Cuts to methane will slow rate of global warming
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, which comes from sources including fossil fuel extraction, waste and agriculture such as livestock and rice, is a short-lived but very potent climate pollutant that is second only to carbon dioxide in driving global warming.
But there are ways to cut methane emissions by nearly half (45%) this decade, which will avoid nearly 0.3C of warming up to 2045, the report from the UN Environment Programme and Climate and Clean Air Coalition said.
As methane contributes to the creation of ground-level ozone, a dangerous air pollutant, nearly halving emissions will also prevent a quarter of a million premature deaths and 775,000 asthmarelated hospital visits 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, the report said.
Emissions could be cut with cost-effective and readily available measures such as controlling leaks and vented gas from oil, gas and coal operations and stopping organic waste going to landfill where it produces methane.
Reducing production of methane gas in cattle and sheep through switching feed and supplements, dealing with manure in different ways and changing rice paddy agriculture could also cut emissions.
Additional measures such as adopting healthier diets, with cuts to red meat and dairy consumption if it is above recommended guidelines to reduce livestock production, and reducing food waste would also curb methane.
The report warned urgent steps must be taken to reduce methane emissions this decade, but 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.
Methane is a greenhouse gas which is tens of times more powerful than carbon dioxide in warming the planet but only lingers in the atmosphere for about a decade, so curbing emissions has a rapid benefit.
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.
Around 35% of human-caused methane emissions come from fossil fuel production – causing climate pollution before the fuels are even burned for energy – while 40% comes from agriculture and 20% from waste.
Readily available targeted measures could cut methane emissions by around 30% in 2030, many at low cost, or actually saving money, for example by capturing methane from fossil fuel production to add to natural gas revenues.
But additional measures are needed to deliver the 45% cuts to emissions by 2030 that are required to help curb global warming to 1.5C, as countries have pledged to try to do under the international Paris climate accord.
These include switching from fossil fuels to renewables, reducing energy use and food waste, and changing diets – which can also improve health.