Food is the most essential to our survival, and over the years it has become one of largest contributors to the greenhouse effect, a new study has found. According to the data, global food consumption alone could add nearly 1 °C to warming by 2100.
The study, which was published in the journal Nature Climate Change, attributed 75% of the heat generated by food production, to foods that have significant sources of methane, specifically those originating from ruminant livestock such as cattle, and rice paddies. The agriculture sector is responsible for nearly half of methane (CH4) emissions, two-thirds of nitrous oxide (N2O) emissions and 3% of carbon dioxide (CO2) emissions from human activities worldwide, according to data released.
Methane gas is able to trap more than 100 times more heat than CO2, and is emitted primarily from the production of animal products and rice, through enteric fermentation, manure management and rice paddy methanogenesis. Nitrous oxide can trap over 250 times more heat than CO2 by mass, and lasts around a century. It is emitted through synthetic fertiliser use, the cultivation of nitrogen-fixing crops and ruminant excretion on rangelands, the study states.
According to scientists, to assess the warming impacts of agriculture that arise from these combined emissions, studies often use the simple metrics of global warming potential (GWP) and its counterpart CO2 equivalence (CO2e) to estimate the impact of these gases on a common scale.
However, the study also states that to encourage more commitments to decreasing GHG emissions from food systems and support effective policy design, it is important to improve understanding of the role of global food consumption in contributing to future warming.
There is also a need for a more comprehensive analysis that investigates the warming impact of all food sources. This will improve the understanding of how food consumption contributes to climate change in the near and distant future. It will also help in identifying the importance of different foods and gases in contributing to climate change and provide guidance for climate mitigation efforts in the food sector.