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1.
Mar Environ Res ; 193: 106284, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38048660

RESUMEN

Epigenetic modifications based on DNA methylation can rapidly improve the potential of corals to adapt to environmental pressures by increasing their phenotypic plasticity, a factor important for scleractinian corals to adapt to future global warming. However, the extent to which corals develop similar adaptive mechanisms and their specific adaptation processes remain unclear. Here, to reveal the regulatory mechanism by which DNA methylation improves thermal tolerance in Pocillopora damicornis under fluctuating environments, we analyzed genome-wide DNA methylation signatures in P. damicornis and compared the differences in the methylation and transcriptional responses of P. damicornis from fluctuating and stable environments using whole-genome bisulfite sequencing and nanopore-based RNA sequencingtranscriptome sequencing. We discovered low methylation levels in P. damicornis (average methylation 4.14%), with CpG accounting for 74.88%, CHH for 13.27%, and CHG for 11.85% of this methylation. However, methylation levels did not change between coral samples from the fluctuating and stable environments. The varied methylation levels in different regions of the gene revealed that the overall methylation level of the gene body was relatively high and showed a bimodal methylation pattern. Methylation occurs primarily in exons rather than introns within the gene body In P. damicornis, there was only a weak correlation between methylation and transcriptional changes at the individual gene level, and the methylation and gene expression levels generally exhibited a bell-shaped relationship, which we speculate may be due to the specificity of cnidarian species. Correlation analysis between methylation levels and the transcriptome revealed that the highest proportion of the top 20 enriched KEGG pathways was related to immunity. Additionally, P. damicornis collected from a high-temperature pool had a lower metabolic rate than those collected from a low-temperature pool. We hypothesize that the dynamic balance of energy-expenditure costs between immunity and metabolism is an important strategy for increasing P. damicornis tolerance. The fluctuating environment of high-temperature pools may increase the heat tolerance in corals by increasing their immunity and thus lowering their metabolism.


Asunto(s)
Antozoos , Animales , Antozoos/fisiología , Adaptación Fisiológica , Calentamiento Global , Aclimatación/genética , Arrecifes de Coral
2.
Insect Sci ; 31(1): 285-298, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37370260

RESUMEN

The climatic variability hypothesis (CVH) predicts that organisms in more thermally variable environments have wider thermal breadths and higher thermal plasticity than those from more stable environments. However, due to evolutionary trade-offs, taxa with greater absolute thermal limits may have little plasticity of such limits (trade-off hypothesis). The CVH assumes that climatic variability is the ultimate driver of thermal tolerance variation across latitudinal and altitudinal gradients, but average temperature also varies along such gradients. We explored intraspecific variation of thermal tolerance in three typical Mediterranean saline water beetles (families Hydrophilidae and Dytiscidae). For each species, we compared two populations where the species coexist, with similar annual mean temperature but contrasting thermal variability (continental vs. coastal population). We estimated thermal limits of adults from each population, previously acclimated at 17, 20, or 25 °C. We found species-specific patterns but overall, our results agree with the CVH regarding thermal ranges, which were wider in the continental (more variable) population. In the two hydrophilid species, this came at the cost of losing plasticity of the upper thermal limit in this population, supporting the trade-off hypothesis, but not in the dytiscid one. Our results support the role of local adaptation to thermal variability and trade-offs between basal tolerance and physiological plasticity in shaping thermal tolerance in aquatic ectotherms, but also suggest that intraspecific variation of thermal tolerance does not fit a general pattern among aquatic insects. Overlooking such intraspecific variation could lead to inaccurate predictions of the vulnerability of aquatic insects to global warming.


Asunto(s)
Escarabajos , Humanos , Animales , Aclimatación , Temperatura , Insectos/fisiología , Calentamiento Global
3.
Mar Pollut Bull ; 197: 115792, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37984089

RESUMEN

Global warming harms coral reefs. Mesophotic coral reef ecosystems (MCEs) have been suggested to serve as refugia for shallow reefs. Information on the adaptation potential of shallow corals at MCEs is a prerequisite for understanding the refuge potential of MCEs. In this study, we investigated the photoacclimation potential of four shallow coral species transplanted at different depths over 1 year. The results showed that the corals-Pocillopora damicornis, Porites cylindrica, and Turbinaria reniformis-survived and acclimated to a wide range of light regimes at the depths of 5, 20, and 40 m. However, Acropora tenuis survived only at 5 and 20 m depth and showed significant morphological alteration at 20 m depth. Our results indicate that shallow corals have substantial plasticity with respect to depth changes. Changes in photosynthetic performance and phenotypic plasticity within these coral species may act as a buffer for depth-related changes and as modulators of evolutionary responses.


Asunto(s)
Antozoos , Animales , Antozoos/fisiología , Ecosistema , Arrecifes de Coral , Adaptación Fisiológica , Calentamiento Global
4.
Wiad Lek ; 76(9): 1922-1929, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37898926

RESUMEN

OBJECTIVE: The aim: To create a mathematical model for predicting the level of heat sensitivity in healthy young people based on multivariate regression analysis. PATIENTS AND METHODS: Materials and methods: 150 healthy young people aged 17-20 years answered the questionnaire "Levels of heat sensitivity", underwent a heat test and mathematical analysis of the heart rate, after which the results were used to build a regression model of heat sensitivity. RESULTS: Results: The model of mathematical prediction of heat sensitivity (CHSL1/CHSL2), which we proposed for the first time, takes into account the most significant factors that influence the determination of higher and lower sensitivity to heat (Q1-Q6, %LF2, %HF1, %HF2, HR1, HR2), so its use will allow timely identi¬fication of individuals who are particularly susceptible to the effects of elevated ambient temperature and prevent the development of potential negative consequences of this exposure. CONCLUSION: Conclusions: Based on the results obtained, it is possible to use this prognostic model in the future to develop a diagnostic system for determining the level of heat sensitivity.


Asunto(s)
Calentamiento Global , Calor , Humanos , Adolescente , Modelos Teóricos , Predicción , Pronóstico
5.
J Environ Manage ; 345: 118912, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37678020

RESUMEN

Seasonal rhythms in biological and ecological dynamics are fundamental in regulating the structuring of microbial communities. Evaluating the seasonal rhythms of microorganisms in response to climate change could provide information on their variability and stability over longer timescales (>20-year). However, information on temporal variability in microorganism responses to medium- and long-term global warming is limited. In this study, we aimed to elucidate the temporal dynamics of microbial communities in response to global warming; to this end, we integrated data on the maintenance of species diversity, community composition, temporal turnover rates (v), and community assembly process in two typical ecosystems (meadows and shrub habitat) on the Qinghai-Tibet Plateau. Our results showed that 21 years of global warming would increase the importance of the deterministic process for microorganisms in both ecosystems across all seasons (R2 of grassland (GL) control: 0.524, R2 of GL warming: 0.467; R2 of shrubland (SL) control: 0.556, R2 of SL warming: 0.543), reducing species diversity and altering community composition. Due to environmental filtration pressure from 21 years of warming, the low turnover rate (v of warming: -3.13/-2.00, v of control: -2.44/-1.48) of soil microorganisms reduces the resistance and resilience of ecological communities, which could lead to higher community similarity and more clustered taxonomic assemblages occurring across years. Changes to temperature might increase selection pressure on specialist taxa, which directly causes dominant species (v of warming: -1.63, v of control: -2.49) primarily comprising these taxa to be more strongly impacted by changing temperature than conditionally (v of warming: -1.47, v of control: -1.75) or always rare taxa (v of warming: -0.57, v of control: -1.33). Evaluation of the seasonal rhythms of microorganisms in response to global warming revealed that the variability and stability of different microbial communities in different habitats had dissimilar biological and ecological performances when challenged with an external disturbance. The balance of competition and cooperation, because of environmental selection, also influenced ecosystem function in complex terrestrial ecosystems. Overall, our study enriches the limited information on the temporal variability in microorganism responses to 21 years of global warming, and provides a scientific basis for evaluating the impact of climate warming on the temporal stability of soil ecosystems.


Asunto(s)
Calentamiento Global , Microbiota , Cambio Climático , Filtración , Suelo
6.
Environ Monit Assess ; 195(9): 1062, 2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37592096

RESUMEN

Recurring floods, droughts, heatwaves, and other hydro-meteorological extreme events are likely to be increased under the climate change scenarios. The increased risk of these extreme events might have more exposure to the population; thus, it is important to discuss such extreme events and their projected behavior under a changing climate scenario. In the present study, we have computed the extreme precipitation and temperature indices over the 10 agro-climatic zones falling under the Ganga River Basin (GRB)utilizing a high-resolution daily gridded temperature and precipitation multi-model ensembled CMIP6 dataset (0.25° × 0.25°) under global warming levels of 1.5 °C, 2 °C, and 3 °C. We found that the annual daily minimum temperature (TNN) showed a higher rise of about 67% than the maximum temperature (TXX) of 48% in GRB. The basin also experiences a greater increase in the frequency of warm nights (TN90P) of about 67.71% compared to warm days (TX90P) of 29.1% for the 3 °C global warming level. Along with extreme indices, the population exposed due to the impact of the extreme maximum temperature has also been analyzed for progressive warming levels. Population exposure to extreme temperature event (TXX) has been analyzed with 20-year return period using GEV distribution method. The study concludes that the exposed population to extreme temperature event experienced an increase from 46.99 to 52.16% for the whole Ganga Basin. Consecutive dry days (CDD) and consecutive wet days (CWD) both show a significant increasing trend, but CWD has a significant increase in the majority of the zones, while CDD shows a significant decreasing trend for some of the zones for three warming levels periods. Extreme climate indices help to understand the frequency and intensity of extreme weather events such as heavy rainfall, droughts, and heatwaves to develop early warning systems and adaptation strategies to mitigate such events.


Asunto(s)
Calentamiento Global , Ríos , Monitoreo del Ambiente , Cambio Climático , Aclimatación
7.
Environ Pollut ; 336: 122443, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37643676

RESUMEN

In the context of global warming, frequent heat wave disasters have seriously threatened the safety of human life and property. The urban agglomeration, as the main region with a high concentration of population and economy, is susceptible to heat weaves due to the existing urban heat island effect. In this study, we investigated the temporal and spatial characteristics of heat waves (heat index, HI) in China from 2000 to 2020 and assess the vulnerability of 19 urban agglomerations to heat waves from the perspective of exposure, sensitivity and adaptability. The results show that: (1) In the past 20 years, the frequency and intensity of HI (greater than 26.67 °C) both showed an upward trend. (2) Shandong Peninsula, Central Henan, Yangtze River Delta, Middle Reaches of Yangtze River, and Mid-southern Liaoning urban agglomerations always maintain a high vulnerability. (3) From 2000 to 2020, the vulnerability of Beijing-Tianjin-Hebei, Yangtze River Delta, Chengdu-Chongqing, Middle reaches of Yangtze River, Guangdong-Fujian-Zhejiang, Harbin-Changchun and Mid-southern Liaoning urban agglomerations were always dominated by exposure. The vulnerability of Shandong Peninsula, Beibu Gulf and Central Henan urban agglomeration has always been dominated by sensitivity. The vulnerability of North Tianshan Mountain, Lanzhou-Xining, Guanzhong and Hu-Bao-E-Yu urban agglomeration has always been dominated by inadequate adaptability. (4) Recently, the factors that contributed most to exposure, sensitivity and adaptability were population density, the proportion of outdoor workers and water supply, with contribution rates of 38%, 55% and 26%, respectively. This study can provide a scientific basis for the rational allocation of resources among urban agglomerations, effectively formulating policies and guiding population migration from high temperature disasters.


Asunto(s)
Calentamiento Global , Calor , Humanos , Ciudades , China , Beijing , Ríos , Urbanización
8.
Nature ; 622(7981): 93-100, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37612511

RESUMEN

The Pacific Walker circulation (PWC) has an outsized influence on weather and climate worldwide. Yet the PWC response to external forcings is unclear1,2, with empirical data and model simulations often disagreeing on the magnitude and sign of these responses3. Most climate models predict that the PWC will ultimately weaken in response to global warming4. However, the PWC strengthened from 1992 to 2011, suggesting a significant role for anthropogenic and/or volcanic aerosol forcing5, or internal variability. Here we use a new annually resolved, multi-method, palaeoproxy-derived PWC reconstruction ensemble (1200-2000) to show that the 1992-2011 PWC strengthening is anomalous but not unprecedented in the context of the past 800 years. The 1992-2011 PWC strengthening was unlikely to have been a consequence of volcanic forcing and may therefore have resulted from anthropogenic aerosol forcing or natural variability. We find no significant industrial-era (1850-2000) PWC trend, contrasting the PWC weakening simulated by most climate models3. However, an industrial-era shift to lower-frequency variability suggests a subtle anthropogenic influence. The reconstruction also suggests that volcanic eruptions trigger El Niño-like PWC weakening, similar to the response simulated by climate models.


Asunto(s)
Movimientos del Aire , Atmósfera , Clima , Tiempo (Meteorología) , Aerosoles/análisis , Atmósfera/química , Modelos Climáticos , El Niño Oscilación del Sur , Calentamiento Global , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Actividades Humanas , Océano Pacífico , Erupciones Volcánicas
9.
Nature ; 621(7979): 536-542, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37558870

RESUMEN

Coral reef ecosystems are being fundamentally restructured by local human impacts and climate-driven marine heatwaves that trigger mass coral bleaching and mortality1. Reducing local impacts can increase reef resistance to and recovery from bleaching2. However, resource managers lack clear advice on targeted actions that best support coral reefs under climate change3 and sector-based governance means most land- and sea-based management efforts remain siloed4. Here we combine surveys of reef change with a unique 20-year time series of land-sea human impacts that encompassed an unprecedented marine heatwave in Hawai'i. Reefs with increased herbivorous fish populations and reduced land-based impacts, such as wastewater pollution and urban runoff, had positive coral cover trajectories predisturbance. These reefs also experienced a modest reduction in coral mortality following severe heat stress compared to reefs with reduced fish populations and enhanced land-based impacts. Scenario modelling indicated that simultaneously reducing land-sea human impacts results in a three- to sixfold greater probability of a reef having high reef-builder cover four years postdisturbance than if either occurred in isolation. International efforts to protect 30% of Earth's land and ocean ecosystems by 2030 are underway5. Our results reveal that integrated land-sea management could help achieve coastal ocean conservation goals and provide coral reefs with the best opportunity to persist in our changing climate.


Asunto(s)
Antozoos , Conservación de los Recursos Naturales , Arrecifes de Coral , Calor Extremo , Calentamiento Global , Océanos y Mares , Agua de Mar , Animales , Conservación de los Recursos Naturales/métodos , Calor Extremo/efectos adversos , Peces , Calentamiento Global/estadística & datos numéricos , Objetivos , Hawaii , Actividades Humanas , Cooperación Internacional , Agua de Mar/análisis , Agua de Mar/química , Aguas Residuales/análisis , Factores de Tiempo
10.
Environ Sci Technol ; 57(33): 12251-12258, 2023 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-37566763

RESUMEN

The United States has begun unprecedented efforts to decarbonize all sectors of the economy by 2050, requiring rapid deployment of variable renewable energy technologies and grid-scale energy storage. Pumped storage hydropower (PSH) is an established technology capable of providing grid-scale energy storage and grid resilience. There is limited information about the life cycle of greenhouse gas emissions associated with state-of-the-industry PSH technologies. The objective of this study is to perform a full life cycle assessment of new closed-loop PSH in the United States and assess the global warming potential (GWP) attributed to 1 kWh of stored electricity delivered to the nearest grid substation connection point. For this study, we use publicly available data from PSH facilities that are in the preliminary permitting phase. The modeling boundary is from facility construction to decommissioning. Our results estimate that the GWP of closed-loop PSH in the United States ranges from 58 to 530 g CO2e kWh-1, with the stored electricity grid mix having the largest impact, followed by concrete used in facility construction. Additionally, PSH site characteristics can have a substantive impact on GWP, with brownfield sites resulting in a 20% lower GWP compared to greenfield sites. Our results suggest that closed-loop PSH offers climate benefits over other energy storage technologies.


Asunto(s)
Gases de Efecto Invernadero , Estados Unidos , Animales , Calentamiento Global , Energía Renovable , Clima , Estadios del Ciclo de Vida
11.
Environ Sci Pollut Res Int ; 30(39): 91377-91395, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37479933

RESUMEN

Due to the increasing emission of greenhouse gases and global warming, the development of renewable energy has become very important. The availability of fossil fuels and the low cost of their extraction compared to renewable energy projects reduce the motivation of countries, especially countries that have abundant natural resources, to develop this technology. Renewable energy deployment has become crucial in response to rising greenhouse gas emissions and global warming. Policies supporting renewable energy play a significant role in this. This study examines the effect of such policies on the deployment of renewable energy technologies, considering the role of natural resources. Two groups of countries were analysed: 20 oil developed countries and 20 oil developing countries. Given the availability of data and the achievement of balanced panels to evaluate short-term and long-term relationships between variables, in current research Data from 2010 to 2020 was used, and various panel data estimators such as Feasible Generalized Least Squares and Generalized Method of Moments were employed. The Quantile estimator was also used to assess the accuracy of the results. The findings suggest that renewable energy policies consistently lead to increased deployment of renewable energy technologies, regardless of a country's group. Of course, this positive effect is different according to the level of development in countries. Due to the higher efficiency of renewable energy policy, developed oil countries have more capacity to support renewable energy projects than oil developing countries. The abundance of natural resources in oil developed countries did not negatively impact renewable energy capacity, but in oil developing countries, the "resource curse" hindered the development of installed renewable energy.


Asunto(s)
Gases de Efecto Invernadero , Política Pública , Combustibles Fósiles , Calentamiento Global , Energía Renovable , Tecnología
12.
Sci Rep ; 13(1): 11324, 2023 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-37443192

RESUMEN

The global production of plant-based foods is a significant contributor to greenhouse gas emissions. Indoor vertical farms (IVFs) have emerged as a promising approach to urban agriculture. However, their environmental performance is not well understood, particularly in relation to operational choices where global warming potentials (GWP) can vary between 0.01-54 kg CO2e/kg-1 of leafy greens produced. We conducted a life cycle assessment (LCA) of a building-integrated IVF for microgreen production to analyse a range of operational conditions for cultivation: air temperature, CO2 concentration, and photoperiod. We analyzed a dynamic LCA inventory that combined a process-based plant growth model and a mass balance model for air and heat exchange between the chamber and the outside. Results showed that the GWP of IVFs can vary greatly depending on the operation conditions set, ranging from 3.3 to 63.3 kg CO2e/kg-1. The optimal conditions for minimizing GWP were identified as 20 ℃, maximum CO2 concentration in the chamber, and maximum photoperiod, which led to a minimum GWP of 3.3 kg CO2e/kg-1 and maximum production of 290.5 kg fresh weight week-1. Intensification of production thus led to lower impacts because the marginal increase in yield due to increased resource use was larger than the marginal increase in impact. Therefore, adjusting growing conditions is essential for the sustainability of urban food production.


Asunto(s)
Dióxido de Carbono , Calentamiento Global , Animales , Granjas , Agricultura/métodos , Estadios del Ciclo de Vida
13.
Plant Cell Environ ; 46(9): 2827-2840, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37278611

RESUMEN

How root respiration acclimates to global warming remains unclear, especially in subtropical forests that play a key role in the global carbon budget. In a large-scale in situ soil warming experiment, the occurrence of, and mechanisms controlling over, the acclimation of fine-root respiration of Cunninghamia lanceolata during the fourth year of warming were investigated. Specific respiration rates (at reference temperature of 20°C; SRR20 ) were measured with exogenous glucose addition, uncoupler addition, or no addition, and root morphological and chemical traits were also measured. Warming decreased SRR20 by 18.4% only during summer, indicating partial thermal acclimation of fine-root respiration under warming. Warming did not change fine-root N concentration, showing no possible enzyme limitation on respiration. Warming decreased root soluble sugar/starch ratio in summer, and glucose addition increased respiration only under warming, indicating a warming-induced substrate limitation on respiration. Uncoupler addition also stimulated respiration only under warming, showing a warming-induced adenylate limitation on respiration. These findings suggest that thermal acclimation of root respiration in subtropical forests, which is at least partially constrained by substrate and adenylate use, is conducive to reducing ecosystem carbon emissions and mitigating the positive feedback between atmospheric CO2 and climate warming.


Asunto(s)
Ecosistema , Árboles , Suelo , Temperatura , Glucosa , Calentamiento Global , Respiración , Carbono
14.
Food Chem ; 426: 136559, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37348394

RESUMEN

Heat and nutritional stresses have a significantly effect on the accumulation of bioactive and other compounds harmful to human health, like nitrates, in green leafy vegetables like lamb's lettuce. Plant growth-promoting bacteria (PGPB) have shown to confer beneficial biochemical changes to various crops under different stresses. The hypothesis proposed here is that the combination of optimal N level (2.5 Mm, 12 mM or 20 mM of N) with the inoculation of PGPB in plants exposed to heat shock (43 °C) may be a good strategy to obtain healthier lamb's lettuce with a higher yield. Results showed that a dose of 20 mM N can be considered as overfertilization. Moreover, the inoculation of plants fed with fertilizers with reduced N and under heat stress, resulted in higher productivity and content of sugars (60 %), amino acids (94 %), nitrogen (21 %), and total phenolic compounds (30 %), and a reduced content of nitrates (27 %).


Asunto(s)
Nitratos , Valerianella , Humanos , Nitratos/metabolismo , Calentamiento Global , Respuesta al Choque Térmico , Bacterias/genética , Bacterias/metabolismo
15.
New Phytol ; 239(6): 2126-2137, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37366062

RESUMEN

The response of Posidonia oceanica meadows to global warming of the Eastern Mediterranean Sea, where the increase in sea surface temperature (SST) is particularly severe, is poorly investigated. Here, we reconstructed the long-term P. oceanica production in 60 meadows along the Greek Seas over two decades (1997-2018), using lepidochronology. We determined the effect of warming on production by reconstructing the annual and maximum (i.e. August) SST, considering the role of other production drivers related to water quality (i.e. Chla, suspended particulate matter, Secchi depth). Grand mean (±SE) production across all sites and the study period was 48 ± 1.1 mg DW per shoot yr-1 . Production over the last two decades followed a trajectory of decrease, which was related to the concurrent increase in annual SST and SSTaug . Annual SST > 20°C and SSTaug > 26.5°C was related to production decline (GAMM, P < 0.05), while the rest of the tested factors did not help explain the production pattern. Our results indicate a persistent and increasing threat for Eastern Mediterranean meadows, drawing attention to management authorities, highlighting the necessity of reducing local impacts to enhance the resilience of seagrass meadows to global change threats.


Asunto(s)
Alismatales , Calentamiento Global , Mar Mediterráneo , Temperatura , Ecosistema
16.
Sci Total Environ ; 884: 163838, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37137364

RESUMEN

This study aimed to elucidate the effect of bio-optical complexity on radiant heating rates in coastal waters of the eastern Arabian Sea. The in situ measurements covered a large spatial domain between 9°35'N and 15°43'N and east of 72°58'E and comprised different bio-optical measurements and in-water light field, along the pre-determined nine transects in the vicinity of riverine discharge sites influenced by Indian Summer Monsoon caused precipitation. In addition to the spatial survey, timeseries measurements were also conducted at 15°27'N and 73°42'E at a depth of 20 m. Analyzing the distinctness in surface remote sensing reflectance, data were clustered into four optical water types, representing different bio-optical states. The nearshore waters had the highest concentrations of bio-optical constituents (more bio-optically complex) while the offshore waters had low concentrations of chlorophyll-a and suspended matter (least bio-optically complex). There was a presence of higher colored dissolved organic matter in the offshore waters than in its global estimations. The estimation of radiant heating rates at the surface increased from offshore to nearshore waters. In contrast, the euphotic depth-integrated estimations of radiant heating rate were similar in nearshore and offshore waters. Because the nearshore waters had much shallower bottom and euphotic depths as compared to the offshore, similarity in radiant heating rate estimates seemed to attribute to the higher concentrations of bio-optical constituents in nearshore waters. In conditions with similar surface-reaching irradiance in nearshore and offshore waters, higher attenuation of underwater solar transmission (shallow euphotic depth) occurred when absorption and backscattering by bio-optical constituents increased. The radiant heating rate for the euphotic column in the four bio-optical water types, i.e., O1T (offshore), O2T, O3T, and O4T (nearshore) were 0.225 ± 0.118 °C hr-1, 0.214 ± 0.096 °C hr-1, 0.191 ± 0.097 °C hr-1, and 0.21 ± 0.12 °C hr-1, respectively.


Asunto(s)
Calefacción , Agua , Clorofila A , Estaciones del Año , Telemetría
17.
Elife ; 122023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-37157843

RESUMEN

Ectotherms are predicted to 'shrink' with global warming, in line with general growth models and the temperature-size rule (TSR), both predicting smaller adult sizes with warming. However, they also predict faster juvenile growth rates and thus larger size-at-age of young organisms. Hence, the result of warming on the size-structure of a population depends on the interplay between how mortality rate, juvenile- and adult growth rates are affected by warming. Here, we use two-decade long time series of biological samples from a unique enclosed bay heated by cooling water from a nearby nuclear power plant to become 5-10 °C warmer than its reference area. We used growth-increment biochronologies (12,658 reconstructed length-at-age estimates from 2426 individuals) to quantify how >20 years of warming has affected body growth, size-at-age, and catch to quantify mortality rates and population size- and age structure of Eurasian perch (Perca fluviatilis). In the heated area, growth rates were faster for all sizes, and hence size-at-age was larger for all ages, compared to the reference area. While mortality rates were also higher (lowering mean age by 0.4 years), the faster growth rates lead to a 2 cm larger mean size in the heated area. Differences in the size-spectrum exponent (describing how the abundance declines with size) were less clear statistically. Our analyses reveal that mortality, in addition to plastic growth and size-responses, is a key factor determining the size structure of populations exposed to warming. Understanding the mechanisms by which warming affects the size- and the age structure of populations is critical for predicting the impacts of climate change on ecological functions, interactions, and dynamics.


Asunto(s)
Ecosistema , Percas , Animales , Calor , Temperatura , Calentamiento Global , Cambio Climático , Percas/fisiología
18.
Mar Environ Res ; 188: 106013, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37209442

RESUMEN

Sargassum species are among the most important canopy-forming algae in the Western Atlantic Ocean (WAO), providing habitat for many species and contributing to carbon uptake. The future distribution of Sargassum and other canopy-forming algae has been modelled worldwide, indicating that their occurrence in many regions is threatened by increased seawater temperature. Surprisingly, despite the recognized variation in vertical distribution of macroalgae, these projections generally do not evaluate their results at different depth ranges. This study aimed to project the potential current and future distributions of the common and abundant benthic Sargassum natans in the WAO (from southern Argentina to eastern Canada), under RCP 4.5 and 8.5 climate change scenarios, through an ensemble SDM approach. Possible changes between present and future distributions were assessed within two depth ranges, namely areas up to 20 m and areas up to 100 m depth. Our models forecast different distributional trends for benthic S. natans depending on the depth range. Up to 100 m, suitable areas for the species will increase by 21% under RCP 4.5, and by 15% under RCP 8.5, when compared to the potential current distribution. On the contrary, up to 20 m, suitable areas for the species will decrease by 4% under RCP 4.5 and by 14% under RCP 8.5, when compared to the potential current distribution. Under the worst scenario, losses up to 20 m depth will affect approximately 45,000 km2 of coastal areas across several countries and regions of WAO, with likely negative consequences for the structure and dynamics of coastal ecosystems. These findings highlight the importance of considering different depth ranges when building and interpreting predictive models of the distribution of habitat-forming subtidal macroalgae under climate change.


Asunto(s)
Sargassum , Algas Marinas , Calentamiento Global , Ecosistema , Cambio Climático , Océano Atlántico
19.
Environ Sci Technol ; 57(16): 6474-6484, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-37051641

RESUMEN

Global hydrofluorocarbon (HFC) cumulative emissions will be more than 20 Gt CO2-equiv during 2020-2060 and have a non-negligible impact on global warming even in full compliance with the Kigali Amendment (KA). Fluorochemical manufacturers (including multinationals) in China have accounted for about 70% of global HFC production since 2015, of which about 60% is emitted outside China. This study built an integrated model (i.e., DECAF) to estimate both territorial and exported emissions of China under three scenarios and assess the corresponding climate effects as well as abatement costs. Achieving near-zero territorial emissions by 2060 could avoid 23 ± 4 Gt CO2-equiv of cumulative territorial emissions (compared to the 2019 Baseline scenario) during 2020-2060 at an average abatement cost of 9 ± 6 USD/t CO2-equiv. Under the near-zero emission (including territorial and abroad) pathway, radiative forcing from HFCs will peak in 2037 (60 ± 6 mW/m2) with a 33% peak reduction and 8 years in advance compared to the path regulated by the KA, and the radiative forcing by 2060 will be lower than that in 2019. Accelerated phase-out of HFC production in China could provide a possibility for rapid global HFC abatement and achieve greater climate benefits.


Asunto(s)
Dióxido de Carbono , Calentamiento Global , Análisis Costo-Beneficio , Dióxido de Carbono/análisis , Rwanda , Cambio Climático , China
20.
Sci Total Environ ; 876: 162712, 2023 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-36921862

RESUMEN

The subsurface application (SA) of nitrogenous fertilizers is a potential solution to mitigate climate change and improve food security. However, the impacts of SA technology on greenhouse gas (GHG) emissions and agronomic yield are usually evaluated separately and their results are inconsistent. To address this gap, we conducted a meta-analysis synthesizing 40 peer-reviewed studies on the effects of SA technology on GHG and ammonia (NH3) emissions, nitrogen uptake (NU), crop yield, and soil residual NO3-N in rice paddies and upland cropping system. Compared to the surface application of N, SA technology significantly increased rice yields by 32 % and crop yield in upland systems by 62 %. The largest SA-induced increases in crop yield were found at low N input rates (<100 kg Nha-1) in rice paddies and medium N input rates (100-200 kg Nha-1) in upland systems, suggesting that soil moisture is a key factor determining the efficiency of SA technology. SA treatments increased yields by more at reduced fertilizer rates (~30 % less N), a shallow depth (<10 cm), and with urea in both cropping systems than at the full (recommended) N rate, a deeper depth (10-20 cm), and with ammonical fertilizer. SA treatments significantly increased NU in rice paddies (34 %) and upland systems (18 %), and NO3-N (40 %) in paddyland; however, NO3-N decreased (28 %) in upland conditions. Ammonia mitigation was greater in paddyland than in upland conditions. SA technology decreased the carbon footprint (CF) in paddyland by 29 % and upland systems by 36 %, and overall by 33 %. Compared with broadcasting, SA significantly reduced CH4 emissions by 16 %, N2O emissions by 30 %, and global warming potential (GWP) by 10 % in paddy cultivation. Given SA increased grain yield and NU while reducing NH3, CF, and GWP, this practice provides dual benefits - mitigating climate change and ensuring food security.


Asunto(s)
Gases de Efecto Invernadero , Oryza , Amoníaco , Fertilizantes/análisis , Óxido Nitroso/análisis , Metano/análisis , Agricultura/métodos , Suelo , Calentamiento Global/prevención & control , Nitrógeno , Fertilización
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