Table 3 Major environmental concerns associated with large-scale biomass and biofuel production

Land use change (direct and indirect)

Entailing economic incentives and a large amount of land to grow perennial biomass to meet the Renewable Fuel Standards [31]

Transnational indirect land use (ILUC) including deforestation elsewhere [32, 33]

Estimation difficulty [34]

Overharvesting of crop residues

Overharvesting due to cost savings [35]

Overharvesting due to temporal and spatial yield variations [29, 36, 37]

Greenhouse gas (GHG) emissions

Varying from case to case [38]

Emissions associated with ILUC [32, 33]

Measurement difficulty [39, 40]

Soil erosion and nutrient loss

Varying from case to case [41, 42]

A potential limiting factor for residue removals in some locations [37]

Air quality

Increased emissions of PM, O₃, and SO_x [6] and NO_x [43]

Varying from case to case [44]

Water use

Increased water use for feedstock production [44, 45], especially in areas already facing water shortage [41, 46]

Water quality

Increased chemical use for biomass production [38, 45] or supplementing soil nutrient loss from residue removals [47,48,49]

Biodiversity

Varying from case to case and unknown impacts [38, 50, 51]

Impacting locally important wildlife species [52]

Habitat alterations by feedstock production [53], especially monoculture plantations [54,55,56]

Risk associated with introduction of genetically modified or non-native plant species [54, 56,57,58,59]