A large proportion of the carbon dioxide emissions that are currently being released into the atmosphere by human activities are absorbed by the surface ocean, making it more acidic. As a result, the tiny organisms (plankton), which lie at the base of the marine food web and make the surface ocean their home, are at risk. The fossil record can tell us how these plankton responded during ancient intervals of climatic change that were similarly associated with increased carbon dioxide emissions.
Deep-sea sediment cores reveal major ecological turnover before warming event 56 million years ago
