Concentrations of carbon dioxide in the atmosphere are now “higher than any time in the history of our species”, a science event in UCD has been told. Photograph:  Andreas Rentz/Getty Images.

Concentrations of carbon dioxide in the atmosphere are now “higher than any time in the history of our species”, a science event in UCD has been told.(...)

Natural disasters such as meteorite impacts or volcanoes have devastated life on Earth. But shifting oxygen levels have also had critical – yet overlo(...)