Historical Southern Hemisphere biomass burning variability inferred from ice core carbon monoxide records.

Biomass burning plays an important role in climate-forcing and atmospheric chemistry. The drivers of fire activity over the past two centuries, however, are hotly debated and fueled by poor constraints on the magnitude and trends of preindustrial fire regimes. As a powerful tracer of biomass burning, reconstructions of paleoatmospheric carbon monoxide (CO) can provide valuable information on the evolution of fire activity across the preindustrial to industrial transition.

Reconciling ice core CO and land-use change following New World-Old World contact.

Ice core records of carbon dioxide (CO) throughout the last 2000 years provide context for the unprecedented anthropogenic rise in atmospheric CO and insights into global carbon cycle dynamics. Yet the atmospheric history of CO remains uncertain in some time intervals. Here we present measurements of CO and methane (CH) in the Skytrain ice core from 1450 to 1700 CE.

Stylasterid corals build aragonite skeletons in undersaturated water despite low pH at the site of calcification.

Anthropogenic carbon emissions are causing seawater pH to decline, yet the impact on marine calcifiers is uncertain. Scleractinian corals and coralline algae strongly elevate the pH of their calcifying fluid (CF) to promote calcification. Other organisms adopt less energetically demanding calcification approaches but restrict their habitat.