Aplicación de una nueva representación de la señal en el reconocimiento del locutor23

22 Table 3.1: Land use in Brazil and expansion possibilities, 2011

*These areas include the Amazon rainforest, protected areas, conservation areas and reforestation, cities and towns, lakes and rivers. **Harvested area for ethanol production based on the allocation of sugar to ethanol, which is currently about 60 per cent.

Source: GBEP (2011); Neves et al. (2011)

3.2.1 Land-use change due to Brazilian sugarcane crops

As discussed in Section 1.2.1 above, this thesis focuses on environmental impacts caused by the expansion of sugarcane crops in Brazil and, more specifically, biodiversity degradation and GHG emissions due to this expansion.

Biodiversity and sugarcane crops

The expansion of agriculture is a long-running historical phenomenon in a large country such as Brazil. The sugarcane industry itself has undergone intensive expansion cycles (Macedo, 2007). On top of the period of the last decade, in which most of the increase in Brazil’s production of sugarcane ethanol has occurred, other cycles of major sugarcane expansion occurred during the National Alcohol programme, 1975-1990. During this programme the Brazilian military government stimulated the conversion of forests into sugarcane plantations to supply the internal

23 market with ethanol. This expansion had a significant negative impact on the Atlantic Forest biome, contributing to reducing this biome to about 26 per cent of its original area of 111 million hectares (Bernard, Melo and Pinto, 2011). The area currently occupied by sugarcane crops in Brazil is largely located in lands that were originally covered by the Atlantic Forest biome (WWF, 2008). Another Brazilian biome which is currently threatened by the expansion of sugarcane crops is the Cerrado savannah.

This is due to the location of sugarcane crops being mainly in the South-Central region, where a large amount of this biome is located (ICONE, 2011).

The Atlantic Forest and Cerrado biomes are the two biodiversity hotspots of Brazil according to Conservation International.⁸ The Atlantic Forest biome, and its associated ecosystems, encompasses nearly 13 per cent of the Brazilian territory and has 20,000 plant species, 40 per cent (~ 8,000) of which are endemic. Even though the area of this biome has been reduced to a highly fragmented area of about 29 million hectares over centuries of environmental pressure (due to, for example, cattle ranching, logging, urbanization, and coffee and sugarcane crops) it still hosts a significant portion of Brazilian biological diversity (MMA, 2009). The Cerrado biome, comprising 24 per cent of the Brazilian territory, is the most extensive woodland-savannah in South America and represents about 9 per cent of the total area of tropical savannahs in the world (Bustamante et al. 2009). The Cerrado biome is considered a biodiversity hotspot as it has about 44 million hectares of remaining primary vegetation of the total of 203 million hectares and 4.400 endemic species.⁹ According to Conservation International (2011), there are currently 90 and 16 endemic threatened animals in the Atlantic Forest and Cerrado savannah, respectively, including birds, mammals, and amphibians. Figure 3.4 shows the six

8 A region is considered a biodiversity hotspot when: (1) it contains at least 1,500 species of vascular plants (> 0.5 percent of the world’s total) as endemics; and (2) it has lost at least 70% of its original habitat (Conservation International, 2011).

9 The exact amount of remaining primary vegetation in the Cerrado biome is controversial. For example, Sano et al. (2009) state that 60.5% of the Cerrado biome’s total area is primary vegetation, while MMA (2009) estimates that 30% of the Cerrado biome is primary vegetation. These estimations are quite discrepant and the reason for this is the use of different classifications, methodologies and satellite images (MMA & IBAMA, 2011).

24 biomes in Brazil: the Amazon rainforest, Caatinga thorny scrub, Cerrado savannahs, Atlantic Forest, Pampa grasslands, and Pantanal wetlands.

Figure 3.4: Brazilian biomes

Source: Brazil’s Ministry for the Environment (MMA, 2009).

25 Greenhouse gas emissions and sugarcane crops

According to Barker et al. (2007), GHG¹⁰ emissions resulting from land use change (LUC) have been estimated at around 17 per cent of total global anthropogenic GHG emissions in 2004. Cederberg et al. (2011) contend that a key driver of deforestation is the expansion of pastures for beef production in South America. In addition, estimates indicate that LUC, mainly deforestation, caused by the growing livestock sector is the source of approximately 6 per cent of global GHG emissions (Cederberg et al. 2011). In Brazil, which is the world’s second largest beef producer and the top global exporter of beef, pasture is the main subsequent land use occupying (60-75 per cent) of newly deforested land (Margulis, 2004; Morton et al. 2006). As shown in Table 3.1 above, pastures have an approximate area of 200 million hectares, whereas sugarcane crops occupy about 9 million hectares. Thus, sugarcane crops emit much less GHGs than pastures, due to direct LUC. Furthermore, because sugarcane crops have occupied, primarily, pasture lands since 2002, some authors, e.g. Nassar et al.

(2010) and Seabra et al. (2011), estimate that sugarcane crops have stored rather than emitted GHGs. Data on GHG emissions from the expansion of sugarcane crops are discussed in Chapter 4. The 2005 Brazil’s GHG inventory estimates that land-use change and ongoing agriculture are responsible for 61 per cent and 19 per cent, respectively, of Brazil’s GHG emissions (see Figure 3.5).

10 GHG includes carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphurhexafluoride (SF₆), whose emissions are covered by the United Nations Framework Convention on Climate Change (UNFCCC). These GHGs are weighted by their 100-year Global Warming Potentials, using values consistent with reporting under the UNFCCC (Barker et al. 2007).

26 Figure 3.5: GHG emissions in CO2-eq¹¹ from different sectors in Brazil, 2005

Source: Ministry of Science and Technology (MCT, 2010)

Note that, unlike most of the developed countries where the burning of fossil-fuels to supply energy for the industry and transport sectors is the main cause of GHG emissions, Brazil’s GHG emissions come primarily from land-use change, mainly deforestation. This difference in the causes of the GHG emissions is primarily because Brazil’s energy supply comes mainly from hydroelectricity (approximately 75 per cent), which emits less GHGs than fossil-fuels, and other energy supplies such as biomass from sugarcane (MME, 2010).

11 To reduce confusion and complexity, scientists use the notion of “Carbon dioxide-equivalent”

(CO₂-eq) units to describe the warming effect in units equivalent to CO₂, exerted by all GHGs and aerosols arising from human activities.

27 The agriculture sector shown in Fig 3.5 above includes crops and livestock, but the livestock sector is the largest emitter of GHGs. This is due, primarily, to the process of enteric fermentation, which occurs when ruminants digest their food. The process of enteric fermentation emits methane and represents around 75 per cent of GHG emissions from the Brazilian beef production, excluding LUC (Cederberg et al.

2011). Additionally, within the agriculture sector, sugarcane crops contribute to GHG emissions through, primarily, the practice of sugarcane burning. This practice is used to facilitate manual cutting by burning most of the straw and leaves, and to increase the quantity harvested (the practice of sugarcane burning is discussed in Chapter 6).