Doomed Planet

Methane madness

Last week Bob Brown wrote to Andrew Robb expressing concern about dam building and in particular mentioned methane. In the previous week Minister Combet talked on the ABC about fugitive emissions “aka” methane. 

Methane was discovered by the Italian scientist Volta at Lake Maggiore in 1778. It was thought by many to explain the will-o’ the wisps, the mysterious flickering fires seen on marshes. 

The contemporary version of this will-o’ the wisp is the demonization of methane as one of the important greenhouse gases. Yet if you look at its annual behaviour in the atmosphere over the last thousand years you see a gentle increase through the nineteenth century, rising in the first half of the twentieth century and then taking off like a rocket to a peak in the 1980s only to fall like a stone from this peak to now be at a level for the last ten years comparable to its annual increases in the nineteenth century.

Annual changes in methane in parts per billion derived from ice core and direct measurements of atmospheric methane. Data source CSIRO

The IPCC is at a loss to explain this. The IPCC states in its Fourth Assessment Report (Working Group 1, Chapter 2 page 142):

The total global CH4 source is relatively well known but the strength of each source component and their trends are not.

This statement was followed by:

The reasons for the decrease in the atmospheric CH4 growth rate and the implications for future changes in its atmospheric burden are not understood but are clearly related to changes in the imbalance between CH4 sources and sinks.

So not only are the sources of methane not well defined but also there is an insightful explanation of the problem. 

There is a simple explanation for this record. The rise in methane from the 1940s to the 1980s comes from the expanding consumption of natural gas and some 5% leakage as a “fugitive gas” from pipelines, particularly in the old Soviet Union. In fact troubles on the Trans-Siberian pipeline led to a massive explosion in June 1982 estimated at 3,000 tonnes equivalent TNT. It was the largest non-nuclear explosion and fire ever seen from space. The CIA was of course blamed having placed secret and corrupt source-code in the control programs for the pumping station compressors. 

Even in Victorian cities at the end of the nineteenth century town gas, that contained some methane,  was distributed through cast iron pipes with joints every few metres. This may well explain the earlier methane annual rise in the nineteenth century and early twentieth century. In Melbourne the losses were estimated at a few percent and when natural gas was first put through the system there were substantial leaks and the old pipes are still being replaced by continuous plastic piping in inner Melbourne. 

The steep fall at the end of the 1980s and early 1990s occurred as the leakage was greatly reduced at the time the Soviets started selling and transporting gas to Western Europe. Since that time variations have followed a natural pattern showing the influence of El Ninos and Pacific decadel oscillations. 

So the will-o’ the wisp behaviour is apparent but what of those who would seek to regulate our green house gases. Neither the United States nor the EU have sought to regulate methane. The IPCC confesses to not understanding. And there may be a quite coherent explanation of what has happened implying no further action is needed. 

Yet the IPCC scenarios include increasing methane in the atmosphere. These scenarios are the basis of future temperature and sea level projections. For instance, the CSIRO is forecasting sea level increases at rates of Biblical proportions using a scenario of 60% increase in atmospheric methane by 2100 (and a CO2 increase that cannot be reached by burning all current proven reserves of fossil fuels). 

But our own scientific establishment, the CSIRO and the Department of Climate Change all want to tax or price fugitive methane. The Department of Climate Change in October 2008 issued a three hundred and forty nine page “Technical Guidelines” document for estimating greenhouse gas emissions by ”facilities” in Australia. Reporting these emissions is mandatory. The estimates of fugitive pipeline gas are derived from a formula that is a simple dependence on the length of the pipeline not the amount of gas transported. 

It is difficult to imagine a more surreal policy, where no one else in the world understands or intends to bother with methane but we must set an example. Minister Combet should think of other ways of making money out of “carbon pollution” perhaps by selling it contained in coal, gas or beef rather than trading in what may well turn out to be carbon indulgences.

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