Environmental Issues

The increasing demand for plant based fuels has displaced areas that were initially used to produce food for human consumption. Food prices go up, and agriculture expands into forested areas (Grunwald, 2008). Most biofuel crops are genetically engineered and need to be closely controlled in a monoculture plantation. They are also more suited to a tropical climate. Therefore this paper will focus on the effects of clearing rainforests to establish a monocrop biofuel plantation.

Ironically, clearing forests for biofuels emits more carbon than can be saved by using the biofuel. Dr. David Tilman (2008) explains that clearing the tropical peatland forests in Indonesia to plant palm trees would release so much greenhouse gasses that it would take 420-840 years to pay it back by using the palm oil. This is because the soil under a tropical peatland forest also contains a huge amount of biomass, and carbon will continue to be released long after clearing operations, until the next 120 years.

Releasing carbon into the atmosphere is the main reason for climate change and global warming. Greenhouse gasses (GHGs) prevent long wave radiation from leaving the earth, reflecting it back to the planet and heating it up. This causes severe climatic changes, such as the ENSO, triggering extreme droughts and floods.

Global warming triggers a chain reaction to planetary destruction. For example, one of the biggest carbon sinks in the planet is the ocean. When this is heated, it absorbs less carbon and actually releases more into the atmosphere. Higher temperatures can also cause higher respiration in plants, releasing more carbon than oxygen. Hotter temperatures disable the planet from absorbing carbon gasses and other GHGs, meaning more long wave radiation will be reflected back to earth, making the situation worse.

One immediately noticeable effect of land conversion is on temperature. Temperature is more stable in a forest than in an open field where it varies greatly from day to night. During the day, the forest provides shade that makes soil temperature generally cooler compared to an open area. At night, the trees shelter the ground from cooling winds, making the forest warmer than in an open field. When the forest is clearcut, the ground is exposed to the elements. Days become hotter and night becomes colder. This will have the most impact on hydrology.

The forest influences rainfall by acting as water pumps. The trees take up water from the ground and releases it into the atmosphere during transpiration. Since the area inside and immediately surrounding a forest is generally cooler, the water vapor released during transpiration condenses and precipitates more readily. Water is always present in the plant biomass, and consequently locked in a closed tropical ecosystem.

In contrast, water will evaporate and dissipate faster in an open field, necessitating irrigation. Even when planted to soya or corn, there are spaces between individual crops that are still exposed compared to the many layers of cover in a tropical rainforest. When it rains, or even during irrigation in an agricultural field, water accumulates in the soil more quickly and disappears just as fast.

Not only is a monoculture plantation more prone to extreme hydrologic events like drought or floods, it is also extremely prone to erosion. In a forest, trees and other vegetation intercept raindrops, making it fall more slowly. Whereas rain directly falling on open ground carries more force in dislodging sediments and carrying it away in surface runoff.

Erosion and leaching causes the nutrient-rich topsoil in a monocropped area to be easily depleted after several rotations. When fertilizers are added to maximize crop yield, excess nutrients are washed away in water bodies, causing algal bloom that reduces the amount of dissolved oxygen. This is called eutrophication and causes fish kills.

Many species thrive in a forest, controlling each others populations in various relationships. Different species depend on particular plants for food and habitat, occupying a particular niche. Since there is only one type of plant in a monoculture, only the few species who depend on it for food will dominate.

Without other species to control their population, organisms feeding on that crop will  reproduce to the point of infestation. Farmers will then resort to using pesticides to quickly save their investment, and this will have a negative impact on water quality.

Pesticides and their degradation products can cause cancers, mutations in the embryos, reproductive disorders, and other health concerns for humans and other non-target organisms. The half life of pesticides may range from 4 days to 6 months, as in the case of some persistent organic pesticides. These toxins are also carried in surface runoff to water bodies and may poison aquatic animals or bioaccumulate in fish and other life forms. The pollution may also seep underground, contaminating aquifers for drinking water.

Although biofuel crops can be planted in marginal areas, increasing demand puts pressure on good lands that can still be used for food crops. According to the Food and Agriculture Organization (2008), in rural parts in Asia, the poor still uses marginal lands for subsistence agriculture and whether they will benefit or not from biofuels depend on the security of their rights to the land.

Even if biofuel crops can grow in poor conditions, they need adequate water and nutrients to have commercially acceptable yields. While there may be environmental benefits to planting biofuel crops in marginal areas, the demand for biofuels puts pressure on producing greater harvests that can only be achieved in fertile lands or by adding more inputs.

In summary, converting a tropical forest into a monoculture biofuel plantation will have immediate adverse effects on the ecosystems microclimate, hydrology, and biodiversity. Long term adverse effects include erosion, pollution and health problems, reduction of food for human consumption (hunger), pests and diseases, and the worsening of global climate change.