The weather effects，both good and bad，are felt in many places.Rich countries gain more from powerful Niños，on balance，than they lose.A study found that a strong Niño in 1997-98 helped America’s economy grow by 15 billion，partly because of better agricultural harvests：farmers in the Midwest gained from extra rain.The total rise in agricultural incomes in rich countries is greater than the fall in poor ones. But in Indonesia extremely dry forests are in flames.A multi-year drought(干旱) in south-east Brazil is becoming worse.Though heavy rains brought about by El Niño may relieve the drought in California，they are likely to cause surface flooding and other disasters.