Ocean-atmosphere changes

Because diatoms play such a large role in the biogeochemistry of silicon, changes in their productivity are thought to have the potential to affect other aspects of the crustal-ocean-atmosphere factory. To consider this future, we first look at the marine silica budget. 

Biogeochemists are working to construct numerical models that include all of these interlinked feedbacks to explain how the chemistry of seawater has changed over time in response to various forces, including tectonism, biological activity, ocean-atmosphere interactions, crustal weathering, and river runoff To incorporate all of these linkages into a numerical multielemental model of seawater is very complex because most of... 

In Chapter 25, we will consider further the important role of the continental shelves in regulating organic matter burial. Because this type of organic matter burial is probably altered by changes in sea level, it provides a feedback in the crustal-ocean-atmosphere fectory that acts on the biogenic gases involved in global climate (CO2 and CH4) and redox (O2) control. 

Because biomagnification and other transport processes take time, the harmful effect of many compoimds may not become evident for decades. This makes direct causal relationships between specific pollutants and environmental change difficult to establish. Substantiating such relationships is further complicated by the complex network of positive and negative feedbacks that occur among most parts of the crustal-ocean-atmosphere fectory. 

Figure 3.16 compares 8 0 profiles from Antarctica and Greenland. The dramatic 5-shifts observed in Greenland cores are less pronounced in the 5-record along the Vostok core, probably because the shifts in Greenland are connected to rapid ocean/atmosphere circulation changes in the North Atlantic (for more details, see Sect. 3.12.1). 

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