Este subcapítulo relaciona a percepção e a comunicação de risco e incerteza de mudanças climáticas. Trata-se de um tema relevante para o Brasil, onde se ampliam a identificação, a avaliação e a adoção de políticas e ações destinadas a mitigar os determinantes do aquecimento global de forma consistente com o desenvolvimento sustentável.

The growing demand for clean energy sources to replace petroleum has substantially expanded the use of biofuels—fuels produced from agricultural products. For Brazil, instead of representing a hindrance to growth because of the need for changes in the country’s energy mix, this represents a great opportunity to generate value and income, since the country has clear comparative advantages in producing these fuels from renewable sources. The main biofuel in the country is ethanol, made from sugarcane. The country’s cane growing sector has been undergoing intense transformations, with the attraction of foreign capital, opening of new distilleries and intensification of mergers and acquisitions. However, doubts have been raised about the socioeconomic effects of the spread of sugarcane growing, such as the effects on the environment, labor market, social conditions and food prices, among others. This work reviews the papers that discuss these impacts. The results suggest that the expansion in recent years helps to improve the capital-labor relationship; the sugarcane growing is not the cause of increased land and food prices; the environmental indicators in sector is better than fossil fuel sector, or other relevant concurrent; the sector has no significant effects (positive or negative) on social conditions in cane growing regions, and that the sector can contribute positively by increasing local tax revenue.

Greenhouse gas reduction and energy saving are becoming two important issues in both industrialized and developing countries, and policymakers are developing means to reduce total domestic energy use. We evaluate and compare the direct and the indirect energy use both in the People’s Republic of China (China) and the United States of America (US) by looking at a series of hybrid energy input–output tables (1997, 2002, and 2007). We also apply SDA (structural decomposition analysis), to identify the factors causing energy intensity (energy use per unit of gross domestic product) to differ between the two countries, which lead to potential energy-saving options. Our results show that, besides the differences in direct energy use, huge differences also exist in indirect energy use between the two countries. Differences in indirect energy use are mainly due to differences in technology. Technological change and industrial-structure change are key factors to explain the inequality of energy intensity, while there is a significant trend towards the convergence of sectoral energy efficiency between the two countries.

In this paper, we aim to assess how the changes in aspects of demand impact the use of energy in the developing economies of Brazil, China, and India and the developed economies of Germany, the United Kingdom, and the United States. To achieve this objective, we use input–output matrices for the years 1995 and 2005 by applying a structural decomposition analysis. We find the following: Brazil is the only country where technology has a positive impact on energy. Germany and the United Kingdom decrease their use of energy over the sample period. China and the United Kingdom are the only countries where the use of renewable inputs decreases; and, in Brazil, China, and the United States, the use of coal increases. When we change the focus of our analysis from aggregated to disaggregated results, these countries can be lined up differently in terms of development in relation to their wealth and energy use.

In this paper we assess the potential economic effects of climate change on Brazilian agriculture scenarios in different regions in a general equilibrium framework, using a detailed regional economic database for the year 2005. Two different climate change impact scenarios are simulated. This paper extends the Brazilian literature in three different ways: by considering detailed shocks by product and region; by highlighting the connections between the potential impacts of climate change on agriculture and the labor market, with an inter-regional focus; and by specifying the links between climate change forecasts for agriculture and household expenditures. Results show that climate change impacts on Brazilian agriculture would have a relatively small economic effect on the Brazilian economy in aggregate terms, but with severe consequences at the regional level, making a strong case for losses that would be concentrated in the poorest regions and for the poorest workers and households in those regions.

This paper analyzes the potential effects of climate change on Brazilian agriculture by considering irrigation as an adaptive strategy. Investigations were performed to determine how climatic variability influences irrigation and whether this adaptive measure actually reduces producers’ vulnerability to climate change. We used a simultaneous equations model with endogenous switching to account for the heterogeneity in the decision of whether to use adaptive measures. We compared the expected land values under the actual and counterfactual cases of farm households that either adapt or do not adapt to climate change. Simulation results show that irrigation can be an effective tool for counteracting the harmful effects of climate change. The income of farmers tends to increase on lands where irrigation technologies are practiced. These conclusions confirm the need to invest in adaptation strategies to prepare Brazil for coping with the adverse effects of global climate change.

We investigate the hypothesis that the conversion of forest and pasture land to cropland in Brazil decreases yields by 50%. Such hypothesis is being used by the California Air Resource Board to estimate the greenhouse gas emissions from indirect land use changes due to the expansion of biofuels production. We formulate several econometric models to test such hypothesis. The results from the majority of the models indicate that yields do not decrease under the expansion of cropland area in the country, or the decrease in yields is very small. Therefore, our results indicate the need for revising and correcting the parameters in the Californian low carbon emissions policy.

The aim of this paper is to analyse the effects of climate change on irrigation adoption in Brazil. Temperature and precipitation projections for the 2010-2099 periods were employed under a number of different climate scenarios according the 4th Assessment Report of Intergovernmental Panel on Climate Change (IPCC). The results show that irrigation adoption will be affected by climate change. Given current conditions, irrigation has generally been adopted in Brazil to cope with reduced precipitation and temperature variations. The estimated irrigation probabilities in the future scenarios were quite different across Brazilian regions. The main explanation for this pattern is the distinct climatic conditions and production structures. Considering future climate change, over the next 30 years (2010 to 2039), the irrigation probability is expected to increase in all Brazilian regions. However, this trend is reversed in the long run.

This paper analyzes the potential effects of climate change on Brazilian agriculture by considering irrigation as an adaptive strategy. Investigations were performed to determine how climatic variability influences irrigation and whether this adaptive measure actually reduces producers’ vulnerability to climate change. We used a simultaneous equations model with endogenous switching to account for the heterogeneity in the decision of whether to use adaptive measures. We compared the expected land values under the actual and counterfactual cases of farm households that either adapt or do not adapt to climate change. Simulation results show that irrigation can be an effective tool for counteracting the harmful effects of climate change. The income of farmers tends to increase on lands where irrigation technologies are practiced. These conclusions confirm the need to invest in adaptation strategies to prepare Brazil for coping with the adverse effects of global climate change.

The aim of this paper is to analyse the effects of climate change on irrigation adoption in Brazil. Temperature and precipitation projections for the 2010-2099 periods were employed under a number of different climate scenarios according the 4th Assessment Report of Intergovernmental Panel on Climate Change (IPCC). The results show that irrigation adoption will be affected by climate change. Given current conditions, irrigation has generally been adopted in Brazil to cope with reduced precipitation and temperature variations. The estimated irrigation probabilities in the future scenarios were quite different across Brazilian regions. The main explanation for this pattern is the distinct climatic conditions and production structures. Considering future climate change, over the next 30 years (2010 to 2039), the irrigation probability is expected to increase in all Brazilian regions. However, this trend is reversed in the long run.

O artigo apresenta os efeitos de mudanças climáticas sobre a economia da Bahia. Os principais resultados indicaram uma variação negativa do PIB real da Bahia entre -0,028% e -0,114%, em um cenário, e entre -0,029% e -0,075% no outro. Estes dados, associados ao fato de que a Bahia possui produtividade agrícola de algumas culturas inferior à média nacional, sugerem que políticas públicas e privadas podem ser adotadas para mitigar os efeitos de mudanças climáticas e aumentar o desempenho, em termos de produção agrícola, relativo aos outros estados do Brasil (incentivo ao cultivo alternativo de algumas lavouras e medidas de estímulo para adaptação às mudanças climáticas). Os resultados foram obtidos a partir do desenvolvimento de um modelo de equilíbrio geral computável (EGC) com especificação detalhada do uso da terra para a Bahia. Tal especificação foi incorporada no modelo de forma a considerar 13 distintos usos da terra. Para analisar os efeitos econômicos de mudanças climáticas, foi utiliza-da uma metodologia que integrou o EGC a um modelo econométrico. As simulações tiveram como referência informações de um período-base e de projeções e cenários climáticos do IPCC.

Changes in agricultural land use have important implications for environmental services. Previous studies of agricultural land-use futures have been published indicating large uncertainty due to different model assumptions and methodologies. In this article we present a first comprehensive comparison of global agro-economic models that have harmonized drivers of population, GDP, and biophysical yields. The comparison allows us to ask two research questions: (1) How much cropland will be used under different socioeconomic and climate change scenarios? (2) How can differences in model results be explained? The comparison includes four partial and six general equilibrium models that differ in how they model land supply and amount of potentially available land. We analyze results of two different socioeconomic scenarios and three climate scenarios (one with constant climate). Most models (7 out of 10) project an increase of cropland of 10–25% by 2050 compared to 2005 (under constant climate), but one model projects a decrease. Pasture land expands in some models, which increase the treat on natural vegetation further. Across all models most of the cropland expansion takes place in South America and sub-Saharan Africa. In general, the strongest differences in model results are related to differences in the costs of land expansion, the endogenous productivity responses, and the assumptions about potential cropland.