Abstract We use an Earth system model to investigate climate change effect on ocean CO2 uptake. Atmospheric CO2 increases from 1 × CO2 (285 ppm) to 4 × CO2 and then returns to 1 × CO2 at a rate of 1% per year. At 4 × CO2, climate change reduces cumulative CO2 uptake by 96 PgC, with the effect of temperature‐induced changes in ocean mixing, CO2 solubility, and biology accounting for 46%, 38%, and 16%, respectively. After CO2 starts to decrease, climate change continues to reduce CO2 uptake due to persistent ocean warming, and the relative role of ocean mixing and biology becomes more important. When atmospheric CO2 returns to 1 × CO2, climate change reduces cumulative CO2 uptake by 198 PgC, with changes in ocean mixing, CO2 solubility, and biology accounting for 52%, 23%, and 25%, respectively. Temperature‐induced changes in phytoplankton growth and remineralization rates each affect CO2 uptake more strongly than solubility, though their effects partially offset each other.
Observations from the Little Bunker
Last updated: November 30, 2025 04:25 AM
Atmospheric CO₂
426.8 ppm
+18.1
ppm/year
Atmospheric CH₄
1927.61 ppb
+2.73
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year