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  • Scientists say ozone layer depletion has stopped

     

    The Scientific Assessment of Ozone Depletion 2010 report said a 1987 international treaty that phased out chlorofluorocarbons (CFC) – substances used in refrigerators, aerosol sprays and some packing foams – had been successful.

    Ozone provides a natural protective filter against harmful ultra-violet rays from the sun, which can cause sunburn, cataracts and skin cancer as well as damage vegetation.

    First observations of a seasonal ozone hole appearing over the Antarctic occurred in the 1970s and the alarm was raised in the 1980s after it was found to be worsening under the onslaught of CFCs, prompting 196 countries to join the Montreal Protocol.

    “The Montreal Protocol signed in 1987 to control ozone depleting substances is working, it has protected us from further ozone depletion over the past decades,” said World Meteorological Organisation head of research Len Barrie.

    “Global ozone, including ozone in the polar region is no longer decreasing but not yet increasing,” he told journalists.

    The 300 scientists who compiled the four yearly ozone assessment now expect that the ozone layer in the stratosphere will be restored to 1980 levels in 2045 to 2060, according to the report, “slightly earlier” than expected.

    Although CFCs have been phased out, they accumulated and persist in the atmosphere and the effect of the curbs takes years to filter through.

    The ozone hole over the South Pole, which varies in size and is closely monitored when it appears in springtime each year, is likely to persist even longer and may even be aggravated by climate change, the report said.

    Scientists are still getting to grips with the complex interaction between ozone depletion and global warming, Mr Barrie explained.

    “In the Antarctic, the impact of the ozone hole and the surface climate is becoming evident,” he said.

    “This leads to important changes in surface temperature and wind patterns, amongst other environmental changes.”

    CFCs are classified among greenhouse gases that cause global warming, so the phase out “provided substantial co-benefits by reducing climate change,” the report found.

    Mr Barrie estimated that it had avoided about 10 gigatonnes of such emissions a year.

    However, the ozone-friendly substances that have replaced CFCs in plastics or as refrigerants – hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) — are also powerful greenhouse gases.

    HFCs alone are regarded as 14,000 times more powerful than carbon dioxide (CO2), which is the focus of international efforts to tackle climate change, and HFC emissions are growing by 8 per cent a year, according to UN agencies.

    “This represents a further potential area for action within the overall climate change challenge,” said UN Environment Programme chief Achim Steiner in a statement.

    – AFP

    Tags: environment, climate-change, science-and-technology, united-states

    First posted 3 hours 38 minutes ago

  • Water Minister tries to shoot the messenger

     
    Dr Kaye said: “Minister Costa was unable to tell yesterday’s Upper House Budget Estimates committee if he had read Hunter Water’s Integrated Water Resource Plans for 2003 through to 2006.
     
    “He seemed to be unaware that these documents placed Tillegra as the second worse supply option.
     
    “He was unable to explain the sudden back-flip in late 2006 that converted the dam into the must-have water supply project.
     
    “Instead he tried to discredit the Greens and groups such as No Tillegra Dam for their opposition to the unpopular, expensive and unnecessary proposal.
     
    “The Minister was also deeply embarrassed by revelations from NSW Office of Water Commissioner David Harriss that his own experts had severe reservations about the dam.
     
    “The Hunter community would be better served by a water minister who spent less time attacking  his opponents and more time listening to the state’s water experts.
     
    “For the record, the Greens stand behind the evidence that Tillegra Dam is expensive, uneconomic, unnecessary, unjustified, environmentally damaging, opposed by a number of senior government water and environment experts, and exposed to price risk because of the complex geology of the site,” Dr Kaye said.
     
    For more information: John Kaye 0407 195 455
     
     
    ———————————-
    John Kaye
    Greens member of the NSW Parliament
    phone: (02) 9230 2668
    fax: (02) 9230 2586
    mobile: 0407 195 455
    email: john.kaye@parliament.nsw.gov.au
    web: www.johnkaye.org.au
     

  • Milne hopes for carbon price compromise

     

    Senator Milne has welcomed the changed approach, and says she had a useful meeting with the new Climate Change Minister Greg Combet.

    She told the 7:30 Report she used the meeting with Mr Combet to talk about introducing a carbon price.

    “It was my first opportunity since he was sworn in as Minister to sit down and talk with him about the whole issue of climate change, about renewables, energy efficiency and the carbon price,” she said.

    “They are things that he’s nominated publicly as things he wants to really progress.”

    She says no particular party won a mandate on climate change policy.

    “The advantage of this committee with experts means that you can talk about what is right, what is wrong with that position, what would work, what would not work,” she said.

    “Out of that, we hope to get a situation where we end up with a carbon price.”

    Tags: environment, climate-change, government-and-politics, federal-government, australia

  • Global Warming could cut number of Arctic hurricanes, study finds

     

    Arctic hurricanes, also known as polar lows, are explosive storms that develop and die over a few days. They form when cold air from the Arctic flows south over warmer water: the air takes up heat, expands and rises, generating convection currents that sometimes snowball into storms.

    Zahn and his colleague Hans von Storch, of the Meteorological Institute at Hamburg University, used a global climate model to project the impact of three scenarios on temperature, humidity and other variables in 2100. They then fed this data into a regional model to assess how polar lows may respond.

    Assuming that greenhouse gas emissions rise rapidly in the future, the frequency of Arctic hurricanes could fall from an average of 36 per winter to about 17 by 2100, the model suggests. If emissions rise more slowly the number of hurricanes could fall to 23 per winter.

    Polar lows are less likely to form in the future because climate change will warm up the air in the north Atlantic faster than it warms up the ocean, reducing the thermal difference and reducing the risk of convection currents forming.

    The Arctic is of great interest to oil and gas companies, but Doug Parr, chief scientist at Greenpeace UK, says many are concerned that extreme weather as well as icebergs could damage rigs and trigger oil spills. However he warns industry against interpreting Zahn’s results as a signal that the region is safe to exploit.

    “As we have seen from BP in the Gulf of Mexico, there are plenty of hazards associated with drilling for oil and gas that have nothing to do with the weather,” says Parr. “Even if the frequency of hurricanes declines, we would be bonkers to go into such a fragile ecosystem and risk sacrificing it just to obtain more oil.”

    Erik Kolstad at the Bjerknes Centre for Climate Research in Bergen, Norway, adds that while polar lows may be reduced in some Arctic regions, they would only move onto others where sea ice has retreated to form new ocean.

    “These regions include the Barents Sea, where the Russians are exploring for gas and oil, the Northern Sea Route, where shipping companies hope to be able to travel from Asia to Europe, and in the Beaufort Sea, where the Canadians are exploring for oil and gas,” says Kolstad.

    Fewer polar storms could also mean less extreme weather in the UK, says Suzanne Gray at the Mesoscale Group at the University of Reading, who was not part of the research team. “Polar lows occasionally lead to heavy snowfall even over England. Motorways get blocked and people have to sleep in their cars overnight. So perhaps we won’t be seeing so many of them in the future.”

  • World Bank invests record sums in coal

    World Bank invests record sums in coal

    Juliette Jowit, Observer environment editor

    16th September, 2010

    Last year, $3.4bn was invested in the dirtiest fossil fuel despite international commitments to cut emissions

    Record sums were invested last year in coal power – the most carbon intensive form of energy on the planet – by the World Bank, despite international commitments to slash the carbon emissions blamed for climate change.

    The World Bank said this week that a total of US$3.4bn (£2.2bn) – or a quarter of all funding for energy projects – was spent in the year to June 2010 helping to build new coal-fired power stations, including the controversial Medupi plant in South Africa. Over the same period the bank also spent $1bn (£640m) on looking and drilling for oil and gas.

    However, the Bank Information Centre, which examined the spending, disagreed and said the figure invested in coal was $4.4bn in the fiscal year 2009-10.

    The discrepancy is due to the World Bank not including in its figure a $1bn project in India which is funding power transmission networks for coal-fired power stations rather than the stations themselves.

    Environmental campaign groups said spending on coal in that period was 40 times more than five years ago, and claimed there was an ‘incoherence at the heart of the World Bank’s thinking about energy’ that would damage long term attempts to cut emissions of carbon and other greenhouse gases from such plants.

    ‘At the same time as the bank is seeking to gain control of the billions which will be channelled to developing countries to help them cope with global warming, the bank is still lending staggeringly large and growing sums to finance coal-fired power,’ said Alison Doig, senior advisor on climate change for the charity Christian Aid.

    ‘We know that coal is the dirtiest of all the fossil fuels – the one which most exacerbates the climate crisis which is having devastating effects on the lives of people living in poverty. We also know that by financing the building of coal power stations the bank is locking countries into coal use for the next 40 to 50 years [the life expectancy of the plants].’

    The World Bank defended its payments saying that the figures for 2010 were distorted by two major coal projects in Botswana and South Africa, while over the five year period from 2005 the bank had spent US$4.5bn on coal power, and $12.5bn on renewable energy and energy efficiency – including a record year for these sectors also last year.

    Coal plants were only subsidised when there were ‘exceptional circumstances where countries have few or no prospects for other energy sources,’ said Roger Morier, a World Bank spokesman.

    ‘Our energy portfolio is increasingly oriented to renewable energy and energy efficiency,” added Morier. “We are fulfilling our mandate of responding to the urgent needs of our client countries for access to efficient, reliable, affordable electricity, while also helping those countries to get on a low-carbon development path as soon as possible.’

    This article is reproduced courtesy of the Guardian Environment Network

  • Geothermal Energy Could Provide all the Energy the World Will Ever need

     

    “If we can drill and recover just a fraction of the geothermal heat that exists, there will be enough to supply the entire planet with energy – energy that is clean and safe,” says Are Lund, senior researcher at SINTEF Materials and Chemistry.

    Inexhaustible Source 

    Geothermal heat offers incredible potential. It is an inexhaustible energy source that is nearly emission-free. Heat energy is found in the different rock types that make up the Earth’s surface, and deeper in the crust. The deeper you get, the hotter it is.

    Around one-third of the heat flow comes from the original heat in the Earth’s core and mantle (the layer closest to the Earth’s crust). The remaining two-thirds originate in radioactivity in the Earth’s crust, where radioactive substances continuously decay and generate heat. The heat is transported to rock layers that are nearer the Earth’s surface. 

    Different Depths 

    Geothermal energy that comes from 150-200 metres below the surface is called low temperature geothermal energy. At these depths, temperatures hover between 6 and 8°C and can be extracted with heat pumps, combined with an energy well. This type of geothermal energy is exploited at a fairly large scale. 

    The Norwegian company Rock Energy wants to be an international leader in geothermal heat and energy. A pilot plant has been planned for Oslo that will collect heat from 5500 metres deep. Temperatures from this depth can heat water to 90-95°C and can be used in district heating plants. The pilot plant will be built in cooperation with NTNU, which is studying the thermal aspects of the plant.  (See illustration, left of a geothermal system as it is used today in Iceland, for example. In areas where the rocks are warmer, it is possible to simply fracture the rocks, as shown in the figure. Credit: Knut Gangåssæter/SINTEF.)

    The plan is to drill two wells, an injection well where cold water is pumped down, and a production well where hot water flows back up. Between these will be so-called radiator leads that connect the wells. The water is then exchanged with water in Hafslund’s district heating plant.

    The normal lifespan for a well like this is approximately 30 years. After that the rock will be so cooled by the cold water that has been injected into the wells that it will no longer produce enough heat. However, after 20-30 years, the heat will have built up again, and the well can be used once more. The Rock Energy facility will be a major step forward in exploiting Norway’s geothermal heat resources. 

    Supercritical Water 

    However, if we want to reduce CO2 emissions and provide clean energy on a scale that will make a difference, we will need go much further down into the Earth itself.

    Researchers at NTNU, the University of Bergen (UiB), the Geological Survey of Norway (NGU) and SINTEF believe this is possible. In 2009, deep geological energy enthusiasts formed the Norwegian Centre for Geothermal Energy Research (CGER), with partners from universities, colleges, research institutions and the industry.

    The researchers’ goal is to reach depths of 10,000 metres or more to exploit deep geothermal heat. Drilling that deep will enable wells to reach what is called supercritical water with a temperature of at least 374°C and a pressure of at least 220 bar. That multiplies by a factor of 10 the amount of energy you can extract from such an arrangement, and the amount of geothermal energy produced can match that created in a nuclear power plant.  (see lead image, which shows solutions for the future: At 10,000-15 000 meters, pressures and temperatures are intense enough to make the rocks plastic, causing any natural cracks to be pressed together. A method of generating geothermal energy from these depths might then be closed heat exchange systems. Credit: Knut Gangåssæter/SINTEF.)

    But there is a very important difference: Geothermal heat does not create radioactive waste. It is clean energy. 

    “If we manage to produce this kind of energy, it would clearly be a ‘moon landing’. This is one of the few sources of energy that we really have enough of. The only thing that we need is the technology to harvest it,” says researcher Odd-Geir Lademo at SINTEF Materials and Chemistry.

    Pros at 5000 Metres 

    Today’s oil companies are making a good living by extracting oil that is as deep as 5000 metres, where temperatures are as high as 170°C. Drilling any deeper than this results in a range of engineering problems, both in terms of the drilling itself and materials. Steel becomes brittle, and materials such as plastics and electronics will be weakened or melt. Electronics operate normally only a short time at temperatures hotter than 200°C. These problems will have to be solved for the deep geothermal industry to be profitable. 
    Nevertheless, SINTEF scientists think that Norway is in a unique position to capture geothermal heat. 

    “We have a strong and innovative oil industry this country. Because the oil industry has wanted to develop oil and gas deposits from inaccessible areas, drilling technology has evolved tremendously over the past ten years. There are test wells for oil that go 12,000 metres into the Earth. Knowledge from the oil and drilling industry may be used in the future to capture geothermal energy,” say Lund and Lademo. 

    The Norwegian drilling and oil and gas industries all demand equipment that makes it possible to drill ever deeper and to do so affordably. The oil fields that are being discovered now are generally deeper and more complicated than before. Even though there have been a number of wells in the world that have been drilled to 10-12,000 meters, the technology does not yet exist to allow for precision drilling at these depths. 

    “We have to have a common commitment. Multidisciplinary expertise is required. Here at Materials and Chemistry, we are working with an internally funded project in which we are assessing SINTEF’s overall ability to contribute. The goal is to work on projects with industry and the Research Council of Norway,” Lund said, adding, “If research and industry succeed in developing the materials and technology needed to bring up the most difficult-to-reach oil, in the long run we will be able to replace oil with geothermal energy for heating and electricity.” 

    Available Everywhere 

    One of the unique aspects of geothermal heat is that it is found everywhere throughout the world. Call it a “democratic” energy source that anyone can take advantage of, regardless of the conditions at the Earth’s surface, such as the weather.

    How far down you have to drill into the Earth’s crust to reach the temperature that you’re interested in varies from country to country. This is because the crust varies in thickness, and controls what is called the geothermal gradient. At more northerly latitudes, like Norway, the temperature increases by about 20 degrees per kilometre into the Earth’s crust. In other parts of the world, it is 40 degrees per kilometre. The average is around 25 degrees.

    The United States, the Philippines, Mexico, Indonesia and Italy are the international leaders in terms of producing electricity from geothermal energy. Iceland comes in at a surprising 8th place.

    Volcanic Activity 

    The fact that Iceland is on the list at all is because it is home to some of the most extensive volcanic activity in the world – and consequently has access to a great deal of  geothermal energy. Volcanic eruptions are too uncontrolled to allow their heat to be used for energy purposes. But weaker heat sources, such as geysers and hot springs, are used extensively both in Iceland and other countries with volcanic activity. 

    This places the country in a class by itself when it comes to using geothermal resources. Since 1930, Iceland has used geothermal energy for district heating, and today about 60 percent of the population is connected to geothermal heating in some way.

    Hundreds of holes have been drilled outside of Reykjavik to harness geothermal temperatures between 100 and 150°C. This warm water is transported to the capital through pipes with a diameter of 35 cm. The pipes are buried under roads, so that they keep the roads free of ice during the winter. Heat loss between the plant and Reykjavik is just 5°C. 

    Iceland is a Hot Testbed 

    “They’re now drilling for supercritical water in Iceland. Geothermal heat is so readily available, the country is essentially a laboratory and the biggest playground for the use of geothermal energy. We’re watching them closely to learn from their experiences,” said Lund.

    If geothermal energy is going to be produced on a scale that makes a difference in terms of energy demand worldwide, it will have to be produced everywhere – even without volcanic sources. These kinds of geothermal energy plants could then be placed near towns and energy intensive industries.

    More and more people beginning to realize that geothermal heating offers a viable energy alternative. The critical question is whether the technology required for deep, safe and economic drilling can be developed. 

    Enova Hesitates 

    Enova, a government-financed energy efficiency agency, is among the institutions and individuals who question the costs associated with producing geothermal energy. 

    “Deep geothermal heat from thousands of metres deep could be promising. But the cost picture here is still uncertain,” said Kjell Olav Skjølsvik, a senior adviser at Enova. 

    The organization has not ranked deep geothermal heat as a possible future energy source. “Many technologies are competing for this title, and we consider it more likely that a future energy system will use multiple sources and multiple technologies in a cost-effective mix,” says Skjølsvik. 

    However, Enova also recognizes the potential in geothermal energy, and has therefore granted support to Rock Energy’s project in Oslo. “We hope the project can help to clarify how mature the technology is, and help us figure out how to calculate the cost of deep geothermal heat in Norway,” says Skjølsvik. 

    “It Will Succeed” 

    Odd-Geir Lademo and Are Lund are not discouraged by these criticisms. They think it should be possible to unite industry, researchers and government to find solutions that are needed to harness the promise of geothermal heat. 

    “The oil and gas industry is conservative. To begin to develop geothermal energy from ten to twelve thousand metres deep will be expensive. But the benefits will also be enormous. That is why the industry will eventually begin to invest. In the 1960s, we were beginners when it came to pumping oil from the North Sea. Tackling that challenge was a huge boost in many ways. As a nation, we bet and we won,” says Lademo. 

    “I believe we can develop the knowledge we need about materials to get down to 300°C in ten years time. It might take 25 years or more of research and development to get down to 500°C,” Lund said, with agreement from Lademo.

    “We are convinced that this is possible. But it requires us to further develop existing technology. To do that requires money, a lot of money. Public funding is the key that’s needed to get the industry overall to invest. Geothermal energy is a unique opportunity for the oil industry to develop in a new way. They will come to realize this, it’s just a matter of time.”

    Unni Skoglund is a writer for GEMINI, the news source for research from NTNU and SINTEF