Food, water, oxygen...the three essentials of life. We humans need them to survive and we need them constantly in moderate supply. Natural ecosystems are not only adapted to natural variability (seasonal or cyclical or spatial) in water supply in the form of rain or snow, in fact, most of the times they depend on it. However, the story is not so simple for humans.
Too much water supply can lead to flood, damaging property and causing loss of life. Too less water supply can lead to draught, damage to crops, water shortage in cities and industries. We cannot control rain or natural water supply, but over time, with our technological advancement, we have learned to control the natural water with dams and reservoirs.
However, climate change is disrupting rain patterns worldwide and it's changing fast. Where and when it rains and how much, is no longer dependent on season and hence not so easily predictable as before. As a result we don't have the time to adapt to the changes to maintain the moderate flow of water vital for our survival.
Given enough time (thousands of years) natural world will adapt to drastic changes in rain pattern as well. The question is, are human beings strong enough to adapt to such changes? This adaptation usually takes several generations. With the recent pace of climate change, will Humans be given so many generations to evolve? Or will human race perish even before the evolution starts?