An uncertain future

Adventures on Earth for February 2 edition of The Review
By George E. Beetham Jr.
It is the polar regions that have moderated Earth’s climate for many hundreds of thousands of years. A succession of ice ages has come and gone as temperatures fluctuated over millennia.
We are currently in a warming period, still recovering from the end of the last ice age some 10,000 years ago.
The scars of that glaciation are still with us – glacial lakes gouged from bedrock, deposits of till, and scars on bedrock where glaciers scoured away earth and rock.
Further, the land in many places continues to rise as it rebounds from the heavy load of ice.
The warming that is taking place is normal. What is not normal is the rapidity with which it is happening.
Almost every year the sea ice in the Arctic Ocean dwindles more and more. Glaciers are shrinking, permafrost is melting, and worldwide weather is subject to storms that seem to grow in severity.
There is concern that ocean levels will rise, ocean currents might shut down, and lands that currently support agriculture could turn to desert.
These are not the rants of alarmists, but the cautions of scientists who have studied Earth’s history of warming and cooling.
What is cause for concern is that the current warming trend is happening a lot faster than anybody previously thought.
We are not yet certain of what triggers changes in weather cycles. Some suggest that Earth’s orbit may change, taking it farther from the sun every so many thousands of years. At any rate, the changes do occur.
Ice ages come and ice ages go. With the coming and going of ice, the effects of climate are felt in the life that makes its home here on Earth.
That includes us. The last ice age caused profound changes. Populations that had thrived either disappeared or shrank drastically.
Areas along the western coast of South America that were once productive agricultural lands supporting large populations dried up and became desert. Cultures that built cities and irrigation canals to support crops disappeared abruptly.
The Clovis people of North America disappeared as the climate became colder at the onset of a new ice age.
Our societies depend on a relatively thin layer of conditions that support life. Alter those conditions and the result would likely be chaos at best, a great dying at worst.
This is not some new, offbeat theory by some whacked out mad scientist. This is a fact recorded in Earth history. This is a reality that stares us in the face.
Nobody knows exactly what the effects of global warming will be. Sea levels will rise, inundating coastal cities and communities. Coastlines will be redrawn as the sea rises.
But people will be crowded into ever smaller areas. Agriculture will surely be affected. As crops dry up, the population will experience famine.
Famine may cause wars as have-nots try to take resources by force. The slow death of starvation will spread from pockets around the world to larger regions and ultimately world wide.
Our inability to stave off over-population will ultimately be decided for us. Species that outgrow the habitat on which they depend face extinction.
It’s a grim future on the face of it. On the other hand, humanity could yet decide to take steps that will allow our species, and other species that share our planet, to live on into an uncertain future.