Los flujos migratorios gallegos durante el contexto de crisis económica

and land rights. This is a concern particularly in countries where land ownership is not secure. The establishment of large-scale biofuels feedstock production can also cause smallholders, tenants and herders to lose access to productive land[353]_.

8.1.3. Air quality and human health issues

Production and use of biofuel generate emissions of various air pollutants, including particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons and volatile organic compounds (VOCs). Unburned hydrocarbons, VOCs and NOx are precursors for the formation of smog and ground-level ozone. These pollutants are associated with increased morbidity and mortality from cardiovascular and respiratory diseases and certain cancers[327,354]_{. Air quality modelling studies show that life cycle}

emissions of some pollutants may be higher for biofuels when compared to fossil fuels, largely resulting from the emissions associated with feedstock production and biofuel processing[327,355]_.

For example, in the case of sugar cane ethanol in Brazil, burning of straw in fields is the common practice in certain areas and is the predominant source of PM[327,355]_{. Studies on health impacts}

of sugar cane ethanol in Brazil suggest that there is strong evidence that burning straw in sugar cane fields causes substantial respiratory diseases, such as asthma and pneumonia, in sugar cane field workers and local populations[327,355–358]_{. However, as}

mentioned in section 7.1.1, our consultation with Brazilian experts suggested that the practice of pre-harvest burning is being phased out.

Vehicular exhaust emissions of bioethanol blends vary with blend strength. Consistent testing of vehicular emissions is also a significant challenge since they are affected by many different parameters, including the type of engine and how it is run (the operational drive cycle), vehicle age and maintenance, the quality of the base fuel and exhaust after treatment[359]_{. However, in}

general, lower bioethanol blends (E5 to E15) have lower CO and PM emissions compared to petrol[359,360]_{. Beer et al.}[360] _{suggest that}

lower PM emissions from low-ethanol blends used in spark-ignition vehicles have slight health benefits over petrol. However, they lead to significantly higher emissions of acetaldehyde, which is one of the precursor VOCs involved in ground-level ozone formation. Similarly, higher ethanol blends (E85) lead to comparable, or slightly lower, levels of PM, NOx and CO emissions than petrol, but five to 10 times higher acetaldehyde emissions[359,361,362]_.

Compared to fossil diesel, biodiesel has generally lower exhaust emissions of PM, CO, hydrocarbons and VOCs, but higher NOx

emissions[363,364]_{. These differences are small for 5% to 20%}

biodiesel blends and would lead to negligible or non-measurable impacts on air quality[363]_{, but increase with higher blends}[359]_.

On the other hand, Larcombe et al.[365] _{argue that, despite having}

lower PM emissions, biodiesel exhaust emissions could potentially be more harmful to human health because of higher proportion of ultra-fine particles (<100 nm diameter) compared to diesel exhaust. This is due to the fact that smaller particles remain suspended in the air for longer, are more easily inhaled and are able to penetrate more deeply into the lungs. However, other assessments on the potential human health implications of biodiesel suggest that the use of biodiesel fuel blends compared to fossil diesel results in minimal changes in health impacts[363,364]_{. Thus, the topic of human}

health impacts from biofuels remains open to debate, requiring further research and evidence.

Besides air pollution, production of liquid biofuels could affect human health directly through water and soil pollution and occupational hazards[327]_{. However, these effects are scarcely}

discussed in the literature and should be explored further to understand whether there are risks that need to be addressed.

8.1.4. Further considerations

Ultimately, as with other sustainability considerations, social impacts of biofuel supply chains depend on the biophysical and socio-economic conditions of the production region and the characteristics of the supply chains, such as types of energy crop, conversion technologies, logistics, etc. Despite the concerns, in existing literature social aspects tend to appear in the form of a checklist of generic social criteria rather than appraisal of real or potential social impacts of biofuels. Furthermore, as mentioned previously, within the RED, sustainability criteria for biofuels cover social aspects in a limited way and their further development thus relies mainly on voluntary certification schemes.

One of the reasons for the social sustainability of biofuels not being assessed more widely and systematically is the lack of an internationally agreed methodology on how these issues could be quantified and evaluated. Many approaches for assessing social sustainability exist in the literature, but few are specific to biofuels, with a notable exception of the RTFO methodology[366]_.

It is also possible to assess the social sustainability of biofuels using a life cycle approach and applying the social LCA (S-LCA) methodology[367]_{. However, this is a complex method with}

over 190 social indicators, raising concerns over practicality of

Overview of socio-economic sustainability of biofuels

is reliant on the blending obligation in place under the RTFO. Biofuel producers consulted as part of this study reported that they would not be able to produce and supply even a single litre of biofuels beyond the mandated quantity since it would not be economically viable. Therefore, any increase in the amount of biofuels supplied would need to be driven by an increase in the blending obligation or some other similarly strong policy incentive.

Although for legitimate sustainability concerns, the obligation has not increased above 4.75% and investors have been badly hit as expected increases in the obligation have not been forthcoming. Further investment in the sector will not occur unless investors have confidence that policies will drive expansion of what is currently a stagnant market.

The evidence reviewed indicates that the UK should be able to meet an increase in the blending obligation in line with current targets set out in the RED because:

• existing first generation biofuel plants in the UK are currently operating below capacity

• producers, supported by the available surveys on resource availability, have reported that they can expand production from existing waste feedstocks, such as UCO, tallow and MSW • expansion in the market would provide producers of fuels from

waste lignocellulosic feedstocks, such as agricultural residues, forest and sawmill residues and wood wastes, with the market necessary to bring these fuels online.

8.2.2. Costs of producing biofuels

Biofuel production costs can vary widely by feedstock, conversion process, scale of production and region. However, in general, for first generation biofuels, the capital costs account for a relatively small proportion of total production cost. Annualised capital costs are estimated at 4% for biodiesel plants and 10% for bioethanol plants[344]_{. On the other hand, the cost of feedstock is a major factor}

in the viability of biofuel production, generally accounting for 60% to 90% of the total operating costs of first generation biofuels[14]_.

Compared with first generation biofuels, the capital costs of second generation biofuels account for a higher share of overall costs, while the feedstock costs are significantly lower. Feedstocks for cellulosic biofuels are expected to range between 30% to 45% of total production costs in the long term[371]_{. Therefore, second generation}

implementation. Instead, some stakeholders consulted in this study argued that a semi-quantitative risk approach would provide a sound and more practicable basis for such assessments[368]_.

Some also highlighted that there are high risks of negative social impacts of both fossil and biofuels and considering social criteria only for biofuels can be seen as an unfair advantage for fossil fuels, since additional investments and other costs are involved in meeting those criteria[351]_.

8.2. Economic impacts

Economic indicators used to evaluate the commercial viability of biofuel projects include capital and operating costs, price of feedstocks, return on investments, fixed and variable costs, life cycle costs and biofuel and fossil fuel prices[369]_{. Other indicators,}

such as contribution of biofuels to gross domestic product (GDP), changes in fossil energy prices, changes in food prices relative to biofuel production and employment levels, are used at a national level to monitor the contribution of biofuels to the economy. Some of these indicators are discussed below.

8.2.1. Competitiveness with fossil fuels

The global biorefinery products market has been valued at £262 billion in 2014 and is expected to grow by 14% per annum to 2020[56]_{. However, biofuels are not currently competitive with fossil}

fuel equivalents, although this depends upon the prevailing price of crude oil. Specifically, in Europe, ethanol from grain and sugar beet and first generation biodiesel are not competitive on price with petroleum fuels on an equivalent energy-content basis[370]_.

In 2013, the wholesale price of bioethanol in Europe was €27.7/ GJ (€0.59/litre), more than double the price of petrol (€13.1/GJ or €0.43/litre). A similar differential applied to the wholesale prices of biodiesel compared to fossil diesel: €25.7/GJ (€0.85/litre) vs €12.9/ GJ (€0.47/litre)[344]_{. By 2020, the wholesale price of bioethanol in}

Europe is estimated to be €14.3/GJ higher than petrol and €11.7/ GJ for biodiesel[344]_{. Similarly, in the US, ethanol remains more}

expensive than gasoline on an energy equivalent basis, but the price gap between the two has decreased in recent years[14]_{. Brazilian}

ethanol from sugar cane is more competitive than US ethanol but, at low oil prices, it is still more expensive than petrol in Brazil.

Given this lack of price competitiveness, biofuels markets tend to be highly dependent on policy for their creation. In the UK, the market

THERE ARE TWO GENERAL AREAS WHERE POTENTIAL

In document Título"Moviendo ficha": jóvenes migrantes, estrategias y trayectorias familiares de movilidad social inter generacional en las migraciones argentinas y marroquíes a Galicia (página 140-143)