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.”