It has been widely believed that the tropical Pacific trade winds weakened in the last century and would further decrease under a warmer climate in the 21st century. Recent high-quality observations, however, suggest that the tropical Pacific winds have actually strengthened in the past two decades. Precise causes of the recent Pacific climate shift are uncertain.

There are many challenges involved in understanding climate variations in the tropics, and how the Pacific climate might change with global warming. One study offers a surprising perspective on the mechanisms involved.