The University of Michigan-led international study sheds light on the complex relationship between urban agriculture and its climate impact. The findings reveal that, on average, fruits and vegetables grown in urban farms and gardens have a carbon footprint six times greater than conventionally grown produce. However, the study also identifies exceptions, such as tomatoes grown in open-air urban plots and air-freighted crops like asparagus, which demonstrated lower carbon intensities than their conventional counterparts. The research underscores the need for careful planning and management in urban agriculture to maximize its climate benefits. The study’s lead author, Jason Hawes, suggests that practitioners can reduce their climate impacts by choosing specific crops, altering site designs, and adopting sustainable management practices.

Urban agriculture has gained popularity as a means of promoting sustainability in cities, offering social, nutritional, and environmental benefits. Despite the well-documented advantages, the carbon footprint of urban agriculture has been understudied, with previous research focusing on high-tech methods rather than the more common low-tech practices. This new study, involving 73 urban farms and gardens across five countries, is the largest of its kind to compare the carbon footprints of urban and conventional agriculture. The findings emphasize the importance of extending the lifetimes of urban agriculture infrastructure, utilizing urban wastes as inputs, and maximizing social benefits to make low-tech urban agriculture more carbon-competitive with conventional methods. The study provides valuable insights for urban planners, policymakers, and practitioners seeking to integrate sustainable agriculture into the fabric of future cities.

The search for alternative gasoline is a constant and pressing one, and there are already lots of pilot projects out there in the attempt of finding a replacement.
But now a crucial substance so frequently used on the US market seems to have revealed that it is more harmful than straight gasoline.
The corn-based ethanol which for years has been mixed into gasoline in the US might be a bigger contributor to global warming.
A recent study published in the Proceeding of the National Academy of Sciences displays the harmful effects of corn-based ethanol and its threats to the environment.
The substance was previously considered a green biofuel, but now that the Biden administration has started to review biofuel policies, some new truths have resurfaced.
The study concluded that corn fuel cannot be categorized as biofuel and that ethanol can increase by up to 24% carbon emissions as compared to gasoline.
This results from the process of growing corn, which is more energy consuming and prone to contribute more to global warming.

“Corn ethanol is not a climate-friendly fuel,” said Dr. Tyler Lark, assistant scientist at University of Wisconsin-Madison Center for Sustainability and the Global Environment and lead author of the study.

“Under the U.S. Renewable Fuel Standard (RFS), a law enacted in 2005, the nation’s oil refiners are required to mix some 15 billion gallons of corn-based ethanol into the nation’s gasoline annually. The policy was intended to reduce emissions, support farmers, and cut U.S. dependence on energy imports.”

The study contradicts previous research commissioned by the U.S. Department of Agriculture (USDA) showing ethanol and other biofuels to be relatively green.