The Tories are clean out of their mind to want new gas plants So Mr Alexander is stepping in. On Monday, he will move a motion at the Lib Dem conference endorsing a similar target and lambasting "the refusal of the Conservatives to acknowledge" that clean technologies can boost growth. His intervention - rather than leaving the matter to Mr Davey - emphasises the issue's importance to his party. Mr Alexander has some good arguments, for the fossil fuel is looking less cheap, secure and clean than its supporters say. It has, for example, been its rising price - rather than the widely blamed support for renewables - that has so far been the main drive of soaring energy bills. Official figures show that gas has caused two thirds of the recent £150 average increase - while between 2004 and 2010 it added nearly 10 times as much as renewables support. Experts expect its cost to go on rising, while wind power becomes cheaper: the crossover point may come this decade, long before new gas plants go offline. As the North Sea dries up, we are ever more dependent on imports, which now account for over half our supplies, and are expected to rise to over three quarters this decade. Most are liquid natural gas (LNG) shipments from Qatar. These make Britain highly vulnerable to Iranian threats to block the Straits of Hormuz, and are easily diverted elsewhere: this year LNG imports fell by 30 per cent as cargoes were diverted to Asia. Gas prices are volatile - they shot up 18 per cent a year ago - posing destabilising dangers to the economy. But what about shale gas, which has seen prices plummet in the US? I was one of the first British journalists, back in January 2010, to report on its "game-changing" potential, but I must admit it seems to have been overhyped. The US cost crash arose from a glut of wells coming on stream as the economy flatlined: prices are now increasing and are expected to double within three years. Even then, it is widely agreed, shale gas will be more expensive to exploit in Europe, and its contribution will be limited. And although burning gas does release half as much carbon dioxide as coal, emissions of methane - 21 times as powerful a warming gas - from both shale and LNG production erode much of the difference. Britain already gets over 80 per cent of its domestic heat and 40 per cent of its electricity from gas, so increasing our dependency, as the Chancellor plans, seems foolhardy. Moving instead to a low-carbon economy, as Mr Alexander advocates, would - says a study carried out for Mr Davey's department - cut price volatility and inflationary pressures in half. With two members of the all-powerful Quad at loggerheads, the Prime Minister will have to resolve the issue. But I shouldn't think that will afford him much delight. The cost-cutting over badger TB will exact a high price Expect a torrid time over badger culling. It's already getting nasty, with protesters planning to publish the names, addresses and phone numbers of those involved. But despite polarising positions, almost everyone agrees on one thing: it would be much better to vaccinate against bovine TB. "We would all like to have a vaccine," said new Environment Secretary Owen Paterson, "but we haven't got one." Er, wrong. Indeed, the National Trust, RSPB and Gloucestershire Wildlife Trust already use it on badgers on their land. The trouble is that the animals have to be caught and injected regularly, which is costly, so the hunt is on for an oral vaccine to be put in bait. But why has more not been done in the time the two sides have been fighting about the cull? And why did this Government scrap five of the six injectable vaccine trials it inherited? It would be even better to have a vaccine for cattle, especially one that would get round current EU restrictions on its use. But, over the 15 years of the culling row, successive governments have invested an average of less than 2 per cent of the current annual cost of the disease each year. As the expense of the cull escalates, not least in paying for policing, their penny-pinching will prove a false economy indeed. Meet the New Zealand river with a personality all its own When is a river not a river? When it is a person. New Zealand has just granted its third-longest waterway, the Whanganui river in North Island, "legal personhood." The move - which gives the river "rights and interests" in the same way as has been accorded to companies - comes as the result of a campaign by the local Maori people, which has been going on since 1873. It's appropriate, since the river's name in the local language means "the big wait" - after a legend in which a Maori ancestor, pursuing his absconding wife, had to kick his heels on its banks until the tide turned (when he caught up with her he turned her into a rock). Making the river a person, says the government, will give it a legal voice and enable it to be represented in court. It will be given two guardians, one representing the Queen and one from a local Maori community, whose job it will be to protect it from pollution and other abuse. But, objectors ask, what will happen if the Whanganui floods, destroying homes, sweeping away possessions and killing people? Will it be arrested and tried for trespass, breaking and entering, theft and murder? Whatever, the development gives a whole new dimension to the concept of Old Man River. And who will now fight for the human rights of Father Thames?