The US and the EU have announced a global partnership to cut emissions of the greenhouse gas methane by 2030.
US President Joe Biden preparing to speak at a COP26 session on forests and land use. Biden and EU Commission chief Ursula von der Leyen announced a global partnership to cut methane emissions by 2020. Photo: AFP
EU Commission chief Ursula von der Leyen and US President Joe Biden made the announcement at the COP26 summit on Tuesday.
The Global Methane Pledge aims to limit methane emissions by 30 percent compared with 2020 levels.
Methane is one of the most potent greenhouse gases and responsible for a third of current warming from human activities.
More than 100 countries have signed up to the initiative, first proposed by the US and the EU in September.
New Zealand is a signatory to the global pledge, but local farmers are off the hook as the government is not planning additional cuts to agricultural emissions in response to joining the agreement.
It is sticking with plans laid out in the Zero Carbon Act to reduce agricultural methane by 10 percent by 2030 and between 24 and 47 percent by 2050.
The main focus of efforts to curb global warming is carbon dioxide (CO2), which is emitted as a result of human activities such as generating power and clearing forests.
But there has been a growing focus on methane as a way of buying extra time to tackle climate change. Although there's more CO2 in the atmosphere and it sticks around for longer, individual methane molecules have a more powerful warming effect on the atmosphere than single CO2 molecules.
And while one of the key goals of COP26 is to get countries to commit to achieving net zero by 2050 - meaning not adding to the amount of greenhouse gases in the atmosphere - both leaders stressed that they needed to act now.
"We cannot wait for 2050," EU Commission chief Ursula von der Leyen told the summit. "We have to cut emissions fast."
She said cutting methane was "one of the most effective things we can do to reduce near-term global warming", calling it "the lowest hanging fruit".
US President Joe Biden echoed her words, calling methane "one of the most potent greenhouse gases there is".
The pledge covers countries which emit nearly half of all methane, and make up 70 percent of global GDP, the US president said.
How is methane emitted?
Around 40 percent of CH4 comes from natural sources such as wetlands but the bigger share now comes from a range of human activities, ranging from agriculture such as cattle and rice production to rubbish dumps.
One of the biggest sources is from the production, transport and use of natural gas and since 2008 there has been a big spike in methane emissions, which researchers believe is linked to the boom in fracking for gas in parts of the US.
In 2019, methane in the atmosphere reached record levels, around two-and-a-half times above what they were in the pre-industrial era.
What worries scientists is that methane has real muscle when it comes to heating the planet. Over a 100-year period it is 28-34 times as warming as CO2.
Over a 20-year period it is around 84 times as powerful per unit of mass as carbon dioxide.
However, there is much more CO2 than methane in the atmosphere and individual molecules of it can remain there for hundreds of years.
- BBC / RNZ