The term "blue energy" refers to salinity gradient power - the energy retrieved from the difference in the salt concentration between seawater and river water. The power is generated using osmosis with ion-specific membranes.

Jan Post, at Wageningen University in the Netherlands, has researched the global potential for electric power generated in this way. His research into the practical applicability, techniques and preconditions for large-scale energy generation from salinity gradients, has shown that very high yields are possible. In the laboratory, it is possible to recover more than 80% of the energy from salinity gradients. In practice, the technical feasibility would be 60-70% and the economic feasibility a little lower than that.

Because of differences in salt concentrations, temperature and other environmental factors, there are significant differences between the continents. The highest technical potential is in Australia where 65% of the energy from salinity gradients could be recovered; South America has the lowest potential at 47%.

There are also significant differences among rivers. The Rhine has one of highest potentials among the world’s 5,742 large rivers. Jan Post estimates that the Rhine has the technical potential to generate 2.4 gigawatts of "blue energy" per annum, of which 1.4 gigawatts could be economically recovered - enough to power around 4 million households.

Jan Post believes that it will take another ten years to bring down the cost of blue energy to a competitive level and to develop membranes which are robust enough to work when the water is polluted and when living organisms accumulate on them.

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Robert and Brenda Vale, two architects who specialise in sustainable living at Victoria University of Wellington, New Zealand, have given a new meaning to the term "pet food" in their new book, "Time to Eat the Dog".

The book compares the ecological footprints of popular pets with those of various other lifestyle choices. New Scientist have added to the debate with research from John Barrett at the Stockholm Environment Institute in York, Englend and David Mackay, the UK government’s energy adviser.

So what are the results?

• According to the Vales, a medium size dog has a larger eco-footprint than a large SUV (specifically, a 4.6 litre Land Cruiser driven for 10,000 kilometres a year),
• A cat has an eco-footprint which is slightly less than a Volkswagen Golf.
• Two hamsters equate to one plasma TV.
• But you can have four canaries for one plasa TV
• And a goldfish has an eco-footnprint (or should that finprint?) equilavent to two mobile phones.

The land required to feed the pet cat population of the top ten cat-owning countries is about one and a half times the area of New Zealand. And the land needed to feed the dogs in the top ten dog-owning countries is five times the area of New Zealand.

To put all this into perspective, the eco-footprint of a British human is about fifty times that of a cat.

We wouldn’t dare suggest what you should conclude from this but this is the Vale’s advice:

• If you have a dog, feed it the same kind of food that you eat rather than meat-rich dog food;
• If you have a cat, feed it on fish heads and other leftovers that you can get from a fishmonger;
• And if you are chosing a pet "Rabbits are good, provided you eat them."

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Ford has showed off a prototype of what is being called called the Model T of the company’s electric car strategy - the battery-powered Focus sedan.

To keep costs down, the Focus will be built on the company’s global “C” platform, which is used in two million cars a year.

“This is about affordable transportation for the masses - this is not about a small niche,” said Nancy Gioia, Ford’s director of global electrification. “The assembly line in Michigan will produce the battery-electric Focus and also, with minor modifications, the gas Focus, We can change production as the market shifts.”

The production electric Focus, due in 2011, will be powered by lithium ion battery packs and will be based on the European version of the car. It will have a range of about 160 kilometres and a top speed of around 145 kilometres an hour.

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It is generally argued that livestock are the cause of about 18% of worldwide greenhouse gas emissions. The figure comes from a 2006 United Nations Food and Agriculture Organisation report titled "Livestock’s Long Shadow". A new study by Robert Goodland and Jeff Anhang, published in Worldwatch magazine, argues that this greatly understimates the impact of livestock and that the real figure should be about 50%.

Robert Goodland and Jeff Anhang argue that the FAO underestimated the impact of livestock in serveral ways:
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Stanford civil and environmental engineering Professor Mark Z. Jacobson and University of California-Davis researcher Mark Delucchi.have written an article for Scientific American analysing how the world could achieve 100% clean energy by 2030.

Their analysis concluded that the key factor is eliminating all forms of combustion as a way of generating power. The reason for this is the inefficiency of the use of fossil fuel and biomass combustion.. For example, when petrol is used to power a vehicle, at least 80 percent of the energy produced is wasted as heat.  On the other hand, in electric vehicles roughly 80 percent of the energy supplied to the vehicle is converted into motion, with only 20 percent lost as heat. Similar comparisons apply to other combustion devices compared to electricity or hydrogen produced by electricity.

The researchers concluded that if the world’s current mix of energy sources is maintained, global energy demand in 2030 would be 16.9 million megawatts. If no fossil fuel or biomass is used to generate energy, the demand will be only 11.5 million megawatts.

To achieve this, the world would have to build wind turbines; solar photovoltaic and concentrated solar arrays and geothermal, tidal, wave and hydroelectric power sources to generate electricity. On the other hand, the need for 13,000 coal-fired power stations would be elimated.
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Tie Jun Cui and Qiang Cheng at the Southeast University in Nanjing, China, have built a "black hole" for microwave frequencies. The device may soon be extended to trap visible light, leading to an entirely new way of harvesting solar energy to generate electricity.

The electromagnetic "black hole" is made of 60 annular strips of so-called "meta-materials", which has previously been used to make invisibility cloaks. Each strip takes the form of a circuit board etched with intricate structures whose characteristics change progressively from one strip to the next. The outer 40 strips make up the shell and the inner 20 strips make up the absorber.

The structure makes ectromagnetic radiation curve inwards in a way which is analogous to the curvature of space-time near a black hole. At the point where the shell meets the core, the "permittivity" of the ring matches that of the core, so that light is absorbed rather than reflected.

"When the incident electromagnetic wave hits the device, the wave will be trapped and guided in the shell region towards the core of the black hole, and will then be absorbed by the core," says Jun Cui. "The wave will not come out from the black hole." The core converts the absorbed radiation into heat.

The researchers believe that they will be able to demonstrate an optical version of their device before the end of 2009.

An optical "black hole" would suck it in light and direct it at a solar cell sitting at the core, eliminating the need for large mirrors.

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The US Department of Energy is beginning a program to demonatrate a way in which the oil  industry can produce useful power from waste heat.

When drilling oil and gas wells and on exploration drilling rigs, fluids are used to provide pressure, to keep the drill bit cool and clean and to carry the drill cuttings out of the bore hole. Because these wells are often deep the fluids are hot when they reach the surface. In the average US oil well, ten times as much hot fluid is produced as oil.

The Department of Energy intends to demonstrate how the waste heat in this fluid can be used to generate electricity.

Because the use of the waste heat produces no new carbon emissions, it effectively lowers the carbon cost of the extracted oil.

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The French Government has announced plans to invest €1.5 billion ($au 2.5 billion) in infrastructure for the two million electric and hybrid cars it wants on the road by 2020.

The plan includes industrial research, making batteries, producing clean cars and building a nation-wide network of battery-charging stations.

Under the plan, a million battery-charging points will be built by 2015. From 2012 all new apartment blocks with parking lots will have to include charging stations. The network will grow to a total of four million points by 2020.

Funds will also be provided for the development of elecric cars by Renault, Peugeot/Citroen and Daimler’s Smart Car division. The French manufacturers presented their plans for electric and hybrid cars at the recent Frankfurt Motor Show. (See http://www.greenbizcafe.com/?p=661).

The electric car announcement comes just two weeks after the French Government announced that it would invest more than €7 billion ($au12 billion dollars) to develop freight transport by rail to reduce road traffic. The French Government also announced last month that a carbon tax would be introduced from next year to help cut fossil fuel consumption.

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Update to "Where Have All the Anthems Gone?"

Do we finally have a worthy green anthem in the Time for Climate Justice campaign’s reworking of Midnignt Oil’s "Beds Are Burning"?

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Scientists at  a conference in London have concluded that global warming could result in increased volcanic activity, earthquakes and tsunamis.

The conference on Climate Forcing of Geological and Geomorphological Hazards suggests that climate change could tip the planet’s delicate balance and unleash a host of geological disasters - and that attempts to stall global warming by burying carbon dioxide could make matters worse.

Simon Day from Oxford University and Bill McGuire and Serge Guilla from University College, London, have shown that there is a link between the arrival of El Niño every few years and a greater frequency of underwater earthquakes in the Pacific. El Niño raises the local sea level by a few tens of centimetres and the scientists believe the extra water weight may increase the pressure of fluids in the pores of the rock beneath the seabed making it easier for geological faults to slip.

A team led by David Pyle from Oxford University and Ben Mason from Cambridge University has shown that volcanic activity varies with the seasons. The team found that there are around 20 per cent more eruptions worldwide during the northern hemisphere’s winter than the summer. The researchers believe that the reason may be that the global sea level drops slightly during the northern hemisphere’s winter. This happens because there is more land in the northern hemisphere and, so, more water is locked up as ice and snow on land than during the southern hemisphere’s winter.

A further indication that volcanic activity is linked to the oceans is the fact that the vast majority of active volcanoes are within a few tens of kilometres from the coast.

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