Eating is one of the human activities that contributes the most to global warming. Due to the emissions of CO2, methane and nitrous oxide (three greenhouse gases) are generated from the production of humanity’s basic food. This fact, already noticed decades ago by scientists, has now been measured more abundantly by a research paper published this Monday in Nature.
Among its conclusions, it stands out that the diet of the world’s population will contribute 1º more to the increase in 2100 temperatures. This information is surprising if one considers the climate change scenarios to change by the end of the century expert. The UN panel (IPCC) talks about increases in global temperature between 2.5º and 3º maximum (in the worst case scenario), taking into account all the human activities that cause this global warming with their emissions. That is, from global transportation, to deforestation, through power generation.
For this reason, 1º is essentially the weight that the food sector would have and which, according to the authors of the work, is not reflected in the obligations of the Paris climate agreements. According to these, only a third of the signatories talk about specific measures to reduce livestock emissions and less than a fifth do so in agriculture.
“Current patterns of consumption and production are inconsistent with increasing sustainability while pursuing a secure climate future,” lead author Catherine C. Ivanovich, a researcher in Columbia University’s Department of Environmental Sciences.
To arrive at this conclusion, the authors assessed the percentage of global warming, due to their emissions, of 12 foods considered basic in the human diet. They are: grains, rice, fruits, oils, eggs, ruminant and non-ruminant meats, shellfish and fish, dairy products, vegetables, beverages, and others. Of all of them, only three products account for 80% of the global warming that causes the world’s food system.
These are meat (from ruminant and non-ruminant animals), dairy products and rice. The two former monopolies account for more than half of the global weight of emissions from the rice sector and 20%. The remaining products would account for only 5% of the global increase in temperature.
These data, the authors recall in the work, were calculated from the fact that humanity does not change its production and behavior with purity. However, they recall that their conclusions are more ominous if the prediction of meat consumption will increase by 90% in 2050 and the remaining animal products by 70% at the same time. “So, the drought can be increased even more.”
To attribute more or less food to global warming, we need to take into account not only CO2 emissions, often the only parameter calculated in many studies. But methane emissions, a powerful greenhouse gas due to its ability to increase and multiply in the atmosphere, and nitrous oxide which can absorb 250 more heat than CO2 per mass.
The first usually comes from the machinery used in food production and transportation. These are more related to the crops themselves: fermentation, manure management, manure, ruminant excrement and, finally, the methanogenesis of rice crops.
Limiting GHG emissions from food, the study is related to the Harvard Medical School’s recommendations for what constitutes a healthy diet. This includes two basic rules of consumption: eating meat (red pork and pork) only once a week and a maximum of two servings a day consisting of fish, chicken and eggs. “We found that introducing these standards into the global diet could reduce global warming by up to 0.19º,” the paper says. In percentage terms, this would mean a 21% increase in the level of feeding alone.
Logically, this conclusion follows from the middle. The models used by the researchers to arrive at this calculation must take into account that in the countries of the quality of the United States of America and Europe their consumption decreases much more, while others like Ethiopia and India want to increase them. to a balance which admits a global account.
Technology as a great transformer
In addition to people’s livelihoods, the work calculates how much this global increase in temperature could be reduced if production systems were changed and improved with new technologies that reduced their emissions. Thus, cattle could reduce their contribution between 10 and 35% and the rice crop, due to high methane emissions, up to 50%.
The last gas mentioned here is one of the most responsible emissions in relation to global warming caused by the sector. Therefore, the three foods are of the greatest importance in global warming, and at the same time emit large amounts of methane.
Finally, in addition to the change of diet and the improvement of production methods through decarbonization technology, they show the importance of controlling food waste, which also contributes to the increase in temperature. “If food waste were divided at the (consumer) level, warming at the end of the century would be reduced by 0.04º, 5% of global warming associated with food,” the paper concludes.