Across
- 2. Published "Walden" and "Civil disobedience".
- 6. Nobel prize winner for his micro-credits system.
- 7. Published more than 300 articles about nature.
- 9. One of the first conservation thinkers.
- 11. Marin biologist who put in march the modern ambiental consciousness.
- 13. The first African American woman
- 15. One of the first Demographers.
- 17. Evolution Homosapiens.
- 19. America's first environmentalist.
- 21. recieve the Nobel prize.
Down
- 1. Notable figure in science and therapeutic medisin.
- 3. A day where people collect garbage, plant trees, sign petitions.
- 4. Get the independence of India.
- 5. Scientist, meteorologist, writer famous for the Gaia hypothesis.
- 8. Lider of the movement "New thinking".
- 10. American environmentalist who warned of the dangers of overpopulation.
- 12. Link the water contaminated because of a bomb that cause the outbreak of cholera in Londres.
- 14. The great increase in production of food grains and better management techniques.
- 16. Discover the cure and create Inmunity to Viruela.
- 18. Implement ational parks and national forests in the United States.
- 20. Danish economist focused on the development of agriculture and its relation to population growth.