Models, oil spills and moving the debate forward

The Greenpeace-commissioned report looking at the estimated impact of a deep water oil well leak in New Zealand waters has received a lot of attention this morning and for good reason.

In the whole argument over oil exploration and whether we should drill or not, there’s been little science-based public discussion of the impact of a spill. Sure, the likes of Anadarko have done the modelling and the Government has its own models, but nothing has been made public that lays out the scenarios as clearly as the animations created by DumPark Ltd, the Wellington-based science data company that Greenpease commissioned to do the modelling.

OIlspillmap-Day120-hoki-300x213Over at the Science Media Centre, we rounded up commentary on the Greenpeace report. Not all of it is positive – for instance Dr Rosalind Archer of the University of Auckland said:

 The report gives no evidence that 40,000 barrels per day spill rate [the largest of the rates modelled] is reasonable for a New Zealand well… my assessment is that this report is likely to overstate the impact of a possible blow out in New Zealand waters.

Dr Willem de Lange, of the University of Waikato said:

The study is a reasonable and credible assessment of the potential impacts of the scenarios modelled. There is, however, no risk analysis of the likelihood of these events occurring, and, hence, the risks are not portrayed.

And Dr Ross Vennell of the University of Otago commented:

The predictions appear to be a reasonable first attempt to estimate the extent of a worst case spill from deepwater sites in NZ. It would require more work to clarify and expand on these predictions.

So a mixed response to the report. Modelling something like oil spills is tremendously complicated and rests on a number of assumptions – such as the nature of the spill, the rate of flow of oil, the sea and weather conditions in the period after the spill and the ability to successfully response to a spill with a relief well and containment methods.

Greenpeace seems to have presented a worst-case scenario that many in the oil industry believe has a tiny probability of happening. That’s fine, the worst case scenario is as bad as it gets and we do need to know what the implications of that would be so we can decide if we are willing to live with the risk, however small.

At least we are now having a science-based discussion in public on the potential impact of an oil spill. For the first time in prime time news slots this morning I heard discussion of rates of oil flow, barrels per day spillage, “weathering of oil” and well capping technology that has been developed since the Deep Water Horizon oil spill. This type of discussion is far more illuminating than the woeful exchange between John Campbell and energy minister Simon Bridges a couple of weeks back on Campbell Live. Bridges did himself few favours in his aggressive and defensive performance that night.

Good on Greenpeace for taking the initiative in commissioning Dumpark to undertake this work, then being willing to have the models subjected to independent peer review by experts chosen by the Science Media Centre.

As a result the issue, finally, seems destined to move beyond the philosophical debate of whether extracting fossil fuels is the right move for the country, to whether we can accurately quantify the risk, the factors that would determine the impact of a spill and the technology that might be employed to respond to a spill.

Hopefully the release of Greenpeace’s report will encourage other groups with a vested interest in the issue to release their own models for public scrutiny. Let us have as much information, in a user-friendly format available, so the public can make an informed call when it decides whether deep sea oil drilling in New Zealand waters is worth the risk.

The New Zealand Oil Spill Map


  1. andy

    There are legitimate concerns about offshore drilling anywhere. The Greenpeace report is contingent on a worst case scenario, of which no discussion is made on the likelihood of this happening.

    Greenpeace activists recently destroyed a crop of GM Magic Rice, which is thought to be a lifesaver for children in developing nations. GMO is also a contentious issue in the public’s mind, and we can have civilised discussions about these issues. However, Greenpeace have a track record of bullying and intolerant behaviour which turns a lot of people off their causes, myself included.

  2. ross

    What about an organisation that supported and actively undertook the re positioning of peoples of this earth after the US bombed the shit out their habitat with radioactive fallout. And then, to sail into our country and end up sitting on the bottom of the harbour after getting bombed by “friendly” terrorists.

    It takes balls to make a stand. They did. They have.

    So. Have you thought about a Rena episode multiplied bay……..lets say… a couple of million?

  3. andy

    I’d be more inclined to read a report that wasn’t commissioned by an organisation that actively encourages and conducts illegal activities such as boarding a Russian oil exploration platform with the intention of shutting down operations.

  4. shanembaylis

    In Greenpeace’s defense regarding the 40,000 bpd figure:

    Their front-page animations all seem to be based on the 10,000 bpd simulations, with the 40,000 bpd simulation data in the technical report. Reading between the lines a little, I gather they’re estimating flow rates in a shortage of data (they cite a couple of spills with known flow-rates, but don’t present a probability distribution of flow rates), which would explain the nearly order-of-magnitude differences between the flow-rates in their best- and worst-case scenario.

  5. Jean

    Shell has said that they are more likely to find gas and condensate in the great south basin, but for me, this is a matter of facing up to the need to change and give up our addiction to fossil fuels.

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