Although emissions from the energy sector, transport and industry that cause climate change were stopped immediately in the world (which has already been verified during the pandemic that it is not recommended that it should happen suddenly), those caused by the global food system alone would raise the planet's temperature above the safe limit of 1.5 ° C.
This is assured by a new study published in the journal
Science
carried out by researchers from the universities of Oxford (UK), Minnesota, California and Stanford (USA), who analyze different strategies for the greenhouse gases generated in the production of food do not undermine the efforts of other sectors to meet the goals of the Paris Agreement against climate change.
"Governments have to put more focus on the food system," says Michael Clark, a researcher at the University of Oxford and lead author of the study.
"Renewable energy and transitional diets will be important parts of the climate solution, we need to do both," he adds.
Scientific work analyzes the extent to which global emissions can be reduced if, between 2020 and 2050, five different strategies are adopted in the food sector on a global scale: a
diet rich in vegetables
with moderate amounts of milk, eggs and meat;
a diet in which
per capita calorie
intake was simply adjusted
to healthy levels
;
an option in which agronomic practices are improved to
get more out of the land
;
another in which
food waste
is cut
in half
;
and a last one in which
emissions
are reduced
in
production
processes
(for example, using fertilizers more efficiently or using additives for ruminants).
Of all these approaches, the one that manages to reduce emissions the most is the diet rich in vegetables.
As can be seen in the graph, this is the only strategy of the five studied with which the emissions of the food system approach those necessary so that the planet does not exceed the limit of 1.5 ° C (in a probability of 50% ).
However, this is so if greenhouse gases are excluded from all other non-food sectors.
In reality, it is expected that the reduction of these other emissions from energy, transport or industry will be more gradual, so the researchers consider that it is essential to join the efforts of the different strategies analyzed in the food sector.
“The diet we have examined is primarily made up of vegetables and contains only small amounts of meat or fish.
We have not analyzed a vegetarian option because for many people it is important to eat meat or fish and for this reason we did not want to completely exclude these foods ”, Clark details, who emphasizes that there are many different ways to follow a diet rich in vegetables, according to different preferences taste, cultural or food availability in the world.
This eating pattern is similar to that advocated by the study published last year in
The Lancet
magazine
to feed 10 billion people in 2050 with a diet of “planetary health” (a concept that includes the health of humans and that of humans). natural systems on which the species depends).
"Our analyzes suggest that reducing greenhouse gases in the global food system will likely be essential to meet the 1.5 ° C and 2 ° C targets," says the study published in
Science
, which estimates that with current trends, emissions accumulated in this sector between 2020 and 2100 would be 1,356 gigatons of CO2, so that even if other emissions related to transport, energy or industry were suddenly stopped, the gases generated in food production would alone exceed the safety limit of 1.5 ° C between the years 2051 and 2063. This is fulfilled if emissions from all other sectors were reduced immediately (as we have already said, something not recommended).
In the case of a more gradual decarbonization of energy, transport or industry (but in line with the objectives sought), if nothing were done in the food system, the study estimates that the increase in planetary temperature would exceed the limit of 1.5 ° C in 11 years and 2 ° C before the end of the century.
As scientific work affects, food production in the world generates greenhouse emissions in very different ways.
The main ones are deforestation --which releases carbon dioxide (CO2) and nitrogen oxide (N2O) -, the use of fertilizers and other agrochemicals --CO2, N2O and methane (CH4) -, ruminant gases (CH4), rice fields (CH4), livestock manure (N2O and CH4) and fossil fuels used in all processes (CO2).
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