1. These problems are worsening, not getting better.
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2. It was the spring of hope; and it was the winter of despair.
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3. Global warming results from the burning of fossil fuels, such as petroleum and coal, resulting in the release of greenhouse gasses into the atmosphere.
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4. The evaporated water then returns as rain, which is vital to areas that are naturally arid.
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5. Millions of people are moving away from rural areas in other countries. In other words, in much of the world there is an exodus from the countryside to the cities.
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