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Abstract(s)
A deterioração das condições ambientais tem sido relatada desde 1960 com o problema sendo relacionado às alterações climáticas a partir dos anos de 1990. Desde então, até o momento atual, o consumo de energia fóssil, o crescimento económico e o grande volume de resíduos sólidos tem sido fatores constantemente associados às emissões de gases de efeito estufa (GEE) e às alterações climáticas. Uma discussão proeminente e de primordial importância no desafio que é a mitigação das emissões de produtos/resíduos poluentes baseia-se na questão de como substituir a principal matriz energética tradicional da economia assente no consumo de combustíveis fósseis por outra em que fontes de energias mais limpas ganhem a primazia. O desafio desta investigação é identificar de que forma as diferentes estruturas económicas que têm estado na base das diversas fases de desenvolvimento económico e social têm integrado as políticas ambientais de redução das emissões de GEE sem prejudicarem o crescimento/desenvolvimento mormente através da integração nas respectivas funções de produção de cotas mais elevadas de energia elétrica renovável, por vezes impostas por organismos e entidades internacionais através de tratados como o Protocolo de Kioto e outros que se lhe seguiram e a pressionante União Europeia. Para responder a estas questões levaram-se a cabo, depois de uma intensa revisão da literatura científica, três ensaios em que o instrumental analítico fundamental foi a abordagem de dados em painel. No caso do primeiro ensaio a amostra de dados em painel compreende diversas variáveis – energéticas, macroeconómicas, tecnologia (abordada por uma proxy) de tendência determinística de oito países em vias de desenvolvimento da América do Sul referente ao período temporal 19802010; a amostra de dados em painel do segundo ensaio engloba 14 países desenvolvidos da organização para Cooperação e Desenvolvimento Económico (OCDE) sendo o período temporal de 1990-2011; o terceiro ensaio tem por base dados estatísticos anuais de 15 países da União Europeia (UE) que se iniciam em 1995 e terminam em 2012. Em consequência dos problemas de endogeneidade e a dependência seccional que se provou afectar os resultados e erros obtidos a partir da estimação dos modelos em causa nos dois primeiros ensaios, foi necessário recorrer à inclusão do mecanismo UECM ou de correcção do erro sem restrições (Unrestricted Error Correction Mechanism) após a estimação de um modelo autorregressivo com lags/desfazamentos/distribuidos - abordagem Autoregressive Distributed Lag (ARDL). No âmbito do terceiro ensaio, estimou-se um modelo adequado e testou-se a hipótese da Curva de Kuznets Ambiental (CKA) em que a variável dependente são as emissões de GEE especificamente do setor de resíduos e as variáveis explicativas o rendimento real per capita e os resíduos depositados em aterros sanitários, a tecnologia abordado por uma Proxy determinística e os consumos de energia de origem renovável (resíduos). Os resultados demostraram que há dependência seccional no caso dos dois painéis (América do Sul e OCDE); que há evidência de cointegração somente para o painel sul americano; que em ambos os painéis existe uma relação de causalidade entre a produção de energia elétrica, o crescimento econnómico e a poluição por emissão de CO2 no meio ambiente; que numa avaliação a longo prazo a produção de energia elétrica fóssil e o crescimento económico tem impactos positivos sobre as emissões de CO2; que as emissões de poluentes anteriores (defasadas um ano) têm efeitos negativos sobre as emissões correntes em ambos os painéis; que a energia elétrica de origem renovável reduz as emissões de CO2 no curto e longo prazo na América do Sul, enquanto, nos países OCDE com tecnologias mais eficientes sob o ponto de vista ambiental a eletricidade renovável reduz as emissões de CO2 no longo prazo. Já os mecanismos de correcção dos erros com os painéis da América do Sul e da OCDE revelaram ritmos de ajustamento ligeiramente diferenciados para ambos os painéis, 27% e 30%, respectivamente, de um período para o seguinte. Com base nos resultados descritos, recomenda-se aos países sul-americanos que mantenham a tendência de longo prazo da produção de energia elétrica de origem renovável e que reduzam gradualmente a parcela de eletricidade de origem fóssil, para além da adopção de tecnologias de maior ‘performance’ em termos da sua eficiência técnico-ambiental. Já aos países OCDE recomenda-se uma aposta decisiva no crescimento económico sustentável, com recurso a melhores e mais eficientes tecnologias sob o ponto de vista energético, sendo que uma maior aposta em fontes de energia renovável é a melhor estratégia para superar os desafios e alcançar os objetivos das metas traçadas para mitigar as alterações climáticas. Os resultados do modelo estimado com o painel de países europeus indicaram evidência empírica a favor da redução das emissões de GEE quando se recorre aos resíduos sólidos (lixo) como matéria-prima que alimenta as centrais de tratamentos, a par da redução da quantidade destes resíduos em aterros sanitários; já a eletricidade gerada nessas centrais causam impactos positivos sobre as emissões de GEE. A confirmação da hipótese CKA não teve o formato de uma CKA tradicional para o setor “resíduos” nos países da UE. Contudo, sugerem-se novas abordagens para identificar padrões nacionais que possam ser confrontados com o desempenho em relação às metas individuais de mitigação dos GEE de cada país.
Deteriorating environmental conditions have been reported since the 1960s with the problem being related to climate change from the 1990s. From then on, the fossil energy consumption, economic growth and the increasing volume of solid waste factors have been consistently associated to emissions of greenhouse gases (GHG) and climate change. A prominent, relevant or of paramount importance discussion in the mitigation of pollutant gases or solid waste challenge is replacing the main traditional energy mix of the economy based on fossil fuel consumption by another one in which cleaner energy sources gain primacy. This research’s challenge shows how the different economic structures that have been at the base of the different economic and social development stages have absorbed or integrated the environmental policies and reduced GHG emissions without harming growth and development particularly through integrating, in the respective production functions, higher shares of renewable electricity sometimes imposed by international organizations or agreements such as the Kyoto Protocol and others that followed it and the pressuring European Union. To answer these questions, and after doing an intensive review of the scientific literature, some essays have been undertaken where the fundamental analytical tools are the panel data approaches. In the case of the first essay the panel data sample comprises several variables (energy, economic growth and technology) from eight South American developing countries whose data covers the period 1980-2010; the panel data sample of the second essay includes 14 OECD developed countries covering the time span 1990-2011; the third study or essay is also based on annual statistical data from 15 countries of the European Union (EU) and the time span covered is 1995-2012. As a result of endogeneity problems and sectional dependence demonstrated to affect the results and errors obtained from the estimation of the models concerned in the first two tests, it had to resort to the inclusion in the model the UECM mechanism or error correction without restrictions (Unrestricted Error Correction Mechanism) after the estimation of an autoregressive model with lags / lags / distributed - approach autoregressive Distributed Lag (ARDL). In the third research, we estimated a suitable model and was tested the hypothesis of the Environmental Kuznets Curve (EKC) where the dependent variable are the GHG emissions specifically from the waste sector and the explanatory variables are real income per capita waste deposited in landfills, technology and renewable energy sources and waste. The results showed that there cross-section dependence for the two first panels (South America and OECD); there is evidence of cointegration only to South American panel; in both panels there is a causal relationship energy-crecimento-environment; in the long run the production of fossil energy and economic growth has positive impacts on emissions of pollutants; emissions of pollutants previous (lagged one year) have negative effects on the emission currents in both panels; that the electricity from renewable sources reduces pollutant emissions in the short and long term in South America as in OECD countries, with more efficient technology from an environmental point of view, this renewable electricity reduces emissions of long-term pollution. Since the correction of errors with the mechanisms of South America and OECD panels showed slightly different adjustment rates for both panels, 27% and 30%, respectively, from one period to the next. To the OECD countries we recommend a decisive gamble on sustainable economic growth, the green economy, using better and more efficient from an energy-environment point of view technologies and greater investments in renewable energy sources, the best strategy to overcome the mitigation targets and challenges set for reducing climate change, recommendations that can also be addressed to South American countries. The results got for the panel of European countries suggest empirical evidence in favor of reducing greenhouse gas emissions when they use electricity generated from solid waste (waste) consumption as raw material to feed the electric plants, together with the reduction of solid waste deposed in landfills. Once examined the issue to check the hypothesis of environmental Kuznets curve that relates the emission levels with real per capita income for the EU countries we found evidence that do not support the traditional CKA hypothesis for the waste sector and at the same time we discovered that the curve that better fits this relationship is the N shaped curve. However, we suggested new approaches to identify national standards that can be confronted with performance individual goals of mitigation of GHG each country.
Deteriorating environmental conditions have been reported since the 1960s with the problem being related to climate change from the 1990s. From then on, the fossil energy consumption, economic growth and the increasing volume of solid waste factors have been consistently associated to emissions of greenhouse gases (GHG) and climate change. A prominent, relevant or of paramount importance discussion in the mitigation of pollutant gases or solid waste challenge is replacing the main traditional energy mix of the economy based on fossil fuel consumption by another one in which cleaner energy sources gain primacy. This research’s challenge shows how the different economic structures that have been at the base of the different economic and social development stages have absorbed or integrated the environmental policies and reduced GHG emissions without harming growth and development particularly through integrating, in the respective production functions, higher shares of renewable electricity sometimes imposed by international organizations or agreements such as the Kyoto Protocol and others that followed it and the pressuring European Union. To answer these questions, and after doing an intensive review of the scientific literature, some essays have been undertaken where the fundamental analytical tools are the panel data approaches. In the case of the first essay the panel data sample comprises several variables (energy, economic growth and technology) from eight South American developing countries whose data covers the period 1980-2010; the panel data sample of the second essay includes 14 OECD developed countries covering the time span 1990-2011; the third study or essay is also based on annual statistical data from 15 countries of the European Union (EU) and the time span covered is 1995-2012. As a result of endogeneity problems and sectional dependence demonstrated to affect the results and errors obtained from the estimation of the models concerned in the first two tests, it had to resort to the inclusion in the model the UECM mechanism or error correction without restrictions (Unrestricted Error Correction Mechanism) after the estimation of an autoregressive model with lags / lags / distributed - approach autoregressive Distributed Lag (ARDL). In the third research, we estimated a suitable model and was tested the hypothesis of the Environmental Kuznets Curve (EKC) where the dependent variable are the GHG emissions specifically from the waste sector and the explanatory variables are real income per capita waste deposited in landfills, technology and renewable energy sources and waste. The results showed that there cross-section dependence for the two first panels (South America and OECD); there is evidence of cointegration only to South American panel; in both panels there is a causal relationship energy-crecimento-environment; in the long run the production of fossil energy and economic growth has positive impacts on emissions of pollutants; emissions of pollutants previous (lagged one year) have negative effects on the emission currents in both panels; that the electricity from renewable sources reduces pollutant emissions in the short and long term in South America as in OECD countries, with more efficient technology from an environmental point of view, this renewable electricity reduces emissions of long-term pollution. Since the correction of errors with the mechanisms of South America and OECD panels showed slightly different adjustment rates for both panels, 27% and 30%, respectively, from one period to the next. To the OECD countries we recommend a decisive gamble on sustainable economic growth, the green economy, using better and more efficient from an energy-environment point of view technologies and greater investments in renewable energy sources, the best strategy to overcome the mitigation targets and challenges set for reducing climate change, recommendations that can also be addressed to South American countries. The results got for the panel of European countries suggest empirical evidence in favor of reducing greenhouse gas emissions when they use electricity generated from solid waste (waste) consumption as raw material to feed the electric plants, together with the reduction of solid waste deposed in landfills. Once examined the issue to check the hypothesis of environmental Kuznets curve that relates the emission levels with real per capita income for the EU countries we found evidence that do not support the traditional CKA hypothesis for the waste sector and at the same time we discovered that the curve that better fits this relationship is the N shaped curve. However, we suggested new approaches to identify national standards that can be confronted with performance individual goals of mitigation of GHG each country.
Description
Keywords
Emissão de gases - Resíduos sólidos Emissão de gases - Crescimento económico Electricidade renovável e fóssil Curva de Kuznets ambiental