“We will have handed over a bit more control of Earth’s climate to microorganisms,” Paul Palmer, atmospheric chemist. The University of Edinburgh; Co-Author of the study posted in Atmospheric Chemistry and Physics.
Scientists at the University of Edinburg believe they have found the reason for a spike in methane from saturated soils - that microbes feed on.
NOAA has found that for the years 2020 and 2021, the atmospheric methane has exploded since 1983, when measurements began. We know this because of newly available data from the Japanese Greenhouse gases Observing SATellite (GOSAT) which can zoom in on methane surface emissions anywhere in the world. The methane data from GOSAT found that using 2019 data as a baseline, the most significant methane emissions during 2020 over East Africa.
If the data proves correct, the feedback process from the Sudd, the largest wetland in Africa, will be beyond our control.
Please stay with me.
From the study ( don’t be afraid of the technical conclusion by the study authors ), a more understandable text is covered by AAAS Science Magazine below the fold):
The atmospheric growth rate of methane in the 21st century has defied a definitive explanation: following a period of near-zero growth during 2000-2007 (Rigby et al. 2008) growth rates have accelerated, with values reported by NOAA for 2020 (15.29±0.38 ppb) and 2021 (16.94±0.38 ppb) exceeding all prior values since their records began in 1983. The underlying 30 reasons for these anomalous growth rates in 2020 and 2021 are currently subject to intense debate with some studies attributing
We reported regional emission estimates of methane during 2020 and 2021, two years with record-breaking atmospheric growth rates, inferred from satellite observations of methane from the Japanese Greenhouse gases Observing SATellite. We find in both years that emissions from Eastern Africa, tropical Asia, and tropical South America dominate the global atmospheric growth rate, increasing by 11-13 Tg/yr, 4-8 Tg/yr, and 3-9 Tg relative to the 2019 baseline year, respectively. 185 During 2020, we also find substantial increased emissions, relative to the 2019 baseline values, from Australia (3 Tg) andtemperate Eurasia (3 Tg). Emission changes relative to 2019 are comparable in 2021, except for temperate South Americathat increases to 5 Tg and temperate North America that increases to 3 Tg. The elevated contributions we saw in 2020 over the western half of Africa (-5 Tg) and Europe (-3 Tg) are substantially reduced in 2021, compared to our 2019 baseline. We findstatistically significant positive correlations between tropical methane emission and hydrological anomalies, consistent with 190 recent studies that have highlighted a growing role for microbial sources over the tropics
I’ve embedded some excerpts from Science Magazine as I am not a scientist and would mangle the science:
If carbon dioxide is an oven steadily roasting our planet, methane is a blast from the broiler: a more potent but shorter lived greenhouse gas that’s responsible for roughly one-third of the 1.2°C of warming since preindustrial times. Atmospheric methane levels have risen nearly 7% since 2006, and the past 2 years saw the biggest jumps yet, even though the pandemic slowed oil and gas production, presumably reducing methane leaks. Now, researchers are homing in on the source of the mysterious surge. Two new preprints trace it to microbes in tropical wetlands. Ominously, climate change itself might be fueling the trend by driving increased rain over the regions.
snip
Most climate scientists already agreed that the post-2006 methane spike has largely not come from fossil fuel production. That’s because atmospheric methane has become ever more enriched in carbon-12, the lighter isotope of carbon, reversing what had been a multicentury trend, says Xin Lan, a carbon cycle scientist at the Earth System Research Laboratories (ESRL) of the National Oceanic and Atmospheric Administration. “This is a very significant signal,” she says. It points to microbes as the source because they favor reactions that use light carbon, giving the methane they produce a distinctive light signature.
Many scientists have believed that the increase from 2006 is due to cattle ranching and landfills in the tropics. Those measurements also coincided with massive urbanization and population growth. But...there has to be another source for the rapid uptick in methane emissions during the past two years, points to another —thee—the Sudd wetlands of South Sudan. The wetlands are over 35,000 square miles making them one of the most extensive wetlands on earth.
The wetland is teeming with endangered wildlife such as elephants, the Nile lechwe, and other endangered and threatened species. It is also the site of a massive migration of Zebra and antelope known as Topi. Approximately one million people call the region home. Unfortunately, the nation has fallen into civil war, so on-the-ground research is impossible. GOSAT provides the data scientists need instead.
Climate change may be setting the pace of the emissions. In work published earlier this year in Nature Communications, Palmer and colleagues showed how East African methane emissions from 2010 to 2019, measured by satellite, synced up with a temperature pattern in the Indian Ocean that periodically warms the waters off the Horn of Africa, causing increased rainfall on land. Climate projections call for this positive phase of the Indian Ocean dipole, as it’s known, to grow in strength and duration with continued global warming. If it does, Palmer says, warming will beget more methane emissions from the Sudd, which in turn could fuel more warming and rains—a positive feedback loop.
Ed Dlugokencky, an atmospheric chemist at ESRL, agrees East African wetlands may well play a big role in the methane emissions of the past 2 years. “But the question of whether it’s a climate feedback yet is very difficult to answer,” simply because of limited records and large yearly variations in rainfall and wetland emissions. Nisbet notes, though, that the same dynamic may be playing out across other tropical wetlands. “A warming world is a wetter world in the moist tropics,” Nisbet says. “We have good reason to expect, if we have a moisture and temperature increase, then biological productivity follows.” Research flights over wetlands in Zambia found methane levels 10 times higher than models suggested, Nisbet and his colleagues reported in May.
The researchers who identified the East Africa link also worked to rule out another possible driver of the 2-year surge: a slowdown in the destruction of atmospheric methane. Unlike carbon dioxide, which lingers for centuries, methane only lasts a dozen years or so before it is washed out of the air, primarily by an atmospheric cleanser called the hydroxyl radical (OH). Nitrogen oxides, common pollutants from fossil fuel burning, help form OH—and nitrogen oxides declined as traffic and industry subsided during the early part of the pandemic, which should have reduced OH and allowed more methane to survive. “But we find that’s not the case at all,” says Daniel Jacob, an atmospheric chemist at Harvard and co-author on the second study. Matching the pandemic’s estimated OH reduction in their models led to a negligible change in methane levels.
Wetlands across the planet are under extreme threat from human activities and climate change. As part of its climate plan, the authors noted that South Sudan proposed draining the wetlands by completing the Jonglei Canal that had been abandoned in the 1980s. The water from the Sudd would instead go to Egypt. Effectively killing off the massive wetland habitats in the country. So drainage will not prevent gases from bubbling into the atmosphere.
Paul Voonsen concludes the article with a warning about destroying the Sudd and other tropical wetlands to prevent spikes in methane.
But draining the Sudd might just replace its methane emissions with carbon dioxide generated as newly exposed peat decomposes, while doing immeasurable damage to its ecosystem, Darbyshire says. “On the surface these seem like reasonable arguments,” he says. “But if you start to think about them a little bit, they start to unravel and you’re left with an overwhelming sense of uncertainty.”
This boneheaded and looming human-caused catastrophe in the Sudd shut down just days ago. Environmentalists avoid the extinction and extirpation of species by pressuring the government of South Sudan to stop. For now, anyway.
JUBA, South Sudan (AP) — South Sudan’s president ordered the suspension Saturday of all dredging-related activities in the country until evidence-based studies are carried out on their impact on surrounding communities and the ecosystems they rely on.
Salva Kiir Mayardit’s announcement, which was made during his address on the country’s 11th independence anniversary, means the dredging project on the Bahr el Ghazal-Naam river, approved by the cabinet last year, and the century-old Jonglei canal project will now be halted.
In May, Unity State government received dredging equipment from Egypt for the project on the Naam river, claiming it would reduce the flooding that displaced thousands in the state. This was met with strong criticism from environmentalists, citizens and activists who said that the plan would result in environmental and economic catastrophe, drying up the country’s White Nile river and the Sudd wetlands which farmers and local wildlife rely on.
Methane is a hazardous greenhouse gas. This feedback is yet another significant challenge for out-of-control climate change.