By Gloria Dickie

Fast-Rising Methane Emissions

BAKU (Reuters) – Fast-rising methane emissions could undermine efforts to limit global warming by mid-century, prompting scientists and policymakers to urge aggressive action to curb output of the potent greenhouse gas.

Nearly 160 countries have pledged a 30% cut from 2020 methane emissions levels by the end of this decade.

Over the last five years, atmospheric methane levels have risen at their fastest rate since record-keeping began in the 1970s, driven in part by natural sources, according to the 2024 Global Methane Budget report.

Importance of Controlling Methane Emissions

Heat-Trapping Power

Methane molecules are more powerful than carbon dioxide (CO2) in trapping heat, meaning fewer methane molecules are needed to cause the same amount of warming. Reducing methane can have a more immediate effect than reducing CO2. Tackling methane also makes financial sense. United Nations analyses indicate that cutting methane emissions is likely cheaper for comparable climate benefits.

While CO2 remains in the atmosphere for centuries, methane breaks down after about a decade, leading to less long-term impact on temperatures. Scientists typically compare the overall warming effects of methane versus CO2 over a century, calculating that methane is about 28 times worse for global warming. Over a shorter timespan of 20 years, methane is 80 times worse.

Methane has contributed to about 0.5 degrees Celsius of warming so far, or roughly one-third of the approximately 1.3 C warming experienced since pre-industrial times.

Surging Emissions

Methane concentrations are rising faster than any other major greenhouse gas, with human activities driving at least two-thirds of global emissions, according to the 2024 Global Methane Budget. This includes the agriculture sector, fossil fuel activities, and landfills.

The report, published every five years, states that methane emissions from human activities have increased overall by 20% over the last two decades. Most mitigation efforts, including EU legislation, focus on the oil and gas sector, where emissions are easier to tackle than in agriculture, according to the food-focused investor initiative, FAIRR.

Natural Sources a Concern

The remaining third of the world's methane emissions comes from natural sources like thawing permafrost, peat bogs, and wetlands, with emissions potentially increasing as temperatures rise. Animals, including humans, are also sources of methane.

While it is easy to measure atmospheric methane, understanding its sources is crucial. By analyzing distinct isotope signatures in detected methane, scientists can determine if the gas originates from biological sources or industry.