[1] Carbon perturbations leading to an increase in atmospheric CO2 are partly offset by the carbon uptake by the oceans and the rest of the climate system. Atmospheric CO2 approaches a new equilibrium state, reached after ocean invasion ceases after typically 1000 years, given by PCO2 = P0exp(dIc/IB), where P0 and PCO2 are the initial and final partial pressures of atmospheric CO2, dIc is a CO2...

The elevation and extent of coastal marshes are dictated by the interplay between the rate of relative sea-level rise (RRSLR), surface accretion by inorganic sediment deposition, and organic soil production by plants. These accretion processes respond to changes in local and global forcings, such as sediment delivery to the coast, nutrient concentrations, and atmospheric CO2, but their relative...

• Understanding and predicting the impacts of elevated atmospheric CO2, elevated nitrogen deposition, and decreases in plant diversity require better understanding of the way in which plant species influence soil CO2 flux. • In experimental grassland plots where atmospheric CO2, nitrogen supply, and species composition and diversity were manipulated, species effects on soil CO2 flux during 19 s...

[1] Paleoproxy records indicate that a marked weakening of the Atlantic Meridional Overturning Circulation (AMOC) during Heinrich events was often accompanied by a notable atmospheric CO2 increase. However, previous modeling studies display conflicting atmospheric CO2 responses to an AMOC shutdown. Here we use model simulations combined with paleoproxy records to show that depending on the deep...

The ability to monitor fossil fuel carbon dioxide (FFCO2) emissions from subcontinental regions using atmospheric CO2 observations remains an important but unrealized goal. Here we explore a necessary but not sufficient component of this goal, namely, the basic question of the detectability of FFCO2 emissions from subcontinental regions. Detectability is evaluated by examining the degree to whi...

In this work we propose a mathematical model, based in a modified version of the Lotka-Volterra prey-predator equations, to predict the increasing in CO2 atmospheric concentration. We consider how the photosynthesis rate has changed with the increase of CO2 and how this affects plant reproduction and CO2 absorptions rates. Total CO2 emissions (natural and manmade) and biomass numerical paramete...

Recent inverse analyses constraining carbon fluxes using atmospheric CO2 observations have assumed that the CO2 source from atmospheric oxidation of reduced carbon is released at the surface rather than distributed globally in the atmosphere. This produces a bias in the estimates of surface fluxes. We used a 3D atmospheric chemistry model (GEOS-CHEM) to evaluate the magnitude of this effect on ...

We estimated a weakening of the Southern Ocean carbon dioxide (CO2) sink since 1981 relative to the trend expected from the large increase in atmospheric CO2. We agree with Law et al. that network choice increases the uncertainty of trend estimates but argue that their network of five locations is too small to be reliable. A future reversal of Southern Ocean CO2 saturation as suggested by Zickf...

Changes in global average temperatures and of the seasonal cycle are strongly coupled to the concentration of atmospheric CO2. I estimate transfer functions from changes in atmospheric CO2 and from changes in solar irradiance to hemispheric temperatures that have been corrected for the effects of precession. They show that changes from CO2 over the last century are about three times larger than...

[1] Recent inverse analyses constraining carbon fluxes using atmospheric CO2 observations have assumed that the CO2 source from atmospheric oxidation of reduced carbon is released at the surface rather than distributed globally in the atmosphere. This produces a bias in the estimates of surface fluxes. We used a three-dimensional (3D) atmospheric chemistry model (GEOS-CHEM) to evaluate the magn...