You might have heard snippets of conversations about food and water shortages, changing climates, and other worrisome topics. If you've brushed them off as unimportant or unrealistic, you might want to reconsider that. If you think that humans are too small to impact their environment or cause disasters, consider this — it's already happened.
During the 1930s, when the Great Depression was already wreaking havoc on the lives of millions, a series of droughts hit the American prairies. The droughts were simply natural events, but the damage done to the land — and subsequently to the residents' lives — could have been easily prevented.
Many people likened it to the end of the world, and some thought the end times had actually come. They had good reason: the natural disasters that arrived closely resembled the Biblical plagues, such as the dust blotting out the sun and making it dark at midday. Because so much of the land had been rendered barren, swarms of insects and herds of rabbits really did descend on towns in search of food, as their natural habitats provided nothing.