scholarly journals Balance and Behavior of Carbon Dioxide at an Urban Forest Inferred from the Isotopic and Meteorological Approaches

Radiocarbon ◽  
2001 ◽  
Vol 43 (2B) ◽  
pp. 659-669 ◽  
Author(s):  
Hiroshi Aoki Takahashi ◽  
Tetsuya Hiyama ◽  
Eiichi Konohira ◽  
Atsuhiro Takahashi ◽  
Naohiro Yoshida ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Wind Velocity ◽  
Atmospheric Carbon Dioxide ◽  
Urban Forest ◽  
Atmospheric Condition ◽  
Vertical Gradient ◽  
Fossil Fuel Burning ◽  
Anthropogenic Contribution ◽  
Strong Winds ◽  
And Behavior

Diurnal variations in δ14C, δ13C and the concentration of atmospheric carbon dioxide in an urban forest were measured on 9 February 1999 to discriminate and quantify contributions from different CO2 sources. The biogenic CO2 concentration remained relatively constant throughout the day. However, anthropogenic CO2 concentration fluctuated with the atmospheric CO2 concentration, and seemed to be controlled by wind velocity and the amount of exhaust gases from fossil fuel burning. The vertical profiles of anthropogenic, biogenic, and total CO2 showed a constant concentration within forest during daytime because of the large vertical CO2 influx, strong winds, and neutral atmospheric condition. The biogenic contribution at night decreased from the forest floor upwards with a smooth gradient, while the anthropogenic contribution showed a direct mirror because of the location of respective CO2 sources—the vertical gradient of wind velocity and the horizontal CO2 supply.

scholarly journals Ocean Acidification: Fish Physiology and Behavior

EDIS ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. 5
Author(s):  
Joshua Patterson ◽  
Lisa Krimsky ◽  
Joseph Henry
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Laboratory Experiments ◽  
Ocean Water ◽  
Dissolved Carbon ◽  
Current State ◽  
Dissolved Carbon Dioxide ◽  
Using Data ◽  
Aquatic Sciences ◽  
And Behavior

Increased atmospheric carbon dioxide has led to increased levels of dissolved carbon dioxide in the oceans and acidified ocean water, which could have direct effects on the physiology and behavior of fishes. This 5-page fact sheet written by Joshua Patterson, Lisa Krimsky, and Joseph Henry and published by the UF/IFAS School of Forest Resources and Conservation, Program in Fisheries and Aquatic Sciences will summarize the current state of our understanding on the topic, with special emphasis on Florida fishes. It will also address current challenges in understanding the real-world effects of a complex global process using data largely collected on isolated fish in laboratory experiments. https://edis.ifas.ufl.edu/fa219

Climate Outlook to 2030

2007 ◽  
Vol 18 (5) ◽  
pp. 615-620 ◽  
Author(s):  
David C. Archibald
Keyword(s):  
Carbon Dioxide ◽  
Solar Cycle ◽  
Atmospheric Carbon Dioxide ◽  
Atmospheric Temperature ◽  
Forecast Period ◽  
Global Average ◽  
Average Temperature ◽  
Solar Cycle 23 ◽  
Anthropogenic Contribution ◽  
Cycle 24

Our forecast for global average temperature to 2030 has been updated for the progression of Solar Cycle 23 and the contribution that will be made by increased carbon dioxide in the atmosphere. The increased length of Solar Cycle 23 supports the view that Solar Cycle 24 will be weak, with the consequence of increased certainty that that there will be a global average temperature decline in the range of 1° to 2°C for the forecast period. The projected increase of 40 ppm in atmospheric carbon dioxide to 2030 is calculated to contribute a global atmospheric temperature increase of 0.04°C. The anthropogenic contribution to climate change over the forecast period will be insignificant relative to natural cyclic variation.

Communication: Photoinduced Carbon Dioxide Binding with Surface-Functionalized Silicon Quantum Dots

2018 ◽  
Author(s):  
Oscar A. Douglas-Gallardo ◽  
Cristián Gabriel Sánchez ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Carbon Dioxide ◽  
Quantum Dots ◽  
Atmospheric Carbon Dioxide ◽  
Density Functional ◽  
Tight Binding ◽  
Carbon Dioxide Concentration ◽  
Research Area ◽  
Silicon Quantum Dots ◽  
Dependent Model ◽  
Photoinduced Charge

<div> <div> <div> <p>Nowadays, the search of efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf -SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). Chemical and electronic properties of the proposed SiQDs have been studied with Density Functional Theory (DFT) and Density Functional Tight-Binding (DFTB) approach along with a Time-Dependent model based on the DFTB (TD-DFTB) framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf -SiQDs for photochemically activated carbon dioxide fixation. </p> </div> </div> </div>

Ammonium application mitigates the effects of elevated carbon dioxide on the carbon/nitrogen balance of Phoebe bournei seedlings

2021 ◽  
Author(s):  
Xiao Wang ◽  
Xiaoli Wei ◽  
Gaoyin Wu ◽  
Shengqun Chen
Keyword(s):  
Carbon Dioxide ◽  
Enzyme Activities ◽  
Atmospheric Carbon Dioxide ◽  
Global Climate ◽  
Co2 Concentration ◽  
Rubisco Activase ◽  
Plant Responses ◽  
N Metabolism ◽  
C And N ◽  
Phoebe Bournei

Abstract The study of plant responses to increases in atmospheric carbon dioxide (CO2) concentration is crucial to understand and to predict the effect of future global climate change on plant adaptation and evolution. Increasing amount of nitrogen (N) can promote the positive effect of CO2, while how N forms would modify the degree of CO2 effect is rarely studied. The aim of this study was to determine whether the amount and form of nitrogen (N) could mitigate the effects of elevated CO2 (eCO2) on enzyme activities related to carbon (C) and N metabolism, the C/N ratio, and growth of Phoebe bournei (Hemsl.) Y.C. Yang. One-year-old P. bournei seedlings were grown in an open-top air chamber under either an ambient CO2 (aCO2) (350 ± 70 μmol•mol−1) or an eCO2 (700 ± 10 μmol•mol−1) concentration and cultivated in soil treated with either moderate (0.8 g per seedling) or high applications (1.2 g per seedling) of nitrate or ammonium. In seedlings treated with a moderate level of nitrate, the activities of key enzymes involved in C and N metabolism (i.e., Rubisco, Rubisco activase and glutamine synthetase) were lower under eCO2 than under aCO2. By contrast, key enzyme activities (except GS) in seedlings treated with high nitrate or ammonium were not significantly different between aCO2 and eCO2 or higher under eCO2 than under aCO2. The C/N ratio of seedlings treated with moderate or high nitrate under eCO2was significantly changed compared with the seedlings grown under aCO2, whereas the C/N ratio of seedlings treated with ammonium was not significantly different between aCO2 and eCO2. Therefore, under eCO2, application of ammonium can be beneficial C and N metabolism and mitigate effects on the C/N ratio.

scholarly journals Snowfall-albedo feedbacks could have led to deglaciation of snowball Earth starting from mid-latitudes

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Philipp de Vrese ◽  
Tobias Stacke ◽  
Jeremy Caves Rugenstein ◽  
Jason Goodman ◽  
Victor Brovkin
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Climate Models ◽  
Hydrological Cycle ◽  
High Surface ◽  
Dust Deposition ◽  
Carbon Dioxide Concentrations ◽  
Maximum Temperatures ◽  
Carbon Dioxide Levels ◽  
Earth’S Climate

AbstractSimple and complex climate models suggest a hard snowball – a completely ice-covered planet – is one of the steady-states of Earth’s climate. However, a seemingly insurmountable challenge to the hard-snowball hypothesis lies in the difficulty in explaining how the planet could have exited the glaciated state within a realistic range of atmospheric carbon dioxide concentrations. Here, we use simulations with the Earth system model MPI-ESM to demonstrate that terminal deglaciation could have been triggered by high dust deposition fluxes. In these simulations, deglaciation is not initiated in the tropics, where a strong hydrological cycle constantly regenerates fresh snow at the surface, which limits the dust accumulation and snow aging, resulting in a high surface albedo. Instead, comparatively low precipitation rates in the mid-latitudes in combination with high maximum temperatures facilitate lower albedos and snow dynamics that – for extreme dust fluxes – trigger deglaciation even at present-day carbon dioxide levels.

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