A 2014 Reuters analysis found that, before 1971, water reached flood levels no more than five days every year (on average) in several U.S. east coast cities. Since 2001, however, that number has risen to 20 days or more (on average).
Answer:
pollution and overpopulation
Ice caps and glaciers is your answer.
Millet is grown in the sahel because it is the main staple of the people there. also the risk of crop failure is greatly reduced when grown alongside cowpea and sorghum. hope this helps :)
The correct answer is rain forests increase greenhouse gases. I know for sure it's not the first or third answer. Rain forests are the habitats for many animal and plants but I'm pretty sure its over 50% not 30%.