What is it that worries me about what the BoM and CSIRO tell us about climate change?

Commenter Chris asked me, in a comment at my last essay, what are your concerns over BoM reporting or data use? I had intended to write about something else, but it seemed sensible to deal with this issue at once. I have written about the Bureau before (here, for example, and here), but to this direct question there is a straightforward reply. I’ll deal first with the more general issue of BoM (Bureau of Meteorology) reporting, and note first that it is directly linked, as anyone who reads the website will see, with CSIRO’s biennnial reports on the State of Climate. So my response to Chris covers both government agencies. And I’ll repeat a statement I’ve made before: I am not criticising the staff or the leaders of all the sections of these large agencies. My criticisms are directed at those who report to the Australian public about the vexed issue of ‘climate change’, and those who approve such one-sided reporting.

Four years ago the Bureau told us that the previous year was the hottest in Australia’s history, and much else that was scary as well. I dissected those statements at the time, and wrote, I don’t think that this is what the Bureau of Meteorology should be doing. And you have to ask whether this drum-beating is being requested by the Minister, or instead the action of enthusiastic staff who are firm believers in the orthodoxy and know that no one will pull them into line for what is shoddy work. It is reminiscent of the IPCC, which produces its Statement for Policy Makers months ahead of the full report, which has the qualifications and uncertainties (if at all) that the Statement itself lacks.

I am still of that opinion. Now, to see what the Bureau actually does in the climate-change area, you need to go to the relevant part of its website, and keep scrolling through a section called ‘Climate Change in Australia’ (a joint effort by the Bureau and the climate change people at CSIRO). You’ll come to a section on global climate change, and you’ll read this: Observational and model studies of temperature change, climate feedbacks and changes in the Earth’s energy budget together provide confidence in the magnitude of global warming in response to past and future forcing. In this regard, human influence on the climate system is clear.

Future global and regional climate change indicate that continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.

Now, first of all, ‘model studies of temperature change’ should not give anyone confidence in ‘the magnitude of global warming’. The data are not good much before the satellite period (1979 to the present). The models have consistently over-estimated the importance of CO2, and have not estimate real change well at all. Nor should we have any confidence in their capacity to provide accurate pictures of climate in the future. ‘Climate feedbacks’ presumably refer to ‘climate sensitivity’, and there is huge disagreement about whether they exist at all, or if they do, about whether  they are at all higher than 1. And how much human influence there is, compared to natural variability, is not at all clear, even though I expect that burning fossil fuels, making cement and clearing forests will have contributed to whatever warming has occurred. There is no suggestion in the Bureau’s sentences that there is any doubt at all.

Second, the second paragraph relies on that overstated first paragraph, while its final sentence is a political statement, not a scientific one. Why, I might ask my local MP, is the Bureau engaging in one-eyed scientific reporting and issuing political statements that have a poor evidential base? Well, I would ask her, if the moment were appropriate. This is not what the Bureau is for. I said that in 2013, and I say it again. But we have only got to global climate change. Keep scrolling, and we come to ‘Is Australia’s climate changing?’ Apparently, according to Australia’s Climate Observation Network (ACORN), Australia’s average temperature has risen by about 0.9 degrees C in the last century. Whether we should be alarmed at such a gentle increase is not clear. But we know from the global section that we must reduce greenhouse gas emissions, or something bad will happen. This section says nothing about that, though the tone is sombre.

Apparently heatwaves have increased since 1950, and rainfall has increased since 1970, in both cases ‘across large parts of Australia’. Dear old ‘sea level’ c0mes in for a broad-brush treatment too: Global mean sea level increased throughout the 20th century and in 2012 was 225 mm higher than in 1880. Rates of sea-level rise vary around the Australian region, with higher sea-level rise observed in the north and rates similar to the global average observed in the south and east. I can’t easily find anything that would support the 225 mm increase. We know that Fort Denison has been at about 8-9 mm per century, and Fremantle is much the same; they are in the south, but what they tell us is in no way comparable to 225 mm.

Similarly, a statement that ‘Sea-surface temperatures in the Australian region have warmed by 0.9°C since 1900’ begs for supporting data and methodology. To learn that this statement relies on ERSSTv.4 does not fill me with any confidence. A statement in the global section that the acidity of the oceans has increased is just rubbish. The seas remain alkaline. It is not clear even that there has been a slight reduction in that alkalinity across the oceans.

In this section the Bureau calls upon its colleagues, the climate people in CSIRO, and refers readers to the 2014 State of the Climate Report, which is another joint effort between the two agencies. Since the 2016 Report is available, I’ve been to that. Those who have read the Fifth Assessment Report of the IPCC will find in this Australia summary lots of familiar statements and projections. As with the IPCC, you need to read a lot of contorted prose carefully. There are qualifications in the Technical Report, but they do not appear in the broad-brush prose of the State of the Climate Reports. Indeed, this 2016 Report seems to me couched in a kind of anxious prose, which stops just short of telling us that we are doomed if all of this keeps going.

Above all, in what I have read there is a clear reluctance to say, in the Report area, that there are lots of uncertainties in all this. Australia may or not be getting warmer, or at least parts of it may be. The sea levels might or might not be rising in an unusual fashion (there is actually nothing I could find that pointed out that seas have been rising slowly and steadily for the last few thousand years). There might or might not be a worrying level of decline in alkalinity. You can find some of this in the Technical Report, but the ordinary reader won’t go there.

Now to the use of particular datasets. The Bureau created ACORN, at least in part, to provide a high-quality data set in which some (it says more than half, but I can’t tell) of the stations go back to 1910. These data have been homogenised. The readings for Alice Springs, for example, are qualified by the stations closest to it. Since Alice Springs station covers about 7 to 10 per cent of the continent it will be clear that its closest stations must be a long way away. And indeed they are. The changes in data for a number of stations, like Alice Springs, Rutherglen and Brisbane were much discussed a few years ago, and I wrote about them at the time too. You will find a good analysis by some sceptical workers on Jo Nova’s website (here and here for a start). (Read what the criticisms were, don’t just balk at the website. Jo Nova is pretty savvy, in my opinion.)

The Bureau was reluctant to explain, and issued a bland statement about how all this was done to highest international standards. As I have said so often, why do it at all? The obvious reason is that there is a (political) need for ‘data’ that show that the earth is warming, and if we could measure the trend we would know what is in store for us. I think it goes back to James Hansen in 1988, but I don’t know when Australia started going down that track. John Howard, while remaining a sceptic throughout, nonetheless set up the Australian Greenhouse Office in 1998. Maybe it started after that innovation.

So we’re back to the beginning. I think these efforts are quite misguided, and they involve government agencies in activities that are not scientific but political. In my opinion they shouldn’t be doing it. Their job is to provide government and the people with accurate knowledge about their sphere of investigation, in this case weather. ‘Climate’ is a thirty-year abstraction, and thirty years is a convention anyway. A couple of hundred years would be more sensible.

I said all this four years ago, and I say it again now. They don’t seem to learn, and that makes you think their commitment is more than just political, though a political commitment would be explicable. After all, it is impossible to work out whether the Australian Government even understands what the issues are. So those responsible in the agencies might well think, why not just keep plugging away at the orthodoxy.