Reduced rice paddy methane emission through dual compound mechanism in novel cultivars

Author(s):  
Yunkai Jin ◽  
Tong Liu ◽  
Jia Hu ◽  
Kai Sun ◽  
Lihong Xue ◽  
...  

Abstract Methane is the second most abundant greenhouse gas after carbon dioxide and its concentrations have risen tenfold in the past decade due to agricultural activity1. Rice paddies are considered a major source of anthropogenic methane, however strategies to mitigate methane emission in rice paddies is not yet successful despite considerable efforts being made. Methane production is caused by microbial communities feeding on organic exudates from the rice root, and regulation of the dominant secretions has been suggested as leading way to put an end to the methane emission from rice paddies. Here, we introduced a new system to reduce methane emission in rice paddies based on the discovery that fumarate and ethanol are two specific rice-orchestrated compounds that determine the levels of methane emission from rice paddies. Moreover, stable low-fumarate high-ethanol secretion lines have been successively bred through hybrid breeding and shown to cut around 70% of methane emission in paddies as compared to control. Approaches to block fumarate reductase or increase ethanol level, were furthermore employed as cultivation managements and resulted in a reduction in methane emissions of around 60%, calculated from two-year four-site field work. All results highlight the application of our findings to largely mitigate influences of rice cultivation on global climate.

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mateusz Taszarek ◽  
John T. Allen ◽  
Mattia Marchio ◽  
Harold E. Brooks

AbstractGlobally, thunderstorms are responsible for a significant fraction of rainfall, and in the mid-latitudes often produce extreme weather, including large hail, tornadoes and damaging winds. Despite this importance, how the global frequency of thunderstorms and their accompanying hazards has changed over the past 4 decades remains unclear. Large-scale diagnostics applied to global climate models have suggested that the frequency of thunderstorms and their intensity is likely to increase in the future. Here, we show that according to ERA5 convective available potential energy (CAPE) and convective precipitation (CP) have decreased over the tropics and subtropics with simultaneous increases in 0–6 km wind shear (BS06). Conversely, rawinsonde observations paint a different picture across the mid-latitudes with increasing CAPE and significant decreases to BS06. Differing trends and disagreement between ERA5 and rawinsondes observed over some regions suggest that results should be interpreted with caution, especially for CAPE and CP across tropics where uncertainty is the highest and reliable long-term rawinsonde observations are missing.


2021 ◽  
pp. 1-9
Author(s):  
Feng Shi ◽  
Anmin Duan ◽  
Qiuzhen Yin ◽  
John T Bruun ◽  
Cunde Xiao ◽  
...  

Abstract The Qinghai–Tibetan Plateau and Arctic both have an important influence on global climate, but the correlation between climate variations in these two regions remains unclear. Here we reconstructed and compared the summer temperature anomalies over the past 1,120 yr (900–2019 CE) in the Qinghai–Tibetan Plateau and Arctic. The temperature correlation during the past millennium in these two regions has a distinct centennial variation caused by volcanic eruptions. Furthermore, the abrupt weak-to-strong transition in the temperature correlation during the sixteenth century could be analogous to this type of transition during the Modern Warm Period. The former was forced by volcanic eruptions, while the latter was controlled by changes in greenhouse gases. This implies that anthropogenic, as opposed to natural, forcing has acted to amplify the teleconnection between the Qinghai–Tibetan Plateau and Arctic during the Modern Warm Period.


Author(s):  
Partha Sarathi Datta

In many parts of the world, freshwater crisis is largely due to increasing water consumption and pollution by rapidly growing population and aspirations for economic development, but, ascribed usually to the climate. However, limited understanding and knowledge gaps in the factors controlling climate and uncertainties in the climate models are unable to assess the probable impacts on water availability in tropical regions. In this context, review of ensemble models on δ18O and δD in rainfall and groundwater, 3H- and 14C- ages of groundwater and 14C- age of lakes sediments helped to reconstruct palaeoclimate and long-term recharge in the North-west India; and predict future groundwater challenge. The annual mean temperature trend indicates both warming/cooling in different parts of India in the past and during 1901–2010. Neither the GCMs (Global Climate Models) nor the observational record indicates any significant change/increase in temperature and rainfall over the last century, and climate change during the last 1200 yrs BP. In much of the North-West region, deep groundwater renewal occurred from past humid climate, and shallow groundwater renewal from limited modern recharge over the past decades. To make water management to be more responsive to climate change, the gaps in the science of climate change need to be bridged.


2021 ◽  
Vol 5 ◽  
pp. 96-104
Author(s):  
Didier Haid Alvarado Acosta

In March of 2020, the COVID-19 outbreak forced people to lock themselves inside their homes and begin the process of transitioning from face-to-face activities at work, schools and universities to a 100 % virtual method. Even when Communication Technologies (ICT) and online platforms have seen growth over the past two decades, including various virtual libraries developed by database publishers or web-based training programs that appear to shorten the learning curve (Lee, Hong y Nian, 2002), many people were unprepared for this transition and all of them are now dedicated to entering the new reality. In this order of ideas, the activities that have traditionally required the assistance of the staff have had to adapt with the use of new tools, which meet daily needs. A clear example is the field work collection tasks. In this group, there are different types such as surveys, photographs, reviews or on-site inspections. The current work presents the use of tools for collecting, validating, analysing and presenting data remotely and in real time. All of them based on the ArcGIS Online platform.


Zootaxa ◽  
2021 ◽  
Vol 4941 (2) ◽  
pp. 239-258
Author(s):  
YUN-HE WU ◽  
XIAO-LONG LIU ◽  
WEI GAO ◽  
YU-FAN WANG ◽  
YING-CHUN LI ◽  
...  

Approximately half of the species in speciose genus Raorchestes were described during the past 10 years, yet only 11 species are known from Southeast Asia and southern China (SEA-SC), adjacent Himalayas, and northeastern India. Field work in northwestern Yunnan province, China resulted in the discovery of one new species in the genus based on morphological and molecular analyses. The new species is diagnosed by small size with 15.0–19.0 mm SVL in adult males (n=3); tongue pyriform, notched posteriorly; rudimentary webbing between toes; fingers and toes with narrow lateral dermal fringes; tibiotarsal articulation reaching anterior of the eye when hindlimb is stretched along the side of the body; relative finger lengths: I < II < IV < III, relative toe lengths: I < II < V < III < IV; inner metatarsal tubercle oval, outer metatarsal tubercle absent; finger discs and toe discs greyish or orange; flank near the crotch with a distinct black region between two creamy white patches, and the thigh having a similar black patch near the groin, proximal to another creamy white patch; a distinct “) (”-shaped dark marking on the back; male with external single subgular vocal sac; nuptial pad absent. A phylogenetic tree was reconstructed based on the mitochondrial genes for 16S rRNA and ND1. The results indicated that these individuals form a monophyletic group, and show high genetic divergence to their closest relatives within the genus (uncorrected p-distances > 3.2%) by distance of 16S comparable to the divergence between recognized Raorchestes species. This study further enriches the diversity of rhacophorids, especially in northwestern Yunnan. 


2012 ◽  
Vol 9 (7) ◽  
pp. 2793-2819 ◽  
Author(s):  
L. Meng ◽  
P. G. M. Hess ◽  
N. M. Mahowald ◽  
J. B. Yavitt ◽  
W. J. Riley ◽  
...  

Abstract. Methane emissions from natural wetlands and rice paddies constitute a large proportion of atmospheric methane, but the magnitude and year-to-year variation of these methane sources are still unpredictable. Here we describe and evaluate the integration of a methane biogeochemical model (CLM4Me; Riley et al., 2011) into the Community Land Model 4.0 (CLM4CN) in order to better explain spatial and temporal variations in methane emissions. We test new functions for soil pH and redox potential that impact microbial methane production in soils. We also constrain aerenchyma in plants in always-inundated areas in order to better represent wetland vegetation. Satellite inundated fraction is explicitly prescribed in the model, because there are large differences between simulated fractional inundation and satellite observations, and thus we do not use CLM4-simulated hydrology to predict inundated areas. A rice paddy module is also incorporated into the model, where the fraction of land used for rice production is explicitly prescribed. The model is evaluated at the site level with vegetation cover and water table prescribed from measurements. Explicit site level evaluations of simulated methane emissions are quite different than evaluating the grid-cell averaged emissions against available measurements. Using a baseline set of parameter values, our model-estimated average global wetland emissions for the period 1993–2004 were 256 Tg CH4 yr−1 (including the soil sink) and rice paddy emissions in the year 2000 were 42 Tg CH4 yr−1. Tropical wetlands contributed 201 Tg CH4 yr−1, or 78% of the global wetland flux. Northern latitude (>50 N) systems contributed 12 Tg CH4 yr−1. However, sensitivity studies show a large range (150–346 Tg CH4 yr−1) in predicted global methane emissions (excluding emissions from rice paddies). The large range is sensitive to (1) the amount of methane transported through aerenchyma, (2) soil pH (±100 Tg CH4 yr−1), and (3) redox inhibition (±45 Tg CH4 yr−1). Results are sensitive to biases in the CLMCN and to errors in the satellite inundation fraction. In particular, the high latitude methane emission estimate may be biased low due to both underestimates in the high-latitude inundated area captured by satellites and unrealistically low high-latitude productivity and soil carbon predicted by CLM4.


2018 ◽  
Vol 20 (4) ◽  
pp. 673-685 ◽  
Author(s):  
Tatiana A. Vishnivetskaya ◽  
Haiyan Hu ◽  
Joy D. Van Nostrand ◽  
Ann M. Wymore ◽  
Xiaohang Xu ◽  
...  

Sulfate-reducing bacteria and methanogens are the primary Hg-methylators in Chinese rice paddies.


2016 ◽  
Vol 566-567 ◽  
pp. 641-651 ◽  
Author(s):  
Kazunori Minamikawa ◽  
Tamon Fumoto ◽  
Toshichika Iizumi ◽  
Nittaya Cha-un ◽  
Uday Pimple ◽  
...  

2012 ◽  
Vol 8 (4) ◽  
pp. 1169-1175 ◽  
Author(s):  
J. Liu ◽  
M. Song ◽  
Y. Hu ◽  
X. Ren

Abstract. Recent studies demonstrate that the Hadley Circulation has intensified and expanded for the past three decades, which has important implications for subtropical societies and may lead to profound changes in global climate. However, the robustness of this intensification and expansion that should be considered when interpreting long-term changes of the Hadley Circulation is still a matter of debate. It also remains largely unknown how the Hadley Circulation has evolved over longer periods. Here, we present long-term variability of the Hadley Circulation using the 20th Century Reanalysis. It shows a slight strengthening and widening of the Hadley Circulation since the late 1970s, which is not inconsistent with recent assessments. However, over centennial timescales (1871–2008), the Hadley Circulation shows a tendency towards a more intense and narrower state. More importantly, the width of the Hadley Circulation might have not yet completed a life-cycle since 1871. The strength and width of the Hadley Circulation during the late 19th to early 20th century show strong natural variability, exceeding variability that coincides with global warming in recent decades. These findings raise the question of whether the recent change in the Hadley Circulation is primarily attributed to greenhouse warming or to a long-period oscillation of the Hadley Circulation – substantially longer than that observed in previous studies.


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