Oxygen climate trends

Wang H., Liu C. L., and Follmer L. R. (1998) Climatic trend and habitat variation based on oxygen and carbon isotopes in paleosols from Liujiapo, Shaanxi, China. Quat. Int. 51/52, 52-54. 

Here we revisit two important topics in limnology just to show that climate change studies that only include data from lakes are not applicable to reservoirs. Firstly, we show that temperature trends in reservoirs and lakes cannot be interpreted in the same way. Secondly, we show that drivers of the deep-water oxygen content in reservoirs and lakes can be very different. This last analysis will be used in the following section as the starting point for a new framework for climate change impact studies in reservoirs. 

Zachos J, Pagani M, Sloan L, Thomas E, BiUups K (2001) Trends, rhythms and aberrations in global climate 65 Ma to present. Science 292 686-693 Zeebe RE (1999) An explanation of the effect of seawater carbonate concentration on foraminiferal oxygen isotopes. Geochim Cosmochim Acta 63 2001-2007 Zeebe RE (2005) Stable boron isotope fractionation between dissolved B(OH)3 and BlOH). Geochim Cosmochim Acta 69 2753-2766... 

Climate changes from the time ofthe disappearance of dinosaurs to our days have also been based up on deep-sea stable isotope data oxygen isotope data provide an insight into the temperature variations, while carbon isotope data are informative on the kind of global carbon cycle perturbation (Zachos 2001). These data suggest that the present conditions of temperature are similar to the late Middle Age. However, the trend toward higher temperatures is now more difficult to contrast because of the drastic deforestation and emission of gases. 

Rozanski K., Araguas-Araguas L., and Gonfiantini R. (1992) Relation between long-term trends of oxygen-18 isotope composition of precipitation and climate. Science 258, 981-985. 

Over the long term, the Cenozoic deep-sea oxygen isotope record is dominated by two important features that relate to major shifts in mean climatic state. The first is a rise in values from 53 to 35. This trend, which is mostly gradual but punctuated by several steps, is an expression of the Eocene transition from greenhouse to icehouse conditions. In the Early Eocene (—53 Ma) the deep sea was relatively warm, —7 °C warmer than present, and there were no ice sheets. Over the next 20 Myr. the ocean cools, and the first large ice sheets appear on Antarctica. The latter event is reflected by the relatively sharp l.2%o increase in 5 0 at 33.4 Ma. This pattern reverses... 

Seawater, compared with all other natural waters, is remarkably constant in composition. However, all elements involved in biological turnovers (oxygen and carbon being the most important) may have variations (and possibly trends), again due to changing key parameters of the climate system, of which the temperature is the most important one. Concerning the global climate, the oceans have two essential functions ... 

---