More on rainfall

15 March, 2007

For those unconvinced about my previous claim that, according to the BOM data, there doesn’t appear to be a drying trend on the east coast and think it might be an artifice of too broad averaging, I note that they should have a look at the trend maps found here. For example the rainfall trends from from 1900 to 2006.
Australian Rainfall trend 1900 - 2006

This shows few regions which have shown a definite drying trend over the period. One clear exception being the south west of WA, which does show a drying trend over pretty much anytime period you pick. In addition it appears that some slight trend could be evident in mid to northern Queensland.

Go and have a look at some of the different time periods on their site, the lack of a clear trend for much of eastern Australia isn’t just for the period 1900-2006. In case any one’s concerned that its because we started the comparison in a drought. Take 1910-2006, 1920-2006 or 1930-2006 and you get something similar.

Indeed its not unless you compare with the 1950’s to 1970’s that you get a really marked decrease in rainfall in most of Eastern Australia.


Food politics

8 December, 2006

An interesting piece in The Economist discussing issues around, organic food, fair trade and ideas about embedded energy, or food miles. Some of these topics I’ve mentioned in earlier posts.

On the claim organic food is better for the environment:

Perhaps the most eminent critic of organic farming is Norman Borlaug, the father of the “green revolution”, winner of the Nobel peace prize and an outspoken advocate of the use of synthetic fertilisers to increase crop yields. He claims the idea that organic farming is better for the environment is “ridiculous” because organic farming produces lower yields and therefore requires more land under cultivation to produce the same amount of food… The more intensively you farm, Mr Borlaug contends, the more room you have left for rainforest.

On fair trade coffee:

The standard economic argument against Fairtrade goes like this: the low price of commodities such as coffee is due to overproduction, and ought to be a signal to producers to switch to growing other crops. Paying a guaranteed Fairtrade premium—in effect, a subsidy—both prevents this signal from getting through and, by raising the average price paid for coffee, encourages more producers to enter the market. This then drives down the price of non-Fairtrade coffee even further, making non-Fairtrade farmers poorer. Fairtrade does not address the basic problem, argues Tim Harford, author of “The Undercover Economist” (2005), which is that too much coffee is being produced in the first place…

But perhaps the most cogent objection to Fairtrade is that it is an inefficient way to get money to poor producers. Retailers add their own enormous mark-ups to Fairtrade products and mislead consumers into thinking that all of the premium they are paying is passed on. Mr Harford calculates that only 10% of the premium paid for Fairtrade coffee in a coffee bar trickles down to the producer. Fairtrade coffee, like the organic produce sold in supermarkets, is used by retailers as a means of identifying price-insensitive consumers who will pay more, he says.

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Winds of change or just more hot air?

14 November, 2006

First it was Rupert Murdoch “The planet deserves the benefit of the doubt.”, then Peter Costello on insiders

I think the ground is changing. I think it is important that we bring new countries into this discussion. And I think, from Australia’s point of view, if the world starts moving towards a carbon trading system, we can’t be left out of that, that Australia has a role…

and now John Howard

JOHN HOWARD has yielded to pressure to consider a global carbon trading scheme, and business leaders say they are ready to take action against global warming.

As Brian has noted at LP, the release of the Stern review has coincided with a sudden shift in the political direction with respect to AGW policy. Previously the Australian government position has been completely intransigent on being involved with carbon trading, but with Peter Costello’s interview on insiders and now this announcement it seems there has been a large shift in government opinion. Even if this is not a complete reversal it is a serious concession that Australia and the rest of the world needs to do more.

Earlier in the year the government used a review of the tax system as a stepping stone on the way to reversing its previously stated opposition to cutting top tax rates. Here’s hoping this review is the same, a facing saving exercise before a policy reversal and not just more hot air.

Government plays Enviro-Santa

26 October, 2006

The government announced yesterday $75 million dollars for a 154 MW concentrated solar power plant to be built in rural northern Victoria. Although the Peter Costello claims its going to cost $280 million, the company building the project Solar Systems, say it will cost $420 million. An additional $50 million is being contributed by Victoria. Perhaps PC is talking about the private costs and has missed $15 million?

The company describes the technology like this.

The power station will use technology known as ‘Heliostat Concentrator Photovoltaic’ (HCPV). It will consist of fields of heliostats (sun-tracking mirrors) focusing sunlight on receivers. The receivers house photovoltaic (PV) modules, which consist of arrays of ultra high-efficiency solar cells that convert the sunlight directly into electricity. Photovoltaic literally means ‘electricity-from-light’. The heliostat control system, PV modules and cooling system are patented by Solar Systems.

Solar Systems has collaborated with US company Spectrolab (a Boeing company) to optimise ultra high efficiency space technology for earth based power stations. The resulting photovoltaic cell arrays are three times more efficient than typical solar panels. Further cell efficiency improvements are underway.
This is a new generation of solar technology,” Mr Lasich said. “The secret is to be able to make a solar power module work about 1500 times harder than typical solar panels. If you can do this at high efficiency using low cost materials, you have the recipe for an infinite supply of clean energy at an affordable price. “This new power station will demonstrate these principles and produce the most affordable solar energy yet generated.”

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Carbon Emission Trading

25 October, 2006

There have been a few interesting pieces around recently on the subject of carbon emissions trading. The first is The Economist (subscription only) noting some of the failures of the European carbon trading market, which has seen prices of CO2 emissions collapse due to the issuing of too many free permits.

In order to get industry to swallow this scheme, allowances were handed out free to companies, rather than being (as economists wanted) auctioned. In power-generation (Europe’s most-polluting industry) companies passed the price of carbon credits on to customers and pocketed the value of the allowances. According to a report by IPA Energy Consulting, Britain’s power-generators alone made a profit of around £800m ($1.5 billion) from the scheme in its first year.

As the article notes, this failure is not a reason to rubbish the idea of emission markets altogether, but it is a good lesson in the mistakes that can be made and the need to either slash the number of permits or auction them off if the scheme is going to be worthwhile.
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Geothermal energy in Iceland

11 October, 2006

Old news, but I didn’t read it at the time and given I’ve mentioned Geothermal energy in Australia before, I thought I’d link to it anyway. The Economist from nearly a month ago mentions some developments that have been making geothermal power at either extreme (low or high temperature) more usable. The low temperature part I think is particularly interesting.

Not all geothermal activity is hot enough to bring water to the boil. The Chena hot springs, in Alaska, for example, are just right for bathers, at a porridge-like 43°C, but not much use for traditional geothermal power generation. Even within the spa’s wells, the water is only 74°C. Nonetheless, its owners, in conjunction with United Technologies, an engineering conglomerate, have worked out how to generate power from the tepid flow—the coldest ever used in a geothermal plant.

The power station at Chena uses the spring water to heat up R134a, a fluid hitherto employed mainly as a refrigerant. Since R134a has a relatively low boiling point, the water is hot enough to convert it into a gas. This gas is used to drive the turbine just as steam would be. Icy water from a nearby river then cools the gas back to liquid form, to start the cycle again.

The designers of the plant at Chena, however, managed to slash their capital outlay by substituting mass-produced parts from air-conditioners for the bespoke components of most geothermal plants. They reckon their design could be mimicked anywhere there is a difference in temperature of at least 50°C between heating and cooling water. That would apply not only to a huge number of geothermal sites, but also to many oil wells, which often bring up warm water from great depths along with their more valuable output.

The idea that you can use off the shelf construction materials to build cheap “warm” power stations is great. These could be much more widely available than the current deep hot rocks that we are drilling for in Australia is interesting. I’m increasingly convinced that some mix of geothermal is going to be an important part of our greenhouse friendly energy usage in the future along with distributed wind power and perhaps nuclear.
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Rainfall patterns

4 October, 2006

While I accept and indeed am concerned about the prospect of global warming, I’ve always been a little bit sceptical of the claim that it will make Australia drier. Naively I expect that if it gets more tropical we’ll get more rain. I also accept that there are many other things happening which may confound this trend. Anyhow I notice via John Quiggin this BOM site, giving maps and time series of annual, monthly etc rainfall for Australia and various other regional breakdowns. John seems to have picked out a graph which makes the browning, appear particularly severe, but is it really so?

Too often we are just presented with just the trend, and without knowledge of the variability over time, how any particular result fits in is difficult to understand. For example if we plot the South Eastern Australia average rainfall for the last 100 years we get this
SE Australia annual rainfall

The obvious things to note is that the average for the first 50 years was well below the later part of the graph. Indeed by the standards of the first half of last century recent drought years with the exception of 2002 haven’t been particularly severe. Instead most have been above the average rainfall experienced in the first half of last century.

If we take the years to 1950, we find an average rainfall of 575mm, for the remaining 55 years the average is 625, with the five highest rainfall measurements all falling in the same half of the graph.
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