A Global Methane Assessment released on Thursday by the Climate and Clean Air Coalition (CCAC) and the United Nations Environment Programme (UNEP) showed that human-caused methane emissions can be reduced by up to 45 per cent this decade.

Such reductions would avoid nearly 0.3 degree Celsius of global warming by 2045 and would be consistent with keeping the Paris Climate Agreement’s goal to limit global temperature rise to 1.5-degree Celsius within reach.

The assessment, for the first time, integrates the climate and air pollution costs and benefits from methane mitigation.

Because methane is a key ingredient in the formation of ground-level ozone (smog), a powerful climate forcer and dangerous air pollutant, a 45 per cent reduction would prevent 260,000 premature deaths, 775,000 asthma-related hospital visits, 73 billion hours of lost labour from extreme heat, and 25 million tonnes of crop losses annually.

“Cutting methane is the strongest lever we have to slow climate change over the next 25 years and complements necessary efforts to reduce carbon dioxide. The benefits to society, economies, and the environment are numerous and far outweigh the cost. We need international cooperation to urgently reduce methane emissions as much as possible this decade” said UNEP Executive Director Inger Andersen.

Rick Duke, Senior Advisor to the US Special Presidential Envoy on Climate Change, said: “Methane accounts for nearly one-fifth of global greenhouse gas emissions and, now that the world is acting to phase down hydrofluorocarbons through the Montreal Protocol, it is by far the top priority short-lived climate pollutant that we need to tackle to keep 1.5 degrees C within reach.

“The United States is committed to driving down methane emissions both at home and globally — through measures like research and development, standards to control fossil and landfill methane, and incentives to address agricultural methane. We look forward to continued partnership with the CCAC on this crucial climate priority.

Kadri Simson, European Union Commissioner for Energy, said: “Building on the EU methane strategy last October, this UN report highlights just how damaging methane emissions can be, and the need to take concerted action at international level.”

The need for action is urgent. Human-caused methane emissions are increasing faster than any time since record keeping began in the 1980s.

Despite a Covid-19 induced economic slowdown in 2020 that prevented another record year for carbon dioxide (CO2) emissions, the amount of methane in the atmosphere shot up to record levels according to data recently released by the United States National Oceanic and Atmospheric Administration (NOAA).

This is a concern because methane is an extremely powerful greenhouse gas, responsible for about 30 per cent of warming since pre-industrial times.

The good news is that unlike CO2 which stays in the atmosphere for 100s of years, methane starts breaking down quickly, with most of it gone after a decade.

This means cutting methane emissions now can rapidly reduce the rate of warming in the near-term.

The report notes that most human-caused methane emissions come from three sectors: fossil fuels, waste, and agriculture.

In the fossil fuel sector, oil and gas extraction, processing, and distribution account for 23 per cent, and coal mining accounts for 12 per cent of emissions.

In the waste sector, landfills and wastewater make up about 20 per cent of emissions.

In the agricultural sector, livestock emissions from manure and enteric fermentation represent roughly 32 per cent, and rice cultivation eight per cent of emissions.