Emission Budget Research Articles

ОБЛАСТЬ СУЩЕСТВОВАНИЯ И МАТЕМАТИЧЕСКАЯ МОДЕЛЬ БЕЗНАЛОГОВОЙ ЭКОНОМИКИ

The article raises the theoretical problem of determining the possible sustainable functioning of the economy in the emission formation of budget revenues in compliance with the conditions of the absence of inflation or its availability within controlled limits. Describes the historical conditionality of occurrence of the tax economy, the interaction between the processes of circulation of money and commodity masses, but also the inefficiency of the tax system in the conditions of monetary circulation. The possibility of an evolutionary transition to the tax-exempt economy in the regime of controlled inflation for developed countries economies. On the basis of the modified equation of exchange Fisher performed a quantitative assessment of the timing of this transition. The possibility is shown of the emission budget for both developing and developed economies. Developed and tested on real economic statistics phenomenological nonlinear mathematical model of macroeconomics that allow forecasting and planning of economic processes. This model with some modification is used to describe the functioning of tax-free economy.

An increase in methane emissions from tropical Africa between 2010 and 2016 inferred from satellite data

Abstract. Emissions of methane (CH4) from tropical ecosystems, and how they respond to changes in climate, represent one of the biggest uncertainties associated with the global CH4 budget. Historically, this has been due to the dearth of pan-tropical in situ measurements, which is particularly acute in Africa. By virtue of their superior spatial coverage, satellite observations of atmospheric CH4 columns can help to narrow down some of the uncertainties in the tropical CH4 emission budget. We use proxy column retrievals of atmospheric CH4 (XCH4) from the Japanese Greenhouse gases Observing Satellite (GOSAT) and the nested version of the GEOS-Chem atmospheric chemistry and transport model (0.5∘×0.625∘) to infer emissions from tropical Africa between 2010 and 2016. Proxy retrievals of XCH4 are less sensitive to scattering due to clouds and aerosol than full physics retrievals, but the method assumes that the global distribution of carbon dioxide (CO2) is known. We explore the sensitivity of inferred a posteriori emissions to this source of systematic error by using two different XCH4 data products that are determined using different model CO2 fields. We infer monthly emissions from GOSAT XCH4 data using a hierarchical Bayesian framework, allowing us to report seasonal cycles and trends in annual mean values. We find mean tropical African emissions between 2010 and 2016 range from 76 (74–78) to 80 (78–82) Tg yr−1, depending on the proxy XCH4 data used, with larger differences in Northern Hemisphere Africa than Southern Hemisphere Africa. We find a robust positive linear trend in tropical African CH4 emissions for our 7-year study period, with values of 1.5 (1.1–1.9) Tg yr−1 or 2.1 (1.7–2.5) Tg yr−1, depending on the CO2 data product used in the proxy retrieval. This linear emissions trend accounts for around a third of the global emissions growth rate during this period. A substantial portion of this increase is due to a short-term increase in emissions of 3 Tg yr−1 between 2011 and 2015 from the Sudd in South Sudan. Using satellite land surface temperature anomalies and altimetry data, we find this increase in CH4 emissions is consistent with an increase in wetland extent due to increased inflow from the White Nile, although the data indicate that the Sudd was anomalously dry at the start of our inversion period. We find a strong seasonality in emissions across Northern Hemisphere Africa, with the timing of the seasonal emissions peak coincident with the seasonal peak in ground water storage. In contrast, we find that a posteriori CH4 emissions from the wetland area of the Congo Basin are approximately constant throughout the year, consistent with less temporal variability in wetland extent, and significantly smaller than a priori estimates.

Spatial and temporal variations of the greenhouse gas emissions in coastal saline wetlands in southeastern China.

Coastal wetlands are crucial to global climate change due to their roles in modulating atmospheric concentrations of greenhouse gases (GHGs) (CO2, CH4, N2O). Under a warming climate, we investigated spatial and temporal variations of GHGs emissions over the coastal wetlands in southeastern China during 2012-2014. Five dominant land cover types in coastal wetlands have been considered, including the bare mud flat (BF), the Spartina alterniflora flats (SAF), the Suaeda glauca flats (SGF), the Phragmites australis flat (PAF), and the Scripus triqueter flat (STF). The results showed that the annual average CO2 fluxes were 305.8, 588.8, 370.2, and 136.5mgm-2h-1 from spring to winter. CH4 fluxes presented to be a sink in spring (- 0.02mgm-2h-1), and functioned as a source in the following seasons. Correlation analysis indicated that the surface air temperature and the cumulative precipitation could be two main factors that influenced the seasonal and inter-annual variations of GHGs emissions. In addition, we provided a regional budget of GHGs emissions that suggested the variations of GHGs emissions under a warming climate.

Intact and managed peatland soils as a source and sink of GHGs from 1850 to 2100

Land-use change disturbs the function of peatland as a natural carbon sink and triggers high GHG emissions1. Nevertheless, historical trends and future trajectories of GHG budgets from soil do not explicitly include peatlands2,3. Here, we provide an estimate of the past and future role of global peatlands as either a source or sink of GHGs based on scenario timelines of land conversion. Between 1850 and 2015, temperate and boreal regions lost 26.7 million ha, and tropical regions 24.7 million ha, of natural peatland. By 2100, peatland conversion in tropical regions might increase to 36.3 million ha. Cumulative emissions from drained sites reached 80 ± 20 PgCO2e in 2015 and will add up to 249 ± 38 Pg by 2100. At the same time, the number of intact sites accumulating peat will decline. In 1960 the global peatland biome turned from a net sink into a net source of soil-derived GHGs. Annual back-conversion of most of the drained area would render peatlands GHG neutral, whereas emissions from peatland may comprise 12–41% of the GHG emission budget for keeping global warming below +1.5 to +2 °C without rehabilitation. Natural peatlands accumulate carbon but land-use change and drainage leads to emission of GHGs from peatlands. Loss of natural peatland area globally has shifted the peatland biome from a sink to a source of carbon, but restoration of drained peatlands could make them carbon neutral.

Environmental benchmarks for buildings: needs, challenges and solutions—71st LCA forum, Swiss Federal Institute of Technology, Zürich, 18 June 2019

The 71st LCA forum was held on 18 June 2019 in Zurich, Switzerland, to discuss the current status and future plans of environmental benchmarking for buildings in view of the 1.5 °C target stipulated in the Paris Agreement. The Paris Agreement requires a significant reduction in greenhouse gas emissions, in fact net zero by 2050. One of the priority areas is the building stock, as it is an important source of greenhouse gas emissions. COP23, the International Energy Agency (IEA) and an increasing number of countries are extending their consideration from aspects such as energy consumption and emissions from building operation to the manufacture of construction materials and building construction. The event offered an excellent platform to exchange ideas and thoughts on existing and planned environmental benchmarking schemes for buildings. The one day event dealt at first with life cycle assessment (LCA) approaches applied in European, Asian, Australasian and American countries to assess the environmental performance of buildings. Within a round robin test, organised within the IEA EBC (Energy in Building and Communities) Annex 72 project, 22 organisations from 21 countries assessed the environmental performance of one identical building, the be2226 office building located in Lustenau, Austria. The materials, the building technologies and the energy consumption were kept constant. This allowed to identify the main differences in LCA data used and LCA methodology applied in the national contexts. In the LCA forum, eight organisations presented the current state or future plans of an environmental benchmarking system in their home country. The systems were characterised in terms of scope, in particular (a) which types of buildings are covered; (b) which life cycle stages are included; (c) which building elements and which operational energy uses are considered; and (d) which environmental impacts are addressed. Furthermore, the default reference service life and the main source of LCA data were specified and the current or planned benchmark values for greenhouse gas emissions of residential buildings were reported. The round robin test revealed the LCA background data as one major source of difference in assessment results. Methodological and modelling choices were less important except for the Danish assessment, which applies a comparatively long reference study period (80 years for office buildings, 120 years for residential buildings) and considering future changes in the electricity mix towards 100% renewables to describe the operational electricity demand during the lifetime of the building. Most benchmarking systems presented are applied on new and retrofit residential, office and school buildings. Other use types such as shops, restaurants, universities or hospitals are covered only in few or just one country. The greenhouse gas emission benchmark for residential buildings (construction and operation) revealed a significant gap between the current level of the building benchmarks on one hand and the target of net zero CO2-eq emissions derived from the 1.5 °C scenarios of IPCC on the other. An online inquiry carried out among the audience during the event showed a preference for a per capita overall budget of 500 kg CO2-eq per year to derive greenhouse gas emission benchmarks for buildings and that life cycle-based benchmarks for buildings should be legally binding. The 71st LCA forum on environmental benchmarks for buildings showed that the experts present acknowledge the net zero CO2 emission target derived from the 1.5 °C scenarios. Several countries have expertise and experience in assessing the environmental impacts of buildings. However, the current (mostly voluntary) benchmarking schemes are way too weak to support the building sector in contributing significantly to the required CO2 emission turn off. The outlook given by several speakers showed that the current benchmarks will likely be tightened and oriented on the planetary boundaries and on the scientifically defined CO2 emission budgets rather than on the technical or economic feasibility. Finally, the responsibility of governments for defining environmental requirements and targets was stressed. The event, the exchange of ideas and the discussions helped to nurture and hopefully accelerate the developments in the construction sector of the home countries of the experts and government representatives. These developments will contribute to a society whose environmental impacts remain within the carrying capacity of our planet.

Assessing Environmental Sustainability Using Ecological Limits Expressed as Mass Flowrates with the Inclusion of a Sustainable Time Perspective

This study explores the concept of ecological limits (ELs) for determining the sustainable extraction of natural resources and sustainable discharge of emissions. ELs are expressed as limiting mass flowrates and equations are developed and presented for their quantitative estimation. These include a sustainable time perspective term. This is a time duration that provides sufficient time for humans to adapt to the depletion of a resource stock or emission budget, e.g., the time for a number of human generations. Thus, even if a resource is utilised at a greater rate than its regeneration rate, it could be considered sustainable if the resource extraction rate is adjusted so that the stock continuously lasts for more than the sustainable timeframe. The application of this ecological limits concept is illustrated by applying it to assessing the environmental sustainability of global fossil fuel energy, specific water resources, and global fertilisers. Exceeding ELs can act as a warning signal and highlight those resources and emissions where actions need to be taken to bring their extraction and discharge rates to within the ELs.

Hybrid Mass Balance/4D-Var Joint Inversion of NO x and SO2 Emissions in East Asia.

Accurate estimates of NOx and SO2 emissions are important for air quality modeling and management. To incorporate chemical interactions of the two species in emission estimates, we develop a joint hybrid inversion framework to estimate their emissions in China and India (2005–2012). Pseudo observation tests and posterior evaluation with surface measurements demonstrate that joint assimilation of SO2 and NO2 can provide more accurate constraints on emissions than single‐species inversions. This occurs through synergistic change of O3 and OH concentrations, particularly in conditions where satellite retrievals of the species being optimized have large uncertainties. The percentage changes of joint posterior emissions from the single‐species posterior emissions go up to 242% at grid scales, although the national average of monthly emissions, seasonality, and interannual variations are similar. In China and India, the annual budget of joint posterior SO2 emissions is lower, but joint NOx posterior emissions are higher, because NOx emissions increase to increase SO2 concentration and better match Ozone Monitoring Instrument SO2 observations in high‐NOx regions. Joint SO2 posterior emissions decrease by 16.5% from 2008 to 2012, while NOx posterior emissions increase by 24.9% from 2005 to 2011 in China—trends which are consistent with the MEIC inventory. Joint NOx and SO2 posterior emissions in India increase by 15.9% and 19.2% from 2005 to 2012, smaller than the 59.9% and 76.2% growth rate using anthropogenic emissions from EDGARv4.3.2. This work shows the benefit and limitation of joint assimilation in emission estimates and provides an efficient framework to perform the inversion.

Strong Evidence of Anomalous Microwave Emission from the Flux Density Spectrum of M31

Abstract We have observed the Andromeda galaxy, Messier 31 (M31), at 6.7 GHz with the Sardinia Radio Telescope. We mapped the radio emission in the C-band, re-analyzed WMAP and Planck maps, as well as other ancillary data, and we have derived an overall integrated flux density spectrum from the radio to the infrared. This allowed us to estimate the emission budget from M31. Integrating over the whole galaxy, we found strong and highly significant evidence for anomalous microwave emission (AME), at the level of Jy at the peaking frequency of ≃25 GHz. Decomposing the spectrum into known emission mechanisms such as free–free, synchrotron, thermal dust, and AME arising from electric dipole emission from rapidly rotating dust grains, we found that the overall emission from M31 is dominated, at frequencies below 10 GHz, by synchrotron emission with a spectral index of , with subdominant free–free emission. At frequencies ≳10 GHz, AME has a similar intensity to that of synchrotron and free–free emission, overtaking them between 20 and 50 GHz, whereas thermal dust emission dominates the emission budget at frequencies above 60 GHz, as expected.

Negative CO2 emissions - An analysis of the retention times required with respect to possible carbon leakage

With present emissions the global CO2 budget associated with a maximum temperature increase of about 1.5–2 °C will likely be spent within a few decades, Thus, it will be very difficult or perhaps even impossible to meet the climate targets agreed upon in Paris only by decreasing emissions of greenhouse gases. Scenarios presented in the IPCC reports accommodate for this by introducing so-called negative CO2 emissions. The idea is that the cumulative CO2 emission budget will be exceeded, but that massive negative emissions, especially during the latter part of the century, will remove the surplus of CO2 in the atmosphere.A number of different Negative Emissions Technologies (NETs) have been proposed, including Biomass Energy with Carbon Capture and Storage (BECCS), afforestation/reforestation, altered agricultural practices, biochar production, enhanced weathering and direct air captured. However, many of the options proposed could be associated with carbon leakage which could compromise the purpose of negative emissions, e.g. storage in of carbon in growing/dead biomass that leaks to the atmosphere. Furthermore, it may be difficult to safely assess the long-term leakage rates. To reach the large negative emissions needed it is expected to require a mix of approaches having different expected retention times, and different safety in terms of leakage rates.Could the risk of leakage mean that we are just delaying the problem and transferring the problem to coming generations? The short answer to this is that it all depends on the leakage rates. Different leakage rates and mixes of leakage rates are investigated in the paper. For the case of a mixture of leakage time scales of 300, 1000 and 10,000 years and assuming that 80% or more was permanently stored, the contribution to the atmospheric stock was small, peaking at about 3 ppm CO2. It was concluded that leakage would not significantly compromise the benefits of negative emissions unless leakage is substantial and rapid. To quantify what could be meant by substantial and rapid, an example would be if 100% of the CO2 stored would leak out at a rate of the order of 1%/year.

Negative CO2 Emissions - An Analysis of the Retention Times Required with Respect to Possible Carbon Leakage

Abstract With present emissions the global CO2 budget associated with a maximum temperature increase of about 1.5–2 °C will likely be spent within a few decades, Thus, it will be very difficult or perhaps even impossible to meet the climate targets agreed upon in Paris only by decreasing emissions of greenhouse gases. Scenarios presented in the IPCC reports accommodate for this by introducing so-called negative CO2 emissions. The idea is that the cumulative CO2 emission budget will be exceeded, but that massive negative emissions, especially during the latter part of the century, will remove the surplus of CO2 in the atmosphere. A number of different Negative Emissions Technologies (NETs) have been proposed, including Biomass Energy with Carbon Capture and Storage (BECCS), afforestation/reforestation, altered agricultural practices, biochar production, enhanced weathering and direct air captured. However, many of the options proposed could be associated with carbon leakage which could compromise the purpose of negative emissions, e.g. storage in of carbon in growing/dead biomass that leaks to the atmosphere. Furthermore, it may be difficult to safely assess the long-term leakage rates. To reach the large negative emissions needed it is expected to require a mix of approaches having different expected retention times, and different safety in terms of leakage rates. Could the risk of leakage mean that we are just delaying the problem and transferring the problem to coming generations? The short answer to this is that it all depends on the leakage rates. Different leakage rates and mixes of leakage rates are investigated in the paper. For the case of a mixture of leakage time scales of 300, 1000 and 10,000 years and assuming that 80% or more was permanently stored, the contribution to the atmospheric stock was small, peaking at about 3 ppm CO2. It was concluded that leakage would not significantly compromise the benefits of negative emissions unless leakage is substantial and rapid. To quantify what could be meant by substantial and rapid, an example would be if 100% of the CO2 stored would leak out at a rate of the order of 1%/year.

Carbon Dioxide Emission and Soil Sequestration for the French Agro-Food System: Present and Prospective Scenarios

France is a major agricultural power, characterized by a high degree of regional specialization, either in stockless cash crop farming, exporting most of its intensive cereal production, or in intensive livestock farming highly dependent on foreign feed imports. This agricultural model is characterized by wide nutrient and carbon cycle opening and severe environmental pollution. Based on the nutrient accounting GRAFS model, two contrasted scenarios for the French agricultural system at the 2050 horizon have recently been designed and evaluated for their capacity to meet both the national population's food demand and environmental standards in terms of water pollution. The first scenario (O/S, for opening and specialization) assumes the continuation of the current trends of intensification, specialization, and opening to international markets. The second one (A/R/D, for autonomy, reconnection, and demitarian diet) assumes a radical change toward organic farming with diversification of crop rotations, reconnection of crop and livestock farming, and reduction of the proportion of animal proteins in the human diet. Herein we calculate the budget of CO2 emissions and C sequestration in soils of these two scenarios compared with the current situation of the French agro-food system, by coupling the GRAFS and AMG models. These simulations reveal that the overall CO2 emissions balance of the O/S scenario is far higher than those of the A/R/D, namely because of the emissions associated with mineral fertilizer manufacture, and imported feed and mechanization of land management requiring a large amount of fossil fuel. As the organic carbon content of the soil is known to be highly path-dependent (in the sense that it is the inheritance of previous land use practices), we tested the effect of two rates of implementation of the two scenarios and evaluated the response time of the C soil store, which is of the order of two decades or more. This reveals that after about two-three decades following the implementation of a scenario, an equilibrium is reached with no more net soil C emission nor sequestration.

Methane Emissions from Artificial Waterbodies Dominate the Carbon Footprint of Irrigation: A Study of Transitions in the Food-Energy-Water-Climate Nexus (Spain, 1900-2014).

Irrigation in the Mediterranean region has been used for millennia and has greatly expanded with industrialization. Irrigation is critical for climate change adaptation, but it is also an important source of greenhouse gas emissions. This study analyzes the carbon (C) footprint of irrigation in Spain, covering the complete historical process of mechanization. A 21-fold total, 6-fold area-based, and 4-fold product-based increase in the carbon footprint was observed during the 20th century, despite an increase in water use efficiency. CH4 emissions from waterbodies, which had not previously been considered in the C footprint of irrigation systems, dominated the emission budget during most of the analyzed period. Technologies to save water and tap new water resources greatly increased energy and infrastructure demand, while improvements in power generation efficiency had a limited influence on irrigation emissions. Electricity production from irrigation dams may contribute to climate change mitigation, but the amount produced in relation to that consumed in irrigation has greatly declined. High uncertainty in CH4 emission estimates from waterbodies stresses a need for more spatially resolved data and an improved empirical knowledge of the links between water quality, water level fluctuations, and emissions at the regional scale.

Biochar improves diary pasture yields by alleviating P and K constraints with no influence on soil respiration or N2O emissions

Dairy pastures can be a major source of soil nitrous oxide (N2O) emissions due to the combination of intensive nitrogen (N) fertiliser use and high soil water content, from either rainfall and/or irrigation. Biochar application is a promising approach to lower soil greenhouse gas emissions, particularly under high soil moisture conditions where denitrification is the primary N-transformation pathway. In a replicated field trial, we evaluated the effects of two contrasting biochars derived from poultry litter and from hardwood on soil N2O emissions, soil ammonium (NH4+) and nitrate (NO3−) status, pasture productivity and herbage nutrient content. A liming treatment to mimic the liming equivalence of the poultry litter biochar was used to separate any effects observed from changes in soil pH. To further separate the effects of biochars on soil N status, N2O emissions and pasture N uptake, high and low N fertiliser doses (annual application of 672 kg N ha−1, 336 kg N ha−1) were superimposed across all of the treatments. The N fertiliser dose had no significant impact on pasture yield. Application of poultry litter biochar resulted in significant increases in pasture productivity under both high and low N inputs. This was achieved by alleviating soil P, and possibly K nutritional constraints that are typical in Australian Ferralsols. Under the high N fertiliser dose, emissions of N2O from the treatments and control were not significantly different (p > 0.05) and ranged between 1.14 and 1.78 kg N2O-N ha−1 across the 11-month study. The low N dose resulted in significantly lower emissions of N2O of between 0.80 and 0.84 kg N2O-N ha−1, but biochar had no significant effect on net emissions across the season. The lack of impact of biochar on N2O emissions was attributed to the relatively dry conditions over the trial period resulting in nitrification being the most likely N-transformation pathway. During brief episodes of high soil moisture, peak emissions from the biochar plots were lower than from the control or lime treatment, but these differences did not impact on the emission budget over the 11-month sampling campaign.

Potential future methane emission hot spots in Greenland

Climate models have been making significant progress encompassing an increasing number of complex feedback mechanisms from natural ecosystems. Permafrost thaw and subsequent induced greenhouse gas emissions, however, remain a challenge for climate models at large. Deducing permafrost conditions and associated greenhouse gas emissions from parameters that are simulated in climate models would be a helpful step towards estimating emission budgets from permafrost regions. Here we use a regional climate model with a 5 km horizontal resolution to assess future potential methane (CH4) emissions over presently unglaciated areas in Greenland under an RCP8.5 scenario. A simple frost index is applied to estimate permafrost conditions from the model output. CH4 flux measurements from two stations in Greenland; Nuuk representing sub-Arctic and Zackenberg high-Arctic climate, are used to establish a relationship between emissions and near surface air temperature. Permafrost conditions in Greenland change drastically by the end of the 21st century in an RCP8.5 climate. Continuous permafrost remains stable only in North Greenland, the north-west coast, the northern tip of Disko Island, and Nuussuaq. Southern Greenland conditions only sustain sporadic permafrost conditions and largely at high elevations, whereas former permafrost in other regions thaws. The increasing thawed soil leads to increasing CH4 emissions. Especially the area surrounding Kangerlussuaq, Scoresby Land, and the southern coast of Greenland exhibit potentially high emissions during the longer growing season. The constructed maps and budgets combining modelled permafrost conditions with observed CH4 fluxes from CH4 promoting sites represent a useful tool to identify areas in need of additional monitoring as they highlight potential CH4 hot spots.

The impact of wetting intensity on soil CO2 emissions from a coastal grassland ecosystem

Rainfall events can stimulate carbon dioxide (CO2) emissions (i.e. the Birch Effect). However, the contribution of wetting-induced CO2 emissions to annual C emissions remains largely unquantified, as does the impact of different rainfall amounts/wetting intensities, particularly at the field scale. In this study, the short-term impact of simulated rainfall amounts (equivalent to 1, 2, 5, 10, 15, 20 and 25 mm h−1) on soil CO2 emissions from a coastal grassland ecosystem were investigated for summer and autumn periods and the results used to assess their impact on annual CO2 emissions. Wetting intensities >2 mm h−1 resulted in greater CO2 emissions (P < 0.05) than smaller wetting intensities (1 and 2 mm h−1). For wetting intensities >2 mm h−1, cumulative CO2 emissions were largely independent of wetting intensity. Significant inverse correlations between cumulative CO2 emissions and soil moisture content prior to water addition (InitSWC) were shown for all wetting intensities. A significant inverse relationship was also shown when all data were combined (r2 = 0.37, P < 0.001), although a better fit (r2 = 0.68, P < 0.001) was obtained when wetting intensities <2 mm h−1 were omitted. This indicates that factors associated with soil drying prior to water addition have the major impact on CO2 emissions, particularly at greater wetting intensities. Using the relationship between CO2 emissions and initial soil water content, together with in situ soil moisture and rainfall measurements, episodic wetting events were estimated to potentially increase the annual C emissions budget by up to 14%, although this will be critically dependent on the extent of soil drying and the frequency of any rainfall events associated with periods of low soil water content.

Source partitioning and emission factor of nitrous oxide during warm and cold cropping seasons from an upland soil in South Korea

Nitrous oxide (N2O) is a major greenhouse gas (GHG) with high global warming potential. A majority of the N2O flux comes from agricultural sources, mainly due to nitrogen (N) fertilization. The soil N2O flux, induced by N fertilization, mainly originated from two different sources, i.e., fertilizer and soil organic nitrogen (SON). It is essential to know the individual contribution of these two different sources in total N2O flux for planning necessary mitigation strategies. It is also indispensable to know the seasonal difference of emission factors (EF) for having more accurate N2O inventory. Therefore, an experiment was conducted in a South Korean upland soil during summer and winter seasons using 15N labeled urea as an artificial N source and source specific N2O emissions were distinguished under different environmental conditions. To characterize the N2O emissions from urea, 0, 50, 100 and 200% of the Korean N recommendation rate was selected for specified crops. The Korean N recommendation rate for red pepper (Capsicum annuum) and garlic (Allium sativum) was 190 and 250 kg N ha−1, respectively. Direct emissions from urea were estimated from the difference of 15N2O flux emitted from 15N-urea treated soil and the natural abundance of 15N2O. From total N2O fluxes, urea originated N2O flux was 0.87% and 0.13% of the applied N in warm and cold seasons, respectively and the rest comes from SON. Nitrous oxide EF in the warm season was 2.69% of applied N and in the cold season that was 0.25%. Nitrous oxide fluxes showed a significant exponential relationship with soil temperature. The results show the necessity of considering the different N2O EF for warm and cold cropping seasons to reduce uncertainty in N2O inventory. The findings of this research may help better understand N2O source partitioning and the emission budget from warm and cold cropping seasons.

Climate Change Mitigation Justice and the No-Harm Principle

When translated into concrete policy, any allocation of emissions leads to the attribution of emissions rights based on distributive justice (even if the policy was previously examined in terms of utilitarianism at the philosophical level). Consequently, the distributive justice approach legitimizes the corresponding amount of emissions. If a certain level of emissions can receive emissions rights, provided they are compatible with a certain emissions budget, to allocate emissions rights when the dangerous concentration level has been overshot could understate the need to preserve the functioning of a “balanced” climate system. From the perspective of Foucault’s archaeology of knowledge, and with the purpose of assessing the epistemology of climate justice, it will be possible to question the possible importation of the mode of production of norms of social law into climate mitigation justice. Additionally, it will be questioned whether the amount of anthropogenic emissions rights can be provided by “the laws of nature” and whether and how the no‑harm principle can contribute to the epistemological relevance of the narrative of climate justice.

Greenhouse Gas Emissions from the Tibetan Alpine Grassland: Effects of Nitrogen and Phosphorus Addition

The cycle of key nutrient elements nitrogen (N) and phosphorus (P) has been massively altered by anthropogenic activities. Little is known about the impacts on greenhouse gas (GHG) emission of the large nutrient additions occurring in the alpine grasslands of the Tibetan Plateau. We investigated soil surface emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) under control, N, P and combined nitrogen and phosphorus (NP) additions from July 2011 to September 2012. Compared to the control, CO2 flux significantly increased by 14.6% and 27.4% following P and NP addition, respectively. The interaction of NP addition had a significant influence on CO2 flux during the non-growing season and the spring thaw period. Compared to the control, CH4 flux decreased by 9.9%, 23.2% and 26.7% following N, P and NP additions, respectively, and no interactive effect of NP addition was found in any period. Soil N2O flux was significantly increased 2.6 fold and 3.3 fold, following N and NP addition treatments, respectively, and there was no interaction effect of NP addition together. The contribution of cumulative CO2 emission during the non-growing season was less than 20% of the annual budget, but cumulative CH4 and N2O emissions during the same period can account for 37.3–48.9% and 44.7–59.5% of the annual budget, respectively. Methane and N2O emissions did not increase greatly during the spring thawing period, with contributions of only 0.4–3.6% and 10.3–12.3% of the annual budget, respectively. Our results suggest that N and P addition could increase CO2 and N2O emissions and reduce CH4 emission. Furthermore, although the non-growing season is very cold and long, cumulative CH4 and N2O emissions are considerable during this period and cannot be neglected by future studies evaluating the greenhouse gas emission budget in the Tibetan plateau.

Assessing the impact of fertilizer application on net soil-derived emission budgets from a temperate willow (Salix miyabeana) short rotation coppice system

Willow (Salix spp.) short-rotation coppice (SRC) systems are productive bioenergy feedstocks that can be cultivated on marginal land and generate high yields when amended with nitrogen (N) fertilizers. However, fertilizer application results in greater N2O emissions and negates the potential carbon (C) neutrality of willow bioenergy systems. We evaluated 1) the effect of N fertilizer application on the soil-atmosphere exchange of CO2-C and (N2O-N emissions, soil NH4+-N and NO3−-N); 2) emissions generated during winter and freeze-thaw cycles (FTCs); and 3) the net annual emission (CO2-equivalents [CO2-eq]) from willow SRC systems. CO2-C emissions followed seasonal trends with elevated emissions occurring in the spring and summer. Significantly greater (p < 0.05) CO2-C emissions were observed during the growing season, whereas only 7.2%–13.4% of the total CO2-C emissions occurred during the winter. Freeze-thaw cycles (FTCs) did not significantly (p < 0.05) increase CO2-C emissions. Nitrogen fertilizer application increased soil NH4+ and NO3− availability resulting in an N2O-N hot moment following fertilizer application in the spring. There was a N2O-N hot moment following FTC events, and winter N2O-N emissions were minimal. Overall, N2O-N emissions accounted for 2.2–3.4% of the total annual emissions. Willow SRC systems were a C sink in fertilized treatments with a C sequestration potential of 10.79 Mg CO2-eq ha−1 yr−1. Unfertilized treatments were a slight C source, with net emissions of 1.19 Mg CO2-eq ha−1 yr−1. We recommend a low rate of fertilizer application to willow SRC systems to maintain these systems as a long-term C sink.

Author Correction: Path-dependent reductions in CO2 emission budgets caused by permafrost carbon release

In the version of this Article originally published, data given for total exceedance budgets of CO2 for 1.5 °C and 2 °C targets were incorrect in the main text, although the correct values were given in Supplementary Table 1. These errors also resulted in an incorrect estimation of the percentage difference between the authors’ results and estimates by the IPCC. These errors have now been corrected in the online versions.