More than half the forests that covered the earth 8,000 years ago are gone today.
They’ve disappeared mostly because of human activities.
For many hundreds of years, people have used wood for fuel and for building material.
Millions of trees were also cut down and cleared away to create farmland.
Some scientists estimate that the planet is losing forests at the rate of 146 square miles (375 sq km) a day.
That equals an area the size of Florida each year.