilometres of virtual water in the form of food (sorry about the unit, but it is more than half the annual flow of the Nile). We like to think we have few water problems, but that’s because we can rely on other peoples’ water. For now.
As the world’s demand for water continues to grow, and as more and more rivers run dry, that doesn’t look so clever. Thanks to rising global demand and the increasing uncertainly of supply due to climate change, water is destined to be a growing food security issue in the 21st century. It is not hard to imagine a future world where countries that still have water will not export it as willingly as they do now. If that happens, importers like Britain could find themselves in trouble.
Food is the bottom-line requirement for human existence. We have heard that it shares that distinction with shelter and clothing, but it takes only a crude hut and a few scraps of cloth to provide those other needs. Without adequate food, no human can long survive. And without adequate water, there will not be enough food to provide for the 6.7 billion human beings now present on Planet Earth.
For more on the dangers to our environment, you may want to read my review of Pearce’s book, “With Speed and Violence — Why Scientists Fear Tipping Points in Climate Change,” posted here on May 12, 2007. Use the search field at the upper right to find that and other related articles.