What is Geology?
Geology, broadly, is the study of the Earth. Geologists and friends—geophysicists, geochemists, geobiologists—study the rocks that make up the Earth, the history of the Earth as recorded in those rocks, and the processes that change those rocks. This includes oil and ores, landslides and volcanoes, dinosaurs, meteorites, and much more. Most geologists are involved in one of four areas: i) finding valuable things in the Earth (gold and silver, diamonds, oil, building stone, sand, and gravel, clean water, etc.); ii) warning of geological hazards (volcanic explosions, earthquakes, landslides, groundwater pollution, etc.); iii) building an operators' manual for the Earth (Earth System Science); and iv) informing/entertaining (What killed the dinosaurs? How has the Earth changed over time?). Many geologists do more than one of these, or even all of them, at the same time, and there surely is a lot of overlap.
Historically, most geologists have worked at finding valuable things. These geologists have been truly successful, too successful for their own good, in fact. Some of the things we extract from the ground are very cheap today (after you subtract inflation and taxes), so there have been fewer jobs for geologists with companies mining some things than in years gone by. Oil prices have fluctuated a lot over time, with boom-and-bust cycles occurring over and over, but there still are some good jobs in this area. The US used to spend a lot more money on cleaning up groundwater pollution than we have recently, but it turns out that an immense amount of that money was spent on lawyers arguing about paying for cleanup rather than on scientists and engineers cleaning up. A lot of geologists are not happy with this situation and hope that finding and restoring clean water will be more vigorously pursued in the future.
Warning of geological hazards is also a growing field. As more and more humans build houses on floodplains, debris-flow deposits, and other indicators of past disasters, these people become more dependent on someone to tell them if and when the trouble will return. Many geologists favor a different approach—find out where the dangers are, and then don’t build in those places—but real estate developers often don’t listen. (In the spring of 2012, a bill was introduced to the North Carolina legislature—although not passed in its original form—to make it illegal to use the best science to tell coastal people the regions that might be attacked by the sea. This echoed efforts a century before by developers in San Francisco to discredit scientists who correctly argued that the earthquake that had just devastated the city meant that additional earthquakes were possible or even likely. Other such efforts to ignore or downplay large dangers have occurred and continue to occur.)
The disaster of Hurricane Katrina in New Orleans and its surroundings in 2005 showed the dangers of building in harm's way. With almost 1400 dead, and over $100 billion in damages (that is $300 for every person in the US!), Hurricane Katrina definitely caught the attention of many people. Interestingly, geologists had known of the impending disaster, and warned of it, for decades, as the city slowly sank beneath river level and sea level. Thousands of Geosciences 10 students had studied this issue in the years before the storm struck (and you will get to look into the issue soon). Fortunately for New Orleans, the storm’s strength had ebbed before it hit the city, or the damage could have been even worse.
The operators’ manual for Earth is a new idea. It may be the most important thing geologists can do for the future of humans. We, humans, are everywhere today — living on every continent, tilling more and more of the land, claiming as our own more and more of the productivity of the planet. We have changed the forests, changed the soils, changed the atmosphere, changed the waters—nowhere on Earth remains free of our imprint. A scientific analysis from the year 2023 found that all the humans on Earth together weigh about 390 megatons, our domestic animals outweigh us at 630 megatons, and we dwarf all the wild mammals on Earth together at only about 60 megatons—add up all the whales and elephants and wildebeest and moose and mice and…, and the number is still small compared to us. Credible estimates indicate that we and our close friends—cows and corn and chickens and house cats and Chihuahuas—are using more than half of everything made available by the planet, leaving less and less for all other species. We are managing to support roughly 5 billion people pretty well (out of the 8-plus billion of us here), with the population projected to reach 9 or 10 billion in a few decades, so we are planning on greatly increasing, perhaps even doubling, the number of people we support well.
Given that we are doing this, and we will continue to do so, many thinkers believe it would be wise to have a better idea of how this works and what we are doing. You would not try to repair a fine watch or a cell phone without knowing how it works—take a few pieces out and you may never get it running well again. We are doing precisely that to the planet, changing a lot of things we do not understand. Earth System Science is the attempt to understand the planet, its water, air, ice, rock, and life, well enough to learn the consequences of our actions so that we can make wise decisions. Earth System Science is still a new science, providing much that is useful but with much more to learn, and many of us believe that it is an incredibly important effort.
And there is always education and entertainment. Some people like to know things, and geologists have some of the most interesting stories to tell. We hope you agree after taking our class!