Chapter 19, Key Finding 4

The enhanced carbon uptake capacity of ocean and terrestrial systems in response to rising atmospheric carbon dioxide (CO2) will likely diminish in the future. In the ocean, warmer and more CO2-enriched waters are expected to take up less additional CO2. On land, forest maturation, nutrient limitations, and decreased carbon residence time in soils will likely constrain terrestrial ecosystem response to rising CO2 (high confidence).