Sundin column: Water — A blessing and a curse
As I See It
Water (H2O) is the second most common molecule in the universe; the most common is hydrogen (H2). More substances are soluble in water than in any other liquid, allowing it to carry a wide variety of chemicals, minerals and nutrients. Water also has a high surface tension, which gives it the capillary action needed to overcome gravity and deliver nutrients to the tops of trees and blood through the capillaries in our bodies.
Fortunately it exists in liquid form from 0-100 degrees C (32-212 degrees F), just right for the temperature range of our planet. The ability to boil water into steam made the Industrial Revolution possible. Water also has the rare property of expanding when it freezes so ice floats instead of sinking. If this were not the case, all water on the planet would be solid ice.
There is no question that the presence of water on our planet is a blessing. Without it, life on Earth would be impossible — there would be no food, no forests, no grasslands, no animals and no people. Water makes up 50-65 percent of our bodies.
Water is extremely plentiful on Earth. There are 325 million cubic miles of water in our oceans, which cover 71 percent of the earth’s surface and comprise 97 percent of our planet’s water. Unfortunately, sea water is too salty for domestic or agricultural use. More than half of the remaining 3 percent is locked up as ice and snow in ice caps and glaciers. Most of the rest is ground water, of which half is also too salty to be of use. The surface portion of fresh water — our lakes and rivers — amounts to a miniscule 0.02 percent of the world’s water. The demands for water of steadily increasing populations are exceeding the supply in many parts of the world.
Where surface water has not been able to supply the large amounts needed for agricultural use, wells have been drilled to tap into the water in underground aquifers. But in many places that demand is so great that we are literally “mining” water — pumping it out at rates exceeding the rate of replenishment, causing wells to go dry. One of the largest aquifers in the world is the 274,000 square-mile Ogallala formation underlying most of Nebraska, the Panhandle of Texas, parts of South Dakota, Wyoming and New Mexico, and eastern Colorado and western Kansas. Wells in the Texas Panhandle have been pumped dry and in Colorado and Kansas over-pumping is lowering the water level at the rate of five feet per year.
Some coastal cities have resorted to desalination of sea water to meet their peak demands, but the cost is around $3.00 per thousand gallons, which would be prohibitive for agricultural use. Furthermore, desalination is applicable only near an ocean and is energy intensive.
Whereas too little water is creating a serious problem throughout much of the world, too much water can be even more serious in the damage it can cause. Flooding caused by hurricanes and deluges can leave massive property damage and loss of life in their wake. In the past 100 years floods have taken nearly 5.5 million lives in China, India and Bangladesh (mostly in China). Recent heavy rains on burned-over hillsides caused mudslides that buried parts of Montecito, California, taking 20 lives. In 1976 the Big Thompson Flood here in Colorado killed 140 people. Intensive rains also are washing away valuable topsoil from farms, reducing crop production and filling reservoirs with silt.
Global warming is creating more intensive hurricane-induced downpours and tidal waves, striking with increasing frequency. In 2017, powerful hurricanes deluged Houston with its third 500-year frequency storm in just three years.
In the long run, the ice caps and glaciers, which contain nearly 2 percent of the world’s fresh water, are a “Sword of Damocles” hanging over our heads. Each one percent of that ice melted by global warming will raise ocean levels two feet, with catastrophic results.
Another effect of global warming that is contributing to the rising ocean levels is the expansion of the water in the oceans due to rising water temperature, which currently is responsible for approximately half of the rise in sea levels. If we don’t very soon take effective action to reduce carbon dioxide emissions into the atmosphere, which a predominant number of climate scientists have identified as the major cause of global warming, humanity faces a very uncertain future.
“As I See It” appears on the first Thursday of the month. Hal Sundin lives in Glenwood Springs and is a retired environmental and structural engineer. Contact him at firstname.lastname@example.org.