Efforts to control climate change require the stabilization of atmospheric CO(2) concentrations. This can only be achieved through a drastic reduction of global CO(2) emissions. Yet fossil fuel emissions increased by 29% between 2000 and 2008, in conjunction with increased contributions from emergin...
por Portal Padrão
publicado
26/08/2009
1:16 PM
Tipping points for the Amazon forest
The stability of the Amazon forestclimate equilibrium is being perturbed by a number of human drivers of change (e.g. deforestation, global warming, forest fires, higher CO2 concentrations, and increased frequency of droughts and floods). Quantitative assessments for the maintenance of the tropical ...
por Portal Padrão
publicado
26/08/2009
1:15 PM
Dynamical coupling of multiscale land change models modelling, Amazonia: deforestation models
No single model or scale can fully capture the causes of land change. For a given region, land changes may have different impacts at different places. Limits and opportunities imposed by biophysical and socio-economic conditions, such as local policies and accessibility, may induce distinct land cha...
por Portal Padrão
publicado
26/08/2009
1:14 PM
Meteorological downscaling methods and artificial neural network models
The mathematical models used to simulate the present climate and project future climate when forced by greenhouse gases and aerosols are generally referred to as General Circulation Models (GCMs). While they have demonstrated significant skill in the continental and hemispherical scales and incorpor...
por Portal Padrão
publicado
26/08/2009
1:13 PM
Future change of temperature and precipitation extremes in South America as derived from the PRECIS regional climate modeling system
Using the PRECIS regional climate modeling system this study analyses the distribution of extremes of temperature and precipitation in South America in the recent past (19611990) and in a future (20712100) climate under the IPCC SRES A2 and B2 emissions scenarios. The results show that for the prese...
por Portal Padrão
publicado
26/08/2009
1:12 PM
Tropical South America east of the Andes
Most of tropical South America east of the Andes and south of 23°S experienced a warm 2008, with annual mean temperatures 2° to 3°C warmer than normal. Likewise, warm conditions (1° to 2°C above normal) were observed in northern Venezuela, interior Brazil between Amazonia and Northeast Brazil, ...
por Portal Padrão
publicado
26/08/2009
1:10 PM
Long-term trends and cycles in the hydrometeorology of the Amazon basin since the late 1920s
Rainfall and river indices for both the northern and southern Amazon were used to identify and explore long-term climate variability on the region. From a statistical analysis of the hydrometeorological series, it is concluded that no systematic unidirectional long-term trends towards drier or wette...
por Portal Padrão
publicado
26/08/2009
1:07 PM
Crossing thresholds in regional climate research: synthesis of the IPCC expert meeting on regional impacts, adaptation, vulnerability, and mitigation
Contributions of regional scale climate change research to the management of climate risks were explored at a meeting of researchers, policymakers, and practitioners in June 2007 (convened by the Task Group on Data and Scenario Support for Impact and Climate Analysis of the Intergovernmental Panel o...
por Portal Padrão
publicado
26/08/2009
1:05 PM
A science-policy interface in the global south: the politics of carbon sinks and science in Brazil
The IPCC and other global environmental assessment processes stress the need for national scientific participation to ensure decision makers' trust in the associated scientific conclusions and political agendas. The underpinning assumption is that the relationship between scientists and decision mak...
por Portal Padrão
publicado
26/08/2009
1:04 PM
Isotopic view of vegetation and carbon and nitrogen cycles in a cerrado ecosystem, southeastern Brazil
Carbon and nitrogen biogeochemical cycles in savannas are strongly regulated by the seasonal distribution of precipitation and pulses of nutrients released during the wetting of the dry soil and are critical to the dynamics of microorganisms and vegetation. The objective of this study was to investi...
por Portal Padrão
publicado
26/08/2009
1:03 PM
Long-term potential for tropical-forest degradation due to deforestation and fires in the Brazilian Amazon
Biome models of the global climate-vegetation relationships indicate that most of the Brazilian Amazon has potential for being covered by tropical forests. From current land-use processes observed in the region, however, substantial deforestation and fire activity have been verified in large portion...
por Portal Padrão
publicado
26/08/2009
1:03 PM
Atmosphere and hydrological controls of the evapotranspiration over a floodplain forest in the Bananal Island region, Amazonia
This article discusses seasonal and interannual variations of the evapotranspiration (ET) rates in Bananal Island floodplain, Brazil. Measurements included ET and sensible heat flux using the eddy covariance method, atmospheric forcings (net radiation, Rn, vapor pressure deficit, VPD, wind speed and...
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