Wednesday 5 November 2014

Methane emissions

For those of us living in NZ who see this series of graphs you will notice high levels of methane over both the North and South Island. Methane is the pirate that has taken control of our ship's helm now.

As we come ever closer to climate change disaster we look around at the culprits. Our main focus is the burning of fossil fuels to run our post industrial revolution society's. Like most people I blamed carbon but the new elephant in the room 
(the cow) is methane. 

In NZ our major green house gas is methane generated from livestock. Getting the majority of people to stop eating meat will be impossible until the food chain collapses and meat becomes so expensive that like most people in Africa no one will be able to afford it. 

Methane is between 40 and 100 times more potent a green house gas than carbon. It was the main culprit in the permian extinction and will be the same again in this one. We willfully release methane into the atmosphere knowing full well what it is doing, heating the atmosphere and the oceans, melting the sea ice and polar ice caps releasing more methane hydrates from the ocean floor and sequestered methane from the permafrost where it has languished for millions of years. 

Our species walks knowingly over the cliff like the much ridiculed lemmings

---Kevin Hester

Methane emissions over New Zealand


Comparison between CO2 (left) and methane (right) indicate that large amounts of methane are broken down at higher latitudes on the Northern Hemisphere, especially over the Arctic Ocean. 


I suspect this might also have something to do with the levels of methane above New Zealand

This is #35 of positive feedbacks identified by Guy McPherson.


Hidden network of methane found on East Coast


12 May, 2014

The vast deposit has been revealed by Kiwi and German scientists using state-of-the-art 3D seismic and echosounder technology to map methane within the ocean and seafloor.

NIWA marine geologist and voyage leader Dr Joshu Mountjoy said the number of gas flares observed beneath the ocean was "phenomenal".

More than 100 flares, some shooting up columns more than 250m high, were found in an area of only 50km2, in what is now believed to be the densest concentration of seafloor gas vents so far known in New Zealand.

"What we've found probably equals the number of known underwater seeps in New Zealand to date," Dr Mountjoy said.


Dr Mountjoy said the four-week expedition sought to understand what was triggering huge underwater landslides off the East Coast, some which had been as large as 15km long and 100m thick.

What they discovered was direct evidence of widespread gas in the sediment and ocean, and indications of large areas of methane hydrate, ice-like frozen methane below the seafloor.

They also found a hydrate and gas field very different from others known in New Zealand.

"Previously all gas venting sites have been in deeper water and associated with large earthquake faults," Dr Mountjoy said.

"What we have found is high density methane flares in very shallow water, as well as gas building up beneath a large landslide and being released along the landslide margins."

In a newly submitted scientific paper, the research team proposed that these landslides might be the seafloor equivalent of glaciers, but with frozen methane instead of water ice, or that pressurised gas was causing them to progressively move downslope.

The findings of the expedition indicated that both could be possibilities, but also gave an important insight into just how much methane lurked close to our shores.

Dr Mountjoy said methane was a highly effective greenhouse gas and seabed methane release has the potential to dramatically alter the earth's climate.

As ocean temperatures changed, the methane hydrate system had the potential to become unstable.

"In terms of natural hazards, the occurrence of very large slow landslides, rather than catastrophic ones, has major implications for the tsunami generating potential of landslides globally as slow landslides are unlikely to cause tsunami," he said.

"This type of slow moving submarine landslide is essentially unknown around the world, but it is very likely that they do occur widely and are an important process shaping continental margins."

It was too early to say whether the methane deposits could prove an economic resource for the country.

Dr Mountjoy said the newfound gas were not coming from deep within the earth's surface or connected to any large reservoirs with commercial potential.

But researchers in Japan were investigating how frozen methane could be converted back into a gas as a potential hydrocarbon resource.

The expedition forms the first part of a collaborative project between scientists from New Zealand, Germany, the United States and Malta, and another is planned for 2016.



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