Methane is a greenhouse gas that is about 25 times more potent than carbon dioxide. So, the current rapid increase of methane in our atmosphere is another factor driving global heating.

Methane levels are soaring

Graph of methane levels (NASA)

The graph shows how methane levels in the atmosphere have moved over the last 802,000 years.

• Each section on the timeline is 100,000 years.
• Methane moved between 400 and 600 parts per billion (ppb) for about 700,000 years.
• In 1750, at the start of the Industrial Revolution, it was about 700 ppb.
• By 2020, the levels had skyrocketed to 1,875 ppb.

Methane comes from many natural sources, including swamps, rivers, and volcanoes, and from human activities such as cattle raising, gas wells, gas pipelines, oil wells, coal mines, rubbish dumps, sewage treatment, and rice fields.

The permafrost feedback cycle.

There are vast quantities of carbon: methane, dead plants, and dead animals, trapped in permafrost, and global heating is thawing this permafrost. The thawing releases the trapped carbon, adding to the greenhouse gases in the atmosphere.

While this feedback dominates: (1) higher global temperatures cause (2) more melting of ice containing carbon, releasing (3) more carbon dioxide & methane into the atmosphere, which causes (4) higher global temperatures, and then (5) the cycle repeats.

This feedback is dangerous as permafrost holds enormous amounts of carbon, about 1.6 times more carbon than our atmosphere. There are vast areas of permafrost; about 25% of the ground in the Northern Hemisphere has permafrost beneath it. The release of this carbon threatens our nurturing climate.

This vicious cycle is dominant now: (1) global temperatures are climbing, (2) permafrost is in decline, and (3) methane and carbon dioxide levels are soaring. This cycle is reinforced by human emissions of greenhouse gases and by other vicious heating cycles.

Arctic soil thaw may unleash runaway global warming (Scientific American, 2008)

This feedback is not reversible.

The permsfrost cycle is not reversible. In the unlikely event of a decrease in global temperatures, this might consolidate the remaining permafrost; however, the methane and carbon dioxide that have already escaped from melting permafrost would not be drawn back into the permafrost.

Permafrost

As the name “permafrost” suggests, people have regarded it as permanently frozen ground; however, global warming is thawing it. The thawing can make the ground buckle and sink, causing trees to lean and fall.

Thawing permafrost has caused severe damage to forests, buildings, roads, and sewerage.

The Earth’s methane levels are rising, and we do not know why
(New Scientist: May 2019)

The current warming could lead to methane release dominating our climate, and spiralling global warming, even if humans stopped burning fossil fuels.

Related pages on this site

• Amplifying feedback cycles and climate change
• Carbon dioxide levels in the air are soaring
• Methane levels in the air are soaring
• Air Temperatures are increasing

Updated: 16 March 2026