Direct land-use change emissions – does conversion of natural lands always contribute to extra GHG emissions compared to fossil fuels? Lange (2011).

As mentioned in my previous post, the conversion of agricultural lands entails major indirect land-use changes and socio-economic consequences, so let’s now consider the effects of converting of natural lands in greater detail.

It may not be surprising that 20% of global GHG emissions arise due to forest degradation and deforestation (Lange, 2011), meaning that if biofuel production entails forest destruction, it is not saving emissions. However, what about the emissions from the conversion of other types of natural habitats? Let's look at this in more detail.

While Mellilo et al. (2009) model uncontrolled future biofuel expansion, Lange (2011), uses a more realistic scenario for the EU by including sustainability regulations, such as the prohibition of converting lands where the indirect emissions are too large to lead to the minimum of 35% emissions reduction compared to fossil fuels (Lange, 2011). While Lange’s (2011) study focuses on EU reduction targets, the results apply to other areas of the world, as the indirect land-use change emissions involve global land-use changes, provided the land-use changes outside the EU are carried out in a similarly controlled manner.

They found that apart from converting savannah grasslands to biofuel cultivation, conversion of other natural vegetation types is unlikely to contribute towards the 35% minimum GHG emissions reduction aim posed by the EU. This means that lands which were previously used for agriculture or other anthropogenic activities and degraded lands are most suitable for biofuel production, producing most GHG emissions reductions.

However, this poses problems such as pressure on the food production industry and on biodiversity, which is often high in these areas despite the low primary productivity (Lange, 2011); these issues will be discussed in more detail later on in the blog. Additionally, due to the market-driven nature of biofuel production, it would be unrealistic not to include the economic factors of using such lands. Incorporating these factors, it seems that it is unlikely that degraded lands will be economically viable to convert under the current policy within the EU, where cultivation subsidies decline with land degradation level. This is especially detrimental when considering that biofuel crop fertility on degraded lands will be lower than on non-degraded, further limiting the economic benefit and thus the potential of degraded lands conversion (Lange, 2011).

In conclusion, according to Lange (2011), when considering just the GHG emissions potential, only some savannah grasslands, brownfield sites and degraded lands could potentially be used for biofuel production. This is therefore in agreement with the suggestion of Mellilo et al. (2009). However, socio-environmental impacts of using these lands need to be considered.  Additionally, taking into account the economic factors, some policy changes need to be made before the use of degraded lands becomes viable.