Leading up to the Convention on Biological Diversity Conference of the Parties 15, there is momentum around setting bold conservation targets. Yet, it remains unclear how much of Earth's land area ...remains without significant human influence and where this land is located. We compare four recent global maps of human influences across Earth's land, Anthromes, Global Human Modification, Human Footprint and Low Impact Areas, to answer these questions. Despite using various methodologies and data, these different spatial assessments independently estimate similar percentages of the Earth's terrestrial surface as having very low (20%–34%) and low (48%–56%) human influence. Three out of four spatial assessments agree on 46% of the non‐permanent ice‐ or snow‐covered land as having low human influence. However, much of the very low and low influence portions of the planet are comprised of cold (e.g., boreal forests, montane grasslands and tundra) or arid (e.g., deserts) landscapes. Only four biomes (boreal forests, deserts, temperate coniferous forests and tundra) have a majority of datasets agreeing that at least half of their area has very low human influence. More concerning, <1% of temperate grasslands, tropical coniferous forests and tropical dry forests have very low human influence across most datasets, and tropical grasslands, mangroves and montane grasslands also have <1% of land identified as very low influence across all datasets. These findings suggest that about half of Earth's terrestrial surface has relatively low human influence and offers opportunities for proactive conservation actions to retain the last intact ecosystems on the planet. However, though the relative abundance of ecosystem areas with low human influence varies widely by biome, conserving these last intact areas should be a high priority before they are completely lost.
Leading up to the Convention on Biological Diversity Conference of the Parties 15, there is momentum around setting bold conservation targets. Yet it remains unclear how much of Earth's land area remains without significant human influence. We compare four recent global maps of human influences (Anthromes, Global Human Modification, Human Footprint, and Low Impact Areas) and find that about half of Earth's terrestrial surface has relatively low human influence. These findings offer opportunities for proactive conservation actions to retain the last intact ecosystems on the planet, although the relative abundance of ecosystem areas with low human influence varies widely by biome.
Abstract
Global freshwater resources are vital to humanity and Earth’s ecosystems, yet about one third of the global population is affected by water scarcity for at least one month per year. In these ...areas, the overuse of freshwater resources can lead to the threat of depletion, marking them as the global ‘water scarcity hotspots’. This study combines outputs from a global hydrological model (PCR-GLOBWB 2) with an extensive literature search to provide a comprehensive intercomparison of the key drivers, pressures, states, impacts and responses (DPSIR) that shape the water gap between water demand and availability at the most important water scarcity hotspots worldwide. Hydroclimatic change, population growth, and water use for the industrial, municipal and agricultural sectors are the most important driving and pressuring forces on the water gap, affecting both water quality and quantity. These drivers and pressures have been showing increasing trends at all hotspots, which is concerning for the future development of the water gap. Additionally, we identify and characterize seven clusters of hotspots based on shared DPSIR patterns, revealing their common mechanisms. Our work highlights the diversity of water scarcity related issues at hotspots, especially the variety of impacts involved and governmental responses in place. The results of our DPSIR analysis provide valuable insights for building causal networks representing water gap dynamics at the hotspots. They form a foundation for conceptual models that illuminate human-water interactions, trade-offs, and synergies at the hotspots, while guiding policymakers in addressing the multifaceted challenge of closing the water gap.
The Everest region is characterized by its alpine glacial environment. In an effort to understand environmental change and tectonic activity, our team cored Taboche Lake, situated at 4,712 m along ...the western margin of the Ngozumpa Glacier. This research catalogs past earthquakes using geological records of the lake core that are important for the assessment of future earthquake hazards in the region and provides information for tectonic risk of glacial lake floods. Core grain size characteristics and internal sedimentary structures from computed tomographic scan were coupled with radiocarbon dating of organic matter preserved in the core to reconstruct the environmental history of the area. The 58-cm-long core consists of laminated silty sands and sandy silts with particle diameters <2 mm. The core records a syn-sedimentary deformational structure, folded sediments, rhythmically alternating dark- and light-colored laminations, and turbidites, which indicate coeval climatic and tectonic variations over the past ∼1,600 years.
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•Sedimentology and dating are essential to identify environmental changes in lake cores•Post-1807 AD ± 112 years flood turbidite record indicates warming trend in the Himalaya•Earthquake-triggered turbidite and slump event in the core relate to historic tremors•Earthquake records in glacial lake core highlight tectonic risk, which can cause GLFs
Glacial Landscapes ; Glacial Processes ; Sedimentology ; Tectonics
W centers are trigonal defects generated by self-ion implantation in silicon that exhibit photoluminescence at 1.218 µm. We have shown previously that they can be used in waveguide-integrated ...all-silicon light-emitting diodes (LEDs). Here we optimize the implant energy, fluence and anneal conditions to maximize the photoluminescence intensity for W centers implanted in silicon-on-insulator, a substrate suitable for waveguide-integrated devices. After optimization, we observe near two orders of magnitude improvement in photoluminescence intensity relative to the conditions with the stopping range of the implanted ions at the center of the silicon device layer. The previously demonstrated waveguide-integrated LED used implant conditions with the stopping range at the center of this layer. We further show that such light sources can be manufactured at the 300-mm scale by demonstrating photoluminescence of similar intensity from 300 mm silicon-on-insulator wafers. The luminescence uniformity across the entire wafer is within the measurement error.
The focus of this project was to develop and apply novel approaches to investigate Hg chemical speciation in the environment and explore methods that could be used for its remediation. Findings are ...presented as three research papers. Better understanding the mobility and chemical speciation of solid phase Hg at a site is critical for thorough risk assessment. In Paper 1, advanced analytical techniques e.g. X-ray Absorption Spectroscopy (XAS) were applied to identify the chemical speciation of Hg in a canal bed (MLR) sediment impacted by legacy discharge from industry. A sequential extraction protocol (SEP), in combination with ICP-MS, was applied to establish the potential mobility and potential bioavailability of highly toxic Hg. X-ray Diffraction (XRD) indicated that the sediment mineralogy was dominated by calcite and brucite, which are key components of solid waste from Hg-cell chlor-alkali plants. SEPs revealed that the bulk of Hg (>97%) was recalcitrant, likely strongly complexed, or mineral bound, and therefore relatively immobile with limited bioavailability. XAS revealed that >85% Hg was beta-HgS, and the bulk of the remaining portion was likely Hg(II) sorbed to sediment. Organometallic methylmercury (MeHg) 55 ± 1 μg/kg potentially poses the largest risk, despite contributing < 0.1% of total Hg 86 ± 1 mg/kg, due to its high toxicity and its tendency to bioaccumulate. 16S rRNA gene sequencing identified bacterial species potentially capable of catalysing both sulfidation and methylation reactions in the sediment. Iron-based nanoparticles and biostimulation via slow-release electron donor based organic substrates have previously shown capacity for the immobilisation of mobile contaminant metals e.g. Cr(VI) and Tc(VII) in anoxic subsurface water and sediment. The impact of four treatments NanoFER 25S (nZVI), Carbo-Iron® (nZVI and activated carbon composite), biogenic magnetite (biomagnetite) and organic electron donors) on Hg chemical speciation in two sediments MLR and estuarine (EST), were investigated in Paper 2 in the context of changes to key biogeochemical parameters. Analysis of microcosms, containing anoxic Hg-contaminated artificial groundwater (AGW) and sediment, suggested that solid phase Hg transformations were influenced by the type of treatment, the unique geochemical characteristics of sediment matrices and their respective microbial populations. Treatments containing nZVI (NanoFER 25S and Carbo-Iron®) were considered to pose the greatest risk in respect to potential reductive mobilisation (via Hg(0) volatilisation) and Hg methylation. Hg chemical speciation in samples was identified by k3 -weighted LIII-edge EXAFS linear combination fitting to known Hg standard reference materials. Results suggest that NanoFER 25S may present a risk, in respect to potential volatilisation of Hg as Hg(0). nZVI treatments induced and maintained reducing conditions for the duration of the experiment (911 days) independent of sediment type, consistent with the reduction of sorbed Hg(II), and also formation of immobile beta-HgS, identified in the MLR sediment. Notably, Hg methylation increased in both sediments following addition of Carbo-Iron®. Biomagnetite and biostimulation with organic electron donors both accelerated Hg immobilisation, via sulfidation, in EST sediment, but appeared to inhibit sulfidation in MLR sediment when compared to no treatment controls. Natural attenuation of Hg by sulfidation was effective at immobilising Hg(II) as beta-HgS irrespective of sediment type. This work emphasises the importance of considering not only the type of treatment, but also the individual site conditions (e.g. sediment matrix chemical composition, microbial community diversity, additional contaminants, etc.) when considering applying treatments in situ. Findings add to the portfolio of scientific information required to assess the suitability of iron-based nanoparticles (e.g. magnetite, nZVI and Carbo-Iron®) for remediation of Hg-contaminated waters and sediment. Application of treatment materials should be undertaken with caution, as despite potentially beneficial immobilising effects in respect to one contaminant e.g. Cr(VI)) under specific site conditions, intervention may have potentially adverse effects in respect to mobilisation of other contaminants e.g. Hg(II). Mitigating risks posed by formation of volatile Hg(0) in treatment systems, must be a consideration prior to application of iron-based nanoparticles, especially nZVI. Existing technologies that attempt to reduce Hg(II) often require costly capture mechanisms for gaseous Hg(0). A multi-contaminant approach to remediating Hg-contaminated AGW was investigated in Paper 3. Hg amalgams have historically been used widely in dentistry. Amalgam formation with other metals (e.g. Ag and Cu) provide benefits in respect to mechanical strength and stability, potentially reducing the tendency of Hg(0) to volatilise. Hg and Cu were both rapidly removed from AGW following addition of all particle treatments. Hg LIII-edge EXAFS linear combination fitting revealed that a solid Hg-Cu amalgam (HgCuAM) likely formed in three treatment systems in which: (1) NanoFER 25S had been pre-coated with Cu prior to treatment of aqueous Hg(II) in AGW Cu-NanoFER 25S Hg(II); (2) biomagnetite had been pre-coated with Cu prior to treatment of aqueous Hg(II) in AGW Cu-biomagnetite Hg(II); and (3) NanoFER 25S had been applied for treatment of AGW containing aqueous Hg(II) and Cu(II). Cucoating biomagnetite was an important step to enable HgCuAM formation but was of less importance with respect to application of NanoFER 25S. SEP recovery data suggested HgCuAM formed in Cubiomagnetite Hg(II) microcosms may be less stable than that formed in the NanoFER 25S systems containing Cu. Hg and Cu recovery was lowest in extracts from HgCuAM formed in Cu-containing NanoFER 25S systems. However, recovery was lowest for both Hg 50% and Cu 43% from endpoint solids in Cu-NanoFER 25S Hg(II) systems, likely due to the formation of a more recalcitrant HgCuAM. However, due to the volatility of Hg(0) there is uncertainty regarding whether the bulk of residual Hg is associated with Cu as an immobile alloy or whether some gaseous Hg(0) may have been emitted to headspace. There are concerns over the long-term fate, transformation, and eco-toxicity of nanoscale treatment technologies in environmental systems. Therefore, Cu-coated particles maybe more easily applied for treatment of Hg-contaminated industrial wastewaters at the point of pollution source in the shorter term. Future work including advance-TEM, particle size analysis, column experiments and gaseous Hg(0) monitoring are discussed.
The papers in this special section focus on high density integrated multipurpose photonic circuits. The growing maturity of integrated photonic technology makes it possible to build increasingly ...large and complex photonic circuits on the surface of a chip, enabling a generation of photonic circuits that can be programmed using software for a wide variety of functions. Programmability and reconfigurability in photonic integrated circuits allow both multipurpose devices and systems with unprecedent adaptability and flexibility. This emerging field is one of the fastest-growing fields in photonics with applications including optical signal processing, computing and quantum photonics.
The accurate quantification of current and past Himalayan glacier mass budgets is vital if we are to understand the evolution of the Asian water tower, which provides water to the planet’s most ...populous region. In this work, we generated a geodetic time series spanning six decades over 79 glaciers surrounding Mt. Everest and found consistent acceleration of glacier mass loss between the 1960s (−0.23 ± 0.12 mwe a−1) and the modern era (−0.38 ± 0.11 mwe a−1 from 2009 to 2018). Glacier mass loss has varied depending on glacier terminus type and surface characteristics, and glacier thinning is now occurring at extreme altitudes (>6,000 masl). Our time series also captures the first documented surge of a glacier in the Mt. Everest region. These multi-decadal observations of glacier mass loss form a baseline dataset against which physically based glacier evolution models could be calibrated before they are used for predicting future meltwater yield.
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•Glaciers around Mt. Everest have thinned by more than 100 m since the 1960s•The rate of ice mass loss has consistently accelerated over the past six decades•Glacier thinning has occurred at above 6,000 masl•Surge-type glacier behavior has been identified for the first time in the region
Meltwater from Himalayan glaciers sustains the flow of rivers that are heavily depended on by downstream communities across the densely populated region of Southeast Asia. Himalayan glaciers are shrinking in response to a changing climate, and measurements of glacier mass loss are vital for the calibration of models used for predicting the future variability of meltwater runoff. Here, we produced the longest possible time series of glacier mass-change measurements from satellite archives and found that the rate of ice loss from glaciers close to Mt. Everest has consistently increased since the early 1960s. We show how glacial lakes in the region have amplified ice loss and illustrate how ice loss has begun to occur at extreme altitudes, where large volumes of ice that were formerly less susceptible to melt are stored. The rate of ice loss across the Himalaya is likely to increase in the coming decades in response to further warming, which could be amplified at high altitude.
We generated the longest possible time series of glacier elevation-change measurements from satellite image archives to show how glaciers around Mt. Everest have reacted to climatic change since the 1960s. The rate of ice loss in the region has consistently increased over the last six decades, and ice loss is now occurring at extreme altitudes. Accurate, long-term measurements of ice-loss rates are vital if we are to understand the impact of glacier recession on local and regional hydrology.
Disposal of medicinal products Price, Scott; Tait, Alex
Veterinary record,
01/2012, Letnik:
170, Številka:
1
Journal Article
Recenzirano
If you wish to check whether a particular medicine can be classified as hazardous waste, you should contact the appropriate agency: EA - www.environment-agency.gov.uk/default.aspx ; SEPA - ...www.sepa.org.uk/default.aspx ; NIEA - www.doeni.gov.uk/index.htm You may also find it helpful to contact the Royal Pharmaceutical Society of Great Britain ( www.rpharms.com/home/home.asp ) for additional information.
This case study provides a framework for future monitoring and evidence for human source pollution in the Khumbu region, Nepal. We analyzed the chemical composition (major ions, major/trace elements, ...black carbon, and stable water isotopes) of pre-monsoon stream water (4300–5250 m) and snow (5200–6665 m) samples collected from Mt. Everest, Mt. Lobuche, and the Imja Valley during the 2019 pre-monsoon season, in addition to a shallow ice core recovered from the Khumbu Glacier (5300 m). In agreement with previous work, pre-monsoon aerosol deposition is dominated by dust originating from western sources and less frequently by transport from southerly air mass sources as demonstrated by evidence of one of the strongest recorded pre-monsoon events emanating from the Bay of Bengal, Cyclone Fani. Elevated concentrations of human-sourced metals (e.g., Pb, Bi, As) are found in surface snow and stream chemistry collected in the Khumbu region. As the most comprehensive case study of environmental chemistry in the Khumbu region, this research offers sufficient evidence for increased monitoring in this watershed and surrounding areas.
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•Document chemical composition of snow, stream, and ice from Khumbu region, Nepal•Provide a framework for future monitoring of environmental chemistry•Characterize chemical signatures in snow and stream chemistry•Provide evidence for elevated levels of human-sourced metals in snow and streams•Increased tourism in the Khumbu are likely contributors to high metal concentrations
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