1. The world's population is growing.

2. There are now over 7 billion people in the world.

3. During the 20th century, the population grow from 1.65 billion to 6 billion.

4. It's now growing at a rate of around 1.1 percent per year.

5. That means an increase of about 80 million per year.

6. By 2024 the population is expected to be around 8 billion people.

7. The growth rate used to be higher.

8. In the late 1960s, the rate of growth was about 2%.

9. Since then, the growth rate has declined.

10. It is estimated that the growth rate will be less than 1% by 2020.

11. By the year 2050, the growth rate should be even less.

12. Even with a declining growth rate, the population will continue to grow.

13. But it will grow at a slower rate.

14. In the past 50 years, the world's population has more than doubled.

15. It has doubled from around 3 billion in 1960 to more than 7 billion in 2011.

16. Even with a declining growth rate, the population will continue to grow.

17. But it will grow at a slower rate.

18. In the past 50 years, the world's population has more than doubled.

19. It has doubled from around 3 billion in 1960 to more than 7 billion in 2011.

20. The rate of growth varies by country.

21. The growth rate in India is more than twice that of China.

22. And the growth rate in Nigeria, which is in Africa, is more than twice India's growth rate.

23. Russia, on the other hand, has had a negative growth rate in some years.

24. When a country has a negative growth rate, its population is decreasing.