SECRETS OF POLLUTION AND CONSERVATION ANDREW SOLWAY
How Have Humans Damaged the Planet People have been living on Earth for about 200,000 years For most of that time the world population was less than a million people However about 10,000 years ago the population began to grow The Industrial Revolution By the 1800s the world population was more than one billion People in Europe and North America began to make steel and steam engines Steam engines helped build bridges railways and ships but they also caused pollution These machines released smoke and harmful gases into the air 쑼 Trees being cut down in a rain forest in Sumatra Felled forests take decades to recover 4
NOTHING NEW Humans were causing damage to the environment well before the Industrial Revolution Scientists think that hunting by humans as long as 45,000 years ago may have led to the extinction of mammoths saber-toothed tigers and other large animals 쑿 Mammoths disappeared about 10,000 years ago The main cause was probably human hunting The Twentieth Century The pollution of the air continued into the twentieth century as cars choked the roads and airplanes filled the skies Meantime by 1999 the human population topped six billion What Next In this book you will see how human activities are using up resources and damaging the earth You will also discover what steps people are taking to restore the natural environment WORLD POPULATION GROWTH BILLIONS OF PEOPLE 7 50 쑼 The world population has taken thousands of years to reach three billion but it has doubled to six billion in just forty years 6 79 6 06 4 44 1 86 1 65 0 98 0 79 1 26 0 30 0 31 0 40 0 50 3 02 2 30 0 1000 1250 1500 1750 1800 1850 1900 1920 1940 1960 1980 2000 2010 2020 5 7 5 7 0 6 5 6 0 5 5 5 0 4 5 4 0 3 5 3 0 2 5 2 0 1 5 1 0 0 5 0 s n o i l l i b n o i t a u p o P l
