What CO₂ 'jumps' from Antarctic ice tell us about climate change

Analysis of air bubbles trapped in ice cores more than 200,000 years old provides evidence of moments in the planet's history when the concentration of CO2 in the atmosphere suddenly increased. And it suggests we could be on the cusp of a similar event… But this increase, which would overlap with human emissions, remains well below the level of CO2 we're currently emitting. (Etienne Legrain, Emilie Capron, more at science-et-vie.com)