Global and regional trends in greenhouse gas emissions from livestock

Following IPCC guidelines (IPCC 2006), we estimate greenhouse gas emissions related to livestock in 237 countries and 11 livestock categories during the period 1961–2010. We find that in 2010 emissions of methane and nitrous oxide related to livestock worldwide represented approximately 9 % of total greenhouse gas (GHG) emissions. Global GHG emissions from livestock increased by 51 % during the analyzed period, mostly due to strong growth of emissions in developing (Non-Annex I) countries (+117 %). In contrast, developed country (Annex I) emissions decreased (?23 %). Beef and dairy cattle are the largest source of livestock emissions (74 % of global livestock emissions). Since developed countries tend to have lower CO₂-equivalent GHG emissions per unit GDP and per quantity of product generated in the livestock sector, the amount of wealth generated per unit GHG emitted from the livestock sector can be increased by improving both livestock farming practices in developing countries and the overall state of economic development. Our results reveal important details of how livestock production and associated GHG emissions have occurred in time and space. Discrepancies with higher tiers, demonstrate the value of more detailed analyses, and discourage over interpretation of smaller-scale trends in the Tier 1 results, but do not undermine the value of global Tier 1 analysis.     

Estimates of global N2O emissions from cattle, pig and chicken manure, including a discussion of CH4 emissions

Humans seem to have doubled the global rate of terrestrial nitrogen fixation. Globally 50–70% (85 Tg, 1 Tg=10¹² g) of the nitrogen supplied in fertilizer (80 Tg N/a) and leguminous crops (40–80 Tg N/a) are used to feed cattle. The aim of the present study was to derive some estimates of global N₂O production from animal manure. As the parameter giving the most stable numerical basis for regional and global extrapolation we adopted the molar emission ratios of N₂O to NH₃. These ratios were measured in cattle, pig and chicken housings with different manure handling systems, in dung-heaps and in liquid manure storage tanks. Individual molar emission ratios from outside manure piles varied over two orders of magnitude, strongly dependent on the treatment of the manure. A median emission ratio of 1.6×10^-2 (n=65) was obtained in cow-sheds with slatted floors and liquid manure stored underneath and a median ratio of 24×10^-2 (n=31) was measured in a beef cattle housing with a solid manure handling system.We next extrapolated to global NH₃ emissions from those estimated for Europe, using N uptake by the animals as a scaling factor. Multiplication with observed N₂O to NH₃ ratios next provided some estimates of regional and global N₂O emissions. To account for the great variability of the emission ratios of N₂O/NH₃, we developed upper and lower case emission scenarios, based on lower and upper quartiles of measured emission ratios. The global emission from cattle and swine manure is in the range of 0.2–2.5 Tg N-N₂O/a, representing 44+-39% of the annual atmospheric accumulation rate. This N₂O emission arises from about 40 Tg N/a of cattle and pig manure stored in or at animal housings. We did not account for N₂O emissions from another 50 Tg N/a excreted by grazing cattle, goats and sheep, and application of the manure to agricultural fields. Our study makes it clear that major anthropogenic N₂O emissions may well arise from animal manure. The large uncertainty of emission ratios, which we encountered, show that much more intense research efforts are necessary to determine the factors that influence N₂O emissions from domestic animal manure both in order to derive a more reliable global estimate of N₂O release and to propose alternative waste treatment methods causing smaller N₂O releases. In our studies we found large enhancements in N₂O releases when straw was added to the manure, which is a rather common practice. In view of the ongoing discussion in Europe to re-install the traditional solid manure system (bed down cattle) for environmental and animal welfare reasons, it is noteworthy that our measurements indicate highest N₂O release from this particulary system.In a similar manner, but based on a smaller data set, we also estimated the release of CH₄ from cattle and swine manure and from liquid manure only to be about 9 Tg/year in good agreement with the estimate by the Environmental Protection Agency (1994) of 8.6+-2.6 Tg/year. A total annual methane release as high as 34 Tg/a was derived for solid and liquid cattle and pig manure from animals in housings.     

A global model of changing N2O emissions from natural and perturbed soils

A high resolution global model of the terrestrial biosphere is developed to estimate changes in nitrous oxide (N₂O) emissions from 1860–1990. The model is driven by four anthropogenic perturbations, including land use change and nitrogen inputs from fertilizer, livestock manure, and atmospheric deposition of fossil fuel NO _x . Global soil nitrogen mineralization, volatilization, and leaching fluxes are estimated by the model and converted to N₂O emissions based on broad assumptions about their associated N₂O yields. From 1860–1990, global N₂O emissions associated with soil nitrogen mineralization are estimated to have decreased slightly from 5.9 to 5.7 Tg N/yr, due mainly to land clearing, while N₂O emissions associated with volatilization and leaching of excess mineral nitrogen are estimated to have increased sharply from 0.45 to 3.3 Tg N/yr, due to all four anthropogenic perturbations. Taking into account the impact of each perturbation on soil nitrogen mineralization and on volatilization and leaching of excess mineral nitrogen, global 1990 N₂O emissions of 1.4, 0.7, 0.4 and 0.08 Tg N/yr are attributed to fertilizer, livestock manure, land clearing and atmospheric deposition of fossil fuel NO _x , respectively. Consideration of both the short and long-term fates of fertilizer nitrogen indicates that the N₂O/fertilizer-N yield may be 2% or more.C. NBM Definitions AET _mon (cm H₂O) = monthly actual evapotranspiration - AET _ann (cm H₂O) = annual actual evapotranspiration - age _h (years) = stand age of herbaceous biomass - age _w (years) = stand age of woody biomass - atmblc (gC/m²/month) = net flux of CO₂ from grid - biotoc (gC/g biomass) = 0.50 = convert g biomass to g C - beff _h = 0.8 = fraction of cleared herbaceous litter that is burned - beff _w = 0.4 = fraction of cleared woody litter that is burned - bfmin = 0.5 = fraction of burned N litter that is mineralized or converted to reactive gases which rapidly redeposit. Remainder assumed pyrodenitrified to N₂. + N₂O - bprob = probability that burned litter will be burned - burn _h (gC/m²/month) = herbaceous litter burned after land clearing - burn _w (gC/m²/month) = woody litter burned after land clearing - cbiomsh (gC/m²) = C herbaceous biomass pool - cbiomsw (gC/m²) = C woody biomass pool - clear (gC/m²/month) = woody litter C removed by land clearing - clearn (gN/m²/month) = woody litter N removed by land clearing - cldh (month^–1) = herbaceous litter decomposition coefficient - cldw (month^–1) = woody litter decomposition coefficient - clittrh (gC/m²) = C herbaceous litter pool - clittrw (gC/m²) = C woody litter pool - clph (month^–1) = herbaceous litter production coefficient - clpw (month^–1) = woody litter production coefficient - cnrath (gC/gN) = C/N ratio in herbaceous phytomass - cnrats (gC/gN) = C/N ratio in soil organic matter - cnratt (gC/gN) = average C/N ratio in total phytomass - cnratw (gC/gN) = C/N ratio in woody phytomass - crod (month^–1) = forest clearing coefficient - csocd (month^–1) = actual soil organic matter decompostion coefficient - decmult decomposition coefficient multiplier; natural =1.0; agricultural =1.0 (1.2 in sensitivity test) - fertmin (gN/m²/month) = inorganic fertilizer input - fleach fraction of excess inorganic N that is leached - fligh (g Lignin/ g C) = lignin fraction of herbaceous litter C - fligw (g Lignin/ g C) = 0.3 = lignin fraction of woody litter C - fln2o = .01–.02 = fraction of leached N emitted as N₂O - fnav = 0.95 = fraction of mineral N available to plants - fosdep (gN/m²/month) = wet and dry atmospheric deposition of fossil fuel NO _x - fresph = 0.5 = fraction of herbaceous litter decomposition that goes to CO₂ respiration - fresps = 0.51 + .068 ^* sand = fraction of soil organic matter decomposition that goes to CO₂ respiration - frespw = 0.3 ^* (^* see comments in Section 2.3 under decomposition) = fraction of woody litter decomposition that goes to CO₂ respiration - fsoil = ratio of NPP measured on given FAO soil type to NPF_miami - fstruct = 0.15 + 0.018 ^* ligton = fraction of herbaceous litter going to structural/woody pool - fvn2o = .05–.10 = fraction of excess volatilized mineral N emitted as N₂O - fvol = .02 = fraction of gross mineralization flux and excess mineral N volatilized - fyield ratio of total agricultural NPP in a given country in 1980 to total NPP_miami of all displaced natural grids in that country - gimmob _h (gN/m²/month) = gross immobilization of inorganic N into microbial biomass due to decomposition of herbaceous litter - gimmob _s (gN/m²/month) = gross immobilization of inorganic N into microbial biomass due to decomposition of soil organic matter - gimmob _w (gN/m²/month) = gross immobilization of inorganic N into microbial biomass due to decomposition of woody litter - graze (gC/m²/month) = C herbaceous biomass grazed by livestock - grazen (gN/m²/month) = N herbaceous biomass grazed by livestock - growth _h (gC/m²/month) = herbaceous litter incorporated into microbial biomass - growth _w (gC/m²/month) = woody litter incorporated into microbial biomass - gromin _h (gN/m²/month) = gross N mineralization due to decomposition and burning of herbaceous litter - gromin _s (gN/m²/month) = gross N mineralization due to decomposition of soil organic matter - gromin _w (gN/m²/month) = gross N mineralization due to decomposition and burning of woody litter - herb herbaceous fraction by weight of total biomass - leach (gN/m²/month) = leaching (& volatilization) losses of excess inorganic N - ligton (g lignin-C/gN) = lignin/N ratio in fresh herbaceous litter - LP _h (gC/m²/month)= C herbaceous litter production - LP (gC/m²/month) = C woody litter production - LPN _h (gN/m²/month) = N herbaceous litter production - LPN _W (gN/m²/month) = N woody litter production - manco2 (gC/m²/month) = grazed C respired by livestock - manlit (gC/m²/month) = C manure input (feces + urine) - n2oint (gN/m²/month) = intercept of N₂O flux vs gromin regression - n2oleach (gN/m²/month) = N₂O flux associated with leaching and volatilization of excess inorganic N - n2onat (gN/m²/month) = natural N₂O flux from soils - n2oslope slope of N₂O flux vs gromin regression - nbiomsh (gN/m²) = N herbaceous biomass pool - nbiomsw (gN/m²) = N woody biomass pool - nfix (gN/m²/month) = N₂ fixation + natural atmospheric deposition - nlittrh (gN/m²) = N herbaceous litter pool - nlittrw (gN/m²) = N woody litter pool - nmanlit (gN/m²/month) = organic N manure input (feces) - nmanmin (gN/m²/month) = inorganic N manure input (urine) - nmin (gN/m²) = inorganic N pool - NPP _acth (gC/m²/month)= actual herbaceous net primary productivity - NPP _actw (gC/m²/month) = actual woody net primary productivity - nvol (gN/m²/month) = volatilization losses from inorganic N pool - plntnav (gN/m²/month)= mineral N available to plants - plntup _h (gN/m²/month) = inorganic N incorporated into herbaceous biomass - plntup _w (gN/m²/month) = inorganic N incorporated into woody biomass - precip _ann (mm) = mean annual precipitation - precip _mon (mm) = mean monthly precipitation - pyroden _h (gN/m²/month) = burned herbaceous litter N that is pyrodenitrified to N₂ - pyroden _w (gN/m²/month) = burned woody litter N that is pyrodenitrified to N₂ - recyc fraction of N that is retranslocated before senescence - resp _h (gC/m²/month) = herbaceous litter CO₂ respiration - resp _s (gC/m²/month) = soil organic carbon CO₂ respiration - resp _w (gC/m²/month) = woody litter CO₂ respiration - sand sand fraction of soil - satrat ratio of maximum NPP to N-limited NPP - soiloc (gC/m²) = soil organic C pool - soilon (gN/m²) = soil organic N pool - temp _ann (°C) = mean annual temperature - temp _mon (°C) = mean monthly temperature Now at the NOAA Aeronomy Laboratory, Boulder, Colorado.     

Effect of spatial correlation on regional trends in rain events over India

The regional trends are evaluated in the frequency of various rain events using the daily gridded (1°?×?1°) rainfall dataset for the time period 1901–2004, prepared by the India Meteorological Department (IMD). In terms of intensity, the events are classified as low, moderate, heavy and extreme heavy, while short and long spells are classified on the basis of duration of rainfall. The analytical (parametric) and the empirical (bootstrap) techniques were used to incorporate the impact of spatial correlation in regional trends. It is observed that, consideration of spatial correlation reduces the significance level of the trends and the effective number of grid points falling under each category. Especially, the noticeable cross-correlation have reduced the significance of the trends in moderate and long spell rain events to a large extent, while the significance of trends in the extreme heavy and short spell events is not highly affected because of small cross-correlation.     

Stratospheric N2O5, CH4, and N2O profiles from IR solar occultation spectra

Stratospheric volume mixing ratio profiles of N₂O₅, CH₄, and N₂O have been retrieved from a set of 0.052 cm^–1 resolution (FWHM) solar occultation spectra recorded at sunrise during a balloon flight from Aire sur l'Adour, France (44° N latitude) on 12 October 1990. The N₂O₅ results have been derived from measurements of the integrated absorption by the 1246 cm^–1 band. Assuming a total intensity of 4.32×10^–17 cm^–1/molecule cm^–2 independent of temperature, the retrieved N₂O₅ volume mixing ratios in ppbv (parts per billion by volume, 10^–9), interpolated to 2 km height spacings, are 1.64±0.49 at 37.5 km, 1.92±0.56 at 35.5 km, 2.06±0.47 at 33.5 km, 1.95±0.42 at 31.5 km, 1.60±0.33 at 29.5 km, 1.26±0.28 at 27.5 km, and 0.85±0.20 at 25.5 km. Error bars indicate the estimated 1- uncertainty including the error in the total band intensity (±20% has been assumed). The retrieved profiles are compared with previous measurements and photochemical model results.Laboratoire associé aux Universités Pierre et Marie Curie et Paris Sud.     

Modelling long-term HFC emissions from India's residential air-conditioning sector: exploring implications of alternative refrigerants,best practices,and a sustainable lifestyle within an integrated assessment modelling framework

India's growing role in the global climate debate makes it imperative to analyse emission reduction policies and strategies across a range of GHGs, especially for under-researched non-CO₂ gases. Hydrofluorocarbons' (HFCs) usage in cooling equipment and subsequent emissions are expected to increase dramatically in India with the phase-out of hydrochlorofluorocarbons (HCFCs) as coolants in air-conditioning equipment. We focus on the residential air-conditioning sector in India and analyse a suite of HFC and alternative coolant gas scenarios for understanding the implications for GHG emissions from this sector within an integrated assessment modelling framework. We find that, if unabated, HFC410A emissions will contribute to 36% of the total global warming impact from the residential air-conditioner sector in India in 2050, irrespective of the future economic growth trajectory, and the remaining 64% is from energy to power residential air-conditioners. A move towards more efficient, low global warming potential (GWP) alternative refrigerants will significantly reduce the cumulative global warming footprint of this sector by 37% during the period 2010–2050, due to gains both from energy efficiency as well as low GWP alternatives. Best practices for reducing direct emissions are important, but only of limited utility, and if a sustainable lifestyle is adopted by consumers with lower floorspace, low GWP refrigerants, and higher building envelope efficiencies, cumulative emissions during 2010–2050 can be reduced by 46% compared to the Reference scenario.

Policy relevance

Our analysis has important implications for Indian climate policy. We highlight that the Indian government's amendment proposal to the Montreal Protocol is a strong signal to the Indian market that the transition away from high GWP refrigerants towards low/zero GWP alternatives will happen sooner or later. The Bureau of Energy Efficiency should extend building energy conservation code policy to residential buildings immediately, and the government should mandate it. Government authorities should set guidelines and mandate reporting of data related to air-conditioner coolant recharge frequency and recovery of scrapped air-conditioner units. For contentious issues like flammability where there is no consensus within the industry, the government needs to undertake an independent technical assessment that can provide unbiased and reliable information to the market.     

A Note on an improved expression for the atmospheric CO2, N2O,CH4 and O2 integral transmission function: Research note

Abstract

A new analytical expression for the integral transmission function corresponding to the uniformly mixed atmospheric gases (CO₂, N₂O, CH4 and O₂) is proposed for solar radiation models. The expression is based on the latest known spectral absorption data of the gases as well as on the Ñeckel and Labs (1981) extraterrestrial solar spectrum, which is the best currently available. The proposed formula is compared with the known expressions for the integral transmission function of the uniformly mixed gases and the results of this comparison are discussed.     

Controlling GHG emissions from the transportation sector through an ETS: institutional arrangements in Shenzhen,China

Many different approaches are needed to achieve reductions in GHG emissions from the transportation sector. Carbon emissions trading schemes (ETSs) are widely used in industry and are effective in reducing the overall social cost of emissions abatement. This article reports the development of a downstream ETS for the transportation sector and its application in Shenzhen, China. The ETS was devised as a mandatory cap-and-trade scheme and, as a first step, was applied to public transportation. An integrated cap was set on the total emissions from buses and taxis: an absolute cap for existing vehicles and a relative increment for new entrants. Allowances were allocated by grandfathering or benchmarking and a ‘reverse mechanism’ was established to encourage the transformation of urban transportation to a low-carbon system. Online fuel consumption monitoring was used to quantify the emissions from vehicles, and the operators were required to surrender enough allowances or credits to account for their verified annual emissions. The mechanisms for allowance trading and carbon offsets provided sufficient flexibility to make emissions abatement and the use of new-energy vehicles and environmentally friendly travel within Shenzhen's urban transportation system economically attractive.

Policy relevance

The transportation sector is becoming a major contributor to the growth in China's GHG emissions. Achieving large reductions in GHG emissions from the transportation sector is a great challenge and requires both technology and policy innovation. The tradable carbon permit is a popular concept in mitigating climate change, but the introduction of a cap-and-trade ETS into the transportation sector is a relatively innovative concept. Shenzhen has launched the first cap-and-trade ETS in a developing country and is currently exploring ways to mitigate carbon emissions by a downstream cap-and-trade ETS for the transportation sector. This article considers the main institutional arrangements and regulatory framework of Shenzhen's transportation carbon ETS. It not only refreshes the theoretical analysis and practical application of downstream cap-and-trade carbon emissions trading in urban transportation, but also provides developing countries with a cost-effective instrument to mitigate their rapid growth in traffic carbon emissions during urbanization.     

Temperature trends of Chennai City, India

Chennai is the fourth largest metropolitan city in India, and it is one of India's chief industrial and economic growth centers. The temperature change in Chennai is studied in this research by analyzing the mean maximum temperature (MMaxT), mean minimum temperature (MMinT), and mean annual temperature (MAT) from 1951 to 2010. Data are analyzed in three parts by running linear regression and by taking anomalies of all time periods: (a) the whole period from 1951 to 2010; (b) phase 1, 1951–1980; and (c) phase 2, 1981–2010. The trends have been evaluated by Student's t statistics and supported by Mann Kendall rank statistics. The observed change in temperature is positive, which has been clear increasing trends in MMaxT, MMinT, and MAT. MAT has increased 1.3°C since the last 60 years. MMaxT has increased up to 1.6°C, in which the second phase accounts for 75 % of the total change during the last 60 years. MMinT over Chennai has increased 1.0°C. There is a high rise in temperature during winter season.     

An assessment of regional vulnerability of rice to climate change in India

A simulation analysis was carried out using the InfoCrop-rice model to quantify impacts and adaptation gains, as well as to identify vulnerable regions for irrigated and rain fed rice cultivation in future climates in India. Climates in A1b, A2, B1 and B2 emission scenarios as per a global climate model (MIROC3.2.HI) and a regional climate model (PRECIS) were considered for the study. On an aggregated scale, the mean of all emission scenarios indicate that climate change is likely to reduce irrigated rice yields by ~4 % in 2020 (2010–2039), ~7 % in 2050 (2040–2069), and by ~10 % in 2080 (2070–2099) climate scenarios. On the other hand, rainfed rice yields in India are likely to be reduced by ~6 % in the 2020 scenario, but in the 2050 and 2080 scenarios they are projected to decrease only marginally (<2.5 %). However, spatial variations exist for the magnitude of the impact, with some regions likely to be affected more than others. Adaptation strategies comprising agronomical management can offset negative impacts in the near future—particularly in rainfed conditions—but in the longer run, developing suitable varieties coupled with improved and efficient crop husbandry will become essential. For irrigated rice crop, genotypic and agronomic improvements will become crucial; while for rainfed conditions, improved management and additional fertilizers will be needed. Basically climate change is likely to exhibit three types of impacts on rice crop: i) regions that are adversely affected by climate change can gain in net productivity with adaptation; ii) regions that are adversely affected will still remain vulnerable despite adaptation gains; and iii) rainfed regions (with currently low rainfall) that are likely to gain due to increase in rainfall can further benefit by adaptation. Regions falling in the vulnerable category even after suggested adaptation to climate change will require more intensive, specific and innovative adaptation options. The present analysis indicates the possibility of substantial improvement in yields with efficient utilization of inputs and adoption of improved varieties.     

Aerosol, clouds and rainfall: inter-annual and regional variations over India

Inter-annual and regional variations in aerosol and cloud characteristics, water vapor and rainfall over six homogeneous rainfall zones in India during the core monsoon month of July from 2000 to 2010, and their correlations are analyzed. Aerosol optical depth (AOD) and aerosol absorbing index (AAI) in July 2002, a drought year are higher over India when compared to normal monsoon years. The drier conditions that existed due to deficient rainfall in July 2002 could be responsible for raising more dust and smoke resulting in higher AODs over India. In addition, over India precipitation is not uniform and large-scale interruptions occur during the monsoon season. During these interruptions aerosols can build up over a region and contribute to an increase in AODs. This finding is supported by the occurrence of higher anomalies in AOD, AAI and rainfall over India in July 2002. Aerosol characteristics and rainfall exhibit large regional variations. Cloud effective radius (CER), cloud optical thickness and columnar water vapor over India are the lowest in July 2002. CER decreases as AOD and AAI increase, providing an observational evidence for the indirect effect of aerosols. Eighty percent of CER in northwest India, and 30% of CER over All India in July 2002 are <14 μm, the precipitation threshold critical cloud effective radius. Northeast India shows contrasting features of correlation among aerosols, clouds and rainfall when compared to other regions. These results will be important while examining the inter-annual variation in aerosols, cloud characteristics, rainfall and their trends.     

A statistical model for spatial inventory data: a case study of N2O emissions in municipalities of southern Norway

In this paper we apply a linear regression with spatial random effect to model geographically distributed emission inventory data. The study presented is on N₂O emission assessments for municipalities of southern Norway and on activities related to emissions (proxy data). Taking advantage of the spatial dimension of the emission process, the method proposed is intended to improve inventory extension beyond its earlier coverage. For this, the proxy data are used. The conditional autoregressive model is used to account for spatial correlation between municipalities. Parameter estimation is based on the maximum likelihood method and the optimal predictor is developed. The results indicate that inclusion of a spatial dependence component lead to improvement in both representation of the observed data set and prediction.     

Russia's 2020 GHG emissions target: Emission trends and implementation

This article provides an overview of the recent modelling results on Russia's GHG emission trends, and reviews the success of mitigation policies in order to establish whether Russia's domestic target seems feasible. Various Russian GHG emission scenarios indicate that Russia's domestic target – emissions 25% below the 1990 level by 2020 – is not far from the business-as-usual emissions trajectory. In particular, two factors could deliver the required emissions reductions: the currently declining gross domestic product (GDP) growth and ongoing domestic mitigation policies. The former is more likely to secure the target level of emissions, because GDP growth has been contracting significantly in comparison to earlier forecasts of 3–5% annual growth, and this trend is expected to continue. The latter option – success with domestic mitigation measures – seems less likely, given the various meta-barriers to policy implementation, and the marginality of mitigation policies, problems with law-making processes, bureaucratic tradition, and informality of legislative and implementation systems.

Policy relevance

This article provides an assessment of the stringency of Russia's domestically set emissions limitation target by 2020 and the chances of Russia, the fourth largest GHG emitter in the world, achieving it. We base our assessment on a number of recent key sources that analyse Russia's GHG emission paths by applying socio-economic models, which have only been available in the Russian language prior to this publication. This knowledge is applicable for use by other negotiation parties to compare Russia's efforts to mitigate climate change to their own, and thus makes a contribution to facilitating a more equal burden-sharing of climate commitments under the future climate change agreement.     

EU emissions trading and the cement sector: a spatial competition analysis

An oligopoly competition model is described and used to illustrate the potential effect of EU emissions trading and transport issues on the production decisions and profitability of cement producers in a typical western European country market. The role of geography is introduced from three viewpoints: the existence of regional markets, the fact that EU producers may operate multiple plants across these regions, and the possibility of production capacity constraints. A typical EU state is divided into a coastal region which is initially exposed to international competition, and an inland region which is initially protected. Assuming pure auctioning of EU Allowances and a range of CO₂ prices up to €50/t, our model predicts a large increase of imports into the coastal region. Consequences for the inland producers include reduced attractiveness of the coastal market, as well as increased competition from coastal producers and from non-EU imports. The model includes a number of simplifications and therefore does not claim to offer definitive predictions, but our results do suggest that an increase in non-EU imports could feasibly offset more than 70% of the decrease in EU cement sector emissions. The likely impact on producer profits is considered for each region, and the advantages and disadvantages of potential mitigating policy measures are reviewed for either the EU Allowance allocation process or border adjustments on cement products.     

The heterogeneous formation of N2O in air containing NO2, O3 and NH3

In a nighttime system and under relatively dry conditions (about 15 ppm H₂O), the reaction mixture of NO₂, O₃, and NH₃ in purified air turns out to result in the formation of nitrous oxide (N₂O). The experiments were performed in a continuous stirred flow reactor, in the concentration region of 0.02–2 ppm.N₂O is thought to arise through the heterogeneous reaction of gaseous N₂O₅ and absorbed NH₃ at the wall of the reaction vessel % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqaqpepeea0xe9qqVa0l% b9peea0lb9sq-JfrVkFHe9peea0dXdarVe0Fb9pgea0xa9pue9Fve9% Ffc8meGabaqaciGacaGaaeqabaWaaeaaeaaakeaatCvAUfKttLeary% qr1ngBPrgaiuaacqWFOaakcqWFobGtcqWFibasdaWgaaWcbaGae83m% amdabeaakiab-LcaPmaaBaaaleaacqWFHbqyaeqaaOGaey4kaSIaai% ikaiab-5eaonaaBaaaleaacqWFYaGmaeqaaOGae83ta80aaSbaaSqa% aiab-vda1aqabaGccaGGPaWaaSbaaSqaaiaadEgaaeqaaOGaeyOKH4% Qae8Nta40aaSbaaSqaaiab-jdaYaqabaGccqWFpbWtcqGHRaWkcqWF% ibascqWFobGtcqWFpbWtdaWgaaWcbaGae83mamdabeaakiabgUcaRi% ab-HeainaaBaaaleaacqWFYaGmaeqaaOGae83ta8eaaa!59AC!\[(NH_3 )_a + (N_2 O_5 )_g \to N_2 O + HNO_3 + H_2 O\]In principle, there is competition between this reaction and that of adsorbed H₂O with N₂O₅, resulting in the formation of HNO₃. At high water concentrations (RH>75%), no formation of N₂O was found. Although the rate constant of adsorbed NH₃ with gaseous N₂O₅ is much larger than that of the reaction of adsorbed H₂O with gaseous N₂O₅, the significance of the observed N₂O formation for the outside atmosphere is thought to be dependent on the adsorption properties of H₂O and NH₃ on a surface. A number of NH₃ and H₂O adsorption measurements on several materials are discussed.     

Climate change in the Tahoe basin: regional trends, impacts and drivers

The purpose of this study was to quantify the decadal-scale time trends in air temperature, precipitation phase and intensity, spring snowmelt timing, and lake temperature in the Tahoe basin, and to relate the trends to large-scale regional climatic trends in the western USA. Temperature data for six long-term weather stations in the Tahoe region were analyzed for trends in annual and monthly means of maximum and minimum daily temperature. Precipitation data at Tahoe City were analyzed for trends in phase (rain versus snow), decadal standard deviation, and intensity of rainfall. Daily streamflow data for nine gaging stations in and around the Tahoe basin were examined for trends in snowmelt timing, by two methods, and an existing record for the temperature of Lake Tahoe was updated. The results for the Tahoe basin, which contrast somewhat with the surrounding region, indicate strong upward trends in air temperature, a shift from snow to rain, a shift in snowmelt timing to earlier dates, increased rainfall intensity, increased interannual variability, and continued increase in the temperature of Lake Tahoe. Two hypotheses are suggested that may explain why the basin could be warming faster than surrounding regions. Continued warming in the Tahoe basin has important implications for efforts to manage biodiversity and maintain clarity of the lake.     

中国电力行业碳排放达峰及减排潜力分析

推动电力行业低碳发展是中国有效控制CO₂排放和推动尽早达峰的重要抓手。在分别利用学习曲线工具和自下而上技术核算方式分析风电、光伏两类主要的可再生电力和其他各类电源发展趋势的基础上,综合评估了既有政策和强化政策条件下2035年前中国电力行业能源活动碳排放变化趋势。研究发现,既有政策情景下电力行业碳排放在2030年左右达到峰值,届时非化石能源在发电量中比重为44%,而通过强化推动能源绿色低碳发展的相关政策,2025年前即可达到电力行业碳排放峰值,2030年非化石电力在发电量中比重可以提升至51%,其中可再生电力加速发展将分别贡献2025、2030和2035年当年减排量（相对于既有政策情景）的45%、54%和62%。尽管从保障电力稳定安全供应角度,煤电装机仍有一定增长空间,但考虑到电力行业绿色低碳和可持续发展的长期需求,仍应加强对煤电装机的有效控制,“十四五”期间努力将煤电装机控制在11亿kW左右的水平。     

Dynamics of energy sector and GHG emissions in Saudi Arabia

The energy sector is the main contributor to GHG emissions in Saudi Arabia. The tremendous growth of GHG emissions poses serious challenges for the Kingdom in terms of their reduction targets, and also the mitigation of the associated climate changes. The rising trend of population and urbanization affects the energy demand, which results in a faster rate of increase in GHG emissions. The major energy sector sources that contribute to GHG emissions include the electricity generation, road transport, desalination plants, petroleum refining, petrochemical, cement, iron and steel, and fertilizer industries. In recent years, the energy sector has become the major source, accounting for more than 90% of national CO₂ emissions. Although a substantial amount of research has been conducted on renewable energy resources, a sustainable shift from petroleum resources is yet to be achieved. Public awareness, access to energy-efficient technology, and the development and implementation of a legislative framework, energy pricing policies, and renewable and alternative energy policies are not mature enough to ensure a significant reduction in GHG emissions from the energy sector. An innovative and integrated solution that best serves the Kingdom's long-term needs and exploits potential indigenous, renewable, and alternative energy resources while maintaining its sustainable development stride is essential.

Policy relevance

The main contributor to GHG emissions in Saudi Arabia is the energy sector that accounts for more than 90% of the national CO₂ emissions. Tremendous growth of GHG emissions poses serious challenges for the Kingdom in their reduction and mitigating the associated climate changes. This study examines the changing patterns of different activities associated with energy sector, the pertinent challenges, and the opportunities that promise reduction of GHG emissions while providing national energy and economic security. The importance of achieving timely, sustained, and increasing reductions in GHG emissions means that a combination of policies may be needed. This study points to the long-term importance of making near- and medium-term policy choices on a well-informed, strategic basis. This analytical paper is expected to provide useful information to the national policy makers and other decision makers. It may also contribute to the GHG emission inventories and the climate change negotiations.     

Recent climatic change,greenhouse gas emissions and future climate: The implications for India

Summary In this paper, we discuss past climatic trends over India, greenhouse gas emissions due to energy consumption, forest and land-use changes, climate change scenarios for the year 2050, potential consequences for agriculture and cyclone activity and the possibility that India might limit the increasing trend in its emissions.India's mean surface air temperature has increased significantly by about 0.4°C over the past ccntury. Neither monsoon nor annual rainfall shows any significant trend. On average, there has been a rise in sea levels around India over recent decades, though considerable uncertainties exist in the accuracy and interpretation of the available data.Carbon emissions from the energy sector amount to 71 MT a year, equivalent to all other sectors combined. From land-use data, a marginal net sequestration of 5.25 million tonnes of carbon occurred during 1986. Following the IPCC guidelines, methane emissions from rice and livestock are estimated at 17.4 and 12.8 Tg/year, respectively.According to recent climate model projections, India may experience a further rise in temperature of 1 °C by the year 2050, about four times the rate of warming experienced over the past 100 years. A modest increase in precipitation amounts might occur. Cereals production is estimated to decrease and the nutrition security of the population-rich but land-hungry region of India might be hampered. An increase in local tropical cyclone activity may occur over thc next century, posing added problems as large areas in the coastal regions have a dense population.About 70% of the electricity generation in India is from coal-based power stations. Altering this dependence significantly to reduce emissions would imply a substantial change in the present energy policy of India. There is great potential for improving energy efficiency and conservation. The adoption of cleaner coal-technologies should be considered, as must the development of renewable, non-conventional energy sources. In all cases, serious institulional barriers and resource limitations need to be addressed. The scope for carbon sequestration is limiled by land availabilily and other factors. It is argued that any response to global warming must be located firmly in the framework of sustainable development.With 5 Figures