Suchergebnisse

In semiarid Mediterranean agroecosystems, low and erratic annual rainfall together with the widespread use of mouldboard ploughing (conventional tillage, CT), as the main traditional tillage practice, has led to a depletion of soil organic matter (SOM) and with increases in CO2 emissions from soil to the atmosphere. In this study, we evaluated the viability of conservation tillage: RT, reduced tillage (chisel and cultivator ploughing) and, especially, NT (no-tillage) to reduce short-term (from 0 to 48 h after a tillage operation) and mid-term (from 0 h to several days since tillage operation) tillage-induced CO2 emissions. The study was conducted in three long-term tillage experiments located at different sites of the Ebro river valley (NE Spain) across a precipitation gradient. Soils were classified as: Fluventic Xerocrept, Typic Xerofluvent and Xerollic Calciorthid. Soil temperature and water content were also measured in order to determine their influence on tillage-induced CO2 fluxes. The majority of the CO2 flux measured immediately after tillage ranged from 0.17 to 6 g CO2 m−2 h−1 and was from 3 to 15 times greater than the flux before tillage operations, except in NT where soil CO2 flux was low and steady during the whole study period. Mid-term CO2 emission showed a different trend depending on the time of the year in which tillage was implemented. Microclimatic soil conditions (soil temperature and water content) had little impact on soil CO2 emission following tillage. In the semiarid Mediterranean agroecosystems studied, NT had low short-term soil CO2 efflux compared with other soil tillage systems (e.g., conventional and reduced tillage) and therefore can be recommended to better manage C in soil. ; This research was supported by the Comisión Interministerial de Ciencia y Tecnología of Spain (Grants AGL 2001-2238-C02-01 and AGL 2004-07763-C02-02) and the European Union (FEDER funds). The first author was awarded a FPI fellowship by the Spanish Ministry of Science and Education.

As man's ability to disrupt the climate becomes increasingly apparent,evidence is mounting that human-activity-induced climate changes may well rival anything nature can produce.

The definitive version is available at: http://www.sciencedirect.com/science/journal/01671987 ; In semiarid Mediterranean agroecosystems, low and erratic annual rainfall together with the widespread use of mouldboard ploughing (conventional tillage, CT), as the main traditional tillage practice, has led to a depletion of soil organic matter (SOM) and with increases in CO2 emissions from soil to the atmosphere. In this study, we evaluated the viability of conservation tillage: RT, reduced tillage (chisel and cultivator ploughing) and, especially, NT (no-tillage) to reduce short-term (from 0 to 48 h after a tillage operation) and mid-term (from 0 h to several days since tillage operation) tillage-induced CO2 emissions. The study was conducted in three long-term tillage experiments located at different sites of the Ebro river valley (NE Spain) across a precipitation gradient. Soils were classified as: Fluventic Xerocrept, Typic Xerofluvent and Xerollic Calciorthid. Soil temperature and water content were also measured in order to determine their influence on tillage-induced CO2 fluxes. The majority of the CO2 flux measured immediately after tillage ranged from 0.17 to 6 g CO2 m−2 h−1 and was from 3 to 15 times greater than the flux before tillage operations, except in NT where soil CO2 flux was low and steady during the whole study period. Mid-term CO2 emission showed a different trend depending on the time of the year in which tillage was implemented. Microclimatic soil conditions (soil temperature and water content) had little impact on soil CO2 emission following tillage. In the semiarid Mediterranean agroecosystems studied, NT had low short-term soil CO2 efflux compared with other soil tillage systems (e.g., conventional and reduced tillage) and therefore can be recommended to better manage C in soil. ; This research was supported by the Comisión Interministerial de Ciencia y Tecnología of Spain (Grants AGL 2001-2238-C02-01 and AGL 2004-07763-C02-02) and the European Union (FEDER funds). The first author was awarded a FPI fellowship by the Spanish Ministry of Science and Education. ; Peer reviewed

ABSTRACTThe recent literature has explored the ambiguous theoretical links between inequality and environmental impact. However, few studies have investigated those links in developing countries. This paper explores the role of income inequality in the per capita emission of CO2 in Latin America. We estimate the impact of income inequality on carbon dioxide emissions, while simultaneously considering national income levels. The results suggest quadratic relationships between environmental impact and both gross domestic product per capita and inequality. Income inequality influences CO2 emissions, but the direction depends on income level. The complexities of the results are analytically explored in the paper. © 2020 John Wiley & Sons, Ltd.

High emissions of greenhouse gases components have today become a world phenomenon. In Africa, Nigeria is the second-highest emitter of greenhouse gases (GHGs), after South Africa. Carbon dioxide (CO2) emissions constitute the largest source of GHGs; hence it has become a widely discussed and researched subject. This, however, is a negative unintended consequence that has emanated from the growing interdependence of the world economies. One of the major instruments of achieving a global world which also stood as a major determinant of economic growth is trade openness. This paper, therefore, examines the impact and the relationship between trade openness on CO2 emissions in Nigeria. The method employed to achieve the stated objectives is the Autoregressive Distributed Lag (ARDL) cointegration technique, using the annual time series data sourced from the World Bank Development Indicator, 2020, for periods 1980 to 2019. The major findings from the study show that there is an insignificant positive relationship between trade openness on CO2 emissions. Also, there exists an increasing trend of CO2 emissions in Nigeria, while that of trade openness shows fluctuation for the periodic review and this depicts a high vulnerability to external shocks. With these findings, the study recommends that the Nigerian government should be more proactive and tenacious in implementing environmental and trade policies in favour of a cleaner economy. Also, the Nigerian government must become keener toward attracting only investors that will produce clean goods and not compromise on the necessity to improve environmental quality

The European parliament has declared a global &ldquo ; climate and environmental emergency&rdquo ; on 28 November 2019. Given that, climate change is a clear strategic issue all around the world. Then, greenhouse gas emissions are reported by each country to the United Nations Framework Convention on Climate Change (UNFCCC) every year. In addition, The Intergovernmental Panel on Climate Change (IPCC) in the &ldquo ; 2006 IPCC Guidelines for National Greenhouse Gas Inventories&rdquo ; give the procedure to calculate and manage the national greenhouse gases (GHG) emissions. However, these guidelines do not provide any method to consider the net carbon dioxide emissions to the atmosphere (released in clinker fabrication minus those due to concrete carbonation) by the Portland cement clinker industry. This topic should be implemented in the climatic models of the next IPCC assessment report. This paper provides an easy procedure of estimating net CO2 emissions proposed in the &ldquo ; recarbonation project&rdquo ; (simplified method) ; that is to say, carbon dioxide uptake during the service-life stage is considered as the 20% of the CO2 released by the calcination (process emissions), whereas the end-of-life and secondary usage is only the 3% of the CO2 released by calcination. The outcome of this study reveals that 31,290.753 tons of carbon dioxide will be absorbed by the cement-based materials produced in Spain with the cements manufactured from 2005 to 2015.

Accepted manuscript ; The preparation of three-dimensional polycaprolactone scaffolds using dense CO2 as foaming agent, without supercritical conditions, was evaluated in this study towards future applications in bone repair. Herein, 3D foams were obtained at 5.0 MPa and 45 °C. To induce bioactivity, β-tricalcium phosphate (β-TCP, 10 wt%) and dexamethasone (5 and 10 wt%) were dispersed in the scaffolds. Foams revealed a pore size range of 164–882 μm, 73–99% porosity and 79–99% interconnectivity, assessed by micro-computed tomography, and a Young modulus of 1.76–2.92 MPa. Dexamethasone did not impair morphology of the matrices in comparison with PCL+β-TCP, which presented a water uptake of nearly 100% after 14 days. A sustained release of dexamethasone was achieved over 35 days in physiologic solution. This study reports the feasibility of using dense CO2 to produce in one-step a porous matrix loaded with active agents opening new possibilities towards injectable systems for in situ foaming ; European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number REGPOT-CT2012-316331-POLARIS. It was also funded by the project "Novel smart and biomimetic materials for innovative regenerative medicine approaches" (RL1-ABMR-NORTE-01-0124-FEDER-000016) co-financed by North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF) and the project NORTE‐01‐0145‐FEDER‐000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement. The authors would like to acknowledge the funding of the project Associate Laboratory ICVS/3B's, under grant agreement number POCI-01-0145-FEDER-007038 supported by FEDER, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT) ...

Carbon dioxide removal (CDR) moves atmospheric carbon to geological or land-based sinks. In a first-best setting, the optimal use of CDR is achieved by a removal subsidy that equals the optimal carbon tax and marginal damages. We derive second-best subsidies for CDR when no global carbon price exists but a national government implements a unilateral climate policy. We find that the optimal carbon tax differs from an optimal CDR subsidy because of carbon leakage, terms-of-trade and fossil resource rent dynamics. First, the optimal removal subsidy tends to be larger than the carbon tax because of lower supply-side leakage on fossil resource markets. Second, terms-of-trade effects exacerbate this wedge for net resource exporters, implying even larger removal subsidies. Third, the optimal removal subsidy may fall below the carbon tax for resource-poor countries when marginal environmental damages are small.

It is increasingly being recognised that the housing sector can contribute to reductions in the levels of carbon dioxide (CO2). The renewal of existing residential areas offers opportunities to reduce CO2 emissions. However, technical options for CO2-reduction, such as insulation, solar energy, and combined heat and power, often fail to materialise. For a better understanding of why options for CO2-reduction are applied or rejected, it is insufficient to consider only the economic and technical features of these options themselves: factors related to planning processes play an important role as well. Experiences in urban renewal projects suggest that a combination of local process management and national top-down strategies is needed to go beyond conventional building practices.