Climate scientists are bracing for potentially lengthy El Niño and La Niña events, according to a new study revealing how the underlying mechanism for climate variability is responding to increased greenhouse gas emissions in unpredicted ways and inducing El Niño-like conditions after volcanic eruptions. The research published in Nature Wednesday details recently discovered trends of the “Pacific Walker Circulation,” (PWC) an atmospheric phenomenon relating to east-west circulation along the equatorial Pacific. The pattern plays an atmospheric role in the El Niño–Southern Oscillation, the dominant mode of global interannual climate variability that comprises two phases: El Niño and La Niña.