Climate Change: The Long View
Bob Grover
Friday, January 27, 2012
Geologists look at climate change from a long view. Jim Snook of Emporia is a retired petroleum geologist, and he agrees that climate change is occurring — in fact, climate change is continuous. However, he insists that carbon dioxide in the air is only one of several causes.
In a recent conversation, Snook said, “There is climate change occurring. When you take the longer view — millions of years — carbon dioxide as a factor is minute, and many other factors contribute.”
Charles David Keeling’s research, corroborated by other scientists, shows an increase in atmospheric carbon dioxide during the last 100 years. A scientific theory popularized by former vice-president Al Gore focuses on carbon dioxide as a major determinant of climate change and global warming.
Many scientists note that carbon dioxide in the atmosphere causes some solar radiation to be trapped within the atmosphere — radiation that would otherwise be transmitted back into space. If there were no carbon dioxide or other “greenhouse gases” like methane in the air, heat would escape Earth more easily; consequently, the retained heat causes the temperature on Earth to rise — a “greenhouse effect” and global warming.
Snook argues that the carbon dioxide composition of the atmosphere has increased only 80 parts per million (PPM) in the last 150 years — from 280 PPM to 360 PPM. Water in the atmosphere accounts for 10,000 PPM to more than 40,000 PPM, a far greater contributor to the greenhouse effect
Snook agrees that we are now experiencing global warming, but insists that the increase in carbon dioxide as a percentage of the total atmosphere is less than 1/100 of one percent. “We have a huge greenhouse effect in the 10,000 to 40,000 parts per million in the form of water vapor, water droplets, and ice crystals in the form of clouds.”
He notes that the water content in the atmosphere is constantly changing, and it’s “such a vast amount.” “Seventy percent of the earth’s surface is ocean, and there is continuous evaporation and condensation that is precipitation, and this changes rapidly.”
Snook says that the sun plays the major role in climate change: “Earth gets all of its energy from the sun. The sun’s energy output is variable, and the sun’s output reaching the earth is more variable. In the long term, the distance from the earth to the sun changes, and when it changes from the closest to the farthest away--it takes about 93,000 years for a complete cycle. That’s part of the climate change. Also, the tilt of the axis of rotation goes from 22 to 26 percent. You have a lot of variables that cause climate change — short term and long term.”
Another probable contributor to global warming is an increase in the heat island effect caused by the cities, towns, and airports worldwide. Also, Snook notes that minor changes in the energy output of the sun are far more significant than anything that happens in the atmosphere.
Snook points out that over time there have been radical changes in climate, even in more recent history. “If you look at the Medieval Warm Period, about 800-1200 AD, it was warmer than it is now. Between the Medieval Warm Period and now we had the Little Ice Age, from 1450 to 1850. We’ve been warming since the Little Ice Age until now.”
While he argues that the increase of carbon dioxide in the air is but one of many factors in climate change, it is the major factor in the increase of human population. Atmospheric carbon dioxide is a major building block of all plants, and the increase in plants increased our food supply. Over the last 150 years the 28 percent increase in carbon dioxide has mirrored the population increase from one to seven billion people. “I think within 300 years we will have used all of our fossil fuels. When the excess carbon dioxide is absorbed by the oceans, the human population will go down rapidly,” Snook said.
The issue of global warming and climate change is complex. While the infusion of carbon dioxide in the atmosphere contributes to a greenhouse effect, a long view of climate change from a geologist’s perspective, measured in millions of years, attributes other factors as well.
After retiring as a geologist, Snook wrote Ice Age Extinction: Cause and Human Consequences (Algora, 2008). In the conclusion to his book, Snook characterizes the enigma we face analyzing climate change: “We are just passengers on a multifaceted and changing earth, which is far more complex than humans will ever fully understand.”