Through fossil fuel combustion, deforestation, and other industrial and agricultural activities, humans have raised global atmospheric carbon dioxide (CO2) levels to more than 415 parts per million. That concentration represents a 135-parts-per-million increase since preindustrial times in the late 18th century. It is often assumed that this CO2 increase consists entirely of anthropogenically emitted CO2, but a new study challenges that assumption.
Click here for original story, Tracing anthropogenically emitted carbon dioxide into the ocean
Source: Phys.org