Many researchers at PCIGR work on quantifying the biogeochemical cycles of carbon and related elements in marine environments. As the marine biogeochemical cycle of carbon dictates the level of atmospheric CO2, this research has direct implications for societal concerns about climate change. The rapid increase in anthropogenic CO2 and other greenhouse gases in the atmosphere during the last century is placing a strain on Earth’s climatic system that is unprecedented in human history.
Large uncertainties in ocean and climate model predictions still exist, and there is increasing urgency to better understand the underpinning of past climate, better predict future climate, and develop solutions to mitigate the rise of atmospheric CO2.
Examples of research include understanding cellular requirements and acquisition mechanisms of Fe and other bioactive metals (e.g., Cu, Cd) in marine phytoplankton to constrain the cycling of trace elements in seawater; measurement of metal isotopes (e.g., Fe, Si, Pb) in seawater to study their sources and biological cycling in the ocean; reconstruction of oceanic meridional overturning circulation and resulting heat transport to assess the sensitivity of global climate to ocean circulation; measurement of major and trace elements, 230Th, He, O, N and C isotopes in marine sediments to establish the past efficiency of the ocean to naturally sequester atmospheric CO2; and development of new isotopic tracers (Si, Cd, Cr, Mo, Cu, Zn, Fe) to evaluate past changes in ocean productivity, nutrient cycling, redox conditions and anthropogenic impact.