Coral reefs are one of the most biodiverse ecosystems on Earth. They are multi-functional natural habitats allowing marine species to forge, escape from predators, and reproduce. These vibrant underwater ecosystems are under threat from multiple environmental stressors, including noise pollution. Fortunately, a recent study has shown the possibility to restore coral reefs by playing a certain combination of sound in the proximity of a reef. In this piece, we take a look at what underwater soundscapes are and how they can help restore these precious ecosystems.    

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Anthropogenic Noise Pollution in Marine Environments 

Soundscapes refer to a sound or a combination of sounds that forms an acoustic environment, an auditory landscape. Underwater soundscapes are often overlooked as human ears are not adapted to underwater environments. Yet, marine animals are highly dependent on sound cues for navigation, communication, foraging, and predator avoidance, which are essential for survival.  

Unfortunately, not all underwater sounds have a positive impact on marine animals. This is often the case for human-made noise pollution, which comes from various sources, including maritime transportation, offshore construction and operation, fishing, and even military sonar detection. These underwater noises damage marine communities in multiple ways, including physical damage, behavioral alteration, and physiological change.  

More on the topic: The Impact of Noise Pollution on Marine Animals

The Soundscape in Coral Reefs

Healthy coral reefs are naturally noisy where multiple animals like snapping shrimp, soniferous fishes, and also breaking waves creating this underwater soundscape. A 2010 study recognized that larval corals are phonotaxis, meaning they move in response to a sound. Larval coralars are attracted to the natural reef sounds generated by other resident marine organisms, such as fish and crustaceans. Although this mechanism is not fully understood, scientists suggest that the exterior cilia on coral larvae enable them to sense and respond to underwater sound by swimming towards it.  

Acoustic Enrichment: A Novel Approach to Coral Reef Restoration 

Coral recruitment is a vital survival strategy to drive population recovery, which takes place in four phases: mass spawning of eggs and sperms, dispersion of coral larvae, settlement and metamorphosis from plankton to reef, and early post-settlement growth. While coral settlement is a critical early stage within the recruitment process, acoustic enrichment has been shown to facilitate the coral settling process. 

A 2024 study conducted by the Woods Hole Oceanographic Institution – the largest independent oceanographic research institution in the US – demonstrated the potential of coral reef restoration via acoustic enrichment. Scientists installed underwater speakers to shape a soundscape mimicking a healthy reef to encourage coral larval settlement. Settlement rates can be up to seven times higher under acoustic enrichment, potentially enhancing the chance of coral larvae survival.  

Another 2019 study conducted at a degraded coral reef, also known as coral rubble, in Australia’s Great Barrier Reef has also shown noticeable improvement in the fish community by playbacking healthy reef-sound. With a 40-day acoustic treatment period, visual survey conducted on the juvenile fish community found a 50% increase in juvenile damselfish community (the most common reef fish species in the Great Barrier Reef) and an overall increase of five other trophic guilds within the food web, demonstrating an effective enrichment result in fish communities.  

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The ocean’s soundscape can be highly complex, given the multitude of natural and anthropogenic sound sources. While further research will be needed to explore the applicability to other reef habitats and the possibility to scale up as conservation measures, acoustic enrichment has proved promising in recovering and restoring degraded reef habitat.

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Leather has always played a huge role in the fashion industry. Yet, its production process has been subject to environmental and social critiques associated with animal welfare and contamination of water bodies, in spite of how the process has been evolving throughout the years. We explore the new front of lab-grown leather to answer the question of whether this product can actually reduce the detrimental environmental impact of leather production.

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During Industrialisation, the shift from using natural tannins to chrome salt has shortened the time for tanning – the process of treating skins and hides of animals to produce leather – from months to days. Start-up companies have now developed new technologies to grow leather in laboratories. Lab-grown leather appears to be a solution to the aforementioned environmental and social concerns. But how is it manufactured and how is this bio-fabricated material any different from conventionally manufactured leather? 

How Is Traditional Leather Produced?

Turning raw animal hides into leather is not an easy task. It starts by slaughtering animals – mostly cows – to obtain fresh raw hides which are then salted for dehydration to prevent decaying during transportation from the slaughterhouse. The salted hides then go through a series of chemical and enzyme “baths”, fleshing, trimming, and shaving – a process also known as tanning. Upon the completion of tanning, the finished leather can then be further processed into a wide range of products such as footwear, upholstery for sofas, and clothing just to name a few.

Tanning is a chemical and extremely water-intensive process. A study assessing the life cycle of bovine leather production of two product systems in Spain and Italy quantified the environmental impact driven by the whole leather production process. Despite the differences in the assessment of the two different product systems, their total environmental burdens appeared quite similar. The research found that tanning contributes between 70% to 90% to pollution by ways of energy consumption, abiotic resource depletion potential, photochemical oxidant creation potential (POCP), and fresh aquatic ecotoxicity potential.

Effluent from tannery factories contains a complex mixture of harmful organic and inorganic chemicals such as chromium salt, acids and bases, fat liquor as well as organic tannins. Improperly managed effluent may cause a significant environmental impact on surrounding human populations and living organisms.

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How Is Lab-Grown Leather Produced?

Leather is well-known for its comfort and durable properties. Although there are many alternative materials for leather, this still holds a unique position in the market, particularly in luxury products. Unlike artificial or synthetic leather, this bio-fabricated leather retains the texture and even the smell of real leather from a cow.

The sources of raw materials and technologies to synthesise leather are highly diverse. For example, one company is working on cultivating animal stem cells in the lab to produce actual animal hides. The process begins with collecting skin cells from a living animal and transporting them to the specialised bioreactor. Here, the cells are replicated to produce leather. The entire process takes about two weeks to complete, significantly less than the time required to manufacture conventional leather, which can take years if we take into account the time needed for animals to grow.

A London-based company has also developed innovative systems to produce animal-free leather. They utilise microorganisms, terrestrial and marine bacteria, or fungus strains to produce bio-fabricated materials that mimic the leather textures. These microorganisms are fed with a variety of materials such as plant-based protein, agricultural and forestry by-products, sawdust, protein from fish waste, or even air and greenhouse gas. Given that the component of bio-fabricated materials is less complex than actual rawhide (a combination of fats and hair, etc.), this helps simplify the tanning process to reduce material use and the environmental impact from chemical extraction. 

Another company also demonstrated its consideration of the product life cycle by conducting a cradle-to-gate Lyfe-cycle Assessment (LCA) on its bio-fabricated leather. The manufacturing process shows significant improvement in greenhouse gas emission, land use changes, blue water consumption, and eutrophication compared to the conventional chrome-tanned leather process. 

These bio-fabricated materials received increased attention from different industries including footwear, automotive, and  luxury brands. Some of them partner with brands to commercialise the material for manufacturing new products, from mycelium-made sneakers and yoga mats to mushroom and cactus car seats, and some are even funded to build pilot or commercial production plants. 

Is Lab-Grown Leather the Solution?

Lab-grown leather helps streamline the tanning process and reduce material consumption during leather manufacturing. It may perhaps be an alternative to traditional leather in the consumer goods industry, especially to the growing market of vegan or animal-free products. These newly invented materials, however, should take the product’s life cycle into design consideration and be aware of the environmental impact aroused by their manufacturing process, product use, as well as end-of-life stage. 

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Antimicrobial resistance (AMR) has become a major threat to human health across the globe. The World Health Organization (WHO) recognises AMR as one of the top threats to global health. A study estimated that about 4.95 million deaths can be linked to bacterial antibiotic resistance each year but experts fear the number will rise to 10 million by 2050. AMR does not only have a significant impact on the national healthcare system but it also reduces agricultural output and negatively affects economic stability. We take a look at what exactly AMR is, how it developed, and how the world is fighting it.

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What Is Antimicrobial Resistance?

Antimicrobials (or antimicrobial agents) refer to substances that are adopted to prevent and cure infection not only in humans but also aquaculture, livestock, and crop production. These substances can be grouped by the type of pathogen they fight, including antibiotics for bacteria, antivirals for viruses, antifungals for fungi, and antiparasitic for parasites.  

AMR development is, in fact, a natural process, yet bacteria or other microbes submerged in multiple antimicrobial environments can quickly adapt and spread resistant genes. Microbes with resistant genes can restrict access, and actively remove, or destroy, antimicrobials as part of their defense mechanism to survive. 

The AMR developing process can be accelerated due to misuse or overuse of antimicrobials by both humans and animals. Common examples are the initial prescription of broad-spectrum drugs to patients even in cases where they are non-essential or unnecessary. Antibiotics are also applied as feed additives in agriculture and aquaculture to help keep livestock healthy and maintain productivity. This is especially the case in developing countries, were awareness of AMR is limited.  

Do We Need to Be Concerned About AMR?  

Developing AMR has a multi-dimensional impact on human society. For starters, without effective antimicrobials to prevent or treat drug-resistant infections, patients who undertake surgery such as organ transplantation, cancer chemotherapy, or even with chronic disease will be increasingly at risk due to weakened immune response. 

Patients infected by drug-resistant bacteria may also lengthen hospitalisation and cost of treatment due to ineffective therapy by first-line drugs, which are regarded as the best treatment and are generally cheaper and more effective than second- or third-line drugs. Thus, patients with AMR therapy usually face higher healthcare costs due to prolonged hospital stays and increased demand for second- and third-line drugs. 

Scientists are also worried that climate change may exacerbate the situation of AMR, given that the phenomenon is associated with an increased spread of diseases. Indeed, warmer temperatures lead arthropod vectors such as ticks and mosquitoes or reservoir animals such as rodents and birds to migrate to higher latitudes, which often carry vector-borne infectious diseases to northern regions. A study published in the scientific journal Nature estimated that a temperature increase of 10C across US regions was associated with an increase of 2.7% to 4.2% AMR for common drug-resistant bacteria including E. coli (Escherichia Coli), golden staph (staphylococcus aureus), and Klebsiella (Klebsiella pneumoniae). 

Climate change also alters water availability and humidity in nature due to changing precipitation and evaporation patterns. Heavy rainfall and flooding may result in pathogen-containing sediment resuspending or mobilising in soil. This leads to surface or groundwater contamination, especially in regions with limited drinking water treatment facilities. Drought and wind also bring particles on cracked soil that contain disease-associated bacteria to the surface, such as Bacillus anthracis, which also relies on antimicrobials as a standard treatment.   

What Is the World Doing to Address the Problem?  

The World Health Organization (WHO) has often emphasised the importance of adopting a One Health Approach, as joint efforts across multiple sectors are required to develop integrated solutions to tackle human, animal, and ecosystem health problems including AMR.  

As part of the overarching approach, WHO launched a Global Antimicrobial Resistance and Use Surveillance System (GLASS) to standardise AMR surveillance, build capacity, and monitor national performance on antibiotic usage.  

An antibiotic classification system known as the AWaRe Classification to strengthen stewardship of antibiotics was also built in 2017 and subsequently updated in 2021. The system helps to keep track of antibiotic consumption and can be used by the government to define targets and monitor policy effectiveness. Antibiotics are categorised by their level of importance to human society, including their resistance potential and the capability to treat multidrug-resistant pathogens. AWaRe stands for Access, Watch, and Reserve, where Reserve refers to a type of drug extremely effective in treating multidrug-resistant organisms and that should therefore only be used as the last-resort antibiotic for treatment.

Regional efforts from the European Union (EU) have also been made. The 27-nation bloc recently adopted a new proposal to step up action to combat AMR. New 2030 targets include reducing 20% of total antibiotics consumption in humans, reaching a 65% effectiveness rate over the total antibiotics consumption, and reducing infections of three key antibiotic-resistant bacteria at hospitals by strengthening antimicrobial stewardship, infection prevention control, and surveillance.

In contrast, Asia – which is home to about 60% of the world’s population – has shown limited effort to combat AMR, with few exceptions. As one of the countries with the largest population, China issued a 2016-2020 National Action Plan to manage antimicrobial usage among hospital inpatients and successfully reduce the average rate from 59.4% in 2011 to 36% in 2019. The Second National Plan 2022-2025 was also issued by the Chinese government last year for continuous efforts to fight against AMR. 

In 2022, the Hong Kong government published a new strategic action plan for the upcoming five years to strengthen AMR control measures. Given that almost half of the antimicrobials prescribed in 2021 were prescribed by private doctors, the authority will now review and consider mandating proper record-keeping of antimicrobial prescription and dispensing data across the supply chain.  

To engage with the public, some countries and private companies offer drug take-back systems that help diverge unused or expired medicine from entering household waste streams or flushed with sewage that contaminates the surrounding environment. Examples include the National Prescription Drug Take Back Day in the US, the Return Unwanted Medicines Projects (RUM) in Australia, and China’s public welfare campaign on recycling expired medicines.

Conclusion 

Antimicrobial resistance is another example of the interconnection between human society and nature. Analysing its impacts is also helpful in highlighting and understanding why there is an urgent need for cross-sectoral communication, collaboration, and coordination in sustaining human, environmental, and animal health. 

While the development of antimicrobial resistance in microorganisms is a naturally occurring process, the misuse and overuse of antimicrobials enable drug-resistant pathogens to evolve even faster than drug discovery, posing a significant threat to human health. Careful use of antimicrobials and take-back systems are essential to slow down the development of antimicrobial resistance.  

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A recent UN report suggested that the world is on track to warm more than 2C, well above what countries had agreed on with the Paris Agreement. Extreme weather events like heatwaves and rainstorms are on the rise, bringing destruction across the world, with no country spared. Among other necessary and urgent steps, curbing methane emissions has received attention as a quick win to slow down global heating. We take a look at the major sources of methane in the atmosphere and the available cost-effective measures to cut emissions worldwide. 

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Why Should We Care About Methane Emissions?  

According to the latest Emission Gap Report by the United Nations Environment Programme (UNEP), inadequate climate actions in recent decades may lead to a 2.8C global temperature rise by the end of the current century. This modelled temperature rise is considerably higher than the 1.5C target the world committed to when signing the Paris Agreement. Atmospheric methane is a potent greenhouse gas with 84-86 times higher in global warming potential than carbon dioxide across a 20-year period. 

What Are the Major Sources of Methane in the Atmosphere? 

Understanding which processes contribute the most is the first step before intervening or deploying measures to control rising emissions. The Global Methane Assessment (GMA) conducted by the joint effort of the United Nations Environment Programme and Climate and Clean Air Coalition revealed that anthropogenic methane accounts for 60% of the total methane emission, with 90% coming from three main sources: agriculture (40%), fossil fuel (35%), and waste (20%).   

Agriculture is by far the biggest source of anthropogenic methane, with about 32% of total emissions originating from enteric fermentation and manure management, while the remaining 8% is attributed to rice cultivation. Cattle are an enormous contributor that accounts for more than 70% of the total livestock emissions among other kinds of animals including buffalo, sheep, goats, pigs, and chickens. Animal husbandry is also a source of methane emissions from feed production and manure deposition.

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Methane discharged from the fossil fuel industry is attributed to oil and gas extraction, pumping, and transport of fuels, altogether contributing to about 23% of total anthropogenic emissions. Coal mining – including active and abandoned mines – released another 12% as part of the total fossil fuel-derived emissions. Within oil and gas extraction, gas venting and fugitive emissions are the main cause of methane emissions. Gas venting is a practice that pumps out unwanted gas – a fossil fuel predominantly composed of methane – to maintain safe conditions in the oil and gas extraction process. While gas venting is a deliberate methane release, fugitive emissions are unintentional releases of gas across the fossil fuel supply system. The majority of the methane escape comes from downstream processes, which include refining, transmission, and distribution of gaseous products.      

As the third most methane emitter, the waste sector generally releases methane from landfill and sewage treatment. Landfilling organic waste is known to generate landfill gas, which mainly contains methane gas from anaerobic bacteria. Landfills intrinsically create an anoxic environment for the methane-generating bacteria to thrive. This bacteria consume organic matter from waste and produces methane as a by-product. Sewage treatment facilities, on the other hand, introduce anaerobic processes to reduce sludge volume or sludge thickening. 

The geographical distribution of the emissions varies across different sectors, where the fossil fuel and agricultural industries are prominent in particular regions. In the fossil fuel industry, China is the largest contributor to coal mining-related emissions, while Russia and North America are the biggest part of the oil and gas methane emissions. Within the agriculture sector, livestock emissions mainly originated from Latin America, followed by South Asia. While most of the emission from rice cultivation comes from Southeast Asia, Korea, and Japan, followed by South Asia and China. Methane from the waste sector is performed differently where the emissions are more geographically distributed across the continents. 

Apart from human-related emissions, methane also comes naturally and mainly from freshwater and wetland. Similar to the emission from waste, bacteria generally produce methane in an oxygen deficit environment. 

Beyond existing atmospheric methane, a potential source of methane from the Permafrost has received widespread attention given its enormous quantity being stored. Permafrost holds 1,400 billion tons of carbon which is almost double of methane currently in the atmosphere. Rein in emissions is therefore a critical move to prevent permafrost thaw from causing an outbreak of methane gas.  

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What Can Be Done to Reduce Methane Emissions in the Atmosphere?  

More than 100 nations signed the Global Methane Pledge (GMA) at COP26 in Glasgow last year, committing to cut down global methane emissions by at least 30% in 2030 from 2020 levels.

While the world’s biggest emitters, including China and India, have not signed the pledge, the Chinese envoy Xie Zhenhua agreed to deliver additional measures to cut down methane from oil and gas, agriculture, and waste with a drafted action plan presented at the 27th United Nations Climate Change Conference (COP27), which took place last month in Egypt. 

 The GMA summarised cost-effective measures to limit methane emissions with respect to methane-intensive sectors. Action to be in the agriculture sector include feeding changes and supplements to reduce enteric fermentation in livestock as well as improving manure management by installing biogas digester and reducing manure storage time. 

The fossil fuel sector, on the other hand, requires better control of leak events by inspection, detection, and repair, capture and reuse of vented gas, and treatment of abandoned mines. 

Regarding waste management, necessary steps include separating reusable and recycling materials from the rest, recovering energy from landfill gas, and zero landfill of organic waste. Similar to manure management in farms, sewage treatment plants should also be equipped with biogas facilities to recover and utilise it as a type of energy supply. 

Engaging in the aforementioned actions would not only reduce methane outputs but also increase productivity, save costs from improved resource management, and promote better environmental quality.  

The United Nations has also launched a methane detection and notification platform, known as Methane Alert and Response System (MARS). MARS integrates data from methane-detecting satellites to identify methane plumes and emission hotspots, informing governments and companies to take appropriate action, as well as monitoring mitigation progress.  

Conclusion 

Limiting methane emissions is no magic bullet to halt global warming. Nonetheless, it would definitely buy us some time to decarbonise every other sector before the climate crisis becomes irreversible. The latest UN Emission Gap Report has warned us that there is a closing window of opportunity given to recent off-tracking global political actions. Climate action does not require rocket science and technologies have been available and affordable to reverse the devasting consequence of climate change.  

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Although light pollution may not be as acute as other pollution like chemical or oil spillage that results in environmental destruction, light pollution is recognized as one of the most chronic environmental perturbations. With the emergence of light-emitting diodes (LEDs) in the market, the energy cost of lighting has been drastically reduced compared to traditional incandescent light bulbs or even compacted fluorescent lamps. A growing number of studies reveal the alarming negative impact of light pollution on wildlife and human beings. Yet, the issue of light pollution is often overlooked. So, what is light pollution? How does light pollution alter behavior of wildlife and humans, and are there any current practices or solutions that help tackle light pollution?

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What Is Light Pollution?

As defined by the International Dark-Sky Association, light pollution refers to any inappropriate or excessive use of artificial light, which affects humans, wildlife, and the climate. Light pollution can be in the form of glare, skyglow, light trespass, or clutter. The phenomenon of light pollution is a worldwide issue, where 80% of the world’s population currently lives in light polluted areas. A study found that satellite observable light emissions have increased by 49% in 2017 over the last 25 years, indicating a worsening trend of light pollution.

Effect of Light Pollution

Studies reveal the devastating ecological impact of animals dwelling in the natural environment. Artificial light is found to harm survivorship of newborn sea turtles hatching on the beach and disorient them from returning to the sea. Sea turtle hatchlings are known to have developed an instinct to follow light cues to orient themselves when they return to sea. It is observed that beach light is highly attractive to hatchlings, causing them to move away from the sea. 

Another experimental study also discovered that hatchlings can be mis-oriented by artificial lights even in a water environment. Hatchlings suffering from light impacts spend a longer time in near or onshore environments, where nearby predators such as crabs on the beach, reef fishes and sharks in nearshore environments can have higher chances of preying on newborns .A separate study recognised a devastating impact of light pollution on clownfish, where no eggs hatched in the presence of artificial light at night (ALAN) resulting in reproductive failure.

Insects are also one of the most light-sensitive animals as evidence showed that ALAN affects a wide range of behaviour of insects including development, movement, foraging and reproductive success. Study compared the impact of streetlight with an artificially lit and unlit environment. Populations of the studied moth and caterpillar in two botanic environments were reduced by 33 % to 47%. It is also found that white light LEDs may have greater adverse impact than traditional sodium lamps, which may be potentially due to the wider light spectrum in LEDs. Artificial light in the natural environment may even interfere with ecological interactions among animals such as bats and insects. Most bats species exhibit light avoidance behaviour and some insect species are attracted to the light, which therefore changes bat’s foraging behaviour and predation risk of the prey.

Apart from wild animals, humans are found to be also vulnerable to light pollution. Light suppresses the secretion of melatonin, which is an essential hormone determining human’s circadian rhythms, also known as the biological clock. Nocturnal light exposure interferes with vital physiological processes including hormone secretion, cellular function as well as gene expression, which corresponds to greater risk of developing certain types of cancers and disease such as metabolic and mood disorders. On top of that, a study discovered that exposure to outdoor night-time light is associated with an increased risk of coronary heart disease. Given that city dwellers living in highly urbanised areas are more likely to be exposed to high levels of PM2.5 and nighttime traffic noise impact, added health risk is also observed in a combination of these three environmental hazards. 

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What Steps Could be Taken to Prevent Light Pollution?

Illumination at night serves a wide range purposes for living and even safety purposes, especially for night traffic, therefore it is practicable to remove all lights at nighttime. 

A guideline published by the Institutional of Lighting Professionals (ILP) helps lighting designers to reduce the amount of obtrusive light to the neighbourhood environment, which is embedded in green building certifications such as BREEAM in the UK and BEAM Plus in Hong Kong. The guideline defines the obtrusive light standards based on the Environmental Zones, where the zoning depends on the level of urbanisation of the site surroundings. More stringent requirements are imposed on regions originally with less brightness as well as in the Curfew period, where a further limitation is applied for late night (i.e. 11pm). Several parameters are also considered including upward light ratio for determining skyglow, light intrusion into windows, luminaire intensity estimating the light that lit outside the site, as well as building luminance providing a general picture of the district brightness. 

Green building design also promotes daylight access in an indoor built environment, which reduces the amount of lighting and is beneficial to both human health and economy. A study demonstrated that daylight helps cognitive performance and satisfaction which in turn enhance worker’s productivity and helps reduce lighting energy consumption.

Artificial light is undoubtedly one of the greatest inventions in human history. It plays an irreplaceable role for humanity’s economy, living and even aesthetic purposes. Given the increasing number of evidences demonstrating the adverse impact of light pollution, it is time for policymakers to implement measures for regulating artificial light for further deteriorating human health and the natural environment. 

The post Explainer: What Is Light Pollution? appeared first on Earth.Org.

Agricultural activities are known to be one of the major sources of greenhouse gas emissions (GHGs), which contributes to 16%-27% of the total anthropogenic-related emissions. Yet, the climate warming impact from agriculture does not solely lie on the production of carbon dioxide (C02), but also on nitrous oxide (N2O) due to the overuse of nitrogen fertiliser. How is nitrous oxide produced? Why should we be concerned about this laughing gas? And what measures can be taken to reduce its emission?

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Where Does Nitrous Oxide Come From?  

There are multiple sources of nitrous oxide both anthropogenically and naturally occurring – ranging from ocean, atmosphere, and soils. Agricultural activities including animal husbandry is considered the largest source of N2O, which accounts for more than one-third of the total N2O emission. 

One of the reasons why agriculture contributes to the significant amount of N2O is due to the over application of fertilisers.  With the development of the Haber-Bosch process allowing fast production of chemically synthesised fertilisers, commercial farmers can apply synthetic fertilisers in soil to boost crop yield. Another major source of N2O is the feed production and manure deposition from managed pastures, which accounts for 45% and 39% respectively of total greenhouse gas emissions by livestocks. Nitrogen that is not taken up by plants or remains in the manure is then consumed by the soil microbes, where nitrous oxide is produced through microbial processes.

There are two processes contributing to the production of N2O; namely nitrification and denitrification. Nitrification involves the transformation of ammonia into nitrate that can then be directly consumed by plants, while denitrification helps in the balance of nitrogen present in the soil by converting excess nitrate back into atmospheric nitrogen. N2O is produced as a by-product during these nitrogen conversions. Soil eutrophication due to excess use of nitrogen in soil offers a favourable condition for these microbes to proliferate, resulting in N2O emitted from soil.

Why Should We Be Concerned With N2O? 

The quantity of N2O is comparatively less than carbon dioxide; however, this gas is long-living, which on average, stays in the atmosphere for 114 years whilst containing much higher (i.e. 298 times more) global warming potential than carbon dioxide.

N2O also leads to other environmental problems such as ozone depletion. It has been recognised as a dominant anthropogenic ozone-depleting substance (ODPs) and it is anticipated to be the biggest anthropogenic emission source of ozone depleting compounds in the foreseeable future. 

Aside from the environmental issues from N2O itself, the release of nitrogen also raises other environmental problems such as leaching of nitrogen-containing nutrients into the water bodies causing eutrophication that damages the local environment. Production of synthetic fertilisers by the Haber-Bosch process is also energy demanding; contributing up to 1% of global energy consumption and 1.4 % of CO2 emissions, it further intensifies the impact on global warming.

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Solutions to Mitigate N2O Emissions

Scientists have proposed multiple approaches in tackling the issue of  N2O production. Given that the major issue of N2O emission from agricultural land is due to the excess nitrogen retained in the soil body, one of the solutions is to avoid the overuse of fertilisers by adopting remote sensing technology to suitably apply fertiliser to the crops only as and when (and where) needed. Other source control measures include applying nitrification inhibitors to suppress microbial activity for generating N2O,  allowing a longer retention time in soil for plants to uptake the nitrogen. 

New technologies are also developing to reduce reliance on synthetic fertilisers, which in turn could reduce the production of N2O. One such example is genetically modifying microbes to supply nitrogen to the plants, per the model of symbiotic relationships as nitrogen fixing bacteria have with legumes, where the bacteria provide nitrogen to the plants to grow, while the plants in turn offer shelter for survival of the bacteria. 

Another solution to reduce emissions is to promote better management practices by avoiding or reducing tillage to the soil. A meta-analysis study with over 200 papers was conducted to compare the soil N2O emission by conventional tillage (CT), and no-tillage and reduced tillage (NT/RT) practices. It concluded that a long period (i.e. 10 years) of implementing NT/RT practices can help reduce N2O emissions. Given that denitrification is an anoxic process, which is carried out in the absence of oxygen, it is suggested that microbes produce less N2O in undisturbed farmland with loose soil due to the presence of a higher oxygen content.

We are all now facing the increased frequency of extreme weather such as wildfires in Greece, flooding in both Australia and China, and a severe storm surge by Hurricane Ida in the United States. Cutting off greenhouse gas emissions is necessary to avoid further worsening of our climate. N2O is a significant source of greenhouse gas emissions and is at its highest level since human existence. Unfortunately, atmospheric N2O is still rising continuously due to the growing number of agricultural activities to meet our food demand. Implementing more sustainable agricultural practices may help lower the GHGs emissions, and hopefully alleviate the impacts that have already and still being done to the Earth.

Featured image by: Pxfuel

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The United Nations has plans to launch a USD$1 trillion, 10-year ecosystem restoration programme across the world. Several barriers and respective solutions have been suggested to initiate and expand the global effort on natural habitat restoration. What are the anticipated obstacles that may hinder the restoration efforts and actions to overcome these challenges? How does it link to the Sustainable Development Goals (SDGs)? 

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This 10-year environmental programme, known as the United Nations Decade on Ecological Restoration 2021-2030, aims to restore damaged ecosystems following the COVID-19 pandemic. The UN Decade programme also supports the implementation of 17 Sustainable Development Goals (SDGs), and other conventions and targets related to climate change, desertification, biodiversity as well as other landscape restoration projects. The programme has categorised nine vital earth’s ecosystems for restoration, they are: farmlands, forests, freshwaters, grasslands, shrub lands and savannahs, mountains, oceans and coasts, peatlands and urban areas. 

The UN Decade proposal was supported by over 70 countries, which has committed to restoring over 1 billion hectares of ecosystems, approximately to the geographic area of China. The UN Decade programme also supports other concurrent restoration projects such as Bonn’s challenge, which aims to recover degraded habitat of 350 million hectares by 2030. It is estimated that a USD$1 trillion investment over the 10-year programme may be needed to implement such a large-scale restoration project. 

Obstacles to Ecosystem Restoration and Ways to Tackle Them

Six barriers ranging from social, economic, and ecological aspects have been identified for the restoration programme, namely public awareness, political will, legislative and policy environments, technical capacity, finance, and scientific research. Three pathways are suggested to overcome these barriers.

1. Building a Global Movement 

The best course of action in ensuring the decade programme is achievable is promoting a global movement. This would require setting up a digital hub for information exchange, utilising a variety of media channels, and building a task force for developing standard guidelines for ecosystem restoration. There’s also a need to prioritise ecosystem restoration opportunities both at a local and global level, incorporating ecosystem restoration into mainstream education, as well as encouraging investments. 

2. Enhancing Political Support 

Given that political support plays an important role in the restoration programme, especially when it comes to financing, actions that need to be taken include reforming policy to support the restoration programme, promoting interactions between governments, non-governmental organisations, or other sectors to develop innovative ideas on facilitating the restoration, as well as identifying national ecosystem restoration opportunities by the head of states, planning, development and financial officials and business sectors. 

3. Expanding Technical Capacity and Scientific Knowledge

Technical capacity and scientific knowledge are the backbone of ecosystem restoration. It is critical to develop and research methods for designing, implementing, monitoring, and sustaining restoration initiatives such as producing technical content and conducting scientific research that could aid the recovery of ecosystems. 

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How Does It Relate to the 17 SDGs? 

The UN decade programme will likely support all 17 sustainable development goals under the 2030 Agenda for Sustainable Development. Restoring global ecosystems can not only help improve the quality of natural habitats and enhance adaptivity to climate change, for instance, how wetlands act as a natural barrier against typhoon damages, but also creates green employment opportunities. It may also improve health and living conditions for both rural and urban areas by supplying clean water and sustainable food. The restoration programme fosters global collaborations, innovations of climate-resilient technologies and infrastructures, as well as better managing natural resources and ecosystem services.

A large-scale ecosystem restoration such as this is undoubtedly a herculean task from a political, financial, societal perspective. Multiple barriers ranging from social, economic, and ecological have been identified. Different courses of action will need to be taken to implement a restoration programme at a global scale but it has significant potential in promoting a healthy and green recovery especially the support of over 70 countries in the wake of the COVID-19 pandemic.  

Featured image by: Volker Sander

The post An Ambitious 10-Year Global Ecosystem Restoration Programme is in the Works appeared first on Earth.Org.

Preliminary studies have identified a positive correlation between COVID-19-related mortalities and air pollution. There is also a plausible association of airborne particles assisting the viral spread. How does air pollution as an environmental health hazard contribute to the spread of COVID-19 in societies ? And how does it play a role in further affecting human health in this pandemic?

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It has been widely established that air pollution compromises the respiratory system. According to the WHO, ambient air pollution causes 4.2 million premature deaths annually. Amidst the COVID-19 pandemic, scientists have discovered that excess pressure may be exerted on the patient’s respiratory system due to air pollution.  

How Air Pollution as an Environmental Health Hazard Could Contribute to the Spread of COVID-19

A previous ecological study conducted during the SARS pandemic of 2003 that affected parts of China, Hong Kong and Canada discovered a positive correlation between SARS-related deaths and ambient air pollution in both short-term and long-term exposure. Given the close relationship and similarities in the symptoms of COVID-19 and SARS, it is anticipated that a similar observation may be found in the COVID-19 pandemic. This provides an indication of how air pollution may affect a person infected with COVID-19. 

A pre-print (i.e. studies awaiting peer-review) ecological study from Harvard University investigates whether long-term average exposure to fine particulate matter (PM2.5) is associated with an increased risk of COVID-19 death in the US. The study found that even a small increase of 1 μg/m3 in PM2.5 levels was associated with an 8% increase in COVID-19-related fatality.

Some scholars however, argue that an ecological study cannot be regarded as epidemiology due to ecological bias (i.e. lack of individual-level data), therefore it is unable to establish a cause-and-effect relationship. There are also multiple factors involved that may affect the results, for example, the temporal difference of the virus outbreak among the individual county, and the intervention time of the county to adopt physical distancing policies. Consequently, the study may overestimate the risk of COVID-19-related deaths owing to air pollution.     

This positive correlation between increased death rates due to COVID-19 and air pollution has also been observed in Italy. Northern Italy is one of the most polluted areas in Europe, where a higher level of mortality related to the COVID-19 virus was discovered. A study concluded that the high air pollution loading could be a co-factor causing the high fatality rate due to the COVID-19 infection.  

Prior exposure to air pollution may aggravate the health impacts of COVID-19 and increase the risk of death by suppressing immunity. A systematic review has identified that people with prior chronic diseases like hypertension, diabetes, respiratory system disease and cardiovascular disease could be more vulnerable to COVID-19 by triggering pro-inflammatory responses and causing immunity impairment.      

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Does Air Pollution Affect the Viral Spread of COVID-19?

It is believed that the main route of transmission of the virus is through human respiratory droplets and direct contact, according to the Joint Mission report from China in late February. Yet, it has also been hypothesised that the COVID-19 virus can be transmitted by particulate matter (PM) and aerosols. A preliminary experimental analysis was conducted which identified the gene of COVID-19 in an ambient PM sample in Italy, and concluded that PM may potentially act as a transporter of the virus, although the virulence of COVID-19 remains unknown (i.e. vitality of the virus). Scientists also suggest that PM may serve as an early indicator of the epidemic recurrence by identifying the virus genome in PM. 

Current Air Quality Improvement From Lockdowns

Many countries have been locked down to maintain physical distancing among citizens to slow down the viral spread of COVID-19. The lockdowns have not only helped to reduce viral transmission but also the air pollution. A preprint study in China estimated that the lockdown mitigated a quarter of PM2.5 emissions and improved the Air Quality Index, helping prevent monthly premature deaths of 24 000 to 36 000 people.

The NO2 level also dropped dramatically after the lockdown (NO2 irritates human airways and impairs immunity to lung infections). Another study from China estimated that the improved NO2 levels from January to March due to the imposed lockdowns helped prevent more than 8,000 NO2 -related deaths, 65% of which are due to cardiovascular disease and chronic obstructive pulmonary disease (COPD). 

Fossil fuel burning is one of the major anthropogenic sources of air pollution. A study modelled that emissions from fossil fuel combustion is one of the major causes of air pollution, which contributes to 65% of additional mortality due to the exposure. Given that renewable energy is cleaner than fossil fuel burning, a transition to renewable energy is essential to mitigate the climate crisis.    

The plausible linkage between air pollution and viral spread still requires more thorough studies to confirm the hypothesis. Air pollution, on the other hand, has long been proving its harmful effect on human health and causes a burden on healthcare systems. The preliminary studies that have shown a possible link between air pollution exposure and COVID-19 related deaths, no matter how small, should be an indication that air pollution needs to be urgently tackled. A global transition to cleaner energy will help safeguard the health of humanity and prevent these unnecessary deaths.

Local governments should focus on mitigating air pollution to address the urgent issue of deaths caused by COVID-19, rather than aspire towards eliminating air pollution altogether. The positive effects of localised lockdown regulations in alleviating air pollution can be a blueprint towards this end. Without invoking a national mandate, discriminative regulations should be introduced that focus on areas more severely affected by COVID-19 or air pollution. Measures could include designating times for motor vehicle use, reducing smoke from agricultural and waste burning around cities, and pausing activities which create dust plumes such as construction while expanding public sanitation services and related employment to keep streets cleaner. 

The post How Air Pollution Contributes to the Spread of COVID-19 appeared first on Earth.Org.

Large-scale deep-sea mining operations will soon be undertaken on the international seabed. The International Seabed Authority (ISA) has drafted the long-awaited mining code and is anticipating granting licences to mine in the seabed for precious metals by this summer. What effects will deep-sea mining have on marine habitats and are there any alternatives? 

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It was discovered nearly 50 years ago that it was feasible to extract rare earth metals and minerals from the sea floor. Companies and countries have promised that they would start pulling valuable ores from the depths, owing to a rise in demand for batteries for electric cars and to store renewable energy, but commercial efforts have stalled for a variety of reasons, including massive startup costs and the lack of regulations. Until now.

Before deep-sea mining operations can become commercialised, they must adhere to this mining code in order to be granted licences by the International Seabed Authority, an organisation established by the United Nations Convention on Law of the Sea (UNCOLS). The Code intends to provide the rules, regulations and technical guidelines for regulating mining contractor operations. Once approved, a 30-year license is granted to contractors allowing them to mine assigned ‘claim areas’ in parts of the international seabed.

What Are They Looking For? 

The seabed has an abundance of valuable metals such as copper, silver, zinc, manganese, cobalt and other rare earth metals. Three types of mineral deposits valuable to the mining industry are polymetallic nodules, polymetallic sulphide and cobalt crusts. 

Polymetallic nodules are found in the abyssal plains, ranging from depths of 3000 to 6000 meters. The abyssal plains cover 70% of the seabed, making it the largest habitat on the Earth’s surface. Areas where these nodules are found include the Clarion-Clipperton fracture zone (CCFZ) in the central Pacific Ocean. However, the area is not well understood in terms of its ecological function and biodiversity. 

Polymetallic sulphides contain prized metals including copper and gold. They can be found near one of the most productive areas in the ocean- the hydrothermal vents, which provide organic carbon for organisms in the nutrient-limited deep-sea environment. Many of these species are also endemic to these hydrothermal vent areas. 

Cobalt crust is formed by the settling of minerals in seawater on the rocky surface. Cobalt is one of the most essential components of electronic technology, particular for lithium-ion batteries. Deep-sea mining grinds the crust and transports the ore back to the surface, a process which generates plumes that cause particle suspension and blankets the water column with toxic materials. In addition, the seamount may contain a variety of organisms that are harmed by mining. 

An ecological risk assessment on the effects of deep-sea mining was conducted which attempts to evaluate the risk sources and perceived vulnerabilities of the mineral-rich habitat. It concluded that key habitats are vulnerable to habitat transformation due to the effects of deep-sea mining. 

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Understanding the Impacts of Deep-Sea Mining

There is limited knowledge about the deep-sea environment, especially about microorganisms; however, it is known that they play an irreplaceable role in its ecosystem. Recent studies have found that benthic bacteria sequester 200 million tons of carbon dioxide into the biomass on an annual basis. 

On top of that, microbial communities in these deep-sea habitats are highly diverse. Even in the most studied area- the CCFZ, with over 35 years of surveys, new species have been discovered in recent years. Given that it is difficult to cultivate deep-sea microbes due to their highly adaptive characteristics (i.e. ability to withstand high pressure and temperatures), habitat destruction may potentially result in the loss of these and other ecosystem services. 

There is also a prolonged effect of the disturbance on the deep-sea environment. A pioneer impact assessment named DISCOL has been conducted since 1989 which aims to examine the potential impact of future commercial manganese nodule mining in the seabed environment. Artificial disturbances had been made through dragging tracks on the seafloor with a device called a plough harrow. A long-term impact study called the Mining Impact Project shows that these tracks are still visible after 26 years and both the microbial communities and benthic animals have not recovered from the disturbance. 

Why Do We Need Deep-Sea Mining? 

A report conducted by the Institute for Sustainable Futures concluded that even under the ambitious target to undergo a global transition to 100% renewable energy supply by 2050, the demand can be met without deep-sea mining, and that its effects do not warrant the efforts. Additionally, the demand for metals changes overtime. Cobalt is one of the major minerals extracted through deep-sea mining and is one of the most expensive and critical metals for lithium-ion batteries. Many companies, including Tesla, intend to cut down on the use of cobalt batteries and use lithium iron phosphate (LFP) batteries instead.

Some enterprises including Microsoft and Apple are also facing lawsuits; they are accused of violating human rights by forcing children to conduct harmful work without offering safety equipment in the Democratic Republic of Congo, the largest cobalt-producing country in the world. This may also affect the demand of  cobalt in the future, encouraging the development of cobalt-free electronic products. 

What Are The Alternatives? 

Urban mining has been discussed in recent years, which recovers valuable minerals from electronics waste (E-waste) and metal scrap. Mining this waste has potential to benefit both the economy and society. E-waste is categorised as hazardous waste under the Basel Convention, however this has been largely ineffective in controlling the illegal traffic of e-waste. Ghana, as one of the largest receivers of e-waste, imports 150 000 tons of so-called second-hand electronics annually, according to Ghana’s e-waste Country Assessment in 2011, where over 30% was non-functional e-waste. Many of the Ghanaians also rely on open burning to extract metals, while unusable items are transferred to open dumping sites that contaminate the surrounding environment. 

Urban mining is also less expensive compared to conventional mining. A study says that the urban mining of copper and gold from cathode-ray tube televisions and printed circuit boards is 13 and 7 times cheaper than mining virgin metals respectively. 

Commencing on commercial deep-sea mining depends on three criteria claimed by Michael Lodge, secretary general of the ISA, namely the regulation (i.e. Mining Code), technology advancements and market price of the metals. In the last ISA meeting in 2019, delegates convened to review a draft of the Code. The latest draft was released in 2019 and is pending approval in the next meeting by July. The mining may commence as soon as 2023.  

Considering that the international seabed area covers multiple locations, there is still a lack of knowledge on the deep sea environment, including the abundance of sea life in these environments. Urban mining, on the other hand, may serve as an alternative to meet the demand for future technology development, solve public health issues in developing countries, as well as achieving sustainability by close-the-loop.

The post The Detrimental Effects of Deep-Sea Mining on Marine Ecosystems appeared first on Earth.Org.

Corals are well-known for their captivating colours due to microscopic algae inhabitants. However, some have been seen glowing, which is unusual. Researchers have sought to understand the reason behind this glowing in a new study, which has found that it plays a significant role in maintaining the symbiotic relationship between corals and its zooxanthellae. How do these fluorescent pigments help corals to adapt to climate change? 

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Coral reefs are one of the most productive ecosystems on the planet, and the primary production that occurs through photosynthesis is established by the mutualistic relationship between the zooxanthellae and corals. Zooxanthellae is a type of algae, known as dinoflagellates, that live symbiotically with corals. Zooxanthellae carry out photosynthesis to provide nutrients to corals, while corals offer shelter to the algae.

Fluorescent Pigments Act as a Protective Shield

In surface water, sunlight is a key driver for the photosynthetic primary production, where zooxanthellae undergo photosynthesis. Yet, high energy wavelengths such as UV rays may cause photoinhibition and photodamage to the algae. Previous studies have found that corals possess types of protein with fluorescent pigments to counteract the environmental stress induced by sunlight by absorbing or diverging the damaging wavelengths and converting them into lower-energy light such as visible and infra-red light. A similar mechanism can also be found in terrestrial plants such as blueberries, which contains a pigment called anthocyanins, to reduce light stress when exposed to sunlight. 

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Why are Corals Glowing in the Deep Sea? 

Apart from the surface water, corals also display psychedelic colours in the deep-sea region, where there is little or no sunlight. A recent study found evidence that corals use fluorescence to increase its survival in the deep-sea environment, which serve a different purpose than that of corals living in shallow water. 

Given that the deep sea environment is dominated by blue light, deep-sea corals are equipped with a specific protein, known as photoconvertible red fluorescent protein, which converts the blue light into longer wavelength (i.e. orange-red light). Orange-red wavelengths help enhance light penetration and reflection, and allow even distribution of light within the coral tissue and its skeleton, thus increasing the productivity of zooxanthellae living in deeper coral tissue.  

Studies have also discovered that more of the red fluorescent proteins in corals was found in the lower water column, demonstrating the ecological significance of the red fluorescent protein to help corals better adapt to the deep-sea region.

The glowing colour may also appear in cases where coral bleaching occurs. Given that coral symbionts are sensitive to heat and light stress, corals who suffer from these stressors would result in symbiont expulsion. Experimental studies demonstrated that corals have developed a self-regulating mechanism, known as an optical feedback loop, which is triggered by the increased internal backscattering light from the coral skeleton due to reducing symbiont density in coral tissue. Corals can enhance photoprotection through increasing internal light absorption by protein pigments to lower the light stress, which in turn helps facilitate the recolonisation of symbionts on bleached coral tissue. 

Scientists have just provided a new explanation as to why corals are being seen glowing in deep-sea environments, showing that it does so to adapt to environmental stresses. The study also emphasises how little we know about coral reefs and marine ecosystems. Coral reefs have long been known to be the most productive and biodiverse ecosystem on Earth and have recently been found to be a new reservoir for medicine discovery in recent years. 

In view of the increasing rate of coral bleaching due to the climate crisis, effective actions will need to be taken collaboratively by government and international organisations to prevent further degradation of environmental quality. 

The post Why are Corals Glowing? appeared first on Earth.Org.