scholarly journals Greenhouse Gas Forcing a Necessary Causation for Marine Heatwaves Over the Northeast Pacific Warming Pool

Author(s):  
Armineh Barkhordarian ◽  
David Marcolino Nielsen ◽  
Johanna Baehr

Abstract Over the last decade, the northeast Pacific (NP) experienced strong marine heatwaves (MHWs) that produced devastating marine ecological impacts and received major societal concerns. Here, we assess the link between the well-mixed greenhouse gas (GHG) forcing and the occurrence probabilities of the duration and intensity of the NP MHWs. To begin with, we apply attribution technique on the SST time series, and detect a region of systematically and externally-forced SST increase -- the long-term warming pool -- co-located with the past notably Blob-like SST anomalies. The anthropogenic signal has recently emerged from the natural variability of SST over the warming pool, which we attribute primarily to increased GHG concentrations, with anthropogenic aerosols playing a secondary role. With extreme event attribution technique, we further show that GHG forcing is a necessary, but not a sufficient, causation for the multi-year persistent MHW events in the current climate, such as that happened in 2019/2020 over the warming pool. However, the occurrence of the 2019/2020 MHW was extremely unlikely in the absence of GHG forcing. Thus, as GHG emissions continue to firmly rise, it is very likely that GHG forcings will become a sufficient cause for events of the magnitude of the 2019/2020 record event.

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Philip J. Ball

Abstract A review of conventional, unconventional, and advanced geothermal technologies highlights just how diverse and multi-faceted the geothermal industry has become, harnessing temperatures from 7 °C to greater than 350 °C. The cost of reducing greenhouse emissions is examined in scenarios where conventional coal or combined-cycle gas turbine (CCGT) power plants are abated. In the absence of a US policy on a carbon tax, the marginal abatement cost potential of these technologies is examined within the context of the social cost of carbon (SCC). The analysis highlights that existing geothermal heat and power technologies and emerging advanced closed-loop applications could deliver substantial cost-efficient baseload energy, leading to the long-term decarbonization. When considering an SCC of $25, in a 2025 development scenario, geothermal technologies ideally need to operate with full life cycle assessment (FLCA) emissions, lower than 50 kg(CO2)/MWh, and aim to be within the cost range of $30−60/MWh. At these costs and emissions, geothermal can provide a cost-competitive low-carbon, flexible, baseload energy that could replace existing coal and CCGT providing a significant long-term reduction in greenhouse gas (GHG) emissions. This study confirms that geothermally derived heat and power would be well positioned within a diverse low-carbon energy portfolio. The analysis presented here suggests that policy and regulatory bodies should, if serious about lowering carbon emissions from the current energy infrastructure, consider increasing incentives for geothermal energy development.


2020 ◽  
Author(s):  
Matthias Kuhnert ◽  
Viktoria Oliver ◽  
Andrea Volante ◽  
Stefano Monaco ◽  
Yit Arn Teh ◽  
...  

<p>Rice cultivation has high water consumption and emits large quantities of greenhouse gases. Therefore, rice fields provide great potential to mitigate GHG emissions by modifications to cultivation practices or external inputs. Previous studies showed differences for impacts of alternated wetting and drying (AWD) practices for above-ground and below-ground biomass, which might have long term impacts on soil organic carbon stocks. The objective of this study is to parameterise and evaluate the model ECOSSE for rice simulations based on data from an Italian rice test site where the effects of different water management practices and 12 common European cultivars, on yield and GHG emissions, were investigated. Special focus is on the differences of the impacts on the greenhouse gas emissions for AWD and continuous flooding (CF). The model is calibrated and tested for field measurements and is used for model experiments to explore climate change impacts and long-term effects. Long term carbon storage is of particular interest since it is a suitable mitigation strategy. As experiments showed different impacts of management practices on the below ground biomass, long term model experiments are used to estimate impacts on SOC of the different practices. The measurements also allow an analysis of the impacts of different cultivars and the uncertainty of model approaches using a single data set for calibration.</p>


1999 ◽  
Vol 26 (3) ◽  
pp. 166-168 ◽  
Author(s):  
TIM NEWCOMB

Many nations have recognized the need to reduce the emissions of greenhouse gases (GHGs). The scientific assessments of climate change of the Intergovernmental Panel on Climate Change (IPCC) support the need to reduce GHG emissions. The 1997 Kyoto Protocol to the 1992 Convention on Climate Change (UNTS 30822) has now been signed by more than 65 countries, although that Protocol has not yet entered into force. Some 14 of the industrialized countries listed in the Protocol face reductions in carbon dioxide emissions of more than 10% compared to projected 1997 carbon dioxide emissions (Najam & Page 1998).


2021 ◽  
pp. 159-178
Author(s):  
Christopher Dye

Climate change is prevention’s biggest challenge—its effects on health and well-being will be wide-ranging, long-term, and global. The pressures and opportunities for action are growing as the risks and hazards become clearer, greater, and nearer. Mitigation—cutting greenhouse gas (GHG) emissions (primary prevention)—benefits health, economy, environment, and society through agriculture, transport, air quality, energy supply, and waste management. Adaptation (secondary prevention) is the essential back-up when mitigation fails; there are strong incentives for local adaptation to counter predictable local threats such as extreme urban temperatures, flooding, and water scarcity. Carbon taxes are a powerful but underexploited mechanism for reducing greenhouse gas emissions, so need to be reinforced by other incentives, including subsidies for wind, solar, hydrogen, and hydropower. Now more than ever, the pressure for transformative action on climate change has the potential to stimulate sudden and rapid movement towards clean energy sources and technologies.


2019 ◽  
Vol 11 (8) ◽  
pp. 2282 ◽  
Author(s):  
Chengliang Zhang ◽  
Tong Xu ◽  
Hualiang Feng ◽  
Shaohua Chen

The landfill is an important method of disposal of municipal solid waste. In particular, the landfill is especially vital in many developing countries, with it being the main biodegradable waste disposal method due to its simple management and ability for mass manipulation. Landfills have recently been shown to be an important source of greenhouse gas (GHG) emissions by researchers in different countries. However, few reviews have been conducted within the related fields, which means that there is still a lack of comprehensive understanding related to relevant study achievements. In this study, a bibliometric analysis of articles published from 1999 to 2018 on landfill GHG emissions was presented to assess the current trends, using the Web of Science (WOS) database. The most productive countries/territories, authors and journals were analyzed. Moreover, the overall research structure was characterized based on co-cited references, emerging keywords and reference citations by means of bibliometric analysis. Due to the increasing amount of attention being paid to the GHG emissions and their mitigation methods, this study provided comprehensive bibliometric information on GHG emissions from landfills over the past two decades and highlighted the importance of the development and dissemination of updated knowledge frameworks.


2018 ◽  
Vol 31 (14) ◽  
pp. 5507-5524 ◽  
Author(s):  
Alexis Hannart ◽  
Philippe Naveau

Multiple changes in Earth’s climate system have been observed over the past decades. Determining how likely each of these changes is to have been caused by human influence is important for decision making with regard to mitigation and adaptation policy. Here we describe an approach for deriving the probability that anthropogenic forcings have caused a given observed change. The proposed approach is anchored into causal counterfactual theory ( Pearl 2009 ), which was introduced recently, and in fact partly used already, in the context of extreme weather event attribution (EA). We argue that these concepts are also relevant to, and can be straightforwardly extended to, the context of detection and attribution of long-term trends associated with climate change (D&A). For this purpose, and in agreement with the principle of fingerprinting applied in the conventional D&A framework, a trajectory of change is converted into an event occurrence defined by maximizing the causal evidence associated to the forcing under scrutiny. Other key assumptions used in the conventional D&A framework, in particular those related to numerical model error, can also be adapted conveniently to this approach. Our proposal thus allows us to bridge the conventional framework with the standard causal theory, in an attempt to improve the quantification of causal probabilities. An illustration suggests that our approach is prone to yield a significantly higher estimate of the probability that anthropogenic forcings have caused the observed temperature change, thus supporting more assertive causal claims.


2020 ◽  
Vol 66 (No. 4) ◽  
pp. 167-174
Author(s):  
Fa Wang ◽  
Zhijian Mu ◽  
Tao Guo ◽  
Aiying Huang ◽  
Xiao Lin ◽  
...  

A field campaign was conducted using six treatments under the summer rice-winter wheat cultivation system to evaluate the response of soil greenhouse gas (GHG) emissions to long-term differentiated fertilisation regimes. The treatments included control, phosphorus plus potassium, nitrogen only, nitrogen plus phosphorus (NP), nitrogen plus potassium, and NP plus potassium (NPK). Compared to the control, mineral fertilisation increased CH<sub>4</sub> emissions during the rice season by 69% to 175%. Phosphorus amendment also enhanced seasonal CO<sub>2</sub> emissions by 21% to 34% when compared with the treatments without receiving P, while combined use of P and potassium suppressed seasonal N<sub>2</sub>O emission to the same level of control. Net CO<sub>2</sub> and N<sub>2</sub>O emissions from the dried fallow and wheat seasons and CH<sub>4</sub> emissions from the flooding rice season dominated annual budgets of individual GHGs. All of the soils under different treatments were net sources of global warming and the overall net global warming potential ranged from 9 799 to 14 178 kg CO<sub>2</sub> eq/ha/year with CO<sub>2</sub> emission contributing 52% to 76%, CH<sub>4</sub> contributing 20% to 40% and N<sub>2</sub>O occupying the rest. The annual maximum grain yields and minimum GHG intensity was observed at the NPK treatment, suggesting it to be the environmental-friendly optimum fertilisation regime.


Author(s):  
Markus Millinger ◽  
Kathleen Meisel ◽  
Maik Budzinski ◽  
Daniela Thrän

Transport biofuels derived from biogenic material are used for substituting fossil fuels, thereby abating greenhouse gas (GHG) emissions. Numerous competing conversion options exist to produce biofuels, with differing GHG emissions and costs. In this paper analysis and modelling of the long-term development of GHG abatement and relative GHG abatement cost competitiveness between crop-based biofuels in Germany is carried out. Presently dominant conventional biofuels and advanced liquid biofuels were found not to be competitive compared to the substantially higher yielding options available: sugar beet based ethanol for the short to medium term least-cost option and Substitute Natural Gas (SNG) for the medium to long term. The competitiveness of SNG was found to depend highly on the emissions development of the power mix. Silage maize based biomethane was found competitive on a land area basis, but not on an energetic basis. Due to land limitations as well as cost and GHG uncertainty, a stronger focus on the land use of crop-based biofuels should be laid in policy.


2021 ◽  
Vol 14 (2) ◽  
pp. 1111-1126
Author(s):  
Florian Dietrich ◽  
Jia Chen ◽  
Benno Voggenreiter ◽  
Patrick Aigner ◽  
Nico Nachtigall ◽  
...  

Abstract. In order to mitigate climate change, it is crucial to understand urban greenhouse gas (GHG) emissions precisely, as more than two-thirds of the anthropogenic GHG emissions worldwide originate from cities. Nowadays, urban emission estimates are mainly based on bottom-up calculation approaches with high uncertainties. A reliable and long-term top-down measurement approach could reduce the uncertainty of these emission inventories significantly. We present the Munich Urban Carbon Column network (MUCCnet), the world's first urban sensor network, which has been permanently measuring GHGs, based on the principle of differential column measurements (DCMs), since summer 2019. These column measurements and column concentration differences are relatively insensitive to vertical redistribution of tracer masses and surface fluxes upwind of the city, making them a favorable input for an inversion framework and, therefore, a well-suited candidate for the quantification of GHG emissions. However, setting up such a stationary sensor network requires an automated measurement principle. We developed our own fully automated enclosure systems for measuring column-averaged CO2, CH4 and CO concentrations with a solar-tracking Fourier transform spectrometer (EM27/SUN) in a fully automated and long-term manner. This also includes software that starts and stops the measurements autonomously and can be used independently from the enclosure system. Furthermore, we demonstrate the novel applications of such a sensor network by presenting the measurement results of our five sensor systems that are deployed in and around Munich. These results include the seasonal cycle of CO2 since 2015, as well as concentration gradients between sites upwind and downwind of the city. Thanks to the automation, we were also able to continue taking measurements during the COVID-19 lockdown in spring 2020. By correlating the CO2 column concentration gradients to the traffic amount, we demonstrate that our network is capable of detecting variations in urban emissions. The measurements from our unique sensor network will be combined with an inverse modeling framework that we are currently developing in order to monitor urban GHG emissions over years, identify unknown emission sources and assess how effective the current mitigation strategies are. In summary, our achievements in automating column measurements of GHGs will allow researchers all over the world to establish this approach for long-term greenhouse gas monitoring in urban areas.


Soil Systems ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 14 ◽  
Author(s):  
Gerald Jurasinski ◽  
Sate Ahmad ◽  
Alba Anadon-Rosell ◽  
Jacqueline Berendt ◽  
Florian Beyer ◽  
...  

Of all terrestrial ecosystems, peatlands store carbon most effectively in long-term scales of millennia. However, many peatlands have been drained for peat extraction or agricultural use. This converts peatlands from sinks to sources of carbon, causing approx. 5% of the anthropogenic greenhouse effect and additional negative effects on other ecosystem services. Rewetting peatlands can mitigate climate change and may be combined with management in the form of paludiculture. Rewetted peatlands, however, do not equal their pristine ancestors and their ecological functioning is not understood. This holds true especially for groundwater-fed fens. Their functioning results from manifold interactions and can only be understood following an integrative approach of many relevant fields of science, which we merge in the interdisciplinary project WETSCAPES. Here, we address interactions among water transport and chemistry, primary production, peat formation, matter transformation and transport, microbial community, and greenhouse gas exchange using state of the art methods. We record data on six study sites spread across three common fen types (Alder forest, percolation fen, and coastal fen), each in drained and rewetted states. First results revealed that indicators reflecting more long-term effects like vegetation and soil chemistry showed a stronger differentiation between drained and rewetted states than variables with a more immediate reaction to environmental change, like greenhouse gas (GHG) emissions. Variations in microbial community composition explained differences in soil chemical data as well as vegetation composition and GHG exchange. We show the importance of developing an integrative understanding of managed fen peatlands and their ecosystem functioning.


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