scholarly journals A nature-based negative emissions technology able to remove atmospheric methane and other greenhouse gases

Author(s):  
Tingzhen Ming ◽  
Renaud de Richter ◽  
Franz Dietrich Oeste ◽  
Robert Tulip ◽  
Sylvain Caillol
2021 ◽  
Author(s):  
Ingeborg Bussmann ◽  
Holger Brix ◽  
Norbert Kamjunke ◽  
Uta Ködel ◽  
Matthias Koschorreck ◽  
...  

<p>Surface waters are known to be significant sources of greenhouse gases (CH<sub>4</sub> and CO<sub>2</sub>), but our understanding of large scale patterns is still incomplete. The greenhouse gases in rivers originate both from in-stream processes and interactions with the catchment. For coastal seas, rivers are suspected to be one of the main source of greenhouse gases, while the role of the interjacent tidal flats is still ambiguous. Especially the reaction of the entire system on terrestrial hydrological extremes such as low flow situations are still under consideration. The functional understanding of such events and their impacts on the water chemistry along its transition pathway in the terrestrial and limnic compartment as well as in the coastal marine environment is crucially needed for the evaluation of its relevance in the Earth system. As part of a MOSES campaign (Modular Observation Solutions for Earth Systems) spanning disciplines as well as earth system compartments we investigated the aquatic as well as the atmospheric compartemt in and above the Elbe River from inland waters through the tidal section of the river and the estuary to the North Sea with the goal to explore spatial heterogeneity of CO<sub>2</sub> and CH<sub>4</sub> concentrations in the water and in ambient air above the water during a low water period in summer 2020.</p><p> </p><p>Overall, dissolved CH<sub>4</sub> concentrations ranged over three orders of magnitude. Along the freshwater part of the transect, dissolved CH<sub>4</sub> increased and weirs and harbors appeared to be hot spots of elevated CH<sub>4</sub> concentrations both for the dissolved and atmospheric phase. We observed a longitudinal gradient of CO<sub>2</sub> in the river which was closely linked to primary production. In the estuary and the marine part, dissolved CH<sub>4</sub> concentrations of the transect were determined by the variability of temperature and salinity. Correlations with other water parameters revealed the complex regulation of dissolved CH<sub>4</sub> concentrations along the freshwater-seawater continuum. For atmospheric CH<sub>4</sub> above the North Sea, wind direction and wind speed proved to be crucial. Besides the typical diurnal fluctuations of atmospheric CO<sub>2</sub> and CH<sub>4</sub>, an observed link between dissolved and atmospheric concentrations has to  be further clarified.</p>


2021 ◽  
Author(s):  
Ingeborg Levin ◽  
Ute Karstens ◽  
Samuel Hammer ◽  
Julian DellaColetta ◽  
Fabian Maier ◽  
...  

Abstract. Correlations of night-time atmospheric methane (CH4) and 222Radon (222Rn) observations in Heidelberg, Germany, were evaluated with the Radon Tracer Method (RTM) to estimate the trend of annual CH4 emissions from 1996–2020 in the catchment area of the station. After an initial 30 % decrease of emissions from 1996 to 2004, no further systematic trend but small inter-annual variations were observed thereafter. This is in accordance with the trend of emissions until 2010 reported by the EDGARv6.0 inventory for the surroundings of Heidelberg. We show that the reliability of total CH4 emission estimates with the RTM critically depends on the accuracy and representativeness of the 222Rn exhalation rate from soils in the catchment area of the site. Simply using 222Rn fluxes as estimated by Karstens et al. (2015) could lead to biases in the estimated greenhouse gases (GHG) fluxes as large as a factor of two. RTM-based GHG flux estimates also depend on the parameters chosen for the night-time correlations of CH4 and 222Rn, such as the night-time period for regressions as well as the R2 cut-off value for the goodness of the fit. Quantitative comparison of total RTM-based top-down with bottom-up emission inventories requires representative high-resolution footprint modelling, particularly in polluted areas where CH4 emissions show large heterogeneity. Even then, RTM-based estimates are likely biased low if point sources play a significant role in the station/observation footprint as their emissions are not captured by the RTM method. Long-term representative 222Rn flux observations in the catchment area of a station are indispensable in order to apply the RTM method for reliable quantitative flux estimations of GHG emissions from atmospheric observations.


2018 ◽  
Vol 1 ◽  
Author(s):  
Nils Markusson ◽  
Duncan McLaren ◽  
David Tyfield

Non-technical summaryIn the face of limited carbon budgets, negative emissions technologies (NETs) offer hopes of removing greenhouse gases from the atmosphere. It is difficult to determine whether the prospect of NETs is significantly deterring or delaying timely action to cut emissions. This paper sets out a novel theoretical perspective to this challenge, enabling analysis that accounts for interactions between technologies, society and political and economic power. The paper argues that, seen in this light, the scope of NETs to substitute for mitigation may be easily exaggerated, and thus that the risk of harm from mitigation deterrence should be taken seriously.


Author(s):  
Nosiri Chidi ◽  
Anyanwu Chukwuma ◽  
Nwaogwugwu Joel

There are many definitions of emerging contaminants (ECs). They are not usually new chemicals and could be substances that have stayed long in the environment with their presence and importance being recognized now. They may be chemicals or microorganisms which are not usually monitored in the environment but with known or suspected potential to cause ecological damage or adverse human effects. Some natural products and those transformed through biochemical processes from synthetic chemicals may be formed in the environment as ECs. Emerging Agricultural Contaminants are released to the environment or enter indirectly to the soil during the application of manure, fertilizers, biosolids or other solid waste materials. Once they enter the soil, they may be transported by leaching, runoff and drainage processes to water bodies. The extent of the transport is dependent on the persistence of the EC and on how it interacts with soil and air. These ECs contribute to global warming through the emissions of Greenhouse gases. The largest source of GHG emission from Agriculture is Nitrous oxide (N2O) and it accounts for 38% of the total global emission through the process of nitrification and denitrification, anthropogenic activities (use of nitrogen fertilizer, production of nitrogen-fixing crops and forages, retention of crop residues, application of managed livestock manure) which are either through direct additions and/or through indirect additions (atmospheric deposition of applied nitrogen). The natural digestive processes in ruminants otherwise known as enteric fermentation account for the key source of methane production under livestock production hence the second largest source of total agricultural emission with 34% global share and rice cultivation being the third with 11%. The three important greenhouse gases (Methane, Carbon dioxide and Nitrous oxide) are not harmful in naturally occurring quantities for their atmospheric presence helps in sustaining life on the planet when they trap heat energy near the surface of the earth. Concentration of greenhouse gases from both the natural and human factors have been increasing and contributing to Global Warming and Climate Change. Increase in greenhouse gases may cause tremendous changes to our civilization positively or negatively but the total impact is uncertain. Climate change comes as a result of a warming planet which can affect the weather adversely in many ways. So, as climate changes, extreme weather activities release severe threats on human society. Indicators of global warming include sea surface temperature, temperature over land, snow cover on hills, temperature over land and humidity. It is expected that climate change may cause more floods, storms, droughts, heatwaves and other extreme weathers activities. IPCC estimated that temp may rise from 2 to 6°C within 2021. Mitigation of greenhouse effect could be achieved through Biochemical methods on enteric fermentation, development of good environmental policies even Methanotrophs also aid in recycling the atmospheric Methane.


2011 ◽  
Vol 3 (7) ◽  
pp. 570-572
Author(s):  
Sangeet Markanda ◽  
◽  
R K Aggarwal R K Aggarwal

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