Usually I read only one book at a time. Lately, I am reading several, one of which is Apocalyptic Planet: Field Guide to the Future of the Earth by Craig Childs. Childs is a sort of combined explorer/adventurer/scientist. He goes to places few go to see what occurs there, the wind, the flora and fauna, the weather, the climate. The next couple of days I intend to share some of his most pithy observations and ruminations. We will start with the desert. He and a friend literally wandered around the most arid and hostile portion of the Sonoran Desert in northwestern Mexico. This desert has enlarged and become more arid due to an extended drought.
Deserts come and go. If you live in a lovely lush green landscape, wait long enough and it, too, may become a desert. Six thousand years ago lakes, marshes, and grassland lay where the Sahara is today. A slight orbital change in earth’s relation to the sun caused nearby oceans to heat up, changing atmospheric conditions. Humans living there had no choice but to move. Forty per cent of the earth’s population lives in semiarid regions. Even a small drought changes survival chances for the people who live there. The Sahara, the Gobi, and the Taklimakan are growing, arable farmland decreasing. Vulnerable areas include southern Spain, Greece, Bolivia, Australia, central Asia, and our own West. The entire American High Plains (I live in the southern part) sits on top a giant desert. Without pivot irrigation, only grass grows here. In the last decade many irrigation wells have dried up or gone too saline. The giant bulges you see in places like the sand hills of Nebraska are really a sand dune sea covered with grass. Take away a little rain and here comes the desert.
Childs and his friend carried water with them and buried them with markers in the sand so they could find them later. As the desert grows in parts of India, women carry water farther and farther, an average of six miles a day, four gallons at a time. In the Sahel just south of the Sahara a difference in rainfall of just an inch or two can mean the difference between survival and starvation. Without water, there is no civilization.
What causes these changes? Human behavior and the increase in greenhouse gases are part of the reason. Humans are creating enough changes that we are moving toward more deserts, not fewer. One climate expert, Jonathan Overpeck, thinks we are seriously underestimating the severity of drought we will face in the not so distant future. Forget five and seven year droughts and think fifty years. Hadley cells also affect climate change. Tomorrow I will explain Hadley cells and how they affect our weather.
Eastern New Mexico