Rising levels of atmospheric CO2 are thought to increase C sinks in terrestrial ecosystems. The potential of these sinks to mitigate CO2 emissions, however, may be constrained by nutrients. By using metaanalysis, we found that elevated CO2 only causes accumulation of soil C when N is added at rates well above typical atmospheric N inputs. Similarly, elevated CO2 only enhances N2 fixation, the m...

[1] Iron fertilization of macronutrient-rich but biologically unproductive ocean waters has been proposed for sequestering anthropogenic carbon dioxide (CO2). The first carbon export measurements in the Southern Ocean (SO) during the recent SO-Iron Experiment (SOFeX) yielded 900 t C exported per 1.26 t Fe added. This allows the first realistic, data-based feasibility assessment of large-scale i...

A record of atmospheric carbon dioxide (CO2) concentration during the transition from the Last Glacial Maximum to the Holocene, obtained from the Dome Concordia, Antarctica, ice core, reveals that an increase of 76 parts per million by volume occurred over a period of 6000 years in four clearly distinguishable intervals. The close correlation between CO2 concentration and Antarctic temperature ...

The general assumption, in the first phase of elevated carbon dioxide (CO2) research, was that increasing atmospheric CO2 concentration would act as a fertilizer for plant systems. Under this “large-plant-scenario” (Fig. 9.1), increased photosynthesis at elevated CO2 would lead to higher plant biomass which would induce a negative atmospheric feedback loop that would offset anthropogenic carbon...

......................................................................................................................... xvi Chapter 1: Introduction ..................................................................................................... 1 1.1 Atmospheric CO2: the background ....................................................................... 1 1.2 Effects of elevated atmospher...

The authors evaluate the United Nations Intergovernmental Panel on Climate Change (IPCC) consensus that the increase of carbon dioxide in the Earth’s atmosphere is of anthropogenic origin and is causing dangerous global warming, climate change and climate disruption. The totality of the data available on which that theory is based is evaluated. The data include: (a) Vostok ice-core measurements...

[1] Estimates of fossil fuel CO2 are a critical component in atmospheric CO2 inversions. Rather than solving for this portion of the atmospheric CO2 budget, inversions typically include estimates of fossil fuel CO2 as a known quantity. However, this assumption may not be appropriate, particularly as inversions continue to solve for fluxes at reduced space and timescales. In this study, two diff...

A record of atmospheric carbon dioxide (CO2) concentrations measured on the EPICA (European Project for Ice Coring in Antarctica) Dome Concordia ice core extends the Vostok CO2 record back to 650,000 years before the present (yr B.P.). Before 430,000 yr B.P., partial pressure of atmospheric CO2 lies within the range of 260 and 180 parts per million by volume. This range is almost 30% smaller th...

Atmospheric carbon dioxide (CO2) is an important greenhouse gas that significantly contributes to the carbon cycle and global radiation budget on Earth. Active remote sensing of CO2 is important to address several limitations that contend with passive sensors. A 2-micron double-pulsed, Integrated Path Differential Absorption (IPDA) lidar instrument for ground and airborne atmospheric CO2 concen...

[1] The availability of iron exerts a significant control on primary production and the export of organic matter over large areas of the ocean, especially those far from land sources. We explore the regulation of the global soft tissue pump of carbon and atmospheric CO2 by the atmospheric delivery of iron in a three-dimensional ocean circulation and biogeochemistry model. There is only a small ...