PARIS – Emissions of methane – a gas that heats the planet several times more powerful than carbon dioxide – have increased by 9% in ten years, driven by humanity’s insatiable hunger for energy and food, concluded an important international study on Wednesday.
Methane (CH4) has a heating potential 28 times greater than CO2 over a period of 100 years and its concentration in the atmosphere has more than doubled since the industrial revolution.
Over a period of 20 years, it is more than 80 times more powerful.
Although there are a number of natural sources of methane such as wetlands and lakes, the study team concluded that 60% of CH4 emissions are now of human origin.
These sources fall mainly into three categories: extraction and combustion of fossil fuels for electricity, agriculture, including livestock, and waste management.
The Paris climate agreement of 2015 saw countries commit to limiting temperature increases to “well below” two degrees Celsius (3.6 Farenheit) above pre-industrial levels.
While emissions are expected to decrease somewhat this year due to the pandemic, atmospheric methane levels are increasing by approximately 12 parts per billion each year.
This trajectory is in line with a scenario modeled by the Intergovernmental Panel on Climate Change (IPCC) which predicts global warming of 3 to 4 ° C by 2100.
“Regular updates to the global methane budget are necessary … because reducing methane emissions would have a rapid positive effect on the climate,” said Marielle Saunois, researcher at the Laboratory for Climate and Environmental Sciences in France. and responsible for the study. .
“To achieve the objectives of the Paris Agreement, not only must CO2 emissions be reduced, but also methane emissions. ”
The Global Carbon Project, a consortium of more than 50 research institutions worldwide, has collected data from more than 100 observation stations.
The world today produces around 50 million tonnes more methane per year compared to 2000-2006.
It is estimated that around 60% of CH4 emissions from human origin come from agriculture and waste, including 30% from the digestive processes of cattle and sheep.
According to the study, 22% comes from the extraction and combustion of oil and gas, while 11% comes from the world’s coal mines.
But recent studies based on new techniques to spot methane leaks using satellite data suggest that emissions from the oil and gas sector could be considerably higher than those presented in the study, which included only data until 2017.
– Short-term threat –
Although the general trend is increasing, emission levels vary by region.
For example, Africa, China and Asia each produce 10 to 15 million tonnes per year. The United States produces around 4 to 5 million tonnes.
Europe is the only region where methane emissions are falling – between 2 and 4 million tonnes since 2006, according to the estimation method.
The United Nations says that to reach the more ambitious Paris goal of a 1.5 C ceiling, all greenhouse gas emissions must fall by 7.6% per year this decade.
“The 20-year framework (of the methane warming effect) might be more appropriate given our political goals,” said Mr. Saunois.