Have you ever wondered why we celebrate Earth Day? It's a little like a birthday party for the Earth. But why do people want to pick up trash, plant trees, and recycle? Why do we have Earth Day?
In the late 1700s, great changes took place in the world. New machines that made products were invented. Some machines did certain jobs more quickly and easily. Factories were built. Industries were established. This time came to be called the Industrial Revolution.
Over the years, more factories were built. They used a lot of coal and oil for fuel. These natural resources take millions of years to form. They are called fossil fuels. Factories began using them up faster and faster.
All of these factories and industries also created a lot of pollution. Factory smoke stacks sent black clouds of smoke up into the air. Dirty water filled with harmful chemicals traveled through pipes from the factories. It wound up in rivers and streams. The polluted water then ran into the oceans.
In the 1900s, cars were built. Because the factories could make cars so cheaply, more and more Americans bought cars. Gasoline is needed for car engines to run. Gasoline is another fossil fuel. Car engines send out smoke that pollutes the air, too. At the same time, the population of the Earth was growing faster than ever before. More and more people were living in the same amount of space. More and more factories were being built to provide for more people.