By Carolyn Opio
Livestock Policy Officer of FAO-Subregional Office for Mesoamerica
The study points out that this gas represents approximately half of the net increase of 1.0 degrees Celsius in the global average temperature since the pre-industrial era. Since 2007, atmospheric CH4 has increased and in 2020 reached 262 percent of the pre-industrial level due to booming emissions from anthropogenic sources.
Although China, South Asia and North America stand out as the main emitters, the levels observed in all regions of the planet are significant.
METHANE AND CLIMATE DISCOURSE
Methane is the second largest contributor to global warming, ranking below CO2, and is at least 84 times more potent than carbon dioxide over a 20-year period.
It is also a precursor to ozone: chemical reactions in the atmosphere involving methane produce ozone, a pollutant that poses significant health risks.
Therefore, due to the short duration of methane in the atmosphere, a considerable decrease in its emissions can give the world a little more time to continue working on the reduction of other greenhouse gases such as carbon dioxide and nitrous oxide. .
CH4 has the ability to greatly heat the atmosphere over a period of about 12 years, but then it dissipates and its heating power decreases.
This means that if the rate of methane emissions remains constant, the amount of CH4 emitted today will replace the methane that disappeared, and its atmospheric concentration will remain stable. That’s why methane is crucial, because it’s essentially a flow resource, going in and out of the atmosphere.
In this sense, it is essential to control methane emissions, which can reduce the exchange rate in the short term.
Lower CH4 emissions would offset some of the considerable costs associated with rapidly reducing CO2 emissions. It will also make it possible to ensure that ecosystems, food systems and the economy can adapt and make it more likely that the goals of the Paris Agreement will be achieved. However, reducing methane emissions does not replace the need to reduce CO2 emissions, as the gases are not really “equivalent” to each other. The substitution of efforts to decrease one gas instead of another, does not obtain the same result.
The relative permanence of CO2 and the cumulative effects of its continued emission imply that we are ‘committed’ to warming in the future, even if all sources of methane were removed today.
Carbon dioxide is largely a reserve resource. Every time we produce carbon dioxide, it accumulates in the atmosphere and adds to the CO2 previously emitted.
It takes hundreds or even thousands of years for carbon dioxide added to the atmosphere to dissolve in the oceans or to turn into inert forms, such as coal or oil.
This implies that if we continue to burn fossil fuels at the current rate, the planet will continue to warm. Even if we reduce the consumption of fossil fuels, the planet will continue to warm as the stock of CO2 in the atmosphere continues to increase.
METHANE SOURCES
Methane is produced naturally in the environment, by animals, and as a result of human activity.
Today, about 60 percent of the methane in the atmosphere is human-induced, while the rest comes from sources that existed before humans began influencing the carbon cycle.
According to the Global Methane Assessment 2021 report, anthropogenic methane emissions come from three sectors: fossil fuels (35 percent), waste (20 percent), and agriculture (40 percent).
It should be noted that in the agricultural sector, methane emissions from manure and enteric fermentation – chemical reactions in the stomachs of cows and other grazing animals as they break down plants – account for about 32 percent and rice cultivation 8.0 percent of global anthropogenic emissions.
Ruminants are one of the main contributors to methane emissions. In fact, about 70 percent of the methane in the agricultural sector comes from enteric fermentation.
In regions with a significant presence of ruminants such as Latin America and the Caribbean, livestock contribute about 60 percent of total regional methane emissions.
If we want to find innovative climate solutions, we have to consider the bigger picture. In addition to climate, there are ethical, nutritional, socio-cultural and livelihood-related arguments that need to be analyzed to understand the benefits and costs associated with ruminant production.
The debate on ruminants and climate change must go beyond methane, including a full explanation of the role ruminant systems play in different contexts.
(Keep going)
arb/ga/co
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