A study led by Princeton researchers published in the journal Nature found that the inefficient use of land for agriculture — and even alternative-fuel production — greatly increases greenhouse gas emissions. According to the study, policymakers and researchers have underestimated the effect that changes in land management and people’s diets would have on limiting greenhouse gas emissions and countering the effects of climate change.
The researchers found that diets in wealthy nations have far higher greenhouse gas consequences than typically calculated. The average European diet produces as much greenhouse gases per year — 9 gigatons, or 9 billion metric tons — as is normally calculated for their consumption of everything else combined, including energy. Shifting from a diet based on meat such as beef, lamb and dairy to other foods would reduce these emissions by 70 percent.
Even land-intensive steps to reduce carbon dioxide emissions such as growing crops for alternative fuels can be ultimately counterproductive. Consuming ethanol or biodiesel contributes two to three times the greenhouse gas emissions of gasoline or diesel over a 30-plus-year period. On the other hand, vehicles that run on solar-sourced electricity produce 12 percent of the greenhouse gases that result from the average use of gasoline and diesel.