Environment, Ecology, Biodiversity

Farmington Hills, Michigan, USA October 2011

Indian Mounds near Chillicothe, Ohio, July 2011

Farmland near Chillicothe, Ohio, July 2011.

The historic home district of Chillicothe which  remained Ohio's capital until 1810

Hayes State Park, Michigan, USA, August 2011

Join me in fighting for the environment. The polluters have to face time in court if things are going to change.

The Renewable Fuel Standard (RFS) specifies the use of biofuels in the United States and thereby guides nearly half of all global biofuel production, yet outcomes of this keystone climate and environmental regulation remain unclear. Here we combine econometric analyses, land use observations, and biophysical models to estimate the realized effects of the RFS in aggregate and down to the scale of individual agricultural fields across the United States. We find that the RFS increased corn prices by 30% and the prices of other crops by 20%, which, in turn, expanded US corn cultivation by 2.8 Mha (8.7%) and total cropland by 2.1 Mha (2.4%) in the years following policy enactment (2008 to 2016). These changes increased annual nationwide fertilizer use by 3 to 8%, increased water quality degradants by 3 to 5%, and caused enough domestic land use change emissions such that the carbon intensity of corn ethanol produced under the RFS is no less than gasoline and likely at least 24% higher. These tradeoffs must be weighed alongside the benefits of biofuels as decision-makers consider the future of renewable energy policies and the potential for fuels like corn ethanol to meet climate mitigation goals.

Our results showed that traditional first-generation biofuel crops including soybean, maize and oil palm were the most detrimental to local species richness and total abundance, worse even than urban environments. Although comparatively better, second-generation biofuel crops were also damaging to these measures of biodiversity overall, but with differences between individual crops. The demand for biofuels and the associated land required to grow biofuel crops is likely to increase in the future (International Energy Agency 2014), leading to land-use change and implications for biodiversity. Due to the variation we identified in biodiversity in different biofuel crop systems, and in order to minimize the negative impacts of biofuels on biodiversity, biofuel policies that guide future land-use decisions should be tailored to consider how local biodiversity might respond to particular crops, grown in particular geographic regions. All else being equal, those biofuel crops with the least harmful impacts on local biodiversity should be prioritized over other potential biofuels.

Land clearance to cultivate biofuel crops reduces local biodiversity

Mangrove forests in southern coastal US

Tutorial on Mangrove coastal forests from The Smithsonian

A mangrove is a woody tree or shrub that lives along sheltered coastlines within the tropic or subtropic latitudes. In fact, the various species of mangroves aren’t necessarily closely related to one another, but they do share the unique capability of growing within reach of the tides in salty soil. Some mangrove species live so close to the shoreline that they are flooded with salt water every day as the tide comes in and submerges their roots. All mangroves have evolved special adaptations that enable them to live in salty, oxygen-poor soil.