Southwest Environment

Stories written by University of Arizona students

Department of Soil, Water and Environmental Science
The Stories

Growing human population puts pressure on environment

Priscilla Garcia

house under construction in TucsonPhoto by Priscilla Garcia
A house under construction in Tucson, where population has more than doubled since 1960.

“What kind of world is your child or your grandchild going to live in 50 years from now? 75 years from now? What is that world going to look like with 15 billion people?” asked Randy Serraglio, a conservation advocate for the Tucson-based Center of Biological Diversity.

The non-profit group has a found a unique way to bring awareness to how the growing human population affects other species – Endangered Species Condoms. Each package of condoms has a catchy phrase about a specific species facing possible extinction. Slogans include: “Use a stopper, save the hopper,” “Hump smarter, save the snail darter,” and “Wrap with care, save the polar bear.”

The center is one of many environmental non-governmental organizations campaigning about how the growing human population affects other species. Others include the Sierra Club, the National Audubon Society and Defenders of Wildlife.

The human population is growing exponentially and it does not seem likely to slow down any time soon.  The world population was about 6.9 billion as of May 2011, according to the United Nations Population Fund.  The group projects that the global population will reach at least 9.2 billion by the year 2050. Meanwhile, the U.S. population hit about 309 million in 2010, and it is projected to reach about 392 million by mid-century, according to the U.S. Census Bureau.

In the U.S., having big families is often rewarded and portrayed as positive. The government provides tax breaks to families that have children less than 18 years old. Television shows such as Jon and Kate Plus 8, and 19 kids & Counting are among the reality TV shows featuring large families.  

Yet population growth creates problems for wildlife, and even for humans because of the pressure on resources.

More humans mean more resource use. Water, food, wood, and other resources will be in higher demand. Land will have to be developed to make room for houses, businesses and agriculture – even schools.

Development has affected many species, including the cactus ferruginous pygmy owl in Tucson. Much controversy surrounded the idea of building a high school on a populated pygmy owl habitat, located near what is now La Cholla Boulevard and Naranja Drive in Oro Valley.

cactus ferruginous pygmy owl Photo courtesy of B. Dunnette
A cactus ferruginous pygmy owl rests in a cage in Tucson Estates, Arizona.

The proposal to build the school arose after the sister school, Canyon del Oro High School, was deemed overcrowded, with too many students per teacher and not enough teaching space. In response, the school district bought land on which to build a new school.

The Center for Biological Diversity and Defenders of Wildlife fought to protect the endangered bird species and its habitat, but the courts upheld the school district’s right to build the high school in that location.

Once the building for Ironwood Ridge High School was finished in 2000, the pygmy owl population dropped precipitously.

“Development just basically ran over the place,” said Serraglio, who said the pygmy owls have left the area. “There’re still little patches of habitat, but they were too small, too fragmented to keep the population together.”

In Tucson, population growth is not driven by new births, but by immigration. People are immigrating to Arizona from other states and from other countries, especially Mexico. The Tucson population has nearly doubled in the past half a century. The U.S. Census Bureau reports that the population within the city limits was about 543,910 in 2009 compared to 265,660 in 1960.

Globally, population growth relates to new births. Every year, 190 million women become pregnant, at least a third of them unintentionally, according to the U.N. Population Fund. The group publishes pamphlets supporting family planning.

The Sierra Club advocates and campaigns to make society more aware of the environment and issues related to population. Members are campaigning to allow birth control to be easily accessible to all women and to increase funding for family planning programs.

"There are actually 215 million women in the world who have what is called an ‘unmet need for family planning’,” said Kim Lovell, Conservation Organizer for the Sierra Club’s Global Population and Environment program, “meaning they would like to be able to plan the time and spacing of their children but don’t have access to contraceptives or other services to be able to do so." 

Poverty may keep women from purchasing birth control. If birth control were easily accessible to more people, then the unwanted pregnancy statistic would eventually decrease, she said.

Another problem is that birth control is not easily accessible to the young public. About half of U.S. teens of ages 15 to 19 have been sexually active, according to a 2009 report by the U.S. Department of Health and Human Services. Yet minors cannot obtain birth control prescriptions without their parents’ approval.

As birth control continues to by unavailable for many, the population continues to grow at an uncontrolled rate.

“While human numbers are increasing, the number of resources we have is finite in this world. The amount of fresh water we have is finite, the amount of a lot of minerals we have is finite, even some food sources (are). So the population is growing but we have no way of increasing the availability of those resources. So resource scarcity is going to be a huge problem,” said Lovell.

As these resources are being used in larger quantities, they leave little for wildlife habitat or use for future human generations.

“It is like a Ponzi scheme. Bernie Madoff, this guy who ripped off all these people on Wall Street, he was taking money from one place, putting it in another – pretending it was new money. It was a little shell game. Well it’s kind of what we’re doing. We are stealing resources from our future generations. We’re putting off the consequences,” said Serraglio.

Will there be a cutoff point for the Earth to be able to successfully sustain humans and wildlife?

“We don’t have to tear down modern society in order to solve all these problems,” said Serraglio. “We just need to do a much better job of being realistic about the consequences of our actions. That’s what we have to do.”


Priscilla Garcia is a full-time student at the University of Arizona studying wildlife conservation and management. 

next story (class of Spring 2010)
return to main stories page