Leaders of 103 countries have signed a deal brokered by the EU and USA to reduce methane emissions by 30 % by the end of the decade. If fully implemented, the pledge could limit global warming by about 0.2 – 0.3 degC by 2050. 

The agreement was initiated by the USA and the EU, which announced an international partnership, the Global Methane Pledge, to cut emissions of the GHG methane by 30% by 2030 compared to 2020 levels. Methane is one of the most potent greenhouse gases and responsible for a third of current warming from human activities.

There has been a growing focus on tackling methane as a way of buying extra time to tackle climate change. "We cannot wait for 2050," EU Commission chief Ursula von der Leyen told the summit. "We have to cut emissions fast." The pledge covers countries which emit nearly half of all methane, and make up 70% of global GDP.

The main focus in the short-term will be the fossil fuel industry, because most of the curbs can be achieved at little or no cost. And the potential benefits are huge – scientists believe it could help the world avoid 0.3 degC of warming by 2040.

The agreement is seen as very encouraging, and a sign of increasingly serious commitment to the cause globally. But there are some significant barriers to full implementation. Major emitters Russia, China and India have so far declined to take part. And all the commitments are voluntary.