It seems we've been "fudging the numbers" in a sense, when comparing the global warming potential of methane to CO2. When global warming potential (GWP) of a gas is calculated, a time frame is assumed. The IPCC decided to use a 100 year time frame.
With a 100 year time frame methane heats up the planet 21 times as much as CO2. The problem with that assumption is that we don't have 100 years. A 20 year time frame would be much more realistic, given the urgency of climate crisis. With a 20 year time frame...
... any CH4 released today is at least 56 times more heat-trapping than a molecule of C02 also released today. And because of the way it reacts in the atmosphere, the number is probably even higher, according to research conducted by Drew Shindell , a scientist at NASA’s Goddard Space Center. [emphasis mine]
What if we were to use the IPCC’s 20-year comparison instead of its 100-year comparison? For starters, it would force us to get much more serious about tackling the sources of methane emissions. Here in the US, the top methane sources are the decomposition of wastes in landfills, agriculture (from ruminant digestion), and leaks from natural gas drilling and transmission. A new emphasis on methane would require us to get smarter about capturing methane at landfills, reduce the market incentives that encourage Americans’ meat-heavy diets, and ensure that methane isn’t leaking from fracking operations.
But beyond the policy specifics, adopting the 20-year global warming potential comparisons would be useful for changing how we think about climate change.
And we appear to be approaching some irrevocable tipping points that will create powerful negative feedback loops, the most worrisome being the release of methane stores at the bottom of the ocean and locked into sub-Arctic permafrost.
Image from Arctic Methane Release Tipping Point Diagram
With 56 times as much warming as CO2 in mind, we'd take this feedback more seriously.
That 28% statistic about the contribution of CH4 does not include water vapor, whose effect vastly outweighs all other greenhouse gases, but is hard to quanitfy because its concentration is highly variable and doesn't "decay" from the atmosphere in the traditional sense.
There is a reason why the Earth did not in fact become Venus at times like the Paleocene-Eocene Thermal Maximum, when there must have been no permafrost in the Arctic. It will still get pretty bad though.
When I read estimates like this of how delicate is the stability of our planet's habitability, I feel as if scientists are like a Dad, telling his 3-year old son not to touch the blowtorch trigger in his hand, and 99.9% of adults are ignoring a warning they don't comprehend like that about-to-immolate himself kid.
Ruth, you provide us with a vivid image of your feelings. There are still those who do not understand how serious this is. The child imbeded in these flames clearly shows terror, too late. The father and the scientists speaks from knowledge; people don't hear, or don't care, or don't understand the significance before the explosion.
My guess is our soils and forest will dry up as will the grasslands and all make fine material for fire. We have a new one brewing just north of us in British Columbia.
Update on methane craters.
It seems only the pingos on the Yamal and Taimyr peninsulas explode, and sometimes erupt into flames. This is the first I'd heard that Gazprom punctures pingos to release methane, to avoid explosions.
He believes that the phenomenon is 'unique' the geological conditions on the Yamal and Taimyr peninsulas, where. 'We now know that these objects form when there is a coincidence of a thick layer of permafrost and thick sedimentary cover of 3.5 to 5 kilometres,' he said.
'This is why we can observe pingos in Yakutia or Alaska, but they do not explode.'
Such 'degassing' is happening in many locations but uneven thawing in permafrost regions means methane is not released evenly and can collect in pockets, eventually exploding.
'Strong degassing is occurring in the Arctic,' he said.
'But what we have just seen is a drop in the ocean of this global degassing of subsoil.'
'I know that oil and gas producing companies have maps of such objects and monitor them constantly.
'I have heard that for example Gazprom-Dobycha Yamburg make punctures and release gas to avoid eruption risk.
'When I was working at VNIIGAZ, I made a map of such objects for Gazprom.'
He said: 'The companies are very interested in minimising risks, they do not need any accidents, so they make maps and observe these objects very closely.
A second new crater - also formed this year - was created after an explosion on bulging ground around 500 km north of the town of Salekhard.
'This plot of land was absolutely flat just two years ago,' he said.
'A year ago in 2016 it bulged and we could see that soil has cracked there.'
Thanks for the update!
What's Gazprom's / Russia's official line on climate change? We know that US fossil fuel companies have been manufacturing doubt for decades (just like tobacco companies did with lung cancer and other dangers of smoking) at the same time that they recognized reality by, for instance, raising their offshore drilling platforms.
We may be grossly under-accounting for methane in our existing climate models.
We thought that all methane-generating microbes required anaerobic conditions. Enter Candidatus Methanothrix paradoxum.
... 80 percent of the methane in the wetland under study came from oxygenated soils. The microbe’s habitat extends from the deepest parts of a wetland, which are devoid of oxygen, all the way to surface soils.
“We’ve always assumed that oxygen was toxic to all methanogens,” said Kelly Wrighton, project leader and professor of microbiology at Ohio State. “That assumption is so far entrenched in our thinking that global climate models simply don’t allow for methane production in the presence of oxygen. Our work shows that this way of thinking is outdated, and we may be grossly under-accounting for methane in our existing climate models.”
"The researchers found traces of Candidatus Methanothrix paradoxum in more than 100 sites across North America, South America, Europe and Asia. The organism lives in rice paddies, wetlands and peatlands—even as far north as the Arctic. It just hadn’t been cataloged before, and its unusual metabolism hadn’t been discovered."
A new study of Lake Hallwil discovered a new, overlooked, methane-production phenomenon. Instead of coming from anaerobic bottom sediment, 90% of methane produced was coming from the oxygen-rich well-mixed top 5 meters. So far they're not exactly sure of the mechanism, offering several hypotheses.
Lakes and freshwater systems account for over 20% of all methane emissions into the atmosphere – much more than previously estimated, according to scientists at the University of Geneva
“Something huge is going on in the surface water, and nobody has been paying attention to it so far,” said study co-author Daniel McGinnis. A similar phenomenon has been reported in the surface of the oceans but on a smaller scale, about 1,000 times lower. [emphasis mine]
Stirring up the methane in Lake Hallwil
Wildfires have been going down globally, it seems, despite the recent fires in North America, Europe, and Russia, because agriculture replaced wild lands. And since fires release methane, the decrease has masked increases from other sources.
The area of the planet burned each year decreased by about 12% between the early 2000s and the more recent period of 2007 to 2014, according to satellite observations.
Dr Worden’s team calculates that 17 teragrams per year of the methane increase in the atmosphere is due to fossil fuels, another 12 is coming from wetlands or rice farming, while fires are decreasing by about 4 teragrams per year.
The three numbers combine to 25 teragrams a year – the same as the observed increase.