Jump in methane levels

Dairy farm in the Strzelecki ranges about 20 K from where I live
Cattle are a major source of methane which is a potent greenhouse gas.

From The Guardian:

Dramatic rises in atmospheric methane are threatening to derail plans to hold global temperature rises to 2C, scientists have warned.

In a paper published this month by the American Geophysical Union, researchers say sharp rises in levels of methane – which is a powerful greenhouse gas – have strengthened over the past four years. Urgent action is now required to halt further increases in methane in the atmosphere, to avoid triggering enhanced global warming and temperature rises well beyond 2C.

“What we are now witnessing is extremely worrying,” said one of the paper’s lead authors, Professor Euan Nisbet of Royal Holloway, University of London. “It is particularly alarming because we are still not sure why atmospheric methane levels are rising across the planet.”

Methane is produced by cattle, and also comes from decaying vegetation, fires, coal mines and natural gas plants. It is many times more potent as a cause of atmospheric warming than carbon dioxide (CO2). However, it breaks down much more quickly than CO2 and is found at much lower levels in the atmosphere.

During much of the 20th century, levels of methane, mostly from fossil fuel sources, increased in the atmosphere but, by the beginning of the 21st century, it had stabilised, said Nisbet. “Then, to our surprise, levels starting rising in 2007. That increase began to accelerate after 2014 and fast growth has continued.”
Studies suggest these increases are more likely to be mainly biological in origin. However, the exact cause remains unclear. Some researchers believe the spread of intense farming in Africa may be involved, in particular in tropical regions where conditions are becoming warmer and wetter because of climate change. Rising numbers of cattle – as well as wetter and warmer swamps – are producing more and more methane, it is argued.

This idea is now being studied in detail by a consortium led by Nisbet, whose work is funded by the Natural Environment Research Council. This month the consortium completed a series of flights over Uganda and Zambia to collect samples of the air above these countries.

“We have only just started analysing our data but have already found evidence that a great plume of methane now rises above the wetland swamps of Lake Bangweul[u*] in Zambia,” added Nisbet.

[Read more here]


From EcoWatch:

As the global temperature steadily rises, it ensures that levels of one of the most potent greenhouse gases are increasing in a way new to science: the planet will have to reckon with more methane than expected.

Researchers who monitored one bog for three years in the Alaskan permafrost have identified yet another instance of what engineers call positive feedback. They found that global warming meant earlier springs and with that, earlier spring rains.

And as a consequence, the influx of warm water on what had previously been frozen ground triggered a biological frenzy that sent methane emissions soaring.

One stretch of wetland in a forest of black spruce in the Alaskan interior stepped up its emissions of natural gas (another name for methane) by 30 percent. Methane is a greenhouse gas at least 30 times more potent than carbon dioxide.

As a consequence, climate scientists may have to return yet again to the vexed question of the carbon budget, in their calculations of how fast the world will warm as humans burn more fossil fuels, to set up ever more rapid global warming and climate change, which will in turn accelerate the thawing of the permafrost.

The evidence so far comes from a detailed study of water, energy and carbon traffic from just one wetland. But other teams of scientists have repeatedly expressed concern about the integrity of the northern hemisphere permafrost and the vast stores of carbon preserved in the frozen soils, beneath the shallow layer that comes to life with each Arctic spring.

"We saw the plants going crazy and methane emissions going bonkers," said Rebecca Neumann, an environmental engineer at the University of Washington in Seattle, who led the study. "2016 had above average rainfall, but so did 2014. So what was different about this year?"

What mattered was when the rain fell: it fell earlier, when the ground was still colder than the air. The warmer water saturated the frozen forest, flowed into the bog, and created a local permafrost thaw in anoxic conditions: the subterranean microbial communities responded by converting the once-frozen organic matter into a highly effective greenhouse gas.

[Read more here]

Feedbacks, people.  Tipping points.  We don't have time to phaff around.  Move, move, move!  Cut emissions now.  One thing you can do straight up is to eat less meat.   Or none.  It won't kill you.  And it might extend your life.  And when you get the chance, vote for  politicians who will actually do something about climate change.  Yes, EVs are replacing petrol-driven cars.  Yes, the economics of renewables are encouraging a shift away from fossil fuels in electricity generation.  But I am frightened that it won't happen fast enough.  We've delayed serious action for decades; we've listened to the lies from fossil fuel advocates and denialists for decades; we've phiffed and phaffed and delayed---and now we face a real risk of runaway global warming.