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Wintertime aerosol pollution in the North China Plain has increased over the past several decades as anthropogenic emissions in China have increased, and has dramatically escalated since the beginning of the 21st century, but the causes and their quantitative attributions remain unclear
. Here we use an aerosol source tagging capability implemented in a global aerosol-climate model to assess long-term trends of PM2.5 (particulate matter less than 2.5 μm in diameter) in the North China Plain. Our analysis suggests that the impact of China’s increasing domestic emissions on PM2.5 concentrations over the last two decades of 20th century was partially offset (13%) by decreasing foreign emission over this period. As foreign emissions stabilized after 2000, their counteracting effect almost disappeared, uncovering the impact of China’s increasing domestic emissions that had been partially offset in previous years by reductions in foreign emissions. A slowdown in the impact from foreign emission reductions together with weakening winds explain 25% of the increased PM2.5 trend over 2000–2014 as compared to 1980–2000. Further reductions in foreign emissions are not expected to relieve China’s pollution in the future. Reducing local emissions is the most certain way to improve future air quality in the North China Plain
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Rockström, J.; Williams, J.; Daily, G.; Noble, A.; Matthews, N.; Gordon, L.; Wetterstrand, H.; Declerck, F.; Shah, M.; Steduto, P.; De Fraiture, C.; Hatibu, N.; Unver, O.; Bird, J.; Sibanda, L.; Smith, J.
There is an ongoing debate on what constitutes sustainable intensification of agriculture (SIA)
. In this paper, we propose that a paradigm for sustainable intensification can be defined and translated into an operational framework for agricultural development. We argue that this paradigm must now be defined—at all scales—in the context of rapidly rising global environmental changes in the Anthropocene, while focusing on eradicating poverty and hunger and contributing to human wellbeing. The criteria and approach we propose, for a paradigm shift towards sustainable intensification of agriculture, integrates the dual and interdependent goals of using sustainable practices to meet rising human needs while contributing to resilience and sustainability of landscapes, the biosphere, and the Earth system. Both of these, in turn, are required to sustain the future viability of agriculture. This paradigm shift aims at repositioning world agriculture from its current role as the world’s single largest driver of global environmental change, to becoming a key contributor of a global transition to a sustainable world within a safe operating space on Earth
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Rockström, J.; Williams, J.; Daily, G.; Noble, A.; Matthews, N.; Gordon, L.; Wetterstrand, H.; Declerck, F.; Shah, M.; Steduto, P.; De Fraiture, C.; Hatibu, N.; Unver, O.; Bird, J.; Sibanda, L.; Smith, J.
There is an ongoing debate on what constitutes sustainable intensification of agriculture (SIA)
. In this paper, we propose that a paradigm for sustainable intensification can be defined and translated into an operational framework for agricultural development. We argue that this paradigm must now be defined—at all scales—in the context of rapidly rising global environmental changes in the Anthropocene, while focusing on eradicating poverty and hunger and contributing to human wellbeing. The criteria and approach we propose, for a paradigm shift towards sustainable intensification of agriculture, integrates the dual and interdependent goals of using sustainable practices to meet rising human needs while contributing to resilience and sustainability of landscapes, the biosphere, and the Earth system. Both of these, in turn, are required to sustain the future viability of agriculture. This paradigm shift aims at repositioning world agriculture from its current role as the world’s single largest driver of global environmental change, to becoming a key contributor of a global transition to a sustainable world within a safe operating space on Earth
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In 2014, Chojnacky et al
. published a revised set of biomass equations for trees of temperate US forests, expanding on an existing equation set (published in 2003 by Jenkins et al.), both of which were developed from published equations using a meta-analytical approach. Given the similarities in the approach to developing the equations, an examination of similarities or differences in carbon stock estimates generated with both sets of equations benefits investigators using the Jenkins et al. (For Sci 49:12–34, 2003) equations or the software tools into which they are incorporated. We provide a roadmap for applying the newer set to the tree species of the US, present results of equivalence testing for carbon stock estimates, and provide some general guidance on circumstances when equation choice is likely to have an effect on the carbon stock estimate
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Mantgem, P. J.; Stephenson, N. L.; Larson, A. J.; Byrne, J. C.; Daniels, L. D.; Franklin, J. F.; Fulé, P.; Harmon, M. E.; Smith, J. M.; Taylor, A. H.; Veblen, T. T.
Persistent changes in tree mortality rates can alter forest structure, composition, and ecosystem services such as carbon sequestration
. Our analyses of longitudinal data from unmanaged old forests in the western United States showed that background (noncatastrophic) mortality rates have increased rapidly in recent decades, with doubling periods ranging from 17 to 29 years among regions. Increases were also pervasive across elevations, tree sizes, dominant genera, and past fire histories. Forest density and basal area declined slightly, which suggests that increasing mortality was not caused by endogenous increases in competition. Because mortality increased in small trees, the overall increase in mortality rates cannot be attributed solely to aging of large trees. Regional warming and consequent increases in water deficits are likely contributors to the increases in tree mortality rates
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In many countries, governments are seeking advice from a wide range of disciplines on the potential impacts of climate change on the environment and their society and economy
. This handbook is designed to help those conducting research supporting such advice. Underlying the research are two fundamental questions: “What does climate change mean to us?” and “What might be done about it?” This handbook is designed to provide newcomers to the field of climate impact and adaptation assessment with a guide to available research methods, particularly for answering the first question. The handbook will also serve as a ready reference for many others currently engaged in impacts and adaptation research.
This comprehensive handbook covers a wide range of potential research areas, including:
- Socio-Economic Scenarios
- Climate Change Scenarios
- Integration
- Adaptation to Climate Change: Theory and Assessment
- Water Resources
- Coastal Zones
- Agriculture
- Rangeland and Livestock
- Human Health
- Energy
- Forest
- Biodiversity: Species, Communities, and Ecosystems
- Fisheries.
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A bacterial phylogenetic survey of three environmentally distinct Antarctic Dry Valley soil biotopes showed a high proportion of so-called "uncultured" phylotypes, with a relatively low diversity of identifiable phylotypes
. Cyanobacterial phylotypic signals were restricted to the high-altitude sample, whereas many of the identifiable phylotypes, such as the members of the Actinobacteria, were found at all sample sites. Although the presence of Cyanobacteria and Actinobacteria is consistent with previous culture-dependent studies of microbial diversity in Antarctic Dry Valley mineral soils, many phylotypes identified by 16S rDNA analysis were of groups that have not hitherto been cultured from Antarctic soils. The general belief that such "extreme" environments harbor a relatively low species diversity was supported by the calculation of diversity indices. The detection of a substantial number of uncultured bacterial phylotypes showing low BLAST identities (< 95%) suggests that Antarctic Dry Valley mineral soils harbor a pool of novel psychrotrophic taxa
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The success of participatory conservation projects depends greatly on the interest shown by the local population and on the strategies used to incorporate all stakeholders from the initial stages
. In the highly diverse region of the tropical Andean páramos, threats to ecosystem integrity come mainly from agriculture and cattle grazing. Approaches to biodiversity conservation have often been based on top-down regulations imposed by government agencies. The implementation of an alternative approach, incorporating local communities in the design of action plans for conservation, was the central objective during the design phase of the Andean Páramo Project. These plans will be executed in a network of key pilot sites along the South American páramos. Here the authors report on experience at the two Venezuelan sites, where the design process involved a series of participatory workshops. The multidisciplinary nature of the facilitation team was essential in addressing the complex links between biodiversity conservation, land use strategies, and human welfare. The success of the approach was associated with the local population's great interest in and detailed knowledge of the ecosystem, as well as with our emphasis on empowerment through incorporating local knowledge and views as the basis for planning
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Agrobiodiversity - biological resources that directly and indirectly contribute to crop and livestock production - is arguably the single most important natural resource in worldwide efforts to intensify agriculture while protecting the environment
. Agrobiodiversity is key to transforming agricultural systems that are currently wreaking havoc on wildlife and human health and is also essential to boosting yields to satisfy the world's growing appetite for food, fiber, and other crop and livestock products. This report highlights case studies in which modern and traditional agriculture have been successfully transformed to enhance biodiversity without sacrificing yield. Lessons learned from this review help identify sound practices for designing and monitoring agricultural projects so that they improve rural incomes while safeguarding environmental assets, particularly biodiversity. The successful protection and deployment of biodiversity hinges on a favorable policy environment and on agricultural research and extension activities that stress farmer participation and greater sensitivity to the off-site impacts of agriculture. Suggestions for sound practices, therefore, include modification of the policy environment, and ways to strengthen research institutions and extension services so that agriculture can be intensified while better protecting and managing biological resources
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