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.