Evaluating the Effectiveness of Natural Carbon Sinks Through a Temperature-Dependent Model

Articles have recently been circulating in the media around the world, claiming that natural CO2 sinks have “suddenly and unexpectedly” ceased to function. It turned out that these articles were based on a single preprint of a meanwhile published article. Its reasoning is essentially based on the large spike of CO2 concentration growth in 2023 despite constant anthropogenic emissions. However, there are no obvious indications that photosynthesis or oceanic sinks have decreased. In this paper, it is shown that besides the natural sink systems of the land plants and oceans, the variability of natural emissions has to be considered. Based on a previous publication, it is made evident that natural emissions are temperature-dependent. Therefore, the careful analysis of monthly sea surface temperature and CO2-concentration data for 2023 and 2024 gives a consistent explanation for the rise in atmospheric carbon concentration growth without referring to the implausible hypothesis of failing carbon sinks. The temperature dependence of natural CO2 emissions indicates a clear causality from temperature to CO2 concentration. This is confirmed by the time shift between temperature and the subsequent concentration change. This suggests a new component in climate models with implications for climate policies.