A climatic record from ^(14)C-dated wood fragments from southwestern Colorado

Deuterium concentration in trees are related to the climatic temperature at which the Trees grew. Deuterium analyses were made on all available (39) ^(14)C-dated (all ^(14)C dates cited are uncorrected) wood fragments collected from Lake Emma sediments. The ^(14)C dates range from 9600 to 5400 "B.P.". Tree line was above Lake Emma at 9600 "B.P.", was at Lake Emma at about 5000 "B.P.", and is 80 m below Lake Emma at the present time. The isotopic records at the various intervals of time coincide very well with this history. The range of δD values is maximum at 9600 "B.P." and is minimum at about 5400 "B.P.". These data allow us to estimate the temperature range for the area between tree line and Lake Emma between these times. These results confirm previously observed cooling trends from several sources in the Western Hemisphere

ENERGY FUTURES AND CLIMATE CHANGE MITIGATION: A QUALITATIVE AND QUANTITATIVE ASSESSMENT IN THE SUSTAINABLE DEVELOPMENT GOALS PERSPECTIVE

The 2030 Agenda – with its seventeen Sustainable Development Goals (SDGs) – and the Paris Agreement represent a turning point for Sustainable Development. For the first time, the world’s leaders have developed an integrated sustainable agenda and ratified a global agreement to reduce greenhouse gas emissions, recognizing that the current development model is not sustainable from an economic, social and environmental standpoint. Sustainable energy, being the driver of social and economic growth, will play a crucial role in the achievement of the 2030 Agenda objectives and for closing the gap to the mitigation targets of 2°C and 1.5°C defined by the Paris Agreement.This paper aims at showing that SDG 7 – the SDG dedicated to energy – can be considered as an enabling factor for the implementation of the other SDGs, and in particular of SDG 13, the goal on climate action.  This relation is bidirectional, meaning that mitigation of climate change is positively driven by the deployment of sustainable energy services, and that the integration of climate change mitigation strategies into national policies positively contributes to the deployment of sustainable energy solutions. The paper also shows that future energy scenarios, compatible with the above-mentioned ambitious mitigation targets, are in line with the SDG 7 Targets that can benefit from the strong technology innovation that those scenarios will require. The digitalization of the electricity sector through smart meters for demand side management and smart grids for distributed renewable generation is one example of the role of technology innovation toward SDG 7

Raw materials demand for wind and solar PV technologies in the transition towards a decarbonised energy system

Raw materials are essential to securing a transition to green energy technologies and for achieving the goals outlined in the European Green Deal. To meet the future energy demand through renewables, the power sector will face a massive deployment of wind and solar PV technologies. As result, the consumption of raw materials necessary to manufacture wind turbines and photovoltaic panels is expected to increase drastically in the coming decades. However, the EU industry is largely dependent on imports for many raw materials and in some cases is exposed to vulnerabilities in materials supply. These issues raise concerns on the availability of some raw materials needed to meet the future deployment targets for the renewable energy technologies. This study aims at estimating the future demand for raw materials in wind turbines and solar PV following several decarbonisation scenarios. For the EU, the materials demand trends were built on the EU legally binding targets by 2030 and deployment scenarios targeting a climate-neutral economy by 2050. At a global level, the generation capacity scenarios were selected based on various global commitments to limit greenhouse gas emissions and improve energy efficiency. Alongside the power generation capacity, the materials demand calculations considered three more factors such as the plant lifetime, sub-technology market share and materials intensity. By evaluating and combining those factors, three demand scenarios were built characterised by low, medium and high materials demands. For wind turbines, the annual materials demand will increase from 2-fold up to 15-fold depending on the material and the scenario considered. Significant demand increases are expected for both structural materials - concrete, steel, plastic, glass, aluminium, chromium, copper, iron, manganese, molybdenum, nickel, and zinc - and technology specific materials such as rare earths and minor metals. In the EU the biggest increase in materials demand will be for onshore wind, with significantly lower variations for offshore wind, while on a global scale the situation is opposite. The most significant example is that of rare earths (e.g. dysprosium, neodymium, praseodymium and terbium) used in permanent magnets-based wind turbines. In the most severe scenario, the EU annual demand for these rare earths can increase 6 times in 2030 and up to 15 times in 2050 compared to 2018 values. As consequence, by 2050, the deployment of wind turbines, according to EU decarbonisation goals, will require alone most of the neodymium, praseodymium, dysprosium and terbium currently available to the EU market. In the high demand scenario, the global demand for rare earths in wind turbines could increase between 8-9 times in 2030 and 11-14 times in 2050 compared to 2018 values, a slightly lower increase compared to the EU. For solar PV technologies there are large differences in material demand between different scenarios, especially for those specific materials used in the manufacturing of PV cells. In the most optimistic case, improvements in material intensities can lead to a net decrease in materials demand. In the medium demand scenario, the balance between capacity deployment and the material intensities will result in a moderate increase in demand ranging from 3 to 8 fold for most materials. In the high demand scenario it is expected an increase in demand for all materials, for example a 4-fold increase for silver and up to a 12-fold increase for silicon in 2050. For cadmium, gallium, indium, selenium and tellurium the change in the demand will be more significant, up to a 40 times increase in 2050. The highest demand in 2050 is expected for germanium, which might increase up to 86 times compared to 2018 values. In the most severe conditions, the EU will require around 8 times in 2030 and up to 30 times in 2050 more structural materials such as used in frame and staffing materials compared to 2018 values. Instead, the EU annual demand for PV cells materials varies more broadly such as between 4 times for silver and 86 times for germanium in 2050 according to the high demand conditions. For silicon, the EU demand is expected to increase 2 times in 2030 and 4 times in 2050 under the medium demand scenario, and 7 times in 2030 and 13 times in 2050 under a high demand scenario. Considering both technologies, such high increases in materials demand will put additional stresses on the future availability of some raw materials. The EU transition to green energy technologies according to the current decarbonisation scenarios can be put in dangerous due to weaknesses in future supply security for several materials such as germanium, tellurium gallium, indium, selenium, silicon and glass for the solar PV and rare earths for the wind turbines technologies.JRC.C.7-Knowledge for the Energy Unio

Determinants of Sexual Activity and Its Relation to Cervical Cancer Risk among South African Women

BACKGROUND. Invasive cervical cancer is the commonest cause of cancer morbidity and mortality in South African women. This study provides information on adult women's sexual activity and cervical cancer risk in South Africa. METHODS. The data were derived from a case-control study of hormonal contraceptives and cervical cancer risk. Information on age of sexual debut and number of lifetime sexual partners was collected from 524 incident cases and 1541 hospital controls. Prevalence ratios and adjusted prevalence ratios were utilised to estimate risk in exposures considered common. Crude and adjusted relative risks were estimated where the outcome was uncommon, using multiple logistic regression analysis. RESULTS. The median age of sexual debut and number of sexual partners was 17 years and 2 respectively. Early sexual debut was associated with lower education, increased number of life time partners and alcohol use. Having a greater number of sexual partners was associated with younger sexual debut, being black, single, higher educational levels and alcohol use. The adjusted odds ratio for sexual debut < 16 years and ≥ 4 life-time sexual partners and cervical cancer risk were 1.6 (95% CI 1.2 – 2.2) and 1.7 (95% CI 1.2 – 2.2), respectively. CONCLUSION. Lower socio-economic status, alcohol intake, and being single or black, appear to be determinants of increased sexual activity in South African women. Education had an ambiguous effect. As expected, cervical cancer risk is associated with increased sexual activity. Initiatives to encourage later commencement of sex, and limiting the number of sexual partners would have a favourable impact on risk of cancer of the cervix and other sexually transmitted infections.National Cancer Institute (R01 CA 73985

Aligning integrated assessment modelling with socio-technical transition insights: an application to low-carbon energy scenario analysis in Europe

In this study, we present and apply an interdisciplinary approach that systematically draws qualitative insights from socio-technical transition studies to develop new quantitative scenarios for integrated assessment modelling. We identify the transition narrative as an analytical bridge between socio-technical transition studies and integrated assessment modelling. Conceptual interaction is realised through the development of two contrasting transition narratives on the role of actors in meeting the European Unions' 80% greenhouse gas emission reduction objective for 2050. The first transition narrative outlines how large-scale innovation trajectories are driven by incumbent actors, whereas the second transition narrative assumes more ‘alternative’ strategies by new entrants with strong opposition to large-scale technologies. We use the multi-level perspective to draw out plausible storylines on actor positioning and momentum of change for several technological and social niche-innovations in both transition narratives. These storylines are then translated into quantitative scenarios for integrated assessment modelling. Although both developed transition pathways align with the European Union's low-carbon objective for 2050, we find that each pathway depicts a substantial departure from systems that are known to date. Future research could focus on further systematic (joint) development of operational links between the two analytical approaches, as well as work on improved representation of demand-oriented solutions in techno-economic modelling

Exploring pathways of solar PV learning-by-doing in Integrated Assessment Models

International audienc

HIV and pre-neoplastic and neoplastic lesions of the cervix in South Africa: a case-control study

BACKGROUND: Cervical cancer and infection with human immunodeficiency virus (HIV) are both major public health problems in South Africa. The aim of this study was to determine the risk of cervical pre-cancer and cancer among HIV positive women in South Africa. METHODS: Data were derived from a case-control study that examined the association between hormonal contraceptives and invasive cervical cancer. The study was conducted in the Western Cape (South Africa), from January 1998 to December 2001. There were 486 women with invasive cervical cancer, 103 control women with atypical squamous cells of undetermined significance (ASCUS), 53 with low-grade squamous intraepithelial lesions (LSIL), 50 with high-grade squamous intraepithelial lesions (HSIL) and 1159 with normal cytology. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multiple logistic regression. RESULTS: The adjusted odds ratios associated with HIV infection were: 4.4 [95% CI (2.3 – 8.4) for ASCUS, 7.4 (3.5 – 15.7) for LSIL, 5.8 (2.4 – 13.6) for HSIL and 1.17 (0.75 – 1.85) for invasive cervical cancer. HIV positive women were nearly 5 times more likely to have high-risk human papillomavirus infection (HR-HPV) present compared to HIV negative women [OR 4.6 (95 % CI 2.8 – 7.5)]. Women infected with both HIV and high-risk HPV had a more than 40 fold higher risk of SIL than women infected with neither of these viruses. CONCLUSION: HIV positive women were at an increased risk of cervical pre-cancer, but did not demonstrate an excess risk of invasive cervical cancer. An interaction between HIV and HR-HPV infection was demonstrated. Our findings underscore the importance of developing locally relevant screening and management guidelines for HIV positive women in South Africa

OpenET : filling a critical data gap in water management for the western United States.

The lack of consistent, accurate information on evapotranspiration (ET) and consumptive use of water by irrigated agriculture is one of the most important data gaps for water managers in the western United States (U.S.) and other arid agricultural regions globally. The ability to easily access information on ET is central to improving water budgets across the West, advancing the use of data-driven irrigation management strategies, and expanding incentive-driven conservation programs. Recent advances in remote sensing of ET have led to the development of multiple approaches for field-scale ET mapping that have been used for local and regional water resource management applications by U.S. state and federal agencies. The OpenET project is a community-driven effort that is building upon these advances to develop an operational system for generating and distributing ET data at a field scale using an ensemble of six well-established satellite-based approaches for mapping ET. Key objectives of OpenET include: Increasing access to remotely sensed ET data through a web-based data explorer and data services; supporting the use of ET data for a range of water resource management applications; and development of use cases and training resources for agricultural producers and water resource managers. Here we describe the OpenET framework, including the models used in the ensemble, the satellite, meteorological, and ancillary data inputs to the system, and the OpenET data visualization and access tools. We also summarize an extensive intercomparison and accuracy assessment conducted using ground measurements of ET from 139 flux tower sites instrumented with open path eddy covariance systems. Results calculated for 24 cropland sites from Phase I of the intercomparison and accuracy assessment demonstrate strong agreement between the satellite-driven ET models and the flux tower ET data. For the six models that have been evaluated to date (ALEXI/DisALEXI, eeMETRIC, geeSEBAL, PT-JPL, SIMS, and SSEBop) and the ensemble mean, the weighted average mean absolute error (MAE) values across all sites range from 13.6 to 21.6 mm/month at a monthly timestep, and 0.74 to 1.07 mm/day at a daily timestep. At seasonal time scales, for all but one of the models the weighted mean total ET is within ±8% of both the ensemble mean and the weighted mean total ET calculated from the flux tower data. Overall, the ensemble mean performs as well as any individual model across nearly all accuracy statistics for croplands, though some individual models may perform better for specific sites and regions. We conclude with three brief use cases to illustrate current applications and benefits of increased access to ET data, and discuss key lessons learned from the development of OpenET