This week I interviewed Dr Damien Maher, the first scientist I can remember to be denounced by a federal minister. Thankfully, it wasn’t the minister for science, but for mining (and tourism). I suppose we should be pleased to learn Martin Ferguson knows what peer reviewed means, since he certainly hasn’t acted as though he does as minister, or for that matter at any point in his career.
While it would be very easy to get carried away on a hatefest on Ferguson, I’ll try to keep my mind on what this very important research is, and what it isn’t.
Maher and the ironically named Dr Isaac Santos sampled the air at various points around the Tara Coal Seam Gas field and detected levels of methane up to 3.5 times as high as normal atmospheric levels. The obvious conclusion is that methane is leaking as a result of the gas extraction. If this is so it is one of the most important scientific studies of the decade. Methane is generally considered to be 25 times as potent a Greenhouse gas as carbon dioxide, although some argue for a higher multiple. If even 2% of the methane extracted from a coal seam gas bed leaks into the atmosphere the claims for coal seam gas to be a cleaner source of energy than coal disappear, at least as far as climate change is concerned. Any substantial leakage would make CSG completely unviable anywhere emissions are taxed or otherwise penalised. Moreover, substantial methane leakage would give credibility to farmers’ reports of methane contaminating groundwater, causing explosions etc. Given how huge an issue CSG is in Australia and the United States this would be truly, well, huge.
There are no large wetlands or other obvious sources of methane in the area and Maher and Santos have backed up their findings by showing that the isotopic signature of the methane they detected was similar to that in the Tara gasfield. Methane produced by bacteria has a different isotopic signature to that from geological sources, although the Tara gas field has a signature suggesting it contains some from each source. They also measured the methane in some locations around Lismore, and found normal atmospheric levels.
Nevertheless, it is important not to overstate this study for a bunch of reasons. The first is that I usually say that any single piece of research should be treated with care until confirmed by other scientists. A lot of studies turn out to be wrong for all sorts of reasons. The chance of two studies being wrong in the same way is much, much smaller, but so far no one else in Australia has done anything like this. Indeed in some ways it appears to be a world first – surprising given that CSG has been going longer in the US and affecting higher population areas. There have been quite a few efforts to estimate the methane leakage in American CSG fields, producing estimates from the one favoured by the drilling companies of 0.12% up to 8% quoted by some opponents. However, these have used different, and probably less reliable, techniques. Obviously the high variation calls them into question anyway.
Caution needs to be even higher in this case because the work has yet to be peer reviewed. It is this that Ferguson and the Australian Petroleum Production & Exploration Association have used to attack Maher and Santos (along with some nasty swipes at their university and misrepresentations of the facts). As a rule I argue that anything that has not been published in a peer reviewed paper should be treated with great caution, but there are exceptions. In this case Maher and Santos have submitted the work to a prestigious international journal (they won’t say which one, which I gather is standard practise). However, since it takes months for papers to pass peer review, and a Department of Climate Change inquiry was closing submissions in October, Maher and Santos decided they needed to report what they had found to the inquiry. They also had a public lecture in Lismore revealing their findings, which Maher says is in keeping with the common practice of reporting unpublished work at seminars and conferences. Under the circumstances I think their behaviour was quite appropriate (they seem to have been as honest as they can about the status of their work) but it is possible some major flaw in their procedure or analysis will be picked up in peer review.
Most crucially, even if methane levels are elevated in the area, and even if they are coming from the coal seam gas, we don’t know the mining is responsible. Maher told me, “Any geological area that has gas deposits is going to have natural seeps.” The fact that the same concentrations have not been found around Lismore, where there are coal seam gas deposits but no mining, is interesting but far from conclusive. It may be that the Tara field was naturally more leaky and has been for centuries. There have also been suggestions that over-extraction of groundwater can cause leakage from previously stable methane deposits. If water extraction rates around Tara have been measured I could not find it online.
The only way we are likely to really know if the mining is responsible is to take background measurements in an area before mining begins, and remeasure once it is under way. A quicker, although not quite as conclusive test, would be to measure the background in a large number of areas where mining is proposed but has not begun, and compare it with that in operating fields. If there is a consistent discrepancy it will be unlikely to be by chance.
There are a couple of other points to make: Even if there is leakage in this area, it does not mean all CSG drilling operations leak. Not all CSG drilling involves fracking (or hydrolic fracturing) the most controversial aspect of CSG, but Maher said he believed some of the Tara bores use fracking. It’s possible that extraction can be done with low leakage under some soil conditions, but not in others.
Furthermore, Maher does not know how much leakage would be required to explain the measurements he has gained, and says he will need to develop atmospheric models of the area to place an estimate on this, although it seems likely the figure will be high enough to arouse concern – particularly since the measurements are higher than those taken in the Siberian gas fields, one of the world’s largest conventional sources of natural gas.
Despite all these reservations, it is clear that the chances of significant leakage from CSG in general, and Tara in particular have gone up a lot. The need for further research is desperate and urgent. Until such research is done the case for a moratorium on drilling, or at least new mines, is very, very strong. Presumably this is why Ferguson and the APPEA have reacted so aggressively. If the findings are confirmed, and similar leakage is not occurring without mining, then the industry has to be shut down. It would be climatic terrorism, as well as posing considerable danger to local farmers, to allow it to continue. Those who are either making big money from the practice, or who have staked their political career on backing CSG to the hilt, would be very scared indeed.
Additional notes: I interviewed Maher just a month ago regarding a different study he has led. He’d found that three Australian estuaries are trapping more carbon than they release into the atmosphere, although the behaviour varies with the seasons. This is in contrast with studies of North American estuaries that found them to be net carbon sources. It was a huge study and he’s clearly a very busy man.
It’s also great to see that the Vice Chancellor of Southern Cross University, instead of running scared like so many university administrators in recent years, has come out and strongly backed Maher and Santos. His statement perhaps spends more time than is necessary promoting the prestige of Southern Cross in this area, but he expresses great confidence in his researchers and refuses to be intimidated by the pressure. I’m not sure that the Labor MP for Page, a highly marginal seat, will be too happy about her minister casting aspersions on both the research capacity and ethical standards of one of the largest employers in the electorate.