Levels of methane have surged in recent years and the atmospheric concentration of the greenhouse gas has now reached a record high, a study shows.
Scientists say several human activities are to blame for the soaring levels, including coal mining; oil and gas production; cattle and sheep farming; and landfills.
Stanford University researchers and the Global Carbon Project assessed emissions from 2010 up until 2017, the last year complete data was available.
It found that in 2017 Earth’s atmosphere absorbed nearly 600 million tons of the colourless, odourless gas that is one of the most potent pollutants.
Methane traps almost 30 times more heat than the same amount of carbon dioxide and more than half of all methane emissions now come from human activities.
Carbon emissions dropped drastically during the coronavirus lockdown as people stopped going out and much of the world shut down.
Data from London city centre in the middle of lockdown revealed methane levels had dropped, but experts involved in the latest study say there is ‘no chance’ that methane emissions declined as significantly as CO2 and any drop will soon reverse.
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In 2017 Earth’s atmosphere absorbed nearly 600 million tons of methane, the colourless, odourless gas that is one of the most potent pollutants (pictured). Natural sources soaked up around most of this, but there was a net positive output of methane of around 16million tons
Annual methane emissions are up by around nine per cent, equivalent to 50 million tons per year, from the early 2000s, the new data shows.
This, scientists say, is roughly the same as putting 350 million more cars on the world’s roads or doubling the total emissions of Germany or France.
Professor Rob Jackson, who led the study, said: ‘We still haven’t turned the corner on methane.’
On a global scale, there are two major drivers of methane emissions in the world, fossil fuels and farming, the latest figures show.
While there is a concerted effort to cut down on fossil fuel emissions, livestock farming is a booming business as demand grows for meat and dairy.
Cows are a huge source of the hydrocarbon methane as it is produced by their unique stomach system and released in flatulence.
‘Emissions from cattle and other ruminants are almost as large as those from the fossil fuel industry for methane,’ Professor Jackson said.
‘People joke about burping cows without realising how big the source really is.’
Pictured, a visualisation of global methane on January 26, 2018. Red shows areas with higher concentrations of methane in the atmosphere. Notable culprits for methane emissions include Africa, the Middle East, China, South Asia, Oceania and the US, the latest data shows
Methane traps almost 30 times more heat than the same amount of carbon dioxide and more than half of all methane emissions now come from human activities. Carbon emissions dropped drastically during the coronavirus lockdown but experts say there is ‘n chance’ such a significant decrease also occurred for methane
Cutting air pollution could help curb greenhouse gas emissions and combat climate change
World leaders have been urged to slash the planet’s level of air pollution as efforts to tackle the climate crisis are ramped up.
Greenhouse gases have long been condemned by scientists for fuelling global warming, but now a UN branch has also called for a reduction in all toxic fumes.
It hopes to stop high emissions of some chemicals which do not receive widespread attention.
While most greenhouse gases contaminate the air, not all air pollutants have a warming effect and cutting emissions of all toxic chemicals is thought to have both ecological and public health benefits.
Carbon monoxide and lead particles, for example, are not greenhouse gases but still contaminate the air.
The shifting focus to promoting clean air marks a sea change in environmentalism – which has historically centred on carbon dioxide – and reflects the growing presence of climate change on the world stage.
In 2017, a total of 227 million tons of methane was produced globally by agriculture, an 11 per cent rise on the average yearly figure between 2000 and 2006.
In comparison, fossil fuels produced 108 million tons in 2017, up nearly 15 per cent from the earlier period.
The issue, according to the latest studies, is a global one, with many regions contributing to the surge in methane levels.
Notable culprits include Africa, the Middle East, China, South Asia, Oceania and the US.
‘Natural gas use is rising quickly here in the US and globally,’ Professor Jackson said.
‘It’s offsetting coal in the electricity sector and reducing carbon dioxide emissions, but increasing methane emissions in that sector.’
The only region to see a drop in emissions is Europe, due in part to tamping down emissions from chemical manufacturing and growing food more efficiently.
‘Policies and better management have reduced emissions from landfills, manure and other sources here in Europe,’ said Marielle Saunois of the Université de Versailles Saint-Quentin in France, lead author of one of the two studies.
‘People are also eating less beef and more poultry and fish.’
This may be the blueprint for reining in the runaway train that is methane emissions, the academics warn.
Professor Jackson says: ‘We’ll need to eat less meat and reduce emissions associated with cattle and rice farming,’ Jackson said, ‘and replace oil and natural gas in our cars and homes.’