North Americans have adapted to their landforms and climate regions. But, they've also changed the natural, physical environment, too. Thus, environmental change and human-impact on their environment is also worth discussing in this chapter.

As we tour North America from one region to the next in later chapters, we will discuss several key environmental challenges. Some of these include:
-over-fishing cod in New England
-acid rain in the Rust Belt
-strip-mining in Appalachia
-the diminishing Ogallala Aquifer
-fracking in the Dakotas
-urban sprawl in Las Vegas
-subsidence in the San Joaquin Valley

When each of these challenges are presented, I want you to keep the following IPAT Formula in mind.

Disclaimer: The following section discusses humans and their impact on the environment. As you read the following, I hope to remain impartial. In other words, I hope you have no idea about my political viewpoints, who I vote for, my thoughts on Global Climate Change, or any other "my side vs. your side" kinda viewpoint about controversial topics most of you know well. I have college degrees in Earth Science, Business, Finance, Marketing, and Geography, which means I learned about some pros and cons about some things.

Human-Impact on the Environment: The IPAT Formula
A useful way to understand human-impact on the environment is via application of the IPAT Formula. This very simple mathematical equation is a way to measure the environmental impact of different groups across the world. Although the IPAT Formula has been around for over 30 years, very few students have ever heard of it, even previous students of mine who already learned it. The formula is:

I = P × A × T

I = environmental impact
P = population
A = affluence (consumption per person)
T = technology (environmental impact per unit of consumption)

Essentially, the formula suggests that an increase in population (P), affluence (A), or technology (T) would lead to an increase in the environmental impact (I). Conversely, a decrease in P, A, or T would lead to a decrease in I.

It makes sense that an increasing size of population will require more resources, thus increasing the environmental impact. As John Denver once stated in a song, “More people, more scars upon the land.” Even with a declining birth rate and women on average having fewer children, population will continue to grow in North America. Why? More and more people are moving to North America and people across the world (especially in North America) are living longer.

Across the world, as more areas become developed and groups of people see increasing levels of wealth and affluence, they, on average, will consume more resources. For example, in fast growing India and China, people are acquiring more and more extra or disposable income that they can use to purchase an automobile, which is something many have never had before. More cars added to the road is great for car companies, but at the moment, automobiles are a key source of anthropogenic air pollution. Per person, high-income countries use more energy from oil, produce more air pollution, and use much higher amounts of electric power than middle or low-income countries. This clearly showcases the role of higher levels of affluence leading to an increasing rates of resource consumption.

Another good example of increasing affluence and changing consumption habits is the increase of meat and milk as food sources. Across the world, more and more people are eating meat as advancements in transportation and refrigeration technologies have allowed meat to be exported from one part of the world to another. Over the past 20 years, Brazil, in particular, has quickly increased the amount of meat exports to meet the increasing demand. For example, Brazillian steak has become an increasingly sought after food source, which is noticeable by the number of Brazillian steakhouses that are popping-up in the United States (e.g., Fogo de Chao). Increasing demand for meat has led to an increase in the number of cattle in Brazil from 25 million in 1990, to over 250 million today. That is a massive increase in just a 20-30 year time period.

Although often going hand-in-hand with affluence, the level of technology of a country or group can also impact the environment. Areas with high technology often have increased resource usage and produce higher amounts of industrial and hazardous waste. For example, consider the number of laptops or computers the average college student will go through in their lifetime. As soon as you buy a new computer, it’s suddenly out of date. Same is true for many smartphones, as once a new model of a phone is released, people who already own the latest model go out at midnight to purchase the newest one as it first hits the shelves. The short life spans of these various electronic devices reveal high levels of technology usage and change, but they also produce a lot of waste as the various components, plastics, and minerals inside are disposed. Further, after three years, faculty at IUPUI get a brand new school-issued laptop. During my last year using my laptop from IUPUI, I asked if I could keep using it since I liked it and didn’t want to change. They told me I couldn’t keep it and I had to get a new one. In other words, company policy caused me to increase my environmental impact.

Another good example of increasing technology and environmental stress is the computer chip industry. Usually, when a new laptop or smartphone comes to market, it is advertised as being lighter, more powerful than previous models. Key to these changes are continued innovation of computer chips that store memory as they get smaller and smaller. This is neat but in order to produce one computer chip, a massive amount of resources and energy is required. In order to produce one memory chip that weighs two grams, the total amount of materials and fossil fuels required to make that chip is 1,400 grams. That's 700 times the weight of the original chip. Why so many resources? Because if there is one speck of dust that comes into contact with a computer chip during its production, it’s essentially rendered useless. That means there are lots of chemicals used and tons of air constantly blowing on the chip in order to keep it clean.

Shortcomings of I = P × A × T
There are several shortcomings of the IPAT formula. This is completely fine as these problems are useful for further understanding human-impact on the environment.

First, affluence and higher levels of technology can provide a higher capability to spend resources and money on counteracting or lessening human-impact measures. For example, high-income countries can set aside large amounts of land for scenic parks, like Yellowstone in the United States. Further, they can also protect endangered species of wildlife by setting aside areas for preservation or conservation. It is much more challenging to set aside large amounts of land for conservation in lower-income countries often plagued with overpopulation, higher population density, and relying heavily upon land-intensive, primary sector jobs. Affluent countries and regions can also develop sophisticated devices and technologies to monitor environmental change. For example, research in Geography using computer mapping (GIS) identified certain industrial toxic waste sites causing higher rates of cancer among residents living nearby. These toxic sites of old, abandoned factories were then cleaned-up. In the image below, a huge solar panel park captures renewable energy from the sun, providing another example of how affluence and technology can lead to solutions to lower our environmental impact.

Second, the IPAT formula doesn’t necessarily account for the role of individual economic or government policymakers. The IPAT formula focused on different groupings of populations, like “low-income countries” or “wealthy, developed regions” but not individuals, who often also play a key role in human-impact on the environment. CEOs of Multinational Corporations, leaders of government, and influential, wealthy people all have considerable clout in all aspects of our lives, including environmental issues as they are the key decision makers.

An example of an individual playing a key role in environmental degradation is Saddam Hussein. He was the former leader of Iraq, which is located in Mesopotamia, which is one of the earliest large settlements of organized humans. Although the Middle East is quite dry, two rivers (Tigris and Euphrates) are crucial for providing a key source of fresh water. Saddam was angry at certain tribes and groups living in a marshy area along the rivers, so he essentially drained the area of much of the surface water by re-directing the river flow via dikes, channels, and irrigation. Aerial photographs from NASA satellites clearly show the evolution of this area going from lush, green vegetation to becoming a dried out, brown landscape. Soon after the end of Saddam’s rule and United States military intervention, the marshy area was returned to its previous condition.

Third, culture, or “one’s way of life” is another human-driving force not necessarily included in the IPAT formula. In other words, our friends and family are important influencers in our lives that have shaped who we are, how we act or behave, and what is important to us. For example, in the winter, when you feel cold in your home, do you put on a sweater or turn-up the thermostat/heat? Obviously one of these options uses more resources than the other, but your response is likely a result of how you have grown up over time.

Do you eat with disposable plates, cups, and plastic utensils each night? When I grew up, every night’s family dinner would include a nice, brand new red, plastic cup for each of us. This was all I knew growing up, so when I went away to college, what would I buy each week at the grocery? A bag of red, plastic cups. By using disposable plastic cups, my impact on the environment increased, but I didn’t know any better since this was how I was raised. Of course now I rarely drink out of a plastic, disposable cup since I’m aware of the resources used or depleted in order to make that cup. As I now start a family, I’m going to emphasize to my children the importance of being conscious and aware of their impact on the environment as I become a key influencer in their “way of life” and how they are socialized.