An investigation into linearity with cumulative emissions of the climate and carbon cycle response in HadCM3LC

We investigate the extent to which global mean temperature, precipitation, and the carbon cycle are constrained by cumulative carbon emissions throughout four experiments with a fully coupled climate-carbon cycle model. The two paired experiments adopt contrasting, idealised approaches to climate change mitigation at different action points this century, with total emissions exceeding two trillion tonnes of carbon in the later pair. Their initially diverging cumulative emissions trajectories cross after several decades, before diverging again. We find that their global mean temperatures are, to first order, linear with cumulative emissions, though regional differences in temperature of up to 1.5K exist when cumulative emissions of each pair coincide. Interestingly, although the oceanic precipitation response scales with cumulative emissions, the global precipitation response does not, due to a decrease in precipitation over land above cumulative emissions of around one trillion tonnes of carbon (TtC). Most carbon fluxes and stores are less well constrained by cumulative emissions as they reach two trillion tonnes. The opposing mitigation approaches have different consequences for the Amazon rainforest, which affects the linearity with which the carbon cycle responds to cumulative emissions. Averaged over the two fixed-emissions experiments, the transient response to cumulative carbon emissions (TCRE) is 1.95 K TtC-1, at the upper end of the IPCC’s range of 0.8-2.5 K TtC-1

Holocene carbon-cycle dynamics based on CO2 trapped in ice at Taylor Dome, Antarctica

A high-resolution ice-core record of atmospheric CO2 concentration over the Holocene epoch shows that the global carbon cycle has not been in steady state during the past 11,000 years. Analysis of the CO2 concentration and carbon stable-isotope records, using a one-dimensional carbon-cycle model,uggests that changes in terrestrial biomass and sea surface temperature were largely responsible for the observed millennial-scale changes of atmospheric CO2 concentrations

The carbon cycle in Mexico: past, present and future of C stocks and fluxes

PublishedThe Supplement related to this article is available online at doi:10.5194/bg-13-223-2016-supplement.We modeled the carbon (C) cycle in Mexico with a process-based approach. We used different available products (satellite data, field measurements, models and flux towers) to estimate C stocks and fluxes in the country at three different time frames: present (defined as the period 2000–2005), the past century (1901–2000) and the remainder of this century (2010–2100). Our estimate of the gross primary productivity (GPP) for the country was 2137 ± 1023 TgC yr−1 and a total C stock of 34 506 ± 7483 TgC, with 20 347 ± 4622 TgC in vegetation and 14 159 ± 3861 in the soil. Contrary to other current estimates for recent decades, our results showed that Mexico was a C sink over the period 1990–2009 (+31 TgC yr−1) and that C accumulation over the last century amounted to 1210 ± 1040 TgC. We attributed this sink to the CO2 fertilization effect on GPP, which led to an increase of 3408 ± 1060 TgC, while both climate and land use reduced the country C stocks by −458 ± 1001 and −1740 ± 878 TgC, respectively. Under different future scenarios, the C sink will likely continue over the 21st century, with decreasing C uptake as the climate forcing becomes more extreme. Our work provides valuable insights on relevant driving processes of the C cycle such as the role of drought in drylands (e.g., grasslands and shrublands) and the impact of climate change on the mean residence time of soil C in tropical ecosystems.The lead author (G. Murray-Tortarolo) thanks CONACYT-CECTI, the University of Exeter and Secretaría de Educación Pública (SEP) for their funding of this project. The authors extend their thanks to Carlos Ortiz Solorio and to the Colegio de Posgraduados for the field soil data and to the Alianza Redd+ Mexico for the field biomass data. This project would not have been possible without the valuable data from the CMIP5 models. A. Arneth, G. Murray-Tortarolo, A. Wiltshire and S. Sitch acknowledge the support of the European Commission-funded project LULCC4C (grant no. 603542). A. Wiltshire was partsupported by the Joint UK DECC/Defra Met Office Hadley Centre Climate Programme (GA01101)

Reação de genótipos de batata à requeima (Phytophthora infestans).

bitstream/item/30474/1/boletim-83.pd

Arabic version of the Personality Inventory for the DSM-5 (PID-5) in a community sample of United Arab Emirates nationals

Background: Section III of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) proposes a model for conceptualizing personality disorders in which they are characterized by impairments in personality functioning and maladaptive personality traits. The Personality Inventory for DSM-5 (PID-5) is a self-report measure that assesses the presence and severity of these maladaptive personality traits. Objective: The current study examined the reliability and validity of the Arabic version of the Personality Inventory for DSM-5 (PID-5) to measure maladaptive personality traits in the Emirati population of the United Arab Emirates. Methods: The Arabic version of the PID-5 was administered to a community sample of 1,090 United Arab Emirates nationals (89.5% female and 10.5% male, mean age = 22.44 years old). The descriptive measures, internal consistency, test-retest reliability, convergent validity with NEO – Five Factor Inventory, as well as PID-5’s factor structure, were all addressed. Results: The PID-5facets and domains mean scores were higher in the Emirati sample compared to the original US sample. Internal consistency of the PID-5 scales was acceptable to high and test-retest coefficients ranged from 0.84 (facets) to 0.87 (domains). As expected, the five domains of the Arabic version of the PID-5 correlated significantly with all Five-Factor Model domains of personality. Additionally, the Arabic version of the PID-5 confirmed a five-factor structure that resembles the PID-5 domains. Conclusion: The findings of this study provided initial support for the use of the Arabic version of the PID-5 to assess maladaptive personality traits in the Emirati population of the United Arab Emirates.info:eu-repo/semantics/publishedVersio

Subocclusive transvenous approach of dural arteriovenous fistula

Introdução: As fístulas arteriovenosas durais (FAVd) são usualmente adquiridas e quando apresentam drenagem venosa cortical estão associadas a um risco elevado de hemorragia. Podem ser tratadas por embolização (transarterial ou transvenosa), cirurgicamente ou pela combinação das duas técnicas. A embolização por via transvenosa induz uma trombose iatrogénica do seio venoso, acarretando risco de enfarte venoso e/ou hemorragia. Objectivo: Rever os casos de FAVd do seio lateral submetidas a embolização transvenosa. O nosso principal objectivo é avaliar a eficácia e a morbilidade deste tipo de tratamento e o segundo é discutir as possíveis vantagens de uma abordagem suboclusiva na primeira sessão de tratamento. Resultados: Os autores apresentam seis casos clínicos de FAVd, cujas formas de apresentação foram: diminuição da acuidade visual (3); sopro pulsátil no ouvido (3); cefaleias (2); hemorragia subaracnoideia (1); hipoacusia subjectiva (1); edema da papila (1); défice motor (1). Angiograficamente: Cognard IIa (3), IIab (2) e IV (1), todas com envolvimento dos seios laterais. As principais aferências eram: ACE ipsilateral (6); ACI ipsilateral (6); AV ipsilateral (6); ACE contralateral (5); AV contralateral (5); ACI contralateral (3); ACP ipsilateral (1). O tratamento inicial foi sempre a abordagem transarterial, com resultados angiográficos aceitáveis, embora transitórios. Posteriormente optou-se pela via transvenosa com preenchimento do seio lateral com GDC coils. Em cinco dos doentes decidiu-se pela suboclusão, com persistência de algumas aferências. Em quatro, a angiografia subsequente demonstrou trombose “espontânea” do seio lateral com resolução clínica e angiográfica da doença. Num deles a trombose ocorreu ainda durante a sessão inicial. Todos os procedimentos decorreram sem complicações e nenhum dos doentes desenvolveu novos défices neurológicos focais. Conclusões: A abordagem transvenosa das FAVd obteve um sucesso técnico e clínico assinalável, sem presença de complicações. Pensamos que a suboclusão do seio venoso com coils poderá induzir menor alteração hemodinâmica aguda, possibilitando uma trombose mais lenta, diminuindo o risco de complicações, mas com resolução angiográfica ulterior da FAVd

Coupling of eastern and western subpolar North Atlantic: salt transport in the Irminger Current

Salt transport in the Irminger Current and thus the coupling between eastern and western subpolar North Atlantic plays an important role for climate variability across a wide range of time scales. High-resolution ocean modeling and observations indicate that 5 salinities in the eastern subpolar North Atlantic decrease with enhanced circulation of the North Atlantic subpolar gyre (SPG). This has led to the perception that a stronger SPG also transports less salt westward. In this study, we analyze a regional ocean model and a comprehensive global coupled climate model, and show that a stronger SPG transports more salt in the Irminger Current irrespective of lower salinities in its 10 source region. The additional salt converges in the Labrador Sea and the Irminger Basin by eddy transports, increases surface salinity in the western SPG, and favors more intense deep convection. This is part of a positive feedback mechanism with potentially large implications for climate variability and predictability

Enhanced Australian carbon sink despite increased wildfire during the 21st century

Climate projections show Australia becoming significantly warmer during the 21st century, and precipitation decreasing over much of the continent. Such changes are conventionally considered to increase wildfire risk. Nevertheless, we show that burnt area increases in southern Australia, but decreases in northern Australia. Overall the projected increase in fire is small (0.72–1.31% of land area, depending on the climate scenario used), and does not cause a decrease in carbon storage. In fact, carbon storage increases by 3.7–5.6 Pg C (depending on the climate scenario used). Using a process-based model of vegetation dynamics, vegetation–fire interactions and carbon cycling, we show increased fire promotes a shift to more fire-adapted trees in wooded areas and their encroachment into grasslands, with an overall increase in forested area of 3.9–11.9%. Both changes increase carbon uptake and storage. The increase in woody vegetation increases the amount of coarse litter, which decays more slowly than fine litter hence leading to a relative reduction in overall heterotrophic respiration, further reducing carbon losses. Direct CO2 effects increase woody cover, water-use efficiency and productivity, such that carbon storage is increased by 8.5–14.8 Pg C compared to simulations in which CO2 is held constant at modern values. CO2 effects tend to increase burnt area, fire fluxes and therefore carbon losses in arid areas, but increase vegetation density and reduce burnt area in wooded areas