A Global Carbon Assimilation System based on the ensemble Kalman filter (GCAS-EK) is developed for assimilating atmospheric CO2 data into an ecosystem model to simultaneously estimate the surface carbon fluxes and atmospheric CO2 distribution. This assimilation approach is similar to CarbonTracker, but with several new developments, including inclusion of atmospheric CO2 concentration in state ...

The reliable prediction of future atmospheric CO2 concentrations and associated global climate change requires an adequate understanding of the CO2 sources and sinks. The sparseness of the existing surface measurement network limits current knowledge about the global distribution of CO2 surface fluxes. The retrieval of CO2 total vertical columns from satellite observations is predicted to impro...

[1] We sought to determine the effect of elevated atmospheric CO2 on mineral weathering reactions in midlatitude carbonate-bearing forest soils of differing nutrient availability. Increased plant growth and soil respiration under elevated atmospheric CO2 suggest increased rates of carbon cycling, which may affect mineral weathering. A randomized complete block experiment was conducted, where as...

Feedbacks from the terrestrial carbon cycle significantly affect future climate change. The CO2 concentration dependence of global terrestrial carbon storage is one of the largest and most uncertain feedbacks. Theory predicts the CO2 effect should have a tropical maximum, but a large terrestrial sink has been contradicted by analyses of atmospheric CO2 that do not show large tropical uptake. Ou...

Terrestrial ecosystems play a significant role in the global carbon cycle and offset a large fraction of anthropogenic CO2 emissions. The terrestrial carbon sink is increasing, yet the mechanisms responsible for its enhancement, and implications for the growth rate of atmospheric CO2, remain unclear. Here using global carbon budget estimates, ground, atmospheric and satellite observations, and ...

It is widely accepted that atmospheric O2 has played a key role in the development of life on Earth, as evident from the coincidence between the rise of atmospheric O2 concentrations in the Precambrian and biological evolution. Additionally, it has also been suggested that low atmospheric O2 is one of the major drivers for at least two of the five mass-extinction events in the Phanerozoic. At t...

1 We compiled from literature annually integrated air-water fluxes of carbon 2 dioxide (CO2) computed from field measurements, in 20 coastal European 3 environments that were gathered into 3 main ecosystems: inner estuaries, upwelling 4 continental shelves and non-upwelling continental shelves. The comparison of annual 5 cycles of the partial pressure of CO2 (pCO2) in 5 contrasting continental ...

and growth of Mangifera indica L. saplings during long-term exposure to a CO2-enriched atmosphere in the seasonally wet-dry tropics of northern Australia. Grafted saplings of M. indica were planted in the ground in four air-conditioned, sunlit, plastic-covered chambers and exposed to CO2 at the ambient or an elevated (700 μmol mol) concentration for 28 months. Light-saturating assimilation (Ama...

Errors in the specification or utilization of fossil fuel CO2 emissions within carbon budget or atmospheric CO2 inverse studies can alias the estimation of biospheric and oceanic carbon exchange. A key component in the simulation of CO2 concentrations arising from fossil fuel emissions is the spatial distribution of the emission near coastlines. Regridding of fossil fuel CO2 emissions (FFCO2) f...

Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presente...