New evidence from analyzing fossil plankton shells has revealed that CO2 concentration in the Earth’s atmosphere was about triple current levels around 52 million years ago. It then declined to levels close to current atmospheric CO2 concentration 34 million years ago when Antarctica began to glaciate.
Based on the latest results from WHO air pollution is now the world’s largest single environmental health risk, linked to 12% of all global deaths. Citizen scientists can contribute to measuring air pollution using a low cost sensor measuring atmospheric particulate matter and share the measurements via open source geospatial web mapping software.
It is known that orbital forcing is involved in glacial/deglacial cycles but is insufficient by itself to explain the glacial/deglacial cycles. This study argues that a biological feedback mechanism kicks in when a threshold is reached and together with orbital forcing results in the sustained and rapidly increasing CO2 and surface temperature of a deglaciation.
Marine cores collected in the western tropical Pacific were used to compare the chronology of Southern Ocean warming near Antarctica and rising CO2 during the last deglaciation. The results provide evidence that the Southern Ocean off Antarctica warmed by ~2°C between 19,000 and 17,000 years before the present, about 1,000 years before the rise in atmospheric CO2.