scholarly journals Amplified Feedback Mechanism of the Forests-Aerosols-Climate System

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Thomas Hede ◽  
Caroline Leck ◽  
Jonas Claesson
Keyword(s):  
Carbon Dioxide ◽  
Feedback Mechanism ◽  
Climate System ◽  
Cloud Formation ◽  
Vegetation Model ◽  
Northern Latitudes ◽  
Carbon Dioxide Fertilization ◽  
Cloud Optical Thickness ◽  
Carbon Dioxide Levels ◽  
Northern Russia

Climate change very likely has effects on vegetation so that trees grow faster due to carbon dioxide fertilization (a higher partial pressure increases the rate of reactions with Rubisco during photosynthesis) and that trees can be established in new territories in a warmer climate. This has far-reaching significance for the climate system mainly due to a number of feedback mechanisms still under debate. By simulating the vegetation using the Lund-Potsdam-Jena guess dynamic vegetation model, a territory in northern Russia is studied during three different climate protocols assuming a doubling of carbon dioxide levels compared to the year 1975. A back of the envelope calculation is made for the subsequent increased levels of emissions of monoterpenes from spruce and pine forests. The results show that the emissions of monoterpenes at the most northern latitudes were estimated to increase with over 500% for a four-degree centigrade increase protocol. The effect on aerosol and cloud formation is discussed and the cloud optical thickness is estimated to increase more than 2%.

scholarly journals Carbon dioxide levels in neonates: what are safe parameters?

2021 ◽  
Author(s):  
Sie Kei Wong ◽  
M. Chim ◽  
J. Allen ◽  
A. Butler ◽  
J. Tyrrell ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Systematic Review ◽  
Side Effects ◽  
Preterm Infants ◽  
Periventricular Leukomalacia ◽  
List Type ◽  
Permissive Hypercapnia ◽  
Prisma Statement ◽  
Carbon Dioxide Levels ◽  
Online Software

Abstract There is no consensus on the optimal pCO2 levels in the newborn. We reviewed the effects of hypercapnia and hypocapnia and existing carbon dioxide thresholds in neonates. A systematic review was conducted in accordance with the PRISMA statement and MOOSE guidelines. Two hundred and ninety-nine studies were screened and 37 studies included. Covidence online software was employed to streamline relevant articles. Hypocapnia was associated with predominantly neurological side effects while hypercapnia was linked with neurological, respiratory and gastrointestinal outcomes and Retinpathy of prematurity (ROP). Permissive hypercapnia did not decrease periventricular leukomalacia (PVL), ROP, hydrocephalus or air leaks. As safe pCO2 ranges were not explicitly concluded in the studies chosen, it was indirectly extrapolated with reference to pCO2 levels that were found to increase the risk of neonatal disease. Although PaCO2 ranges were reported from 2.6 to 8.7 kPa (19.5–64.3 mmHg) in both term and preterm infants, there are little data on the safety of these ranges. For permissive hypercapnia, parameters described for bronchopulmonary dysplasia (BPD; PaCO2 6.0–7.3 kPa: 45.0–54.8 mmHg) and congenital diaphragmatic hernia (CDH; PaCO2 ≤ 8.7 kPa: ≤65.3 mmHg) were identified. Contradictory findings on the effectiveness of permissive hypercapnia highlight the need for further data on appropriate CO2 parameters and correlation with outcomes. Impact There is no consensus on the optimal pCO2 levels in the newborn. There is no consensus on the effectiveness of permissive hypercapnia in neonates. A safe range of pCO2 of 5–7 kPa was inferred following systematic review.

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.

An overview of flow cell architectures design and optimization for electrochemical CO2 reduction

2021 ◽  
Author(s):  
Dui Ma ◽  
Ting Jin ◽  
Keyu Xie ◽  
Haitao Huang
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Electrochemical Reduction ◽  
Atmospheric Carbon Dioxide ◽  
Co2 Reduction ◽  
Value Added ◽  
Flow Cell ◽  
Design And Optimization ◽  
Electrochemical Co2 Reduction ◽  
Carbon Dioxide Levels

Converting CO2 into value-added fuels or chemical feedstocks through electrochemical reduction is one of the several promising avenues to reduce atmospheric carbon dioxide levels and alleviate global warming. This approach...

Insect control with CO2 in a small stack of bagged grain in a plastic film enclosure

1979 ◽  
Vol 19 (96) ◽  
pp. 102 ◽  
Author(s):  
HJ Banks ◽  
AK Sharp
Keyword(s):  
Carbon Dioxide ◽  
Rhyzopertha Dominica ◽  
Pvc Membrane ◽  
Pest Species ◽  
Dry Ice ◽  
Anisopteromalus Calandrae ◽  
Stored Product Pest ◽  
Natural Infestation ◽  
Carbon Dioxide Levels ◽  
Additional Charges

The use of carbon dioxide, added as dry ice, was demonstrated as a means of disinfestation of bagged wheat and rye enclosed in a PVC membrane. The bag stack was dosed with dry ice giving an atmosphere of about 60% CO2. Carbon dioxide levels were maintained over 22 days with additional charges of dry ice added directly on top of the stack or enclosed within a polystyrene box to regulate the CO2 release rate. A natural infestation of Rhyzopertha dominica with small numbers of other stored product pest species was controlled, with complete mortality of adult insects, but slight survival of some early stages of R. dominica. Some of the hymenopterous parasitoids, Anisopteromalus calandrae and Choetospila elegans, survived the treatment, apparently as pupae. The treatment was successful under conditions where many other methods of pest control were inapplicable because of difficulty or expense of application, as in a small bulk (2.8 tonnes), at low temperature (11-13�C), when the commodity is close to working areas and when there is a requirement for freedom from pesticide residues.

Pre-emptive veno-venous ECMO in advanced tracheal malignancy prior to tracheal stenting

2021 ◽  
Vol 14 (8) ◽  
pp. e243596
Author(s):  
Mohammad Salman Siddiqi ◽  
Adil H Al Kindi ◽  
Ahmed Fahmy Mandisha ◽  
Rashid Al Sukaiti
Keyword(s):  
Carbon Dioxide ◽  
Extracorporeal Membrane Oxygenation ◽  
Airway Obstruction ◽  
Jugular Vein ◽  
Femoral Vein ◽  
Ventilatory Support ◽  
Successful Management ◽  
Flexible Bronchoscope ◽  
Carbon Dioxide Levels ◽  
Vv Ecmo

Extracorporeal membrane oxygenation (ECMO) is helpful in providing ventilatory support when other conventional methods of ventilation fail. We report a case of successful management of advanced tracheal malignancy with impeding airway obstruction where veno-venous ECMO (VV-ECMO) was instituted prior to performing critical endotracheal procedure. After securing the VV-ECMO through right jugular vein and left femoral vein under local anaesthesia, the tracheal stent placement was conducted under flexible bronchoscope and fluoroscope control. Oxygenation and carbon dioxide levels were maintained by the ECMO. VV-ECMO is a useful adjunct in the management of subglottic difficult airway obstruction due to complex tracheal pathology where conventional ventilation may not be possible or adequate.

Blood Carbon Dioxide Levels and Adverse Outcome in Neonatal Hypoxic-Ischemic Encephalopathy

2009 ◽  
Vol 27 (05) ◽  
pp. 361-365 ◽  
Author(s):  
Montasser Nadeem ◽  
Deirdre Murray ◽  
Geraldine Boylan ◽  
Eugene Dempsey ◽  
C. Anthony Ryan
Keyword(s):  
Carbon Dioxide ◽  
Adverse Outcome ◽  
Hypoxic Ischemic Encephalopathy ◽  
Carbon Dioxide Levels ◽  
Ischemic Encephalopathy

scholarly journals Modelling key market impacts and land allocation for biofuel production and forestry

2006 ◽  
Vol 2006 ◽  
pp. 1-12
Author(s):  
A. Korobeinikov ◽  
P. Read ◽  
A. Parshotam ◽  
J. Lermit
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Large Scale ◽  
Low Cost ◽  
Wood Products ◽  
Biofuel Production ◽  
Fuel Wood ◽  
Carbon Dioxide Levels ◽  
The Cost ◽  
The Impact

It has been suggested that the large scale use of biofuel, that is, fuel derived from biological materials, especially in combination with reforestation of large areas, can lead to a low-cost reduction of atmospheric carbon dioxide levels. In this paper, a model of three markets: fuel, wood products, and land are considered with the aim of evaluating the impact of large scale biofuel production and forestry on these markets, and to estimate the cost of a policy aimed at the reduction of carbon dioxide in the atmosphere. It is shown that the costs are lower than had been previously expected.

scholarly journals Global 3D modelling of Martian CO2 clouds

2021 ◽  
Author(s):  
Christophe Mathé ◽  
Anni Määttänen ◽  
Joachim Audouard ◽  
Constantino Listowski ◽  
Ehouarn Millour ◽  
...  
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Martian Atmosphere ◽  
Cloud Formation ◽  
Polar Regions ◽  
Northern Latitudes ◽  
1D Model ◽  
Mesospheric Clouds ◽  
Microphysical Processes

<p>In the Martian atmosphere, carbon dioxide (CO<sub>2</sub>) clouds have been revealed by numerous instruments around Mars from the beginning of the XXI century. These observed clouds can be distinguished by two kinds involving different formation processes: those formed during the winter in polar regions located in the troposphere, and those formed during the Martian year at low- and mid-northern latitudes located in the mesosphere (Määattänen et al, 2013). Microphysical processes of the formation of these clouds are still not fully understood. However, modeling studies revealed processes necessary for their formation: the requirement of waves that perturb the atmosphere leading to a temperature below the condensation of CO<sub>2</sub> (transient planetary waves for tropospheric clouds (Kuroda et al., 20123), thermal tides (Gonzalez-Galindo et al., 2011) and gravity waves for mesospheric clouds (Spiga et al., 2012)). In the last decade, a state-of-the-art microphysical column (1D) model for CO<sub>2</sub> clouds in a Martian atmosphere was developed at Laboratoire Atmosphères, Observations Spatiales (LATMOS) (Listowski et al., 2013, 2014). We use our full microphysical model of CO<sub>2</sub> cloud formation to investigate the occurrence of these CO<sub>2</sub> clouds by coupling it with the Global Climate Model (GCM) of the Laboratoire de Météorologie Dynamique (LMD) (Forget et al., 1999). We recently activated the radiative impact of CO<sub>2</sub> clouds in the atmosphere. Last modeling results on Martian CO<sub>2</sub> clouds properties and their impacts on the atmosphere will be presented and be compared to observational data.</p>

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