Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 572
Filtrar
6.
Nature ; 626(8000): 792-798, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38297125

RESUMO

Crop production is a large source of atmospheric ammonia (NH3), which poses risks to air quality, human health and ecosystems1-5. However, estimating global NH3 emissions from croplands is subject to uncertainties because of data limitations, thereby limiting the accurate identification of mitigation options and efficacy4,5. Here we develop a machine learning model for generating crop-specific and spatially explicit NH3 emission factors globally (5-arcmin resolution) based on a compiled dataset of field observations. We show that global NH3 emissions from rice, wheat and maize fields in 2018 were 4.3 ± 1.0 Tg N yr-1, lower than previous estimates that did not fully consider fertilizer management practices6-9. Furthermore, spatially optimizing fertilizer management, as guided by the machine learning model, has the potential to reduce the NH3 emissions by about 38% (1.6 ± 0.4 Tg N yr-1) without altering total fertilizer nitrogen inputs. Specifically, we estimate potential NH3 emissions reductions of 47% (44-56%) for rice, 27% (24-28%) for maize and 26% (20-28%) for wheat cultivation, respectively. Under future climate change scenarios, we estimate that NH3 emissions could increase by 4.0 ± 2.7% under SSP1-2.6 and 5.5 ± 5.7% under SSP5-8.5 by 2030-2060. However, targeted fertilizer management has the potential to mitigate these increases.


Assuntos
Amônia , Produção Agrícola , Fertilizantes , Amônia/análise , Amônia/metabolismo , Produção Agrícola/métodos , Produção Agrícola/estatística & dados numéricos , Produção Agrícola/tendências , Conjuntos de Dados como Assunto , Ecossistema , Fertilizantes/efeitos adversos , Fertilizantes/análise , Fertilizantes/estatística & dados numéricos , Aprendizado de Máquina , Nitrogênio/análise , Nitrogênio/metabolismo , Oryza/metabolismo , Solo/química , Triticum/metabolismo , Zea mays/metabolismo , Mudança Climática/estatística & dados numéricos
8.
Nature ; 625(7996): 722-727, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38110573

RESUMO

Ecosystems generate a wide range of benefits for humans, including some market goods as well as other benefits that are not directly reflected in market activity1. Climate change will alter the distribution of ecosystems around the world and change the flow of these benefits2,3. However, the specific implications of ecosystem changes for human welfare remain unclear, as they depend on the nature of these changes, the value of the affected benefits and the extent to which communities rely on natural systems for their well-being4. Here we estimate country-level changes in economic production and the value of non-market ecosystem benefits resulting from climate-change-induced shifts in terrestrial vegetation cover, as projected by dynamic global vegetation models (DGVMs) driven by general circulation climate models. Our results show that the annual population-weighted mean global flow of non-market ecosystem benefits valued in the wealth accounts of the World Bank will be reduced by 9.2% in 2100 under the Shared Socioeconomic Pathway SSP2-6.0 with respect to the baseline no climate change scenario and that the global population-weighted average change in gross domestic product (GDP) by 2100 is -1.3% of the baseline GDP. Because lower-income countries are more reliant on natural capital, these GDP effects are regressive. Approximately 90% of these damages are borne by the poorest 50% of countries and regions, whereas the wealthiest 10% experience only 2% of these losses.


Assuntos
Mudança Climática , Países Desenvolvidos , Países em Desenvolvimento , Ecossistema , Produto Interno Bruto , Mudança Climática/economia , Mudança Climática/estatística & dados numéricos , Modelos Climáticos , Países Desenvolvidos/economia , Países em Desenvolvimento/economia , Plantas , Densidade Demográfica , Fatores Socioeconômicos
13.
Revista Digital de Postgrado ; 12(3): 378, dic. 2023. graf
Artigo em Espanhol | LILACS, LIVECS | ID: biblio-1526934

RESUMO

Introducción: El tema del cambio climático y sus efectos, en la salud, educación y transporte, es un tema emergente, que pretende la optimización del consumo y la eficiencia energética. Esta investigación se plantea como objetivo,la caracterización del uso y aprovechamiento de energías, en establecimientos de atención médica de la región capital durante el año 2022, considerando la distribución energética, eficiencia y fuentes primarias de energía utilizadas en este país. Métodos: Se trata de una investigación descriptiva, transversal y prospectiva,a través del análisis cuali-cuantitativo, con el uso de informantes clave quienes consideran importante la iluminación natural en los espacios y el mayor aprovechamiento energético en áreas como la quirúrgica y consulta externa. Resultados: Surge el uso de la energía solar, eólica e hidráulica como recursos energéticos aprovechables, así como la sostenibilidad y la mantenibilidad en el diseño y rediseño de infraestructuras hospitalarias. Los tipos de energías utilizados en Venezuela, siguen correspondiendo ala hidráulica y combustibles fósiles, se conoce la tecnología e implementación de paneles solares para la mejoría del cambio climático, la huella del carbono, el uso de energías verdes y reducción de combustibles fósiles. Su aceptación depende de regulaciones y la concientización energética como elementos fundamentales para el cambio.


Introduction: The issue of climate change and itseffects, in health, education and transportation, is an emergingissue, which aims at the optimization of energy consumption andefficiency. e objective of this research is to characterize the useand exploitation of energy in health care facilities in the capitalregion during the year 2022, considering the energy distribution,efficiency and primary energy sources used in this country.Methods: This is a descriptive, cross-sectional and prospectiveresearch, through qualitative-quantitative analysis, with the useof key informants who consider important the natural lightingin the spaces and the greater use of energy in areas such assurgery and outpatient care. Results: The use of solar, windand hydraulic energy emerged as usable energy resources, aswell as sustainability and maintainability in the design andredesign of hospital infrastructures. The types of energy used inVenezuela continue to correspond to hydraulics and fossil fuels; the technology and implementation of solar panels is known forthe improvement of climate change, the carbon footprint, theuse of green energy and reduction of fossil fuels. Their acceptancedepends on regulations and energy awareness as fundamental elements for change.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto Jovem , Mudança Climática/estatística & dados numéricos , Fontes Geradoras de Energia , Consumo de Energia , Energia Solar , Cuidados Médicos , Política de Saúde
15.
Nature ; 624(7990): 109-114, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37938778

RESUMO

There are two main life cycles in plants-annual and perennial1,2. These life cycles are associated with different traits that determine ecosystem function3,4. Although life cycles are textbook examples of plant adaptation to different environments, we lack comprehensive knowledge regarding their global distributional patterns. Here we assembled an extensive database of plant life cycle assignments of 235,000 plant species coupled with millions of georeferenced datapoints to map the worldwide biogeography of these plant species. We found that annual plants are half as common as initially thought5-8, accounting for only 6% of plant species. Our analyses indicate that annuals are favoured in hot and dry regions. However, a more accurate model shows that the prevalence of annual species is driven by temperature and precipitation in the driest quarter (rather than yearly means), explaining, for example, why some Mediterranean systems have more annuals than desert systems. Furthermore, this pattern remains consistent among different families, indicating convergent evolution. Finally, we demonstrate that increasing climate variability and anthropogenic disturbance increase annual favourability. Considering future climate change, we predict an increase in annual prevalence for 69% of the world's ecoregions by 2060. Overall, our analyses raise concerns for ecosystem services provided by perennial plants, as ongoing changes are leading to a higher proportion of annual plants globally.


Assuntos
Ecossistema , Mapeamento Geográfico , Filogeografia , Fenômenos Fisiológicos Vegetais , Plantas , Aclimatação , Evolução Biológica , Mudança Climática/estatística & dados numéricos , Bases de Dados Factuais , Clima Desértico , Atividades Humanas , Região do Mediterrâneo , Plantas/classificação , Chuva , Temperatura
17.
Nature ; 622(7982): 308-314, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37794184

RESUMO

Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action1,2. Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4. Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends.


Assuntos
Anfíbios , Mudança Climática , Ecossistema , Espécies em Perigo de Extinção , Animais , Anfíbios/classificação , Biodiversidade , Mudança Climática/estatística & dados numéricos , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/tendências , Espécies em Perigo de Extinção/estatística & dados numéricos , Espécies em Perigo de Extinção/tendências , Extinção Biológica , Risco , Urodelos/classificação
18.
Nature ; 622(7981): 87-92, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37794266

RESUMO

Disaster losses are increasing and evidence is mounting that climate change is driving up the probability of extreme natural shocks1-3. Yet it has also proved politically expedient to invoke climate change as an exogenous force that supposedly places disasters beyond the influence of local and national authorities4,5. However, locally determined patterns of urbanization and spatial development are key factors to the exposure and vulnerability of people to climatic shocks6. Using high-resolution annual data, this study shows that, since 1985, human settlements around the world-from villages to megacities-have expanded continuously and rapidly into present-day flood zones. In many regions, growth in the most hazardous flood zones is outpacing growth in non-exposed zones by a large margin, particularly in East Asia, where high-hazard settlements have expanded 60% faster than flood-safe settlements. These results provide systematic evidence of a divergence in the exposure of countries to flood hazards. Instead of adapting their exposure, many countries continue to actively amplify their exposure to increasingly frequent climatic shocks.


Assuntos
Cidades , Inundações , Migração Humana , Urbanização , Ásia Oriental , Cidades/estatística & dados numéricos , Mudança Climática/estatística & dados numéricos , Inundações/estatística & dados numéricos , Migração Humana/estatística & dados numéricos , Migração Humana/tendências , Probabilidade , Urbanização/tendências
20.
Nature ; 620(7972): 97-103, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37532816

RESUMO

Earth system models and various climate proxy sources indicate global warming is unprecedented during at least the Common Era1. However, tree-ring proxies often estimate temperatures during the Medieval Climate Anomaly (950-1250 CE) that are similar to, or exceed, those recorded for the past century2,3, in contrast to simulation experiments at regional scales4. This not only calls into question the reliability of models and proxies but also contributes to uncertainty in future climate projections5. Here we show that the current climate of the Fennoscandian Peninsula is substantially warmer than that of the medieval period. This highlights the dominant role of anthropogenic forcing in climate warming even at the regional scale, thereby reconciling inconsistencies between reconstructions and model simulations. We used an annually resolved 1,170-year-long tree-ring record that relies exclusively on tracheid anatomical measurements from Pinus sylvestris trees, providing high-fidelity measurements of instrumental temperature variability during the warm season. We therefore call for the construction of more such millennia-long records to further improve our understanding and reduce uncertainties around historical and future climate change at inter-regional and eventually global scales.


Assuntos
Mudança Climática , Pinus , Temperatura , Árvores , Mudança Climática/história , Mudança Climática/estatística & dados numéricos , Aquecimento Global/história , Aquecimento Global/estatística & dados numéricos , Reprodutibilidade dos Testes , Árvores/anatomia & histologia , Árvores/crescimento & desenvolvimento , História Medieval , História do Século XXI , Modelos Climáticos , Incerteza , Pinus/anatomia & histologia , Pinus/crescimento & desenvolvimento , Internacionalidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...