scholarly journals Inventory of anthropogenic methane emissions in mainland China from 1980 to 2010

2016 ◽  
Vol 16 (22) ◽  
pp. 14545-14562 ◽  
Author(s):  
Shushi Peng ◽  
Shilong Piao ◽  
Philippe Bousquet ◽  
Philippe Ciais ◽  
Bengang Li ◽  
...  

Abstract. Methane (CH4) has a 28-fold greater global warming potential than CO2 over 100 years. Atmospheric CH4 concentration has tripled since 1750. Anthropogenic CH4 emissions from China have been growing rapidly in the past decades and contribute more than 10 % of global anthropogenic CH4 emissions with large uncertainties in existing global inventories, generally limited to country-scale statistics. To date, a long-term CH4 emission inventory including the major sources sectors and based on province-level emission factors is still lacking. In this study, we produced a detailed annual bottom-up inventory of anthropogenic CH4 emissions from the eight major source sectors in China for the period 1980–2010. In the past 3 decades, the total CH4 emissions increased from 24.4 [18.6–30.5] Tg CH4 yr−1 in 1980 (mean [minimum–maximum of 95 % confidence interval]) to 44.9 [36.6–56.4] Tg CH4 yr−1 in 2010. Most of this increase took place in the 2000s decade with averaged yearly emissions of 38.5 [30.6–48.3] Tg CH4 yr−1. This fast increase of the total CH4 emissions after 2000 is mainly driven by CH4 emissions from coal exploitation. The largest contribution to total CH4 emissions also shifted from rice cultivation in 1980 to coal exploitation in 2010. The total emissions inferred in this work compare well with the EPA inventory but appear to be 36 and 18 % lower than the EDGAR4.2 inventory and the estimates using the same method but IPCC default emission factors, respectively. The uncertainty of our inventory is investigated using emission factors collected from state-of-the-art published literatures. We also distributed province-scale emissions into 0.1°  ×  0.1° maps using socioeconomic activity data. This new inventory could help understanding CH4 budgets at regional scale and guiding CH4 mitigation policies in China.

2016 ◽  
Author(s):  
S. S. Peng ◽  
S. L. Piao ◽  
P. Bousquet ◽  
P. Ciais ◽  
B. G. Li ◽  
...  

Abstract. Methane (CH4) has a 28-fold greater global warming potential than CO2 over one hundred years. Atmospheric CH4 concentration has tripled since 1750. Anthropogenic CH4 emissions from China has been growing rapidly in the past decades, and contributes more than 10 % of global anthropogenic CH4 emissions with large uncertainties in existing global inventories, generally limited to country-scale statistics. To date, a long-term CH4 emissions inventory including the major sources sectors and based on province-level emission factors is still lacking. In this study, we produced a detailed bottom-up inventory of anthropogenic CH4 emissions from the eight major source sectors in China for the period 1980–2010. In the past three decades, the total CH4 emissions increased from 22.2 [16.6–28.2] Tg CH4 yr−1 (mean [minimum-maximum of 95 % confidence interval]) to 45.0 [36.4–58.3] Tg CH4 yr−1, and most of this increase took place in the 2000s. This fast increase of the total CH4 emissions after 2000 is mainly driven by CH4 emissions from coal exploitation. The largest contribution to total CH4 emissions also shifted from rice cultivation in 1980 to coal exploitation in 2010. The total emissions inferred in this work compare well with the EPA inventory but appear to be 38 % lower than EDGAR4.2 inventory. The uncertainty of our inventory is investigated using emissions factors collected from published literatures. We also distributed province-scale emissions into 0.5º × 0.5º maps using social-economic activity data. This new inventory could help understanding CH4 budgets at regional scale and guiding CH4 mitigation policies in China.


2019 ◽  
Vol 58 (10) ◽  
pp. 2177-2196 ◽  
Author(s):  
Yingxian Zhang ◽  
Yuyu Ren ◽  
Guoyu Ren ◽  
Guofu Wang

AbstractTypical rain gauge measurements have long been recognized to underestimate actual precipitation. Long-term daily precipitation records during 1961–2013 from a dense national network of 2379 gauges were corrected to remove systematic errors caused by trace precipitation, wetting losses, and wind-induced undercatch. The corrected percentage was higher in cold seasons and lower in warm seasons. Both trace precipitation and wetting loss corrections were more important in arid regions than in wet regions. A greater correction percentage for wind-induced error could be found in cold and arid regions, as well as high wind speed areas. Generally, the annual precipitation amounts as well as the annual precipitation intensity increased to varying degrees after bias correction with the maximum percentage being about 35%. More importantly, the bias-corrected snowfall amount as well as the rainstorm amount increased remarkably by percentages of more than 50% and 18%, respectively. Remarkably, the total number of actual rainstorm events during the past 53 years could be 90 days more than the observed rainstorm events in some coastal areas of China. Therefore, the actual amounts of precipitation, snowfall, and intense rainfall were much higher than previously measured over China. Bias correction is thus needed to obtain accurate estimates of precipitation amounts and precipitation intensity.


2021 ◽  
Author(s):  
Christopher ODell ◽  
Annmarie Eldering ◽  
Michael Gunson ◽  
David Crisp ◽  
Brendan Fisher ◽  
...  

<p>While initial plans for measuring carbon dioxide from space hoped for 1-2 ppm levels of accuracy (bias) and precision in the CO<sub>2</sub> column mean dry air mole fraction (XCO<sub>2</sub>), in the past few years it has become clear that accuracies better than 0.5 ppm are required for most current science applications.  These include measuring continental (1000+ km) and regional scale (100s of km) surface fluxes of CO<sub>2</sub> at monthly-average timescales.  Considering the 400+ ppm background, this translates to an accuracy of roughly 0.1%, an incredibly challenging target to hit. </p><p>Improvements in both instrument calibration and retrieval algorithms have led to significant improvements in satellite XCO<sub>2</sub> accuracies over the past decade.  The Atmospheric Carbon Observations from Space (ACOS) retrieval algorithm, including post-retrieval filtering and bias correction, has demonstrated unprecedented accuracy with our latest algorithm version as applied to the Orbiting Carbon Observatory-2 (OCO-2) satellite sensor.   This presentation will discuss the performance of the v10 XCO<sub>2</sub> product by comparisons to TCCON and models, and showcase its performance with some recent examples, from the potential to infer large-scale fluxes to its performance on individual power plants.  The v10 product yields better agreement with TCCON over land and ocean, plus reduced biases over tropical oceans and desert areas as compared to a median of multiple global carbon inversion models, allowing better accuracy and faith in inferred regional-scale fluxes.  More specifically, OCO-2 has single sounding precision of ~0.8 ppm over land and ~0.5 ppm over water, and RMS biases of 0.5-0.7 ppm over both land and water.  Given the six-year and growing length of the OCO-2 data record, this also enables new studies on carbon interannual variability, while at the same time allowing identification of more subtle and temporally-dependent errors.  Finally, we will discuss the prospects of future improvements in the next planned version (v11), and the long-term prospects of greenhouse gas retrievals in the coming years. </p><p> </p>


2018 ◽  
Vol 18 (14) ◽  
pp. 10419-10431 ◽  
Author(s):  
Jinyang Wang ◽  
Hiroko Akiyama ◽  
Kazuyuki Yagi ◽  
Xiaoyuan Yan

Abstract. Rice cultivation has long been known as one of the dominant anthropogenic contributors to methane (CH4) emissions, yet there is still uncertainty when estimating its emissions at the global or regional scale. An increasing number of rice field measurements have been conducted globally, which allow us to reassess the major variables controlling CH4 emissions and develop region- and country-specific emission factors (EFs). The results of our statistical analysis show that the CH4 flux from rice fields was closely related to organic amendments, the water regime during and before the rice-growing season, soil properties and agroecological conditions. The average CH4 fluxes from fields with single and multiple drainage were 71 % and 55 % that of continuously flooded rice fields. The CH4 flux from fields that were flooded in the previous season were 2.4 and 2.7 times that of fields previously drained for a short and long season, respectively. Rice straw applied at 6 t ha−1 in the preseason can decrease CH4 emissions by half when compared to that applied shortly before rice transplanting. The global default EF was estimated to be 1.19 kg CH4 ha−1 day−1 with a 95 % confidence interval of 0.80 to 1.76 kg CH4 ha−1 day−1 for continuously flooded rice fields without organic amendment and with a preseason water status of short drainage. The lower EFs were found in countries from South Asia (0.85 kg CH4 ha−1 day−1) and North America (0.65 kg CH4 ha−1 day−1) relative to other regions, indicative of geographical variations at sub-regional and country levels. In conclusion, these findings can provide a sound basis for developing national inventories and mitigation strategies of CH4 emission from rice fields.


Author(s):  
Rui Yao ◽  
Lunche Wang ◽  
Xin Huang ◽  
Xiaojun Wu ◽  
Liu Yang ◽  
...  

The global surface air temperature (Ta) has increased significantly in the past several decades. However, it remains disputable how much effect rapid urbanization has had on warming trends in mainland China. In this study, a gridded Ta dataset was created using satellite data. Then, a series of satellite-based methods to evaluate the contribution of urbanization to warming were developed. Subsequently, the contribution of urbanization to warming during 2001–2018 was estimated. The national average Ta was found to have increased significantly (0.23°C/decade) in mainland China. At the national scale, the contribution of urbanization to warming was negligible (less than 1%) since built-up areas account for only approximately 2.66% of the area of China. At the regional scale, the contribution of urbanization was also small in most areas and was even negative in some areas. At the local scale, the contributions of urbanization to warming were 53.18%, 54.30% and 47.25% for the mean, maximum and minimum Ta, respectively, averaged for 31 major cities. This study demonstrated that the contribution of urbanization to warming was significant at the local scale, while the contribution of urbanization to large-scale warming was limited. The contribution of urbanization was underestimated at the local scale but overestimated at the national and regional scales by many previous studies due to the sparse and uneven distribution of meteorological stations.


2017 ◽  
Vol 114 (39) ◽  
pp. 10350-10355 ◽  
Author(s):  
Tara R. Clark ◽  
George Roff ◽  
Jian-xin Zhao ◽  
Yue-xing Feng ◽  
Terence J. Done ◽  
...  

Hard coral cover on the Great Barrier Reef (GBR) is on a trajectory of decline. However, little is known about past coral mortality before the advent of long-term monitoring (circa 1980s). Using paleoecological analysis and high-precision uranium-thorium (U-Th) dating, we reveal an extensive loss of branching Acropora corals and changes in coral community structure in the Palm Islands region of the central GBR over the past century. In 2008, dead coral assemblages were dominated by large, branching Acropora and living coral assemblages by genera typically found in turbid inshore environments. The timing of Acropora mortality was found to be occasionally synchronous among reefs and frequently linked to discrete disturbance events, occurring in the 1920s to 1960s and again in the 1980s to 1990s. Surveys conducted in 2014 revealed low Acropora cover (<5%) across all sites, with very little evidence of change for up to 60 y at some sites. Collectively, our results suggest a loss of resilience of this formerly dominant key framework builder at a regional scale, with recovery severely lagging behind predictions. Our study implies that the management of these reefs may be predicated on a shifted baseline.


Author(s):  
Robert Klinck ◽  
Ben Bradshaw ◽  
Ruby Sandy ◽  
Silas Nabinacaboo ◽  
Mannie Mameanskum ◽  
...  

The Naskapi Nation of Kawawachikamach is an Aboriginal community located in northern Quebec near the Labrador Border. Given the region’s rich iron deposits, the Naskapi Nation has considerable experience with major mineral development, first in the 1950s to the 1980s, and again in the past decade as companies implement plans for further extraction. This has raised concerns regarding a range of environmental and socio-economic impacts that may be caused by renewed development. These concerns have led to an interest among the Naskapi to develop a means to track community well-being over time using indicators of their own design. Exemplifying community-engaged research, this paper describes the beginning development of such a tool in fall 2012—the creation of a baseline of community well-being against which mining-induced change can be identified. Its development owes much to the remarkable and sustained contribution of many key members of the Naskapi Nation. If on-going surveying is completed based on the chosen indicators, the Nation will be better positioned to recognize shifts in its well-being and to communicate these shifts to its partners. In addition, long-term monitoring will allow the Naskapi Nation to contribute to more universal understanding of the impacts of mining for Indigenous peoples.


Author(s):  
Lindsey C Bohl

This paper examines a few of the numerous factors that may have led to increased youth turnout in 2008 Election. First, theories of voter behavior and turnout are related to courting the youth vote. Several variables that are perceived to affect youth turnout such as party polarization, perceived candidate difference, voter registration, effective campaigning and mobilization, and use of the Internet, are examined. Over the past 40 years, presidential elections have failed to engage the majority of young citizens (ages 18-29) to the point that they became inclined to participate. This trend began to reverse starting in 2000 Election and the youth turnout reached its peak in 2008. While both short and long-term factors played a significant role in recent elections, high turnout among youth voters in 2008 can be largely attributed to the Obama candidacy and campaign, which mobilized young citizens in unprecedented ways.


2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Dr. Kamlesh Kumar Shukla

FIIs are companies registered outside India. In the past four years there has been more than $41 trillion worth of FII funds invested in India. This has been one of the major reasons on the bull market witnessing unprecedented growth with the BSE Sensex rising 221% in absolute terms in this span. The present downfall of the market too is influenced as these FIIs are taking out some of their invested money. Though there is a lot of value in this market and fundamentally there is a lot of upside in it. For long-term value investors, there’s little because for worry but short term traders are adversely getting affected by the role of FIIs are playing at the present. Investors should not panic and should remain invested in sectors where underlying earnings growth has little to do with financial markets or global economy.


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