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Topic Review
Clean Development Mechanism
The Clean Development Mechanism (CDM) is one of the Flexible Mechanisms defined in the Kyoto Protocol (IPCC, 2007) that provides for emissions reduction projects which generate Certified Emission Reduction units (CERs) which may be traded in emissions trading schemes. The market crashed in 2012 when the value of credits collapsed and thousands of projects were left with unclaimed credits. The struggle about what to do with the old credits sank the 2019 COP 25 in Madrid. The CDM, defined in Article 12 of the Protocol, was intended to meet two objectives: "Annex I" parties are the countries listed in Annex I of the treaty, the industrialized countries. Non-Annex I parties are developing countries. The CDM addresses the second objective by allowing the Annex I countries to meet part of their emission reduction commitments under the Kyoto Protocol by buying Certified Emission Reduction units from CDM emission reduction projects in developing countries. Both the projects and the issue of CERs units are subject to approval to ensure that these emission reductions are real and "additional." The CDM is supervised by the CDM Executive Board (CDM EB) under the guidance of the Conference of the Parties (COP/MOP) of the United Nations Framework Convention on Climate Change (UNFCCC). The CDM allows industrialized countries to buy CERs and to invest in emission reductions where it is cheapest globally. Between 2001, which was the first year CDM projects could be registered and 7 September 2012, the CDM issued 1 billion Certified Emission Reduction units. As of 1 June 2013, 57% of all CERs had been issued for projects based on destroying either HFC-23 (38%) or N2O (19%). Carbon capture and storage (CCS) was included in the CDM carbon offsetting scheme in December 2011. However, a number of weaknesses of the CDM have been identified. Several of these issues were addressed by the new Program of Activities (PoA), which moves to approving 'bundles' of projects instead of accrediting each project individually. In 2012, the report Climate Change, Carbon Markets and the CDM: A Call to Action said governments urgently needed to address the future of the CDM. It suggested the CDM was in danger of collapse because of the low price of carbon and the failure of governments to guarantee its existence into the future. Writing on the website of the Climate & Development Knowledge Network, Yolanda Kakabadse, a member of the investigating panel for the report and founder of Fundación Futuro Latinamericano, said a strong CDM is needed to support the political consensus essential for future climate progress. "Therefore we must do everything in our hands to keep it working," she said.
  • 2.3K
  • 17 Oct 2022
Topic Review
Wastewater Refinery
The concept of wastewater refinery introduces a new concept of wastewater treatment and management that aims at extracting the most of wastewater components such as water, energy, nitrogen, phosphorous, to co-produce different valuable outputs. It represents a paradigmatic shift in wastewater management, and it is well aligned with the concept of circular economy. A case study on Qatar’s wastewater revealed that significant quantities of valuable resources are embodied in the country’s wastewater, with potential to be recovered. Valorisation of organic constituents and the recovery of nitrogen, phosphorus, and sulphide should be given priority.
  • 2.3K
  • 05 Nov 2020
Topic Review
Goat Breeding for Xerophytic Thickets Management in Madagascar
Spiny thickets or xerophytic thickets (XTs) are a type of shrubby vegetation found in the far south and southwest of Madagascar, the driest parts of the island. This type of vegetation, which is rich in endemic animal and plant species, is endangered. Extensive local goat breeding (Capra hircus, for meat and milk production) based on XT browsing is an important source of household income. Improved goat breeding is an alternative to wood charcoal (WC) production and slash-and-burn agriculture (SBA), which are unsustainable activities.
  • 2.3K
  • 16 Mar 2022
Topic Review
GTL in Wastewater Treatment
Gas-to-liquid (GTL) technology involves the conversion of natural gas into several liquid hydrocarbon products. The Fischer–Tropsch (F–T) process is the most widely applied approach for GTL, and it is the main source of wastewater in the GTL process. The wastewater is generally characterized by high chemical oxygen demand (COD) and total organic carbon (TOC) content due to the presence of alcohol, ketones and organic acids. The discharge of this highly contaminated wastewater without prior treatment can cause adverse effects on human life and aquatic systems. Here, we provide an overview of recent literature related to the application of biotechnology for the treatment of GTL process water.  It examines aerobic and anaerobic biological treatment methods that have been shown to reduce the concentration of COD and organic compounds in wastewater. Advanced biological treatment methods, such as cell immobilization and application of nanotechnology are also evaluated. The removal of alcohol and volatile fatty acids (VFA) from GTL wastewater can be achieved successfully under anaerobic conditions. However, the combination of anaerobic systems with aerobic biodegradation processes or chemical treatment processes can be a viable technology for the treatment of highly contaminated GTL wastewater with high COD concentration. The ultimate goal is to have treated wastewater that has good enough quality to be reused in the GTL process, which could lead to cost reduction and environmental benefits.
  • 2.3K
  • 28 Oct 2020
Topic Review
DPSIR Assessment on Ecosystem Services
The DPSIR framework (Driver – Pressure – State – Impact – Response) is a useful tool to assess and investigate the cause-effect within an ecosystem to aid better systems - thinking approach for stakeholders, policymakers and governance managers to draft response measures. The DPSIR framework helps to identify and analyse the different effects of human activities over the ecosystem services and human well-being in the different ecosystems such as estuarine, delta, river, coastal, etc. The varied human activities involves mining, construction, fishing, infrastructure development, etc. The DPSIR study shows a holistic view on several interlinked pressures and state changes in the ecosystems, also supporting the development of some potential responses to form systematic, sustainable approaches for mitigating and adapting the impacts caused by human activities. This contribution describes the application of DPSIR framework to study the impacts of sand mining and sand consumption in the Vietnam's Mekong Delta ecosystem services, 
  • 2.3K
  • 25 Nov 2020
Topic Review
Historical Climatology
Historical climatology is the study of historical changes in climate and their effect on civilization from the emergence of hominins to the present day. This differs from paleoclimatology which encompasses climate change over the entire history of Earth. These historical impacts of climate change can improve human life and cause societies to flourish, or can be instrumental in civilization's societal collapse. The study seeks to define periods in human history where temperature or precipitation varied from what is observed in the present day. The primary sources include written records such as sagas, chronicles, maps and local history literature as well as pictorial representations such as paintings, drawings and even rock art. The archaeological record is equally important in establishing evidence of settlement, water and land usage.
  • 2.2K
  • 13 Nov 2022
Topic Review
Climate Change (General Concept)
Climate change occurs when changes in Earth's climate system result in new weather patterns that remain in place for an extended period of time. This length of time can be as short as a few decades to as long as millions of years. Scientists have identified many episodes of climate change during Earth's geological history; more recently since the industrial revolution the climate has increasingly been affected by human activities driving global warming, and the terms are commonly used interchangeably in that context. The climate system receives nearly all of its energy from the sun. The climate system also gives off energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth's energy budget. When the incoming energy is greater than the outgoing energy, earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling. The energy moving through Earth's climate system finds expression in weather, varying on geographic scales and time. Long-term averages and variability of weather in a region constitute the region's climate. Climate change is a long-term, sustained trend of change in climate. Such changes can be the result of "internal variability", when natural processes inherent to the various parts of the climate system alter the distribution of energy. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Climate change can also result from external forcing, when events outside of the climate system's components nonetheless produce changes within the system. Examples include changes in solar output and volcanism. Climate change has various consequences for sea level changes, plant life, and mass extinctions; it also affects human societies.
  • 2.2K
  • 14 Apr 2023
Topic Review
Fossil Fuel Phase-Out
Fossil fuel phase-out is the gradual reduction of the use of fossil fuels to zero use. Current efforts in fossil fuel phase-out involve replacing fossil fuels with alternative energy sources in sectors such as transport, heating and industry.
  • 2.2K
  • 16 Nov 2022
Topic Review
Risk-Based Flood Management
“Flood management” refers to the general method involved in flood prevention and subsequent flood loss, whereas “risk-based flood management” is the combination of all of the actions that aim at the amelioration of the overall activities in a floodplain.
  • 2.2K
  • 21 Jan 2021
Topic Review
Methylmercury in Aquatic Environments
Methylmercury (MeHg) is the most important and the most abundant organic Hg pollutant in the aquatic ecosystem that can affect human health through biomagnification. It is the most toxic organic Hg form, which occurs naturally and by human-induced contamination in water and is further biomagnified in the aquatic food web. MeHg is the only Hg form that accumulates in living organisms and is able to cross the blood–brain barrier, presenting an enormous health risk. Anthropogenic activity increases eutrophication of coastal waters worldwide, which promotes algae blooms. Microalgae, as primary producers, are especially sensitive to MeHg exposure in water and are an important entrance point for MeHg into the aquatic food web. MeHg assimilated by microalgae is further transferred to fish, wildlife and, eventually, humans as final consumers. MeHg biomagnifies and bioaccumulates in living organisms and has serious negative health effects on humans, especially newborns and children.
  • 2.2K
  • 07 Feb 2023
Topic Review
Environmental Data Visualization Tools
The visualization of environmental data is important for the assessment of processes taking place in the environment. Visualization of collected data includes plotting charts or drawing maps with values of the variables collected by monitoring system or predicted by modelling software. There are many tools used by environmental scientists developed for the purpose of data visualization.
  • 2.2K
  • 15 Jul 2022
Topic Review
Bivalve Shells’ Waste Valorization
Bivalve shells are mainly formed by CaCO3, giving them the potential to become a promising secondary raw material for several applications, from a circular economy perspective. All the examples reported aimed to map the principal opportunities of mollusk shells waste recovery, in order to implement a circular blue-economy model and provide more sustainable and responsible production systems.
  • 2.2K
  • 31 May 2022
Topic Review
Heavy Metals in Medicinal Plants
It is possible for heavy metals (HMs) to be present in pharmaceutical herb materials coming from anthropogenic activities like agriculture, industrial waste, and natural sources. In various ethnic groups, there is evidence that contaminants were purposefully added in the belief that they had some sort of therapeutic benefit. HM toxicity of medicinal plant products has been linked to a wide range of adverse health effects, causing dysfunction of the liver, kidney, and heart, and even death.
  • 2.2K
  • 17 Feb 2023
Topic Review
Ectomycorrhizal Mushrooms
Environmental changes and heavy metal pollution are some of the consequences of anthropogenic activities. Many ecosystems, including edaphic ecosystems, suffer from the effects of pollution. The accurate assessment of soil heavy metal contamination leads to better approaches for remediating soils. The exploration of different ways, including biological methods, to conduct environmental monitoring is still ongoing.
  • 2.2K
  • 17 May 2022
Topic Review
Biomass and Waste Produced
In the late twentieth century, the only cost-effective opportunity for waste removal cost at least several thousand dollars, but nowadays, a lot of improvement has occurred. The biomass and waste generation problems attracted concerned authorities to identify and provide environmentally friendly sustainable solutions that possess environmental and economic benefits. The present study emphasises the valorisation of biomass and waste produced by domestic and industrial sectors.
  • 2.2K
  • 05 Nov 2021
Topic Review
Bio-energy with Carbon Capture and Storage
Bio-energy with carbon capture and storage (BECCS) is a potential greenhouse gas mitigation technology which produces negative carbon dioxide emissions by combining bioenergy (energy from biomass) use with geologic carbon capture and storage. The concept of BECCS is drawn from the integration of trees and crops, which extract carbon dioxide (CO2) from the atmosphere as they grow, the use of this biomass in processing industries or power plants, and the application of carbon capture and storage via CO2 injection into geological formations. There are other non-BECCS forms of carbon dioxide removal and storage that include technologies such as biochar, carbon dioxide air capture and biomass burial and enhanced weathering. According to a recent Biorecro report, there is 550 000 tonnes CO2/year in total BECCS capacity currently operating, divided between three different facilities (as of January 2012). In the IPCC Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), BECCS was indicated as a key technology for reaching low carbon dioxide atmospheric concentration targets. The negative emissions that can be produced by BECCS has been estimated by the Royal Society to be equivalent to a 50 to 150 ppm decrease in global atmospheric carbon dioxide concentrations and according to the International Energy Agency, the BLUE map climate change mitigation scenario calls for more than 2 gigatonnes of negative CO2 emissions per year with BECCS in 2050. According to Stanford University, 10 gigatonnes is achievable by this date. The Imperial College London, the UK Met Office Hadley Centre for Climate Prediction and Research, the Tyndall Centre for Climate Change Research, the Walker Institute for Climate System Research, and the Grantham Institute for Climate Change issued a joint report on carbon dioxide removal technologies as part of the AVOID: Avoiding dangerous climate change research program, stating that "Overall, of the technologies studied in this report, BECCS has the greatest maturity and there are no major practical barriers to its introduction into today’s energy system. The presence of a primary product will support early deployment." According to the OECD, "Achieving lower concentration targets (450 ppm) depends significantly on the use of BECCS".
  • 2.2K
  • 25 Oct 2022
Topic Review
The Fungi That Degrade Plastic
Plastic has become established over the world as an essential basic need for our daily life. Plastics have many characteristics such as low production costs, inertness, relatively low weight, and durability. The primary disadvantage of plastics is their extremely slow natural degradation. The latter results in an accumulation of plastic waste in nature. Many fungi can be used to degrade plastics.
  • 2.2K
  • 03 Aug 2022
Topic Review
Vermicomposting
Vermicomposting is a process that has been intensively studied for years and has become significant and frequent topic. Numerous papers are describing its mechanism and performance, but each highlights different aspects. Although numerous studies have been conducted on the topic of vermicomposting and each of them has contributed to understanding the role of vermicompost, there are still unknowns that need to be additionally explored to maximize the potential of vermicompost and to recoup the process itself according to specific needs.
  • 2.2K
  • 27 Jan 2022
Topic Review
Biogas Plants
The biogas production technology has improved over the last years for the aim of reducing the costs of the process, increasing the biogas yields, and minimizing the greenhouse gas emmisions. To obtain a stable and efficient biogas production, there are several design considerations and operational parameters to be taken into account. Besides, adapting the process to unanticipated conditions can be achieved  by adaquate monitoring of various operational parameters. This paper reviewa the research that has been conducted over the last years. This review paper summarizes the developments in biogas design and operation, while highlighting the main factors that affect the efficiency of the anaerobic digestion process. The study´s outcomes revealed that the optimum operational values of the main parameters may vary from one biogas plant to another. Additionally, the negative conditions that should be avoided while operating a biogas plant were identified.
  • 2.2K
  • 05 Feb 2024
Topic Review
Moisture Pretreatment for a CEMS
A continuous emission monitoring system (CEMS) is a well-known tool used to analyze the concentrations of air pollutants from stationary sources. In a CEMS, the presence of a high moisture level in a sample causes a loss of analytes due to artifact formation or absorption. This issue brings about a bias in the measurement data. Thus, moisture removal is an important pretreatment step.  
  • 2.2K
  • 25 Jan 2021
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