Answer:
El Niño
Step-by-step explanation:
The natural reason for the rising surface temperatures of the Pacific Ocean, drought in the western United States, and flooding on the Pacific coast of South America Is the El Niño.
El Niño is a climate pattern that happens when there is an unusual warming of the surface temperatures of the Pacific Ocean. This occurs at an interval of two to seven years
During El Niño, the surface waters of the Pacific Ocean become warmer than average and this is as a result of the weakness of trade winds which blows over the entire Pacific Ocean. This makes the atmospheric pressure above the ocean to decrease.
El Niño brings rainfall nd flooding to South America and droughts in the western United States