Global Warming

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Across
  1. 2. another gas produced by cars, less known than C02, poisonous and dangerous for health
  2. 4. the degradation of the environment, mostly caused by human activity
  3. 6. the study of weather over a very long time
  4. 7. a clean type of energy
  5. 8. a dirty type of energy, producing CO2
  6. 9. the effect responsible for global warming, natural but increased by human activity
Down
  1. 1. the gas most responsible for global warming
  2. 3. the junk produced by nuclear reactors
  3. 5. their melting cause the sea-level rise
  4. 9. the fuel of cars the most known to pollute the earth.