HIGH RISK OF ABRUPT CLIMATE CHANGE REQUIRING CLOSELY ESTIMATE BIOFUEL GREENHOUSE GAS EMISSIONS BY LIFE CYCLE ASSESSMENT

The article focuses on a specific environmental evaluation method - Life Cycle Assessment (LCA) and it estimates biofuel greenhouse gas (GHG) emissions and compares to fossil fuels. It is mainly evaluated by the mean Global Warming impact indicator, expressed in grams of CO2 equivalent per MJ of energy (gCO(2)eq.MJ(-1)). Biofuels are highly relevant renewable energy options on a global scale. Comparing with fossil fuels, biofuels in some cases can be carbon neutral or even carbon negative and play an important role in the reduction of GHG emissions. A number of LCA have shown that first generation biofuels provide a little to no benefit for GHG reductions compared to fossil fuels, particularly when indirect effects are considered. LCAs of second and third generation biofuels exhibit great variability and uncertainty but are intended to achieve greater GHG reductions. Highly possible Arctic Ocean ice meltdown in the late summer as soon as in September 2015 and accelerated methane hydrate destabilization in the Arctic Ocean seabed via ocean warming could cause abrupt climate change in the following decade. Mitigation of climate change requires to use only biofuels with the global warming impact indicator close to 0 gCO(2)eq.MJ(-1) (Carbon Neutral) or - gCO(2)eq.MJ(-1) (Carbon Negative).