Greenhouse Gas Emission Rates Research Articles

Impact of desertification and global warming on soil carbon in northern China

While the global rise in mean day/night and seasonal air temperatures (ATE) of recent decades is well documented, its influence on levels of soil‐sequestered organic carbon, and on emission rates of CO2 and other greenhouse gases emanating therefrom, is only beginning to garner serious attention. This has resulted in a limited but growing understanding, particularly in the context of the lands of the Chinese subcontinent, of the mechanisms underlying such emissions. Some 340 soil samples from 12 different sandy land regions in China were analyzed for soil organic carbon (SOC) content. Stepwise regression identified correlations between SOC and a number of climatic factors measured at the sampling sites: winter, summer, nighttime and daytime ATE, and precipitation. In desertified lands, net SOC losses showed a direct correlation with precipitation but no significant relationship with mean ATE. However, in northwest and northeast China, decreases in SOC were linked to rises in day/night and seasonal ATE, while in north central China they were linked to a rise in mean ATE. Between 1900 and 1998, mean ATE in the northwest, northeast, and north central regions rose by 0.14E, 0.28E, and 0.15E decade−1, respectively. Meanwhile, precipitation dropped by 25 mm decade−1 across these regions. In this study, day/night and seasonal ATE showed differing levels of significance with respect to their linear relationships with SOC content. Driven by rises in day/night and seasonal ATE, long‐term alterations to global ecosystemic processes, particularly the carbon cycle, may quantitatively and qualitatively alter the flora of desertified ecosystems. Our study suggests that, over the last 40 years, anthropogenic factors, precipitation, and rises in ATE (particularly nighttime and winter) have contributed 47%, 26%, and 20%, respectively, of greenhouse gas emissions from SOC. It is apparent that for China's desertified lands, human activity is the primary causative factor in the release of SOC‐derived greenhouse gases to the atmosphere, while geography and climatic extremes individually play a lesser role.

Life Cycle Assessment (LCA) of Chinese energy chains for Shandong electricity scenarios

The Life Cycle Assessment (LCA) performed for the China Energy Technology Program (CETP) has established streamlined environmental inventories of coal, nuclear, natural gas, and wind energy systems for supply of electricity to Shandong province with a 20 years time horizon. This paper deals with selected results for air pollutants obtained for the current coal technology and the comparison of current and future Chinese energy chains. The environmental performance of all coal systems is the worst among the considered energy chains. However, with improved or advanced coal technologies, the harm from SO2, NOx, and particle emissions to human health corresponding to the unit of electric service may reduce meaningfully. Also greenhouse gas emission rates reduce due to efficiency improvements and use of nuclear, but total emissions for expected scenarios may significantly increase due to the forecasted dramatic electricity demand growth.

Future energy consumption and greenhouse gas emissions in Jordanian industries

Most, i.e. 85%, of greenhouse gas (GHG) emissions in Jordan emanate as a result of fossil fuel combustion. The industrial sector consumed 23.3% of the total national fuel consumption for heat and electric-power generation in 1999. The CO 2 emissions from energy use in manufacturing processes represent 12.1% of the total national CO 2 emissions. Carbon dioxide is also released as a result of the calcining of carbonates during the manufacture of cement and iron. Electricity, which is the most expensive form of energy, in 1999 represented 45% of total fuel used for heat and power nationally. Heavy fuel oil and diesel oil represented 46% and 7%, respectively, of all energy used by industry. Scenarios for future energy-demands and the emissions of gaseous pollutants, including GHGs, have been predicted for the industrial sector. For these, the development of a baseline scenario relied on historical data concerning consumption, major industries’ outputs, as well as upon pertinent published governmental policies and plans. Possible mitigation options that could lead to a reduction in GHG emissions are assessed, with the aim of achieving a 10% reduction by 2010, compared with the baseline scenario. Many viable CO 2 emission mitigation measures have been identified for the industrial sector, and some of these can be considered as attractive opportunities due to the low financial investments required and short pay back periods. These mitigation options have been selected on the basis of low GHG emission rates and expert judgement as to their viability for wide-scale implementation and economic benefits. The predictions show that the use of more efficient lighting and motors, advanced energy systems and more effective boilers and furnaces will result in a significant reduction in the rates of GHG emissions at an initial cost of between 30 and 90 US$ t −1 of CO 2 release avoided. However, most of these measures have a negative cost per ton of CO 2 reduced, indicating short pay-back periods for the capital investments needed.

État des connaissances et incertitudes sur le changement climatique induit par les activités humaines

Abstract During the 20th century, the mean temperature of the air at the ground level has increased by 0.6±0.2 °C and the warmest air temperatures occurred after 1980. These were significantly warmer than those of the last millennium. Simultaneously, rain and drought, cold and heat wave frequencies have changed, mountain glaciers retreated and the sea-level increased by ∼10 cm. This warming was at least in part induced by human activities and will continue during the next decades. Its amplitude will depend on the rate of greenhouse gas and sulphate aerosols emissions, i.e. on energetic scenarios. Pending scientific uncertainties include cloud variations and interactions between the physical parts of the climate system and the biogeochemical cycles and the biosphere.

The Potential for Fusion Power to Mitigate U.S. Greenhouse Gas Emissions

This study summarizes a recent life-cycle net energy analysis (NEA) on a modern natural gas turbine power plant for comparison against DT fusion and conventional technologies (coal, fission, and wind). The NEA results are used as the basis for developing a life-cycle greenhouse gas (GHG) emission rate. The GHG emission rate for DT fusion is 9 metric tonnes of CO2 equivalent emitted per gigawatt electric hour produced (T/GWeh). This rate compares favorably against gas turbine (464 T/GWeh) and conventional coal (974 T/GWeh), and competitively against fission (15 T/GWeh) and wind (15 T/GWeh). The implications of this research for U.S. GHG mitigation are discussed. In evaluated scenarios, the installed nuclear and renewable capacity in the U.S. must quadruple by 2050 to maintain a Kyoto based emission target, with fusion and/or other renewable sources comprising 43-59% of U.S. capacity.

Global and Regional Greenhouse Gas Emissions Scenarios

This article presents a set of 30 greenhouse gas (GHG) emissions scenarios developed by six modeling teams. The scenarios describe trajectories up to 2100 by four world regions. Today the distribution of both income and GHG emissions is very unbalanced between various world regions. Furthermore, the relative importance of individual gases and sources of emission differ from region to region. A feature shared by all scenarios is higher growth rates of population, income and GHG emissions in the current developing countries (DEV) than in industrialized countries (IND). Today the DEV regions account for about 46% of all emissions, but by 2100 no less they contribute 67–76% of the global total. By that same year the total income generated in the DEV regions reaches 58–71% from only 16% in 1990. As a result of these two developments, GHG emissions per unit of income converge over time. Carbon emitted from fossil fuel use remains the primary source of GHG emissions over the next century; by 2100 CO 2 makes up 70 to 80% of total GHG emissions. The role of sulfur warrants special attention. Contrary to many earlier studies, all scenarios presented here assume that sulfur emissions are controlled in all regions sooner or later, and to various degrees. As sulfur plays a role in cooling of the atmosphere through formation of sulfate aerosols, a local effect, this abatement constitutes a relative local warming effect. The decrease of sulfur emissions is already observed the IND regions, and is expected also in ASIA after an initial rise.

An Overlapping Generations Model of Climate‐Economy Interactions

A numerically calibrated overlapping generations model of climate change and the world econommy is examined in this paper. In the absence of intergenerational transfers, efficient rates of greenhouse gas emissions abatement rise from 16% in the present to 25% in the long run, while mean global temperature increases by 7.4°C relative to the preindustrial norm. A utilitarian optimum, which attaches equal weight to each generation's life‐cycle utility, yields abatement rates that rise from 48% to 89%, with a long‐run temperature increase of 3.4°C. A second‐best utilitarian path, in which intergenerational transfers are by assumption institutionally infeasible, also supports stringent abatement measures.

Thermal limits and ocean migrations of sockeye salmon (Oncorhynchus nerka): long-term consequences of global warming

Ocean surveys show that extremely sharp thermal boundaries have limited the distribution of sockeye salmon (Oncorhynchus nerka) in the Pacific Ocean and adjacent seas over the past 40 years. These limits are expressed as a step function, with the temperature defining the position of the thermal limit varying between months in an annual cycle. The sharpness of the edge, the different temperatures that define the position of the edge in different months of the year, and the subtle variations in temperature with area or decade for a given month probably all occur because temperature-dependent metabolic rates exceed energy intake from feeding over large regions of otherwise acceptable habitat in the North Pacific. At current rates of greenhouse gas emissions, predicted temperature increases under a doubled CO2 climate are large enough to shift the position of the thermal limits into the Bering Sea by the middle of the next century. Such an increase would potentially exclude sockeye salmon from the entire Pacific Ocean and severely restrict the overall area of the marine environment that would support growth.

Thermal limits and ocean migrations of sockeye salmon (<i>Oncorhynchus nerka</i>): long-term consequences of global warming

Ocean surveys show that extremely sharp thermal boundaries have limited the distribution of sockeye salmon (Oncorhynchus nerka) in the Pacific Ocean and adjacent seas over the past 40 years. These limits are expressed as a step function, with the temperature defining the position of the thermal limit varying between months in an annual cycle. The sharpness of the edge, the different temperatures that define the position of the edge in different months of the year, and the subtle variations in temperature with area or decade for a given month probably all occur because temperature-dependent metabolic rates exceed energy intake from feeding over large regions of otherwise acceptable habitat in the North Pacific. At current rates of greenhouse gas emissions, predicted temperature increases under a doubled CO2 climate are large enough to shift the position of the thermal limits into the Bering Sea by the middle of the next century. Such an increase would potentially exclude sockeye salmon from the entire Pacific Ocean and severely restrict the overall area of the marine environment that would support growth.

Inspection of non-CO2 greenhouse gases from emission sources and in ambient air by Fourier-transform-infrared-spectrometry: Measurements with FTIS-MAPS

Infrared spectrometry is a versatile basis to analyse greenhouse gases in the atmosphere. A multicomponent air pollution software (MAPS) was developed for retrieval of gas concentrations from radiation emission as well as absorption measurements. Concentrations of CO, CH4, N2O, and H2O as well as CO2, NO, NO2, NH3, SO2, HCl, HCHO, and the temperature of warm gases are determined on-line. The analyses of greenhouse gases in gaseous emission sources and in ambient air are performed by a mobile remote sensing system using the double-pendulum interferometer K300 of the Munich company Kayser-Threde. Passive radiation measurements are performed to retrieve CO, N2O, and H2O as well as CO2, NO, SO2, and HCl concentrations in smoke stack effluents of thermal power plants and municipal incinerators and CO and H2O as well as CO2 and NO in exhausts of aircraft engines. Open-path radiation measurements are used to determine greenhouse gas concentrations at different ambient air conditions and greenhouse gas emission rates of diffusive sources as garbage deposits, open coal mining, stock farming together with additional compounds (e.g. NH3), and from road traffic together with HCHO. Some results of measurements are shown. A future task is the verification of emission cadastres by these inspection measurements.

Some Implications of Climatic Change for Agriculture in Europe

Initial results are reported of a study to evaluate the broad-scale sensitivity of agriculture in Europe to climatic change. The study relates an agroclimatic index, effective temperature sum (ETS), to the cultivable limits of grain maize. A computer mapping system for the European region is adopted to map ETS on the basis both of present-day and of possible future mean temperatures. In this way, changes in climate can be depicted as geographical shifts of the limit of potential grain maize cultivation. The results indicate that a mean annual temperature increase of only 1 °C (within the present-day range of inter-annual variability) would open up large areas in southern England, the Low Countries, eastern Denmark, northern Germany, and northern Poland to potential grain maize cultivation. An increase of 4°C would move the limit into central Fennoscandia and northern Russia. The latter changes are similar to those projected by general circulation models (GCMs) for an equivalent doubling of atmospheric carbon dioxide, and represent rates of northward shift of approximately 200–350 km/°C in western Europe and 250–400 km/°C in eastern Europe. Results using information from GCM transient-response experiments indicate that such shifts could occur as soon as the 2050s if the current exponential growth in emission rates of greenhouse gases were to continue unabated. The rate of shift of the grain maize limit implied for this high (and improbable) emissions scenario is in the order of 150–200 km per decade over the next 70 years, slower than this during the next few decades, but faster thereafter. It is probable that the actual rate will be lower than this, but even values of half those calculated, if sustained, would still represent rates of shift in agroclimatic potential that are unprecedented in the historical record.

Climatic change and future agroclimatic potential in Europe

AbstractIn this paper, initial results are reported of a study to evaluate the broad‐scale sensitivity of agriculture to climatic change in Europe. The study employs an agroclimatic index, effective temperature sum (ETS), to relate temperature patterns to the cultivable limits of grain maize (Zea mays). A computer mapping system for the European region is adopted to map ETS on the basis both of present‐day and of possible future mean temperatures. In this way, changes in climate can be depicted as geographical shifts of the limit of potential grain maize cultivation.The results indicate that a mean annual temperature increase of only 1°C (within the present‐day range of interannual variability) would open up large areas in southern England, the Low Countries, eastern Denmark, northern Germany and northern Poland to potential maize cultivation. An increase of 4°C would move the limit into central Fennoscandia and northern Russia. These represent rates of northward shift of approximately 200–350 km °C−1 in western Europe and 250–400 km °C−1 in eastern Europe. Comparison of these shifts with those estimated on the basis of general circulation model (GCM) projections of future temperatures suggests that a 1°C warming will be achieved well before the time the global climate responds fully to an equivalent doubling of atmospheric carbon dioxide, possibly as early as 2010. Shifts comparable with those for a 4°C warming are achieved under all the GCM scenarios of doubled CO2, occurring perhaps as soon as 2050 if the current growth in emission rates of greenhouse gases were to continue unabated. The rate of shift of the grain maize limit implied for this (high) emissions scenario is in the order of 150–200 km per decade over the next 70 years, slower than this during the next few decades, but faster thereafter.Such shifts would offer new opportunities for farmers in different regions of northern Europe. However, given the possible rapidity of the shifts, in order for these opportunities to be exploited successfully immediate attention should be directed towards more detailed assessments of crop potential in regions identified as currently marginal for grain maize.

The Greenhouse Effect, Climatic Change and Rising Sea Level: Implications for Development

The 'greenhouse effect' is likely to change the global climate substantially, with serious implications for the developing countries. By the year 2030, it is estimated that the global-mean surface temperature may be about 1-20C higher than today. Given the range of uncertainty in future greenhouse gas emissons, the sensitivity of climate and the rate of oceanic heat uptake, the warming could be as little as 0-50C or as high as 2-50C. By 2030, the corresponding rise in global-mean sea level is estimated to range from 5-44 cm, with a best estimate of 17-26 cm higher than today. The developing countries, so far minor contributors to the increase in atmospheric concentrations of greenhouse gases, are quickly becoming major contributors due to growth in both population and energy consumption. This implies that developing countries must be actively involved in any international agreements to reduce greenhouse gas emissions in order to slow global warming. Moreover, in terms of impacts, the developing countries may be among the most vulnerable countries of the world. Although the regional details of climatic change cannot yet be predicted accurately, there is particular concern about possible changes in the frequencies of climatic extremes, in monsoon regimes, and in the magnitude and frequency of severe tropical storms. A rise in global sea level could exacerbate problems of flooding, salinization and erosion already being experienced in many parts of the developing world. There are compelling reasons to initiate actions to reduce the growth rates of greenhouse gas emissions and slow global warming.