Climate shift 'killing US trees'

Old growth trees in western parts of the US are probably being killed as a result of regional changes to the climate, a study has suggested.

Analysis of undisturbed forests showed that the trees' mortality rate had doubled since 1955, researchers said.

They warned that the loss of old growth trees could have implications for the areas' ecology and for the amount of carbon that the forests could store.

The findings have been published in the journal Science.

"Data from unmanaged old forests in the western US showed that background mortality rates have increased rapidly in recent decades," the team of US and Canadian scientists wrote.

"Because mortality increased in small trees, the overall increase in mortality rates cannot be attributed to ageing of large trees," they added.

"Regional warming and consequent increases in water deficits are likely contributors to the increase in tree mortality rates."

Water woes

After ruling out a variety of other possible factors, including insect attacks and air pollution, the researchers concluded that regional warming was the dominant contributor.

"From the 1970s to 2006, the mean annual temperature of the western US increased at a rate of 0.3C to 0.4C per decade, even approached 0.5C," they observed.

"This regional warming has contributed to widespread hydrological changes, such as declining fraction of precipitation falling as snow, declining snowpack water content, earlier spring snowmelt and a consequent lengthening of summer drought."

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Switch now or wait and see?

British Gas has become the first large energy supplier to break ranks and cut prices, taking 10pc off its standard gas tariff.

The cut will come into effect on February 19 and means that the average British Gas dual fuel bill will drop from £1,328 to £1,240, a saving of £88 a year.

However, experts said the cut nowhere near made up for recent rises in the cost of gas. British Gas increased its prices by 46pc in 2008. Some also advised consumers to wait and see whether other energy providers dropped their prices before switching to a cheaper tariff. It is expected that other providers are likely to announce similar cuts.

"Now that Britain’s biggest supplier has made the move, other suppliers will be under pressure to follow suit. We are sure to see a flurry of pricing announcements," said Ann Robinson, head of consumer policy at financial comparison site uSwitch.

However, she added that the cuts were likely to be "too little, and too late" to help consumers with this winter’s fuel bills.

The British Gas cut means that its WebSaver tariff, which is guaranteed to be 10pc below its ordinary tariff, will be the cheapest option for many customers across the country.

Gareth Kloet, head of utilities at website Confused.com, advised customers to switch now, despite the expected price cuts. "We’ve waited too long for cuts," he said. "We’ve seen suppliers tinkering with tariffs, but this is really good news for customers."

His company provided the table (right, click to enlarge) of the best deals in each area of the country.

Watchdog Consumer Focus welcomed the price cut, saying British Gas had "done the right thing". "We will now turn the heat up on the other five companies that are keeping prices sky high," said chief executive Ed Mayo.

Meanwhile, Age Concern said that, unless there were further price cuts from all suppliers, "many of the poorest pensioners will continue struggle to pay their energy bills".

A spokesman for British Gas said: "Wholesale prices have come down enough for us to begin lowering prices for our customers. We'll continue to watch wholesale prices carefully and if they go down again significantly we will pass this on to our customers."

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British Gas is cutting its gas prices by 10%

British Gas said today it would cut residential gas prices by 10% next month, sparking hopes that the move will put pressure on other suppliers to follow suit.

The company, the biggest gas supplier to the UK residential market, said the move would benefit 7.5m households and save £84 on average household gas bills. The cut will not affect customers on fixed-rate deals or those who only buy electricity from British Gas.

Though some observers described the move as a welcome first step, there was disappointment the company had not gone further in reversing last summer's 35% rise in gas bills, which itself followed a 15% increase last January.

Phil Bentley, British Gas managing director, said wholesale gas prices had almost doubled last year and the market had been very volatile. "We buy gas months before it is used so we can make sure we always have enough for our customers, and can protect them from sudden rises in wholesale prices," he said.

Bentley said the company understood that energy bills represented a "significant cost" for customers. "This price cut will go some way towards helping customers manage their budgets and we will continue to do for them what we can, when we can."

British Gas rejected suggestions from some of the company's competitors that the price cut simply represented a "catch-up" move. It said British Gas had not cut electricity prices because wholesale prices had fallen more slowly and it had increased electricity bills by less than gas prices last year.

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Biofuel Carbon Footprint Not As Big As Feared

Publications ranging from the journal Science to Time magazine have blasted biofuels for significantly contributing to greenhouse gas emissions, calling into question the environmental benefits of making fuel from plant material. But a new analysis by Michigan State University scientists says these dire predictions are based on a set of assumptions that may not be correct.
"Greenhouse gas release from changes in land use – growing crops that could be used for biofuels on previously unfarmed land – has been identified as a negative contributor to the environmental profile of biofuels," said Bruce Dale, MSU University Distinguished Professor of chemical engineering and materials science. "Other analyses have estimated that it would take from 100 to 1,000 years before biofuels could overcome this 'carbon debt' and start providing greenhouse gas benefits."

But as Dale and his co-authors point out in their research, published in the journal Environmental Science & Technology, earlier analyses didn't consider a number of variables that might influence the greenhouse gas emissions associated with biofuels.

"Our analysis shows that crop management is a key factor in estimating greenhouse gas emissions associated with land use change associated with biofuels," Dale said. "Sustainable management practices, such as no-till farming and planting cover crops, can reduce the time it takes for biofuels to overcome the carbon debt to three years for grassland conversion and 14 years for temperate zone forest conversion."

The discrepancies between the time it will take biofuels to offer environmental benefits is due to the models used for each analysis, Dale explained.

"There are no real data on what actually happens as demand increases for land for biofuel production in one part of the world potentially leads to land clearing, because it is impossible to track these relationships in the real world," Dale said. "All the estimates are based on economic relationships and theoretical models with various data and assumptions. It's really one set of assumptions versus another set. The other scientists believe their assumptions are more reasonable, and we believe ours are more reasonable.

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