Social & Ecological Impacts of Using Wood for Liquid Fuels

With concerns mounting about the competition between food and fuel due to crop-based agrofuels (large-scale, unsustainable biofuels), industry is heavily promoting fuel produced from woody sources such as trees as the solution to this conflict. Unfortunately, this is not a solution; and instead will cause detrimental impacts on biological diversity as well as Indigenous and rural communities. It will also further exacerbate the global food shortage and climate crisis. 

Second Generation Biofuels: No solution to Climate Change

It is argued that production of liquid transport fuels from inedible plants will eliminate the food-fuel competition that has heavily contributed to the global food crisis. Cellulose-based agrofuels will not address this problem; but instead will further intensify it. In many countries, industrial timber plantations already compete with agricultural land. The growing economic incentive to develop tree plantations will only increase food-fuel conflicts. This effect is apparent in the Lumaco District of Chile, where pine and eucalyptus plantations are expanding onto agricultural land used by indigenous Mapuche communities. Since 1988, plantations in this region have increased from using 14% of the land to over 52% in 2002. These industrial tree plantations are forcing the people off their land and escalating poverty. Another consequence of the rising emphasis on cellulosic agrofuels as the next generation of agrofuel technology is the accelerated promotion of faster-growing genetically engineered trees (also called genetically modified trees) specifically modified to facilitate production of agrofuels or paper.

GE Trees and Contamination of Wild Forests

Beyond threats to food are the threats to forests. Richard Meilan, a faculty member at Purdue University acknowledges the flexibility of the poplar as an energy crop, but also raises serious concerns about the potential genetic contamination that could be caused by the commercial release of a GE tree with such a large and widespread population of wild relatives. Even the use of non-native tree species, such as the eucalyptus, which has been proposed in the southern U.S., raises concerns about the impacts of the escape of GE trees into native forests. Our understanding of the contamination potential from future plantings of GE trees is largely based on known contamination instances of GE crops and engineered grasses.

Low-lignin Trees

Low-lignin trees are genetically manipulated for decreased lignin production in order to facilitate the production of agrofuels and paper. Lignin is a structural polymer that is also significantly responsible for the high levels of insect and disease resistance in trees. The fact that it is difficult to break down lignin has been shown to be essential to the resiliency of trees in the wild. Fast growing, reduced lignin GE trees, growing undetected in a native forest setting as the result of gene escape, could die off at an early age due to their inability to cope with environmental stresses. Their reduced lignin would cause rapid decomposition, damaging soil structure and emitting carbon. According to the UK-based Institute for Science in Society, low lignin trees have implications for the climate.

Disease and Insect Resistance

Because lignin naturally protects tress from insects and disease, trees with modified lignin will most likely have to be engineered with additional traits for disease and insect resistance, which leads to additional concerns, should these genes escape. One concern is that the evolution of new, more pathogenic viruses may be accelerated by GE tree viral resistance traits. The serious issue of insect resistance has been seen in China, where the problem of desertification was tackled through the planting of huge monoculture plantations of poplars. These poplars, however, fell victim to predation by caterpillars and a great number of them died. As a result, insect resistant poplars were introduced, genetically engineered for the production of Bacillus thuringiensis (Bt) toxin. In 2004, the Nanjing Institute of Environmental Science reported that the Bt poplars were already contaminating native poplars, but it is not known how far this contamination has spread.

Bt is problematic for numerous reasons such as the possible ecological implications of eradicating certain species of insects. The targeted caterpillar in question is a main food source for several species of nesting songbirds.  At least one study has found that Bt-toxin remains active and lethal after ingested and can make its way up the food chain causing significant structural disturbances and intestinal growths of non-target organisms. Since the Bt trait is expressed in every cell of the modified tree, including pollen, impacts on pollinators such as bees and butterflies is a major concern. Bees are already in serious decline, some believe, because of Bt crops.  High levels of Bt toxins have also been found in streams bear Bt cornfields, killing caddisflies, the most diverse aquatic insect and an important food source for reptiles and amphibians.

Bt-toxin also exudes from the roots of GE plants and into the soil, where it can affect organisms present in the soil or the soil community as a whole. Beyond the impacts on forests and wildlife, are the impacts of Bt pollen on humans. Airborne Bt may be toxic when inhaled. This could have serious ramifications for communities living in the proximity of GE tree plantations. This potential health hazard has not been adequately studied. In summary, the long-term consequences of the use of Bt trees, or the escape of this trait have not been sufficiently assessed. 

Introduction of Non-Native Invasive Plants for Cellulosic Agrofuels 

GE tree escape is possible even from non-native species without wild relatives. GE eucalyptus is one non-native tree being proposed by engineers as a potential feedstock for cellulosic ethanol.  Eucalyptus is a favorite for pulpwood plantations globally. It is a notoriously invasive species that often out-competes native plants. In the U.S., eucalyptus was introduced in 1856 and is now widespread throughout California. Because it is extremely fire-prone, California spends millions of dollars each year trying to eradicate this invasive species. 

Development of second-generation agrofuels in Brazil is also a concern. Efforts are currently focusing of the use of bagasse-the biomass left over from the production of sugar cane-based ethanol. While these facilities may be developed under the guise of reducing waste, they are taking a step towards acceptance of other cellulosic feedstocks. ArborGen is already developing GE low-lignin eucalyptus in Brazil, as is pulp giant Aracruz Cellulose. Eucalyptus is already a serious problem in Brazil, where plantations have replaced vast stretches of the Mata Atlantica  coastal forest ecosytem. 

GE Jatropha and Oil Palm

Beyond genetically engineering trees for cellulosic agrofuels production, researchers are also exploring ways to engineer Jatropha and oil palm trees to improve the quality and quantity of their oil, to resist herbicides and/or kill insects.

African oil palm is native to tropical Africa, while American oil palm is native to Central and South America. However, it is now widely cultivated in tropical areas around the world. Jatropha is native to Central America and the Caribbean, and it too is cultivated in huge monocultures in India, China, Africa, Latin America, and elsewhere. 


The pursuit of a global energy strategy that features wood as a major agrofuel feedstock clearly poses a variety of potential problems.  Use of GE trees for agrofuel production would significantly increase this risk, with serious implications for the world’s forests and forest peoples. 

In the U.S., for example, efforts are underway to use the monoculture loblolly pine plantations of the Southeast US for cellulosic ethanol production. A company called Range Fuels is developing an ethanol production facility specifically for this purpose, with funds from the US Department of Energy. The US state of Georgia has been quoted as seeking to become the “biofuels Saudi Arabia”, using their pine plantations as the feedstock.  These same plantations, however, have been the world’s largest source of paper pulp. 

Taking these plantations out of paper production and transitioning them into agrofuels production will have serious global implications. As the raw materials to feed the world’s increasing appetite for paper are no longer available from existing plantations, they will increasingly come from the world’s remaining forests. In addition, the rapidly rising demand for wood, triggered by cellulosic agrofuels production, will accelerate the conversion of native forests into fast-growing monoculture tree plantations and escalate illegal logging. This skyrocketing demand for wood will also further the pressure to commercially develop GE tree plantations, which will in turn threaten the ecological integrity of native forests. 

With current rates of deforestation contributing well over 20% of global carbon emissions annually, the massive increase in deforestation that will accompany the rise of wood-based agrofuels production will have significant impacts on climate, belying the argument that cellulosic agrofuels will be part of the solution to global warming.