Environmental Science and Engineering Seminar

Current global carbon dioxide (CO₂) emissions from anthropogenic sources top most predictions made 10 to 15 years ago. If CO₂ emissions continue unabated, several thousand petagrams of carbon may enter the atmosphere, causing CO₂ concentrations to rise to levels not seen in many millions of years during Earth's recent history. A substantial fraction of the CO₂ will be absorbed by the oceans, causing ocean acidification: a large and rapid decline in surface ocean pH and carbonate mineral saturation state, with potentially detrimental effects on some marine organisms. In this presentation, I will discuss the Earth system response to massive carbon release through time, putting man-made carbon emissions into a geologic and historical context. The rate of the anthropogenic carbon release is likely unprecedented during past several 100 million years. As a result, effects of future ocean acidification will most likely be more severe than during various past events, including the Paleocene-Eocene Thermal Maximum (56 million years ago). I will also discuss the lessons learned from case studies of past climate episodes for future climate change and climate sensitivity.