scholarly journals An Exploration of Common Greenhouse Gas Emissions by the Cyanobiont of the Azolla–Nostoc Symbiosis and Clues as to Nod Factors in Cyanobacteria

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 587 ◽  
Author(s):  
Dilantha Gunawardana
Keyword(s):  
Climate Change ◽  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Greenhouse Gas ◽  
Calvin Cycle ◽  
Carbon Assimilation ◽  
Greenhouse Gas Mitigation ◽  
C3 Plants ◽  
Floating Macrophytes

Azolla is a genus of aquatic ferns that engages in a unique symbiosis with a cyanobiont that is resistant to cultivation. Azolla spp. are earmarked as a possible candidate to mitigate greenhouse gases, in particular, carbon dioxide. That opinion is underlined here in this paper to show the broader impact of Azolla spp. on greenhouse gas mitigation by revealing the enzyme catalogue in the Nostoc cyanobiont to be a poor contributor to climate change. First, regarding carbon assimilation, it was inferred that the carboxylation activity of the Rubisco enzyme of Azolla plants is able to quench carbon dioxide on par with other C3 plants and fellow aquatic free-floating macrophytes, with the cyanobiont contributing on average ~18% of the carboxylation load. Additionally, the author demonstrates here, using bioinformatics and past literature, that the Nostoc cyanobiont of Azolla does not contain nitric oxide reductase, a key enzyme that emanates nitrous oxide. In fact, all Nostoc species, both symbiotic and nonsymbiotic, are deficient in nitric oxide reductases. Furthermore, the Azolla cyanobiont is negative for methanogenic enzymes that use coenzyme conjugates to emit methane. With the absence of nitrous oxide and methane release, and the potential ability to convert ambient nitrous oxide into nitrogen gas, it is safe to say that the Azolla cyanobiont has a myriad of features that are poor contributors to climate change, which on top of carbon dioxide quenching by the Calvin cycle in Azolla plants, makes it an efficient holistic candidate to be developed as a force for climate change mitigation, especially in irrigated urea-fed rice fields. The author also shows that Nostoc cyanobionts are theoretically capable of Nod factor synthesis, similar to Rhizobia and some Frankia species, which is a new horizon to explore in the future.

scholarly journals Do greenhouse gas mitigation cost-effectiveness rankings based on the global warming potential favor sub-optimal allocation of resources?

2021 ◽  
Author(s):  
Franz Weiss ◽  
Adrian Leip ◽  
Vera Eory
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Global Warming ◽  
Cost Effectiveness ◽  
Soil Carbon ◽  
Greenhouse Gas ◽  
Global Warming Potential ◽  
Radiative Forcing ◽  
Greenhouse Gas Mitigation ◽  
Mitigation Measures

Abstract The global warming potential GWPgas(H) relates radiative forcing of a single pulse emission of a greenhouse gas, the absolute global warming potential AGWPgas(H), to the respective radiative forcing of carbon dioxide over a defined time horizon H. Mitigation measures targeting short-lived climate forcers (SLCFs) or reversible measures need to be applied permanently to be effective in the long run, but cost effectiveness for a permanent application of a measure differs from a single application. We propose a concept for an absolute global warming potential of permanent yearly pulses AGWP’gas(H), and several options for alternative indices to replace or complement the GWP: For the GWPgas(H/H) and the GWPcgas(H/H) we keep the AGWPCO2(H) in the denominator, which allows the direct comparison with conventional estimates, while for the GWP’gas(H) we define a new metric replacing the denominator by the AGWP’CO2(H). Different cost-effectiveness indicators can be defined respectively. We demonstrate the concept on the example of typical greenhouse gases emitted or removed by the agricultural sector: methane, nitrous oxide and carbon dioxide, fossil and stored as soil carbon. We show that, compared to GWP-based cost-effectiveness analysis, measures targeting soil carbon are discouraged relative to measures targeting methane, nitrous oxide and fossil carbon dioxide.

scholarly journals Greenhouse gas emissions from the water–air interface of a grassland river: a case study of the Xilin River

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue Hao ◽  
Yu Ruihong ◽  
Zhang Zhuangzhuang ◽  
Qi Zhen ◽  
Lu Xixi ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Land Use ◽  
Nitrous Oxide ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Ghg Emissions ◽  
Nitrous Oxide Emissions ◽  
Gas Emissions ◽  
Sand Land ◽  
Very High

AbstractGreenhouse gas (GHG) emissions from rivers and lakes have been shown to significantly contribute to global carbon and nitrogen cycling. In spatiotemporal-variable and human-impacted rivers in the grassland region, simultaneous carbon dioxide, methane and nitrous oxide emissions and their relationships under the different land use types are poorly documented. This research estimated greenhouse gas (CO2, CH4, N2O) emissions in the Xilin River of Inner Mongolia of China using direct measurements from 18 field campaigns under seven land use type (such as swamp, sand land, grassland, pond, reservoir, lake, waste water) conducted in 2018. The results showed that CO2 emissions were higher in June and August, mainly affected by pH and DO. Emissions of CH4 and N2O were higher in October, which were influenced by TN and TP. According to global warming potential, CO2 emissions accounted for 63.35% of the three GHG emissions, and CH4 and N2O emissions accounted for 35.98% and 0.66% in the Xilin river, respectively. Under the influence of different degrees of human-impact, the amount of CO2 emissions in the sand land type was very high, however, CH4 emissions and N2O emissions were very high in the artificial pond and the wastewater, respectively. For natural river, the greenhouse gas emissions from the reservoir and sand land were both low. The Xilin river was observed to be a source of carbon dioxide and methane, and the lake was a sink for nitrous oxide.

scholarly journals Emission of Greenhouse Gases and Odorants from Pig Slurry - Effect on the Environment and Methods of its Reduction

2018 ◽  
Vol 25 (3) ◽  
pp. 383-394 ◽  
Author(s):  
Marta Marszałek ◽  
Zygmunt Kowalski ◽  
Agnieszka Makara
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Greenhouse Gases ◽  
Atmospheric Pollutants ◽  
Gaseous Pollutants ◽  
Pig Slurry ◽  
Heterogeneous Mixture ◽  
Liquid Fertilizer ◽  
Emission Of Greenhouse Gases

Abstract Pig slurry is classified as a natural liquid fertilizer, which is a heterogeneous mixture of urine, faeces, remnants of feed and technological water, used to remove excrement and maintain the hygiene of livestock housing. The storage and distribution of pig slurry on farmland affect the environment as they are associated with, among others, the emission of various types of gaseous pollutants, mainly CH4, CO2, N2O, NH3, H2S, and other odorants. Methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) are greenhouse gases (GHGs) which contribute to climate change by increasing the greenhouse effect. Ammonia (NH3) and hydrogen sulfide (H2S) are malodorous gases responsible for the occurrence of odour nuisance which, due to their toxicity, may endanger the health and lives of humans and animals. NH3 also influences the increase of atmosphere and soil acidification. The article presents the environmental impact of greenhouse gases and odorous compounds emitted from pig slurry. Key gaseous atmospheric pollutants such as NH3, H2S, CH4, CO2 and N2O have been characterized. Furthermore, methods to reduce the emission of odours and GHGs from pig slurry during its storage and agricultural usage have been discussed.

scholarly journals Greenhouse Gas Emission of Broiler Chicken Production in Malaysia using Life Cycle Assessment Guidelines: A Case Study

2018 ◽  
Vol 3 (2) ◽  
pp. 87-97
Author(s):  
Syakira Afiqah Suffian ◽  
Atiah Abdullah Sidek ◽  
Toshihiko Matsuto ◽  
Muataz Hazza Al Hazza ◽  
Hazlina Md Yusof ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Greenhouse Gas ◽  
Broiler Chicken ◽  
Greenhouse Gas Emission ◽  
Gas Emission ◽  
Chicken Farm

The aim of this research was to evaluate the level of greenhouse gas emission from broiler chicken farming industry in Malaysia. In order to achieve that, Life Cycle Assessment method was chosen as a framework to complete the task. A case study was conducted at a broiler chicken farm to gather the data and information related to the broiler chicken production. Cradle-to-gate assessment including distribution stage was conducted based on the ISO14040/1044 guidelines. Inventory data for this case study was gathered in collaboration with one of the selected case study broiler chicken farm company. Greenhouse gas emission that consists of several most affected gases such as carbon dioxide, methane and nitrous oxide was studied. Result shows that the highest carbon dioxide emission came from manure, which accounted for 1,665,342 kg CO2 equivalent per total broilers while the highest methane emission came from feed, which accounted for 126,207.84 g CH4 equivalent per total broilers. For nitrous oxide emission, the highest values came from bedding which accounted for 20,316.87 g N2O equivalent per total broilers in the commercial modern broiler chicken farm. In this case study, it can be concluded that manure gives the most prominent effect to the greenhouse gas emission followed by feed and bedding materials. 

The Threats to Food Security

2019 ◽  
pp. 61-84
Author(s):  
Gordon Conway ◽  
Ousmane Badiane ◽  
Katrin Glatzel
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Food Security ◽  
Greenhouse Gases ◽  
Acute Stress ◽  
Rural Livelihoods ◽  
Farm Household ◽  
Impacts Of Climate Change ◽  
Socioeconomic Challenges

This chapter explores threats to food security. It reveals many challenges arising from a range of threats external to the farm household, including severe biological threats from pests, disease, and weeds. Moreover, healthy, fertile soils are the cornerstone of food security and rural livelihoods, but African soils are degrading. Water is just as important for the productivity of plants, and lack of water leads to chronic and acute stress. Indeed, Africa is already battling the impacts of climate change. Rising temperatures and variable rainfall are increasing the exposure of smallholders to drought, famine, and disease. Agriculture is an important emitter of greenhouse gases (GHGs), not only carbon dioxide but also such powerful gases as methane and nitrous oxide. In addition, there are often severe socioeconomic challenges, including unstable and high prices of basic commodities. Finally, conflicts cause disruption to food security.

The use of feed supplements to reduce livestock greenhouse gas emissions: direct-fed microbials

2021 ◽  
pp. 261-286
Author(s):  
Natasha Doyle ◽  
◽  
Philiswa Mbandlwa ◽  
Sinead Leahy ◽  
Graeme Attwood ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Large Scale ◽  
Important Variable ◽  
Gas Emissions ◽  
Feed Supplements ◽  
Beneficial Response ◽  
On Farm

This chapter aims to outline the strategy of using feed supplements for the reduction of greenhouse gas emissions (GHG) in ruminants, including methane (CH4), carbon dioxide and nitrous oxide, given that feed intake is an important variable in predicting these emissions. Focus will be given to direct-fed microbials, a term reserved for live microbes which can be supplemented to feed to elicit a beneficial response. The viability of such methods will also be analysed for their use in large scale on-farm operations.

18. Climate Change Law

2019 ◽  
pp. 599-639
Author(s):  
Elizabeth Fisher ◽  
Bettina Lange ◽  
Eloise Scotford
Keyword(s):  
Climate Change ◽  
Greenhouse Gas ◽  
Greenhouse Gas Mitigation ◽  
Eu Member States ◽  
Mitigation And Adaptation ◽  
Law And Policy ◽  
Trading Scheme ◽  
The Uk ◽  
The Eu

This chapter examines the fast-moving area of law relating to climate change. This includes a considerable body of public international law, from the UN Framework Convention on Climate Change to the legally innovative Paris Agreement 2015. The chapter also considers legal developments at the EU and UK levels, which both contain a rich body of climate law and policy. The EU and the UK are both seen as ‘world leaders’ in climate law and policy. In EU law, this is due to the EU greenhouse gas emissions trading scheme and the EU’s leadership in advocating ambitious greenhouse gas mitigation targets and in implementing these targets flexibly across the EU Member States through a range of regulatory mechanisms. The UK introduced path-breaking climate legislation in the Climate Change Act 2008, which provided an inspiring model of climate governance, legally entrenching long-term planning for both mitigation and adaptation. The chapter concludes with an exploration of climate litigation, a new and growing field of inquiry.

Balancing the competing needs of climate change, biodiversity and rural communities

2009 ◽  
Vol 2009 ◽  
pp. 249-249
Author(s):  
H Prosser
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Land Use ◽  
Nitrous Oxide ◽  
Anaerobic Digestion ◽  
Rural Communities ◽  
Carbon Dioxide Emissions ◽  
Energy Use ◽  
New Technology ◽  
The Uk

The work of the UK Climate Change Commission (UKCCC) in recommending targets and options for reducing emissions of greenhouse gases is focusing attention on what agriculture and land use can contribute to deliver these targets. Although overall the major issue is the reduction of carbon dioxide emissions from energy use, agriculture and land use are significant emitters of methane and nitrous oxide. UKCCC has identified three main routes by which emissions can be reduced• Lifestyle change with less reliance on carbon intensive produce -eg switching from sheep, and beef to pig, poultry and vegetables.• Changing farm practices – eg to improve use of fertilisers and manures• Using new technology on farms – eg modifying rumen processes, anaerobic digestion.

scholarly journals Modeling Climate Change Impacts on Rangeland Productivity and Livestock Population Dynamics in Nkayi District, Zimbabwe

2020 ◽  
Vol 10 (7) ◽  
pp. 2330
Author(s):  
Trinity S. Senda ◽  
Gregory A. Kiker ◽  
Patricia Masikati ◽  
Albert Chirima ◽  
Johan van Niekerk
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Population Dynamics ◽  
C3 Plants ◽  
Climate Scenarios ◽  
Herbaceous Layer ◽  
Livestock Population ◽  
Co2 Effects ◽  
Forested Areas ◽  
Carbon Dioxide Co2

Smallholder farmers in semi-arid areas depend on both cropping and livestock as the main sources of livelihoods. Rangeland productivity varies on both spatial and temporal scales and provides the major source of feed for livestock. Rangeland productivity is expected to decline with climate change thereby reducing livestock feed availability and consequently livelihoods that depend on livestock. This study was carried out to assess the impacts of climate change on rangeland productivity and consequently livestock population dynamics using a 30-year simulation modeling approach. The climate scenarios used in the simulations are built from the localized predictions by General Circulation Models (GCMs). The primary climate variables under consideration are rainfall (+/−7% change), carbon dioxide (CO2 up to 650 ppm) and temperature (+4 °C change). This was done by applying the SAVANNA ecosystem model which simulates rangeland processes and demographic responses of herbivores on a temporal and spatial scale using a weekly internal time step and monthly spatial and temporal outputs. The results show that rainfall levels of less than 600 mm/year have the largest negative effect on herbaceous biomass production. The amount of biomass from the woody layer does not change much during the year. The carbon dioxide (CO2) effects are more influential on the tree and shrub layers (C3 plants) than the herbaceous layer (C4 grasses). The CO2 effect was more dominant than the effects of rainfall and temperature. In the baseline simulations, the shrub plant layer increased significantly over 30 years while there is a three-fold increase in the woody plant layer (trees and shrubs) where biomass increased from a 1980 production to that of 2010. The biomass of the herbaceous layer was stable over the historical period (1980 to 2010) with values fluctuating between 200 and 400 g/m2. Grass green biomass has a variable distribution where most production occurred in the fields and cleared areas while lower levels of production were found in the forested areas. The spatial distribution of shrub green biomass was less directly linked to yearly rainfall. Shrub biomass was mostly found in forested areas, and it showed a steady increase in production. Cattle, donkey, and goat populations rose slowly from 1980 but the rise was disrupted by a dry period during the late 1980s to the early 1990s causing a decline in all populations primarily due to grass unavailability. The populations of cattle goats and donkeys started to rise again from 1995 onwards due to improvements in rainfall. Cattle and donkey populations were rising faster than that of goats while sheep population was not changing much for most of the simulation period, otherwise they declined significantly during the drought of 2002. Similar changes in simulated grass biomass (g/m2) were observed in almost all climate scenarios, except for the peak and low years. The livestock population simulation showed few variations in livestock population under all scenarios. The main conclusion from the study is that CO2 effects on rangeland productivity are much more dominant than the localized effects of rainfall and temperature. This has implications of favoring the growth of the tree and shrub layers over herbaceous layer, which meant that in the long run, the species that are able to use tree and shrub layers may be kept as a livelihood source as they will have a feed source.

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