66 resultados para Reliable change
em Scielo Saúde Pública - SP
Resumo:
ABSTRACTThe Amazon várzeas are an important component of the Amazon biome, but anthropic and climatic impacts have been leading to forest loss and interruption of essential ecosystem functions and services. The objectives of this study were to evaluate the capability of the Landsat-based Detection of Trends in Disturbance and Recovery (LandTrendr) algorithm to characterize changes in várzeaforest cover in the Lower Amazon, and to analyze the potential of spectral and temporal attributes to classify forest loss as either natural or anthropogenic. We used a time series of 37 Landsat TM and ETM+ images acquired between 1984 and 2009. We used the LandTrendr algorithm to detect forest cover change and the attributes of "start year", "magnitude", and "duration" of the changes, as well as "NDVI at the end of series". Detection was restricted to areas identified as having forest cover at the start and/or end of the time series. We used the Support Vector Machine (SVM) algorithm to classify the extracted attributes, differentiating between anthropogenic and natural forest loss. Detection reliability was consistently high for change events along the Amazon River channel, but variable for changes within the floodplain. Spectral-temporal trajectories faithfully represented the nature of changes in floodplain forest cover, corroborating field observations. We estimated anthropogenic forest losses to be larger (1.071 ha) than natural losses (884 ha), with a global classification accuracy of 94%. We conclude that the LandTrendr algorithm is a reliable tool for studies of forest dynamics throughout the floodplain.
Resumo:
Due to its recent economic success, Brazil is considered an emerging country, but is it an emerging power concerning global environmental governance? This article argues that although Brazil has a sui generis profile, it can only be considered an emerging power in some environmental regimes, such as global climate change. Thus, international relations theory needs more analytical instruments to assess the impact of emerging powers in global environmental governance
Resumo:
The European Union's (EU) decision to include aviation into the Emissions Trade Scheme was heatedly contested. Countries around the world, but mainly the Brazil, Russia, India, China and South Africa group (BRICS) and the US, denounced the EU's initiate as illegal and unilateral. Following a decade of frustrated negotiations at the International Civil Aviation Organization (ICAO), this paper interrogates why such measure, in principle climate-friendly, inspired so much global resentment. I argue that concerns with competitiveness and risks of legal inconsistency are important, but insufficient elements to explain the core of the conflict. The paper suggests that the EU was strongly criticized because third countries perceived this action as an imposed solution, which fostered an environment of distrust. Therefore, I claim that the problem has more to do with a normative divide than with a substantive divergence on what should be done regarding aviation emissions. My analysis is informed by the present literature on the links between trade and climate change, but gives particular weight to first-hand information through interviews with key stakeholders. The paper is divided in three parts. First, it presents the scope of the EU directive in historical perspective. Second, it explores the EU's measure through three different angles: legal, economical and political. The final part explores some possible solutions to overcome these divergences.
Resumo:
In recent years, erratic global climate conditions have generated an incessant series of natural disasters in China. This article seeks to explore China's climate change policies. This article addresses the impacts of climate change on China's environment and China's perception, principle, objective and policy actions in response to climate change.
Resumo:
Como organização regional, o papel da União Europeia na governança global do clima enfrenta obstáculos que não se aplicam a nenhuma outra parte da Convenção-Quadro das Nações Unidas sobre a Mudança do Clima (CQNUMC) e do Protocolo de Quioto. Avaliando essa singularidade, este artigo fornece uma analise teórica e empírica de como os elementos de actorness (reconhecimento, capacidade, oportunidade e coesão) definem a participação da UE no regime internacional de mudanças climáticas.
Resumo:
This article describes the Brazilian position on forests and climate change from 1997 to 2012. It argues that it has evolved from a veto, which excluded from the climate change regime emissions from the conversion of native forests, to a proposition, as Brazil offered its approach to the international community. It explains the change with domestic developments: governance over deforestation, the emergence of new and relevant actors, and presidential diplomacy.
Resumo:
With regards to the debate about governance of climate change, it should be assumed that the Amazon region plays an important role, as this large area is highly vulnerable to its effects. In this sense, this article aims to discuss how some Amazonian municipalities of Brazil have been taking part in the complexes and multilayered processes of climate governance.