This article provides a synthesis of literature values to trace the fate of 150 Tg/yr anthropogenic nitrogen applied by humans to the Earth's land surface. Approximately 9 TgN/yr may be accumulating in the terrestrial biosphere in pools with residence times of ten to several hundred years. Enhanced fluvial transport of nitrogen in rivers and percolation to groundwater accounts for approximately...

The southeastern landscape is composed of agricultural and forest systems that can store carbon (C) in standing biomass and soil. Research is needed to quantify the effects of elevated atmospheric carbon dioxide (CO2) on terrestrial C dynamics including CO2 release back to the atmosphere and soil sequestration. Longleaf pine savannahs are an ecologically and economically important, yet understu...

Organic carbon buried under the great ice sheets of the Northern Hemisphere is suggested to be the missing link in the atmospheric CO2 change over the glacial-interglacial cycles. At glaciation, the advancement of continental ice sheets buries vegetation and soil carbon accumulated during warmer periods. At deglaciation, this burial carbon is released back into the atmosphere. In a simulation o...

[1] Coupled atmosphere-ocean-land-sea ice climate models (AOGCMs) are often tuned using physical variables like temperature and precipitation with the goal of minimizing properties such as the root-mean-square error. As the community moves towards modeling the earth system, it is important to note that not all biases have equivalent impacts on biology. Bioclimatic classification systems provide...

The image of the colonisation of the land by plants as a spectacular event, when barren wastes suddenly became verdant triggered by a change in some extrinsic environmental factor, is fading. It derived from the appearance and rapid diversification of vascular plants, unequivocal land colonisers, and, almost simultaneously, the earliest terrestrial arthropods, in the late Silurian and early Dev...

When viewed from space, Earth is seen as a blue marble. The dominant features of the planet are the blue of the oceans and the white of the clouds traversing the atmosphere. It is an image of fluids – water and air – in motion. Indeed, the study of Earth’s climate is dominated by the geophysical principles of fluid dynamics. With closer inspection, however, one can discern land masses – the con...

H alter the global cycle of carbon (C) by burning fossil fuels and modifying the land surface. The addition of billions of tons of C greenhouse gases to the atmosphere is changing its heat-trapping capacity, which, in turn, is changing Earth’s climate (IPCC 2007). Although much of the modern increase in the atmospheric C pool results from human activities, the future trajectory of the atmospher...

The Tissint meteorite, a picritic shergottite, fell to Earth in Morocco on the 18th of July 2011, and is only the fifth Martian meteorite witnessed to fall. Hydrogen isotope ratios and water contents are variable within different minerals in Tissint. Ringwoodite and shock melt pockets contain elevated D/H ratios relative to terrestrial values (dD = 761–4224‰). These high ratios in recrystallize...

Data on three major determinants of the carbon storage in terrestrial ecosystems are used with the process-based Terrestrial Ecosystem Model (TEM) to simulate the combined effect of climate variability, increasing atmospheric CO2 concentration, and cropland establishment and abandonment on the exchange of CO2 between the atmosphere and monsoon Asian ecosystems. During 1860–1990, modeled results...

The tidal heating of hypothetical rocky (or terrestrial) extrasolar planets spans a wide range of values depending on stellar masses and initial orbits. Tidal heating may be sufficiently large (in many cases, in excess of radiogenic heating) and long-lived to drive plate tectonics, similar to the Earth’s, which may enhance the planet’s habitability. In other cases, excessive tidal heating may r...