Apocalyptic Planet-Part Six: Cold and Ice


In spite the current global warming, Earth’s past and perhaps distant future is ice.  This past winter, much of the Midwestern and Eastern United States thought it had already returned.  A friend, forced to attend a mandatory training session, reported that the trainer from Minnesota made fun of those who claim we are warming.  Even though it was March, Minnesota remained a frozen land.  I kept thinking to myself, wait until the heatwave hits this summer.  Then what will he think.

Craig Childs likes adventures most of us would avoid even if we feel rather adventurous.  He flies into a camp in Greenland where scientists, all men, study ice.  Ice does not encourage a lot of life.  No animals, no plants, nothing here–the Greenland Ice Sheet.  The weather remains dreadful most of the year.  On the few days when they can leave camp, these scientists go out to take readings on remote sensors stuck in the ice.  These sensors enable them to determine how the ice changes.  They get to the camp by ski plane during the windows of clear weather which sometimes do not occur for days.  What kind of scientists go here?  Physicists, chaos researchers–yes there is such a thing as chaos research, climate change scholars, ice climate researchers, and an occasional adventurer.  The chaos guy’s interests focus on what cannot be predicted.  He records creaks, snaps, ice sounds.  These giant glaciers emit considerable noise.

This Greenland Ice Sheet is nothing like the ordinary ice we think of.  It’s dry and hard.  Shovels do not work very well.  They use chisels to break off big chunks.  The wind shrieks over the ice, sometimes at 80 miles per hour. It is twenty below in the summer.  Not twenty below Fahrenheit, twenty below Celsius.  To urinate, a guy has to wear parka, mittens, the works, and goes out to the pee pole far enough from camp not to contaminate the drinking water made from melted ice.  Now and then some poor bird gets lost or blown off course.  They don’t last long usually.  Here holes drilled find bedrock thousands of feet below the ice sheet.  One drill came up with spruce tree needles.  Once this very same location was a forest.  Greenland was green!

What happened?  One driver is solar radiation changes caused by the earth’s tilt.  Over tens of thousands of years, Earth swings away from the sun and then back.  These are nearly imperceptible changes.  It takes only a little.  The opening and closing of the Bering Strait also affects climate change.  Current warming aside, Earth’s recent past  (the last 60 million years) is an ice age, partly caused by teutonic plates moving and mountain building which reduced carbon dioxide in the atmosphere, making it colder.  All this points to human behavior as a factor in the current change to warmer. When Childs asked these scientist if they thought another ice age was on the way, they all laughed.  One noted that change in and of itself is unpredictable.  As one of my students might say, “Duh!”  On its own Earth makes quick climate jumps.  They did make a point to say , “We are tinkering to the point we could initiate a jump on our own.” Some computer models say global warming can lead to another ice age by disrupting climates.  One scientist indicated that humans may be preventing or delaying the next ice age by warming the earth.

Who knows what the future may bring even one thousand years from now.  In the long distant past the entire Earth was covered with ice.  At other times the poles were forests.  Maureen Raymo, a paleoclimatologist at Columbia University says, “My feeling is that there is never going to be another ice age as long as there are humans on the planet.”  Some scientists think we will develop a technology to control the level of carbon dioxide in the atmosphere.  Raymo notes, “If they (meaning humans) were smart, they’d get their act together.”

Apocalyptic Planet-Part Two: Hadley Cells, Weather and Drought


Hadley cells, the wind systems in each hemisphere , form patterns of atmospheric circulation in which warm air rises near the equator, cools as it travels poleward at high altitudes, sinks as cold air, and then warms as it travels back to the equator.  They are named after George Hadley, an English scientific writer.  Tropical regions receive more heat from solar radiation than they radiate back to space and such areas have constant temperatures.  More simply, warm air rises (heat rises) and then flows poleward at high altitudes, cools, drops, and flows back toward the equator at lower altitudes.   Then the process repeats itself.  When the air rises and leaves these tropical areas, it loses moisture as it heads to subtropical areas.  The majority of the worlds large deserts lay in these subtropical areas.

Hadley cells are expanding.  Precipitation has declined in tropical areas since 1970.  As I mentioned in yesterday’s post, Southern Asia, the Sahel, Southern Africa, the Mediterranean, and the US Southwest are getting drier and drier.  Even wetter areas now experience long dry spells between extreme events of rain and snow.  Examples in the US include the cold and snowfalls in the Midwest and Eastern Seaboard this past winter.  Texas and New Mexico continue to experience a prolonged drought.  In the next thirty years scientists predict a 30 per cent decline in water resources.

In some places both governments and individuals create innovative and sometimes simple measures to counteract desertification.  In India near the Thar Desert, the government mandated the dispersal of grass seed to hold the ground.  Studies indicate that the grass seed grew better when planted by hand than when dispersed from airplanes.  Also in India orans, small sacred groves, have helped preserve shrubs and grasses and even trees, a genetic bank that would otherwise have been lost.  Childs describes how his friends who live on the outskirts of Tuscon have coaxed their water table fifteen feet higher, using ordinary shovels and hard work.  They built contour traps and “massaged” the ground.  Hardly worth noticing except when it rained, the rain sank into underground catches.  Their properties now look like small areas of refuge in the vast desert.  In some areas of the Sahel people have been able to plant and nurture trees in such a way that areas of green exist where they had disappeared.

Archeologists and geologists know that periods of drought occurred repeatedly for millions of years.  For humans and the animals we know, drought has never been easy.  Large areas of civilization cannot exist without water.  We can affect our future in positive ways and prepare ourselves if we choose.

Apocalyptic Planet–Part One


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.

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Northern Arizona

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Eastern New Mexico

 

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Texas Panhandle