In a study of carbon cycle up to the end of the 21st century, Cox "et al." (2000) predicted that the rate of CO2 uptake will begin to saturate at a maximum rate at 5 gigatons of carbon per year by 2100. This was partially due to non-linearities in the seawater carbonate system, but also due to climate change. Ocean warming decreases the solubility of CO2 in seawater, slowing the ocean's response to emissions. Warming also acts to increase ocean stratification, isolating the surface ocean from deeper waters. Additionally, changes in the ocean's thermohaline circulation (specifically slowing) may act to decrease transport of dissolved CO2 into the deep ocean. However, the magnitude of these processes is still uncertain, preventing good long-term estimates of the fate of the solubility pump.