Leonardo Lima (GREEN INTERN)

An aggressive campaign to cut methane emissions could give the world more time to tackle climate change, experts say. One of the main conclusions of the recently released IPCC report is that methane emissions have contributed enormously to the current warming.

The study suggested that 30-50% of the current rise in temperatures is due to this powerful but short-lived gas. The main sources of methane include agriculture, spills from oil and gas production and landfills.

For decades, the focus of efforts to curb global warming has been increasing emissions of carbon dioxide (CO2) from human activities such as energy generation and forest clearing.

There are good scientific reasons for this, as CO2 is the biggest driver of temperatures, responsible for about 70% of the warming that has occurred since the industrial revolution.

Methane (CH4), however, did not have the same focus. That may be changing, as earlier this year a major UN study highlighted its environmental impact.

A recent IPCC report graphically points out that the influence of methane has been calculated as an addition of about 0.5°C to the warming the world is currently experiencing.

So where does all this methane come from?

About 40% of the gas comes from natural sources such as swamps – but most of it now comes from a range of human activities. Since 2008, there has been a huge increase in methane emissions, which researchers believe is related to the rise in gas hydraulic fracturing in parts of the United States.

In 2019, methane in the atmosphere reached record levels, about two and a half times higher than it was in the pre-industrial era. What worries scientists is that methane has real muscles when it comes to warming the planet. Over a 100-year period, it is 28-34 times hotter than CO2.

Over a 20-year period, it is about 84 times more powerful per unit mass than carbon dioxide.

However, an important positive point about CH4 is that it doesn't last as long in air as CO2.

"In two decades, there would be a quarter of a ton, so basically, if we could stop emitting methane today by the end of this century, emissions would drop to the natural levels that were around 1750."

In the short term, experts believe that if methane emissions were to be reduced by 40-45% over the next decade, you would reduce 0.3°C of global temperature rise by 2040.

In a world where every fraction of a degree count, that's a potentially huge difference for the hope of keeping the 1.5°C limit alive.

References: Brazil Environment, BBC News and Matt McGrath