Effects Of CO2 Change Research Articles

Effects of CO2 Changes on Hyperspectral Infrared Radiances and Its Implications on Atmospheric Temperature Profile Retrieval and Data Assimilation in NWP

Although atmospheric CO2 is a trace gas, it has seasonal variations and has increased over the last decade. Its seasonal variation and increase have substantial radiative effects on hyperspectral infrared (IR) radiance calculations in both longwave (LW) and shortwave (SW) CO2 absorption spectral regions that are widely used for weather and climate applications. The effects depend on the spectral coverage and spectral resolution. The radiative effect caused by the increase of CO2 has been calculated to be greater than 0.5 K within 5 years, whereas a radiative effect of 0.1–0.5 K is introduced by the seasonal variation in some CO2 absorption spectral regions. It is important to take into account the increasing trend and seasonal variation of CO2 in retrieving the atmospheric temperature profile from hyperspectral IR radiances and in the radiance assimilation in numerical weather prediction (NWP) models. The simulation further indicates that it is very difficult to separate atmospheric temperature and CO2 information from hyperspectral IR sounder radiances because the atmospheric temperature signal is much stronger than that of CO2 in the CO2 absorption IR spectral regions.

Adiabatic laminar burning velocities of C3H8-O2-CO2 and C3H8-O2-N2 mixtures at ambient conditions-PART II: Mechanistic interpretation

The effect of diluents on the laminar burning velocity of the premixed C3H8-O2-N2 and C3H8-O2-CO2 mixtures was numerically studied. Global flame parameters including adiabatic flame temperature (Tad), overall reaction order (n), activation energy (Ea), Zeldovich number (Ze) and Lewis number (Le) were calculated. Results show that the N2/CO2 alters all flame parameters. Based on asymptotic analysis for one-step overall reaction, these parameters correlates the laminar burning velocity. The change of Arrhenius effect, combination of thermal and chemical effect is the dominant factor, compared to the change of transport effect. Sensitivity analysis revealed that thermal effect is the dominant factor in Arrhenius effect. The correctness of one-step model was validated with experimental and numerical results. Detailed mechanism model analysis illustrates the linear correlations between laminar burning velocity and maximum (H + OH + O) concentration. The chemical effect of CO2 replacement of N2 in oxidizer is smaller than the thermal effect but much bigger than the transport effect in the calculation domain. The chemical effect of CO2 changes drastically with equivalence ratios and oxygen fractions.

A novel decomposition analysis of green patent applications for the evaluation of R&D efforts to reduce CO2 emissions from fossil fuel energy consumption

Abstract Many green technologies have been invented to prevent CO2 emission. But the alarming increased in CO2 emissions in the last half-century can also induce the advancement of green technology. In order to evaluate the effect of changes in CO2 emissions on green R&D investment and the generation of related patents, a new logarithmic mean Divisia index (LMDI) decomposition method is proposed. The method identifies the effect of CO2 changes on patent applications via R&D investment using the following six factors: production, energy intensity, fuel mix, CO2 emission coefficient, R&D reaction, and R&D efficiency. Using the data from 2004 to 2012, we apply the proposed method to the four countries (France, Germany, Italy, and the United Kingdom) in order to compare the main factors driving green patent applications in each country. The findings provide insight for effective generation of green technology patents.

Iron availability modulates the effects of future CO2 levels within the marine planktonic food web

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 565:17-33 (2017) - DOI: https://doi.org/10.3354/meps12025 Iron availability modulates the effects of future CO2 levels within the marine planktonic food web María Segovia1,*, M. Rosario Lorenzo1, María T. Maldonado2, Aud Larsen3, Stella A. Berger4,5, Tatiana M. Tsagaraki4, Francisco J. Lázaro6, Concepción Iñiguez1, Candela García-Gómez1,9, Armando Palma1, Michaela A. Mausz7,10, Francisco J. L. Gordillo1, Jose A. Fernández8, Jessica L. Ray3, Jorun K. Egge4 1Department of Ecology, Faculty of Sciences, University of Málaga, Bulevar Louis Pasteur s/n, 29071 Málaga, Spain 2Department of Earth and Ocean and Atmospheric Sciences, University of British Columbia, 2207 Main Mall, Vancouver, BC V6T 1Z4, Canada 3Uni Research Environment and Hjort Centre for Marine Ecosystem Dynamics, Thormøhlensgt 41, 5006 Bergen, Norway 4Department of Biology, Thormøhlensgt 53A/B, University of Bergen, 5020 Bergen, Norway 5Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, 16775 Stechlin, Germany 6Department of Science and Technology of Materials and Fluids, University of Zaragoza, María de Luna 3, 50018 Zaragoza, Spain 7Institute of Inorganic and Analytical Chemistry/Bioorganic Analytics, Friedrich Schiller University Jena, 07743 Jena, Germany 8Department of Plant Biology, Faculty of Sciences, University of Málaga, Bulevar Louis Pasteur s/n, 29071 Málaga, Spain 9Present address: Spanish Oceanographic Institute (IEO), Puerto Pesquero, 29640 Fuengirola, Málaga, Spain 10Present address: School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK *Corresponding author: segovia@uma.es ABSTRACT: Ocean acidification (OA) due to increased anthropogenic CO2 emissions is affecting marine ecosystems at an unprecedented rate, altering biogeochemical cycles. Direct empirical studies on natural communities are required to analyse the interactive effects of multiple stressors while spanning multiple trophic levels. We investigated the interactive effects of changes in CO2 and iron availability on functional plankton groups. We used mesocosms manipulating the carbonate system from the start to achieve present (low concentration, LC) and predicted future pCO2 levels (high concentration, HC). To manipulate dissolved iron (dFe), half of the mesocosms were amended with 70 nM (final concentration) of the siderophore desferoxamine B (DFB) on Day 7 (+DFB and -DFB treatments). Manipulation of both CO2 and DFB increased dFe compared to the control. During the 22 experimental days, the plankton community structure showed 2 distinct phases. In phase 1 (Days 1-10), only bacterioplankton abundances increased at elevated pCO2. In contrast, a strong community response was evident in phase 2 (Days 11-22) due to DFB addition. Biomass of the coccolithophore Emiliania huxleyi increased massively at LC+DFB. HC negatively affected E. huxleyi and Synechococcus sp., and high dFe (+DFB) had a positive effect on both. The rest of the plankton community was unaffected by the treatments. Increased dFe partially mitigated the negative effect of HC imposed on the coccolithophores, indicating that E. huxleyi was able to acclimate better to OA. This physiological iron-mediated acclimation can diminish the deleterious effects of OA on carbon export and the rain ratio, thus affecting food web dynamics and future ecosystem functioning. KEY WORDS: Global change · Iron · CO2 · Mesocosms · Plankton food web · Emiliania huxleyi · Synechococcus sp. Full text in pdf format Supplementary material PreviousNextCite this article as: Segovia M, Lorenzo MR, Maldonado MT, Larsen A and others (2017) Iron availability modulates the effects of future CO2 levels within the marine planktonic food web. Mar Ecol Prog Ser 565:17-33. https://doi.org/10.3354/meps12025 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 565. Online publication date: February 17, 2017 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2017 Inter-Research.

CO2 price sensitivity of LNG and pipelines

Natural gas is a potential ‘bridge fuel’ to a future low-carbon energy system, raising the question of the environmental footprint of different ways of transporting the gas. This article examines the effects of changes in CO2 prices on the relative cost-efficiency of pipelines and liquefied natural gas (LNG). The analysis shows that pipelines are more cost-efficient for distances below 4726 km at the price of US$ 8.00 per tonne of CO2; above that threshold distance LNG is more cost-efficient. There is an insignificant shift in the break-even distance with a unit change in the price of CO2. That does not imply that pipeline and LNG projects cause similar amounts of carbon emissions, as their total cost functions depend not only on the price of CO2 but also distance, and these two factors can cancel each other out. Thus, it is difficult to generalise across projects about the impact of the cost of CO2 emissions on policy choices between pipeline and LNG infrastructure, because the impact of CO2 prices interacts with the distance of the projects. But for individual projects, scenarios for CO2 price developments should be taken into account.

Resiliency of juvenile walleye pollock to projected levels of ocean acidification

As atmospheric concentrations of CO2 rise, the pH of high-latitude oceans is pre- dicted to decrease by 0.3 to 0.5 units by 2100. Several biological consequences of ocean acidifica- tion across this pH range have already been documented in invertebrates and tropical marine fishes. However, little work has been done examining potential responses of the temperate and boreal marine fish species that support major fisheries. In 2 experiments, we examined the growth responses of juvenile walleye pollock Theragra chalcogramma at ambient and 3 elevated CO2 lev- els. In a short-term experiment with yearlings, CO2 treatment had no significant effect on growth or condition after 6 wk of rearing. Elevated CO2 levels (>450 µatm) increased the rate of otolith deposition, but did not affect otolith elemental composition. In a second experiment, growth in length of sub-yearlings over 12 wk at 8°C was 7.2% faster in the 2 higher CO2 treatments (>1200 µatm) than in the lower CO2 treatments (<900 µatm). Growth of sub-yearlings measured during 11 subsequent weeks of rearing at 2.5°C did not differ among CO2 treatments. There was no effect of CO2 treatment on condition factor following either phase of the experiment. Sub- yearling consumption rates were not directly affected by CO2 treatment, confirming that growth at elevated CO2 levels is not maintained through compensatory feeding. While not exhaustive of potential interactive environmental factors, these experiments demonstrate a general resiliency of growth energetics in juvenile walleye pollock to the direct effects of CO2 changes predicted for the Gulf of Alaska and Bering Sea in the next century.

Ecohydrological responses to multifactor global change in a tallgrass prairie: A modeling analysis

Relative impacts of multiple global change factors on ecohydrological processes in terrestrial ecosystems have not been carefully studied. In this study, we used a terrestrial ecosystem (TECO) model to examine effects of three global change factors (i.e., climate warming, elevated CO2, and altered precipitation) individually and in combination on runoff, evaporation, transpiration, rooting zone soil moisture content, water use efficiency (WUE), and rain use efficiency (RUE) in a North American tallgrass prairie. We conducted a total of 200 different scenarios with gradual changes of the three factors for 100 years. Our modeling results show strong responses of runoff, evaporation, transpiration, and rooting zone soil moisture to changes in temperature and precipitation, while effects of CO2 changes were relatively minor. For example, runoff decreased by 50% with a 10°C increase in temperature and increased by 250% with doubled precipitation. Ecosystem‐level RUE increased with CO2, decreased with precipitation, and optimized at 4–6°C of warming. In contrast, plant‐level WUE was highest at doubled CO2, doubled precipitation, and ambient temperature. The different response patterns of RUE and WUE signify that processes at different scales responded uniquely to climate change. Combinations of temperature, CO2, and precipitation anomalies interactively affected response magnitude and/or patterns of ecohydrological processes. Our results suggest that ecohydrological processes were considerably affected by global change factors and then likely regulate other ecosystem processes, such as carbon and nitrogen cycling. In particular, substantial changes in runoff to different climate change scenarios could have policy implications because it is a major component to replenishing freshwater. These modeling results should be tested by and could influence design of field experiments on ecohydrological processes.

A resource ratio model of the effects of changes in CO2 on woody plant invasion

It is expected that elevated CO2 levels may have an important positive effect on the dominance of woody plants over grasses in savannas and grasslands. I propose that these changes in the relative abundance of trees and shrubs over grasses may be explained by Tilman’s resource ratio models. This change will occur because C3 trees will have higher net photosynthetic rates than C4 grasses which predominate in savannas. This will cause trees to have higher growth rates than grasses. An additional factor in trees and shrubs with carbon-based defences (such as tannins or other polyphenols) is that they may be better defended and, thus, lose less material to herbivory. Consequently, trees and shrubs should invade savannas and grasslands because their R* values will be lower. I compare this model to another less parsimonious model based on fire and carbon storage and allocation. Although these models are not necessarily mutually exclusive, the resource ratio model may be differentiated from the fire-carbon model on the basis of the presence of fire and/or the sensitivity to elevations in global CO2 levels.

Assessing the greenhouse effect in agriculture.

Evidence that concentrations of CO2 and trace gases in the atmosphere have increased is irrefutable. Whether or not these increased concentrations will lead to climate changes is still open to debate. Direct effects of increased CO2 concentrations on physiological processes and individual plants have been demonstrated and the consequences for crop growth and production under various circumstances are evaluated with simulation models. The consequences of CO2 enrichment are considerable under optimal growing conditions. However, the majority of crops are grown under sub-optimal conditions where the effects of changes in CO2 are often less. The same holds for the possible indirect effects of environmental changes such as temperature rise. Studies on individual plants under optimal conditions are therefore not sufficient for evaluating the effects at a farm, regional, national or supra-national level. Simulation studies help to bridge the gap between the various aggregation levels and provide a basis for various studies of policy options at various aggregation levels.

Climatic change effects on the physiology and growth of Pinusponderosa: expectations from simulation modeling

The TREGRO model was used to simulate the growth response of mature Pinusponderosa Dougl. ex Laws. to the interacting effects of changes in CO2 (+200 μL/L), temperature (+4 °C), and O3 (0.5×, 1×, and 2×ambient). Relative to simulated growth under the base-line climate in Corvallis, Oregon, elevated CO2 and temperature individually increased total-tree biomass gain by 29% and 13%, respectively, but when combined increased biomass gain by 49%. Ozone at all exposures reduced total-tree biomass gain by 1%, 19%, and 39%, respectively, as compared with simulated base-line conditions. Elevated CO2 increased photosynthesis and reduced stomatal conductance and partially offset growth reductions due to 2× O3. Elevated temperature, however, increased both photosynthesis and stomatal conductance and was less effective at mitigating growth reductions due to 2× O3. Growth at 2× O3 in elevated CO2 and temperature conditions had little effect on total-tree growth, but decreased fine-root growth by 61%. The simulated changes in stomatal conductance and fine-root biomass are expected to interact with the availability of soil resources to affect tree growth and possibly alter the distribution of Pinusponderosa.

Clear-Sky Nocturnal Temperatures Forecast and the Greenhouse Effect

Nocturnal evolution of air and soil temperatures are computed for clear-sky situations. The model takes into account the soil heat conduction and the atmospheric radiative transfers by using radiosonde data for temperature, water vapor, and ozone. Turbulent exchanges in the surface layer are also taken into account. Simulations of several cases distributed around the year at a midlatitude station (Uccle, located in Brussels) give very good results both at the ground and in the air close to the ground-the errors being usually less than 0.5°C. This can be achieved thanks to Morcrette's accurate IR flux transmission functions and, for the surface temperature computation, by giving up the force-restore method for the benefit of Brunt's analytical solution. A by-product of the study is to use the model to investigate the sensitivity of the results to CO2 changes. Due to close saturation of the present CO2-H2O bands, the dependence appears very weak: when progressively increasing CO2, the surface downward infrared flux tends to an asymptotic value not too distant from the present one. The surface temperature dependence is further smoothed by the fact that soil conduction acts to dissipate the energy excesses reaching the surface. It appears that changing the atmospheric water vapor content by 0.5 kg m−2 has, on the surface temperature, the same effect as doubling CO2. Accordingly, to be convincing, an analysis of the contribution to the greenhouse effect of CO2 changes should, namely, restore the water cycle to a high degree of accuracy.

Local regulation of collateral ventilation by oxygen and carbon dioxide.

The effects of changes in CO2 and O2 on the mechanics of collateral ventilation were studied in anesthetized paralyzed dogs. A doublelumen catheter was wedged into a peripheral airway obstructing a segment of lung distal to the catheter. Through one lumen of the catheter, air, 5% CO2 in air, 10% CO2 in air, 5% O2 in N2, or 5% CO2 in N2 was infused at a constant flow (V). Pressure (Ps) was monitored through the other lumen. At functional residual capacity the resistance to collateral flor Rcoll = Ps/V. When V was interrrupted , the time for Ps to fall 63% was defined as the time constant for collateral ventilation, Tcoll. The effective compliance (Cs') = Tcoll/Rcoll. When air was replaced by 5% CO2, Rcoll fell 46.3% (+/- SE 2.8) and Tcoll fell 41.5% (+/- SE 3.0). When the CO2 concentration was increased from 5% to 10%, Rcoll fell an additional 9.2% (+/- SE 2.2) and Tcoll fell an additional 5.1% (+/- SE 4.4). When air was replaced by 5% O2 in N2, Rcoll rose 36.6% (+/- SE 6.0) and Tcoll rose 13.6% (+/- SE 10.5). No significant changes in Cs' were noted. We conclude that varying concentrations of CO2 and O2 provide potent mechanisms for the control of collateral ventillation which may be of importance in the regulation of ventillation perfusion relationships at the local level.