Swift action to cut methane pollution would rapidly reduce the rate of global warming, while boosting health and food production, a UN report has said.
Methane is a short-lived but very potent climate pollutant that is second only to carbon dioxide in driving global warming.
The gas comes from fossil fuel extraction, waste, and agriculture such as livestock and rice.
Concentrations of the greenhouse gas in the atmosphere are rapidly increasing, and without action will continue to rise to at least 2040, the report said.
But there are ways to cut methane emissions by nearly half (45%) this decade, the report from the UN Environment Programme and Climate and Clean Air Coalition said.
Doing so would avoid nearly 0.3C of warming up to 2045.
What impact would cutting methane emissions have?
Methane contributes to the creation of ground-level ozone, a dangerous air pollutant, so if the 45% drop could be achieved, it would prevent a quarter of a million premature deaths.
The impact on asthma sufferers would be wide-reaching too, cutting asthma-related hospital visits by 775,000 a year.
Ozone pollution also harms plants and natural systems so reducing methane emissions would prevent global crop yield losses of 26 million tonnes a year.
How can the world cut its methane emissions?
Cost-effective and readily available measures are already there to help achieve the goal.
These include controlling leaks and vented gas from oil, gas and coal operations and stopping organic waste going to landfill where it produces methane.
Switching feed and supplements would cut the levels of methane gas produced by cattle and sheep.
Dealing with their manure in different ways and changing rice paddy agriculture could also cut emissions.
What can you personally do?
Individuals can make an impact too by adopting healthier diets, with cuts to red meat and dairy consumption.
Reducing food waste would also curb methane.
The report warned urgent steps must be taken to reduce methane emissions this decade, and that there were numerous benefits which outweighed the costs.
In the foreword to the report, UN Environment Programme executive director Inger Andersen said: "Fast and ambitious methane mitigation is one of the best strategies available today to deliver immediate and long-lasting multiple benefits for climate, agriculture, human and ecosystem health."
Responding to the report, scientists in the UK said it highlighted how tackling methane could deliver quick wins for the climate and other important benefits.
Prof Dave Reay, from the University of Edinburgh, said: "This blunt report makes clear that slashing emissions of methane will deliver large and rapid benefits for the climate, air quality, human health, agriculture, and the economy too."
He said the prime target was the global production and supply of oil, gas and coal.
"By capturing methane from oil wells and coal mines, and plugging all those leaks, a major driver of climate change is cut down to size while simultaneously creating new green jobs and improving air quality for us all."