Which effect on global CO₂ levels results when El Niño suppresses coastal upwelling?

💡 Explanation

Reduced upwelling during El Niño decreases nutrient availability; this limits phytoplankton growth due to nutrient limitation, a bottom-up control. Therefore, CO₂ uptake lessens because phytoplankton draw it down, rather than increase like during algal blooms or affect decomposition significantly.

• Which outcome is accelerated within deeply incised alluvial valleys?
• Which outcome arises when a major river's stream gradient decreases due to regional tectonic subsidence?
• Which geographic effect results from variations in solar insolation related to Earth's orbit around the Sun?
• Which impact occurs to soil composition when prolonged, intense rainfall leads to substantial downward water movement?
• Which mechanism shapes ventifact development given limited dune sand?
• Which risk increases when joints' orientation parallels coastline cliffs?