America’s interest in the environment soared after June 22, 1969. That’s the day Cleveland’s Cuyahoga River caught fire.
It was so polluted with chemicals and garbage, it just burst into flames. The outrage after that incident led to reforms. Soon, new laws were passed. They helped clean filthy rivers, reduce air pollution, and protect some endangered species. Today, water and air in the U.S. are cleaner. A few endangered animals, like the bald eagle, have bounced back. But Earth’s health remains shaky. There are no easy ways to fix overpopulation, urban sprawl (the spread of housing and business to less developed areas), and global warming. Some people even doubt these are problems at all. Sadly, it may take something even more shocking and disastrous than a river catching fire to prove them wrong.
Every minute of every day, two acres of farmland, forest, desert, and other types of land are gobbled up by urban sprawl. Atlanta is one of many cities struggling with sprawl. Air pollution there is so bad that asthma is now the number one reason children go to Atlanta’s emergency rooms. ▶
EXISTING URBAN DEVELOPMENT
Atlanta, Georgia
◀ Earth’s population is growing rapidly. There are about 7 billion people. That’s about three times as many as there were in 1950. Within the next 20 years, it’s estimated that another 1.5 billion will be added to that. Already, at least 700 million people face serious water shortages.
Check It Out!
How long does it take a plastic grocery bag to decompose in a landfill?
Scientists estimate it takes between 500 and 1,000 years!
◀ Even innocent human activities can have a terrible impact. For instance, buildings and towers taller than 199 feet must have flashing lights on top to warn pilots. Unfortunately, the lights attract birds, which fly into them.
Today, most scientists agree that human activity is causing global warming. A hotter planet will likely cause polar ice sheets to melt. More liquid water would upset weather patterns. That would cause awful storms in some areas and droughts in others. Worldwide food production could be disrupted. However, predictions about global warming are tentative and often conflicting. ▶
◀ Even seemingly harmless animals like house cats can be a dangerous alien species. In the U.S., more than 60 million cats have been abandoned or gone wild. They kill for sport and for food. Cats wipe out millions of wild birds—many of them endangered.
◀ Through habitat destruction, hunting, and pollution, humans are crowding some plants and animals off the planet forever. We’re doing it rapidly, too. One-eighth of all bird and plant species and one-quarter of all mammal species may soon be extinct. Here are a few species that have disappeared in the last century: passenger pigeon (left), Xerxes blue butterfly, blue pike.
▲ Two decades ago, fireflies were just a pretty insect. Today, scientists know that the stuff that makes them glow can help detect contaminated food. Nature has also given us hundreds of wonder drugs. These include aspirin, morphine, and penicillin. We’ll never know which extinct plants and animals might have provided new drugs.