How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Owens Lake, East-Central California, USA
Li, H.-C., Bischoff, J.L., Ku, T.-L., Lund, S.P. and Stott, L.D. 2000. Climate variability in East-Central California during the past 1000 years reflected by high-resolution geochemical and isotopic records from Owens Lake sediments. Quaternary Research 54: 189-197.

Based on δ18O data obtained from a sediment core retrieved from the depocenter of the Owens Lake playa (36.4N, 118W) in 1997, the authors were able to chart a history of the lake's paleo-volume over the prior thousand years. This work, as they describe it, indicated the existence of "an effectively dry climate between A.D. 950 and 1220, corresponding to the Medieval Climatic Anomaly (a warm period in northern Europe), during which Owens Lake approached playa conditions." In addition, they report that after reaching its greatest depth in the 1870s, "the lake level has steadily dropped from its historic high stand under strong impact of human activity," noting that "between 1872 and 1931 the lake fell due to desiccation resulting from diversions by agricultural interests and by the City of Los Angeles." And "because these diversions have continued since 1931," they say "the lake remains desiccated except for brief intervals following abnormally wet winters." Hence, it is likely that the dry conditions between AD 950 and 1220 were probably more extreme than those of the last seven decades, when desiccation was only achieved with a huge helping hand from the citizens of Los Angeles and the surrounding agricultural environs.