Greenhouse gas emissions associated with food production and consumption could add almost 1ºC to the warming projected by the end of the century. This is indicated by a study published in the journal Nature Climate Change. Three quarters of this warming comes from the production and consumption of ruminant meat, dairy, and rice, which are foods with a heavy load of methane emissions. However, more than 55% of the projected warming can be avoided with improvements in production practices, global adoption of a healthy diet, and reduced food waste.
The agricultural sector is responsible for a large part of the emissions that warm the atmosphere; specifically, he is responsible for half of methane emissions, two thirds of nitrous oxide (NO2) emissions and 3% of carbon dioxide (CO2) emissions from human activities worldwide. Methane, NO2 and CO2 are 80% of the gases that warm the climate
However, only a third of the countries refer to mitigation measures in agriculture when submitting their climate action plans to the UN to comply with the Paris Agreement against climate change.
The study analyzes the future impacts on warming that derive from the current patterns of global food consumption throughout the 21st century. And for this, it develops an inventory of individualized emissions for foods based on an extensive review of the literature (115 studies and a total of 206 estimates of individual gas breakdowns for each item or food group).
Total global greenhouse gas emissions for the year 2010 were estimated at 4.860 million tons (Mt) of CO2, 151 Mt of methane and 9 Mt of NO2.
And from the analysis of the trajectories of these emissions, the study concludes that if current diets and agricultural production patterns are maintained, food consumption could dangerously increase temperatures.
The bottom line is that maintaining current dietary patterns around the world for the rest of the century could account for almost 1ºC of warming.
And, since temperatures have already risen more than 1 °C above pre-industrial levels by 2021, “just this additional warming is enough to pass the 1.5°C global warming target and approach the 2°C threshold.” C” (goals established in the Paris Agreement), as emphasized.
“Even under a variety of population growth scenarios, we expect at least an additional 0.7–0.9°C warming,” the study adds.
However, the introduction of the best available technologies in production practices, the decarbonization of the energy sector, changes to protect health in eating habits and waste reductions could reduce the projected warming by more than 55%. This would prevent a rise of 0.5 °C in relation to the most foreseeable trend.
“We have found that dairy and meat consumption is responsible for more than half of the warming by 2030 and through 2100,” the report says.
Rice contributes another large fraction to the warming through the end of the century (19%), while vegetables, grains, fish and shellfish, oils, beverages, eggs, fruits and other uncategorized foods contribute 5% or less.
The study assumes that dietary patterns will remain constant until the end of the century. However, ruminant meat is expected to increase by 90% by 2050, and consumption of all animal products is expected to grow by 70%.
On the other hand, scientists stop to analyze the possibilities of avoiding this warming through various methods and practices.
Thus, the potential of the various technologies to reduce these emissions is evaluated.
For example, total CO2 emissions associated with ruminant meat, dairy products, and non-ruminant meat could be reduced by 35%, 30%, and 10%, respectively.
This achievement would be achieved with a decrease in methane and nitrous oxide emissions of enteric origin and manure. In addition, rice has the potential to reduce methane emissions by 50% (although studies suggest that associated production changes could increase nitrous oxide emissions).
Simulations and models show that the immediate adoption of these productive practices would prevent a warming of 0.2°C, a quarter of the warming predicted by food consumption for the year 2100.
For its part, full decarbonization of the energy system (by mid-century) would slow down warming by between -0.15 ºC and -0.17 ºC.
And even more beneficial would be the implementation and generalization of a change in diet in response to environmental concerns.
In this sense, the recommendations of Harvard Medical School, which advocate a reduction in meat consumption and a lower intake of saturated fats and cholesterol, are taken as a basis.
These recommendations highlight the convenience of moderate consumption of red meat (beef and pork: around one serving per week) and limited consumption of fish, poultry and eggs (up to two servings per day).
“If these dietary changes were implemented globally, warming due to food consumption could decrease by 0.19 °C by the end of the century,” the report states.
On the other hand, if food waste at the retail (consumer) level were halved, by the end of the century warming would be reduced by 0.04°C), 5% of the warming associated with the diet.
These reductions, however, do not consider emissions in the production chain, something that has not been evaluated. According to the FAO, 52% of food loss and waste occurs before the retail phase.
