Напишите ответ на вопрос What are the greatest problems the humanity

Today many people have already resigned themselves to the fact that factories and cars pollute our air, all waste from factories merge into rivers, forests are cut down and animals are killed. After all, countries need to develop the economy, and people need to get energy from somewhere and something to eat. In any case, these are still serious problems for humanity.
But the pollution of air and rivers, disappearance of forests and different species may not be as scary as a nuclear war. This, perhaps, is the most horrible thing with which people met. It can lead to the complete destruction of all life on Earth. Thats why it is so terrible.