1,141 research outputs found
The impact of land cover change on surface energy and water balance in Mato Grosso, Brazil
The sensitivity of surface energy and water fluxes to recent land cover changes is simulated for a small region in northern Mato Grosso, Brazil. The Simple Biosphere Model (SiB2) is used, driven by biophysical parameters derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) at 250-m resolution, to compare the effects of different land conversion types. The mechanisms through which changes in vegetation alter surface fluxes of energy, momentum, water, and carbon are analyzed for both wet and dry seasons. It is found that morphological changes contribute to warming and drying of the atmosphere while physiological changes, particularly those associated with a plant’s photosynthetic pathway, counterbalance or exacerbate the warming depending on the type of conversion and the season. Furthermore, this study’s results indicate that initial clearing of evergreen and transition forest to bare ground increases canopy temperature by up to 1.7°C. For subsequent land use such as pasture or cropland, the largest effect is seen for the conversion of evergreen forest to C3 cropland during the wet season, with a 21% decrease of the latent heat flux and 0.4°C increase in canopy temperature. The secondary conversion of pasture to cropland resulted in slight warming and drying during the wet season driven mostly by the change in carbon pathway from C4 to C3. For all conversions types, the daily temperature range is amplified, suggesting that plants replacing forest clearing require more temperature tolerance than the trees they replace. The results illustrate that the effect of deforestation on climate depends not only on the overall extent of clearing but also on the subsequent land use type
Generating carbon finance through avoided deforestation and its potential to create climatic, conservation and human development benefits
Recent proposals to compensate developing countries for reducing emissions from deforestation (RED) under forthcoming climate change mitigation regimes are receiving increasing attention. Here we demonstrate that if RED credits were traded on international carbon markets, even moderate decreases in deforestation rates could generate billions of Euros annually for tropical forest conservation. We also discuss the main challenges for a RED mechanism that delivers real climatic benefits. These include providing sufficient incentives while only rewarding deforestation reductions beyond business-as-usual scenarios, addressing risks arising from forest degradation and international leakage, and ensuring permanence of emission reductions. Governance may become a formidable challenge for RED because some countries with the highest RED potentials score poorly on governance indices. In addition to climate mitigation, RED funds could help achieve substantial co-benefits for biodiversity conservation and human development. However, this will probably require targeted additional support because the highest biodiversity threats and human development needs may exist in countries that have limited income potentials from RED. In conclusion, how successfully a market-based RED mechanism can contribute to climate change mitigation, conservation and development will strongly depend on accompanying measures and carefully designed incentive structures involving governments, business, as well as the conservation and development communities
Recommended from our members
Sensitivity of grain yields to historical climate variability in India
Fluctuations in temperature and precipitation influence crop productivity across the planet. With episodes of extreme climate becoming increasingly frequent, buffering crop production against these stresses is a critical aspect of climate adaptation. In India, where grain production and diets are closely linked, national food supply is sensitive to the effect of climate variability on monsoon grain production. Here we quantitatively examine the historical (1966–2011) relationship between interannual variations in temperature and rainfall and rainfed yield variability for five monsoon crops—rice and four alternative grains (finger millet, maize, pearl millet, and sorghum). Compared to rice, we find that alternative grains are significantly less sensitive to climate variation and generally experience smaller declines in yield under climate extremes. However, maximizing harvested area allocations to coarse grains (i.e. holding maize production constant) reduced grain production by 12.0 Mtonnes (−17.2%) under drought conditions and 12.8 Mtonnes (−18.0%) during non-drought years (non-drought). Increasing the harvested area allocated to all alternative grains (i.e. including maize) can enhance production by +39.6% (drought) and by +37.0% (non-drought). These alternative grains therefore offer promise for reducing variations in Indian grain production in response to climate shocks, but avoiding grain production shortfalls from increased alternative grains will require yield improvements that do not compromise their superior climate resilience
Differential genetic etiology of reading disability as a function of mathematics performance
In order to assess the etiology of reading disability as a function of mathematics performance, data from 168 monozygotic (MZ) and 127 same-sex dizygotic (DZ) twin pairs in which at least one member of each pair was reading-disabled were subjected to quantitative genetic analyses. MZ and DZ concordance rates for reading disability were computed for different levels of mathematics performance, and reading performance data were fitted to an extension of the basic multiple regression model for the analysis of selected twin data. Results of these analyses suggest that genetic factors may be especially salient as a cause of reading disability in children with borderline deficits in mathematics performance: thus, mathematics performance may be a valid dimension for diagnosing subtypes of reading disability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43574/1/11145_2004_Article_BF00395110.pd
Integrating evidence, politics and society: a methodology for the science–policy interface
There is currently intense debate over expertise, evidence and ‘post-truth’ politics, and how this is influencing policy formulation and implementation. In this article, we put forward a methodology for evidence-based policy making intended as a way of helping navigate this web of complexity. Starting from the premise of why it is so crucial that policies to meet major global challenges use scientific evidence, we discuss the socio-political difficulties and complexities that hinder this process. We discuss the necessity of embracing a broader view of what constitutes evidence—science and the evaluation of scientific evidence cannot be divorced from the political, cultural and social debate that inevitably and justifiably surrounds these major issues. As a pre-requisite for effective policy making, we propose a methodology that fully integrates scientific investigation with political debate and social discourse. We describe a rigorous process of mapping, analysis, visualisation and sharing of evidence, constructed from integrating science and social science data. This would then be followed by transparent evidence evaluation, combining independent assessment to test the validity and completeness of the evidence with deliberation to discover how the evidence is perceived, misunderstood or ignored. We outline the opportunities and the problems derived from the use of digital communications, including social media, in this methodology, and emphasise the power of creative and innovative evidence visualisation and sharing in shaping policy
Fire-Related Carbon Emissions from Land Use Transitions in Southern Amazonia
Various land-use transitions in the tropics contribute to atmospheric carbon emissions, including forest conversion for small-scale farming, cattle ranching, and production of commodities such as soya and palm oil. These transitions involve fire as an effective and inexpensive means for clearing. We applied the DECAF (DEforestation CArbon Fluxes) model to Mato Grosso, Brazil to estimate fire emissions from various land-use transitions during 2001-2005. Fires associated with deforestation contributed 67 Tg C/yr (17 and 50 Tg C/yr from conversion to cropland and pasture, respectively), while conversion of savannas and existing cattle pasture to cropland contributed 17 Tg C/yr and pasture maintenance fires 6 Tg C/yr. Large clearings (>100 ha/yr) contributed 67% of emissions but comprised only 10% of deforestation events. From a policy perspective, results imply that intensification of agricultural production on already-cleared land and policies to discourage large clearings would reduce the major sources of emissions from fires in this region. Copyright 2008 by the American Geophysical Union
Healthy, affordable and climate-friendly diets in India
India has among the highest lost years of life from micronutrient deficiencies. We investigate what dietary shifts would eliminate protein, iron, zinc and Vitamin A deficiencies within households’ food budgets and whether these shifts would be compatible with mitigating climate change. This analysis uses the National Sample Survey (2011–12) of consumption expenditure to calculate calorie, protein and the above micronutrient intake deficiencies and relate them to diets, income and location. We show that more than two-thirds of Indians consume insufficient micronutrients, particularly iron and Vitamin A, and to a lesser extent zinc. A greater proportion of urban households than rural households are deficient at all income levels and for all nutrients, with few exceptions. Deficiencies reduce with increasing income. Using constrained optimization, we find that households could overcome these nutrient deficiencies within their food budgets by diversifying their diets, particularly towards coarse cereals, pulses, and leafy vegetables, and away from rice. These dietary changes could reduce India’s agricultural greenhouse gas (GHG) emissions by up to 25%. Current agricultural and food pricing policies may disincentivize these dietary shifts, particularly among the poor
On Population Growth Near Protected Areas
Background: Protected areas are the first, and often only, line of defense in efforts to conserve biodiversity. They might be detrimental or beneficial to rural communities depending on how they alter economic opportunities and access to natural resources. As such, protected areas may attract or repel human settlement. Disproportionate increases in population growth near protected area boundaries may threaten their ability to conserve biodiversity. Methodology/Principal Findings: Using decadal population datasets, we analyze population growth across 45 countries and 304 protected areas. We find no evidence for population growth near protected areas to be greater than growth of rural areas in the same country. Furthermore, we argue that what growth does occur near protected areas likely results from a general expansion of nearby population centers. Conclusions/Significance: Our results contradict those from a recent study by Wittemyer et al., who claim overwhelming evidence for increased human population growth near protected areas. To understand the disagreement, we re-analyzed the protected areas in Wittemyer et al.’s paper. Their results are simply artifacts of mixing two incompatible datasets. Protected areas may experience unusual population pressures near their edges; indeed, individual case studies provid
Comorbidity of Reading and Mathematics Disabilities
Although children with learning disabilities frequently manifest comorbid reading and mathematics deficits, the cause of this comorbidity is unknown. To assess the extent to which comorbidity between reading and mathematics deficits is due to genetic and environmental influences, we conducted a twin study of reading and mathematics performance. Data from 148 identical and 111 fraternal twin pairs in which at least one member of the pair had a reading disability were subjected to a cross-concordance analysis and also fitted to a bivariate extension of the basic multiple regression model for the analysis of selected twin data. Results of these analyses suggest that genetic and shared-environmental influences both contribute to the observed covariance between reading and mathematics deficits.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68572/2/10.1177_002221949502800204.pd
- …