| RSS |
|
A Shade Greener
6/12/2010 6:27:48 AM
|
Good news... if you live within a 1 hour travel zone from junction 36 of the M1 motorway and own a home with a south facing roof. |
|
Making Solar Power Pay in the UK.
6/6/2010 7:08:43 PM
|
| UK residents are being rewarded for switching over to solar power. From the 1st of April 2010, any property with solar electric panels (photovoltaics) will receive a payment from the government for every unit of electricity produced regardless of whether the property consumes the electricity or not. This is based on the new tariff which is fixed for 25 years. The initial rate of payment is 41.3 pence per kilowatt hour, which is around four times higher than the market rate. Electricity that is produced and not consumed can be sold to the National Grid for a further payment of 44.3 pence per kilowatt hour. Other reported benefits of switching over to photovoltaics solar panels are: Property value increase by up to 8.5%. Financial return on the initial investment of around 8 to 10% each year. Over a tonne of CO2 saved per year. If the initial cost of photovoltaics still make your eyes water, there is still the option of choosing a solar thermal panel for water heating. Solar thermal panels are approximately five times cheaper than PV panels. Thermal systems are not eligible for the payback scheme, however homeowners can apply for a grant, up to a maximum of £400 or 30% of the total cost (excluding VAT). |
|
November 2009 - News Round Up
11/29/2009 6:23:34 PM
|
| Other items that have appeared in the news this month... Bioengineered Bottles?
Fossils fuel based plastics could become a thing of the past.
South Korean scientists have successfully produced polylactic acid (PLA), a biobased polymer, using bioengineering. PLA can be used to make plastics; it is bio-degradable, has a low toxicity to humans and is also renewable.
Until now, PLA production has not been economically viable. It required a complex series of reactions; which included bacterial fermentation, to produce lactic acid, follwed by carefully controlled polymerisation (the formation of a chain of molecules), whereby the lactic acid is first catalytically converted into cyclic lactide monomer.
The team has now developed a one step process that can produce PLA and its copolymers through direct fermentation. The achievement has been made possible thanks to a metabolically engineered strain of E-Coli.
The research will be published in the journal of Biotechnology and Bioengineering.
Related Articles: Great Pacific Garbage Patch - Item 2 & Plastics do decompose and add to pollution - Item 3.
Carbon Dioxide Emissions Rise Trebles over the last decade.
Since the year 2000, carbon dioxide emissions have increased threefold compared to the 1990s.
Each year we now observe an increase amounting to 3.4% per year (for the period 2000 to 2008). In the 1990s this was much lower, at around 1% per year.
Global emissions have increased by 29% since 2000, attributed largely to the increase in trade and manufacture (in particular from emerging economies), the shift from oil to coal and the waning capacity of the Earth’s carbon sink.
The report was submitted by the Global Carbon Project, a team of some 30 researchers around the world.
Tackling Climate Change is Good for Us.
Cutting greenhouse pollutants could save millions of lives, according to a series of papers published in the journal Lancet (25th November 2009). The research indicates that low income countries will fare the worst if the problem is not confronted.
Read full article: http://www.sciencedaily.com/releases/2009/11/091125081622.htm
Related Articles: Ozone related deaths, Air pollution link to appendicitis and Tackling indoor air pollution.
|
|
Weighing Up the Oceans.
11/16/2009 8:39:06 PM
|
As a result of variations in precipitation / evaporation, the seasonal storage of water as snow and the melting of glaciers and ice masses in Greenland and the Antarctica; the total mass of the world’s oceans varies, on average, by approximately 3 quadrillion kilogrammes (3 x 1015 kg) between seasons. The difference in mass translates to a global sea level variation of around 7 to 8 mm.
The volume of the oceans can be deduced from sea level height, when the topography of the seabed is known. Geodesists can therefore rely on gauging stations and satellite altimetry to work out the volume. However calculating the mass is not as straight-forwards, simply because additional variables, water temperature and salt content, must be taken into account.
Water expands when heated and so weighs less than an equal volume of cold water. Dissolved salt content would also add to the total mass, by a varying amount, based on the local salt profile.
Another factor that has also been considered is the bending of the sea bed under the weight of the water.
Scientists have used this information to formulate numerical models of the ocean. Surprisingly, they discovered that significant fluctuations in mass were occurring, especially at higher latitudes, in a very short space of time (only 1 or 2 weeks).
What Next?
The next step of the mission will be to ascertain how much heat is being stored in the oceans by comparing variations in volume and mass. It is hoped, after long term analysis, that this will lead to improved climatic models.
|
|
US Water Drops.
11/16/2009 6:46:46 PM
|
The United States is using less water than during the peak years of 1975 and 1980, according to water use estimates for 2005. Despite a 30 percent population increase during the past 25 years, overall water use has remained fairly stable according to a new U.S. Geological Survey report.
Alternative technologies that are now used for cooling in power generation and more efficient irrigation systems are responsible for the overall reduced consumption.
The breakdown of daily water consumption in the USA, accounting for 410 billion gallons (approx. 1.55 million MLD [megalitres per day]) is as follows:
49% - Electricity production at thermoelectric power plants.
31% - Irrigation.
11% - Public water supplies.
9% - Other uses including self supplied industrial, livestock, aquaculture, mining and rural domestic uses.
Read full article: http://www.sciencedaily.com/releases/2009/11/091106120807.htm
|
|
Greenland Speeds Up Weight Loss
11/14/2009 8:03:06 PM
|
The rate at which the Greenland icesheet is losing mass is accelerating.
If the whole of the Greenland icesheet were to melt; it would cause the global sea level to rise by 7 metres.
 From 2000 to 2008; Greenland icesheet melt has contributed to an average of 0.46mm rise, per year, in global sea level. 1500 gigatonnes* of ice have been lost during this time. However, for the period 2006 to 2008, alone, the amount of ice loss that occurred totalled 273 gigatonnes* per year. This is equivalent to a 0.75 mm rise in global sea level each year. The apparent increase in the last three years suggests the rate of ice loss is speeding up.
Two processes, as a result of warmer temperatures, were reported to be equally responsible for the loss of ice mass that is taking place. Namely; surface melting on land and glacier melting caused by warmer ocean currents.
It was also suspected that the surface melt started to increase in the 1990s but was masked by snowfall; which increased at the same rate.
Two independent methods were used to quantify the loss. One method modelled ice sheet behaviour in conjunction with regional weather data and the other used satellite measurements from GRACE (Gravity Recovery and Climate Experiment). Both estimates came to the same conclusion.
*1 gigatonne = 1 x 109 tonnes = 1000 x 109 kg. 1 gigatonne of water has a volume of 1 km3.
Source: http://www.sciencedaily.com/releases/2009/11/091112141311.htm |
|
Cut Back on Cutting Back
11/13/2009 7:58:54 PM
|
Just over 7,000 sq km of the Amazon Rainforest was destroyed between July 2008 and August 2009, according to the latest annual figures; which indicate a 45% drop in deforestation levels that are now at their lowest since records began 21 years ago.
Brazil intends for half of its proposed carbon emissions to come from reducing deforestation and is hoping to cut deforestation rates by 80% by 2020.
Some environmentalists fear that the decline in deforestation has only come about because of the global recession and will pick up again after economic recovery.
Source: BBC News
|
|
Recycled Fire Fighter.
11/5/2009 4:43:36 PM
|
"Scientists have developed a new building material made largely from recycled material that that is fire resistant to temperatures in excess of 1,100oC. The so-called 'liquid granite' can reduce the fire risk in buildings as, unlike concrete, it doesn't explode at high temperatures. It can also withstand high temperatures for longer periods of time. The material is made up of between 30 and 70 per cent recycled material, mainly base products from industry. It uses less than one-third of the cement used in precast concrete, which also reduces its carbon footprint. |
|
Support for Algae Blooms.
11/5/2009 4:37:25 PM
|
Algae oil (biodiesel) moved a step closer to becoming a commercial renewable energy source; in a bid to wean us off fossil fuels.
Despite the potential of some algae that can deliver a high yield, up to 6000 gallons of oil per acre*, the costs involved during its production are often prohibitive.
Almost half the cost goes towards providing the steady supply of food and water that is essential for growth. Considerable expense is also incurred when harvesting the algae because current growing methods use ponds and bioreactor columns, in which algae is suspended and free to float around. Centrifugation and additional energy are therefore required to harvest the ‘moving target’.
At present it costs approximately $56 to produce one gallon of biodiesel from algae, using the best technologies available. Researchers hope to reduce this to around $5 per gallon, over the next five to ten years, through gaining a better understanding of large scale algae production.
How?
The scientists plan to use the oceans as a plentiful source of food and water, to support algae in the growth phase. This offers another advantage because it eliminates the requirement for land; which could instead be used for food production.
The next challenge is how to overcome the difficulties of harvesting algae in such an environment. The answer could lie (quite literally) in the use of solid media, such as thin film stainless steel, upon which algae blooms could be encouraged to grow and easily collected for harvest. A support structure, rolling like a conveyor belt, could be used as a platform in the ocean.
One researcher described how he envisaged the system working in practice, “The algae would grow on the thin-film surface submerged under the ocean. At some point, the growth surface rolls up into the sunlight and the algae dries. A harvesting knife at the end of the conveyer system scrapes off dried algae, at which point the surface submerges to become home to the next growth of oil-rich algal material.”
The team are looking into the mechanisms that algae use to attach to various surfaces and also the materials and surface textures which encourage algae to bloom and grow.
Preliminary findings indicate two species of algae, high in oil content and fast growing, attached very well to a stainless steel, thin film surface that was slightly dimpled.
*As compared with 50 gallons of oil that are produced per acre of land from soyabeans.
|
|
Iron Controls Nitrogen Fixing.
11/2/2009 8:06:58 PM
|
A positive correlation was discovered between the rate of nitrogen fixation and dissolved iron concentration, in a study of the Atlantic Ocean.
Nitrogen gas (N2) must be fixed through the action of diazotrophic bacteria.
The role of nitrogen is important because a shortage of fixed nitrogen limits the growth of phytoplankton. This in turn may be critical in the fight against global warming, because phytoplankton also remove carbon dioxide, absorbed from the atmosphere, through photosynthesis.
Iron fertilisation of the oceans has long been linked to creating favourable conditions for carbon sequestration. See related article: Adding iron to the oceans for carbon storage.
It was previously held that iron did play a big part in fixing nitrogen, simply because the enzyme responsible, for the conversion, contains a lot of iron. However, this idea was ruled out by other research that suggested phosphorus was the dominant element in the process. Until now...that is.
The preliminary findings, in today's publication, showed the rate of nitrogen fixing was actually negatively correlated with dissolved phosphorus concentration. It is clear that further research is required, into the role and sources of nutrients as well as how oceanic circulation may affect nitrogen fixing, to improve our understanding.
|
|
Green Light for Blue Energy?
11/2/2009 3:43:23 PM
|
Dutch researcher, Jan Post, is proposing that energy generated by mixing salt and freshwater could be exploited and deployed, on a global scale, if R&D receives greater attention and funding. To date, such technology has been largely experimental although the principle of generating electricity using osmotic power has been known for over 100 years.
Of the two practical methods; reverse electrodialysis (RED) and pressure retarded osmosis (PRO), Post focused his research on the former. He demonstrated that it could be possible to recover more than 80% of the energy from salinity gradients; technical feasibility would be 60 – 70 % and economic feasibility would be marginally lower than that.
Findings
The global variations in the salt concentration difference between rivers and seas mean that the potential to take advantage of the technology will vary according to location. For example, the technical potential in Australia is 65%, in Africa it is 61%, but in South America it is only 47%. There are also stark differences in the individual potential of rivers, owing to salt concentration, temperature and other environmental factors.
The Rhine was reported to have one of the highest potentials, in Europe, for this application.
Post’s research estimates the technical potential of the Rhine and Maas rivers, together, is 2.4 gigawatts per year. He goes on to say that it would be economically feasible to harness 1.5 gigawatts, which is enough to supply 4 million households.
Conclusions
A proposal for a large scale trial, involving the construction of 200 megawatts power station, at Afsluitdijk (Netherlands) was put forwards. Freshwater discharge from Afsluitdijk into the sea is currently very high, making it the ideal location.
Post recommended further development and mass production of membranes in order to reduce the high price associated membrane technology, along with more robust techniques that would be able cope with biofouling caused by polluted waters. He also suggested that the ecological impact of building and operating the power station should be comprehensively reviewed.
Source: Science Daily and Blue Energy Implementation.
Drawbacks?
Post anticipates there will be, at least, a ten year wait before the first commercial power stations are operational.
Despite the green appearance of blue energy; further research is required to study the effect, for example, that discharging brackish water would have on the environment and biodiversity.
Future freshwater water shortages, globally, could make osmotic power less attractive, as more energy would then be required to treat brackish water and freshwater abstraction may be prioritised.
More Information: Blue Energy Brief.
Related Articles: Generating electricity from wastewater.
|
|
October 2009 - News Round Up
10/29/2009 9:17:18 PM
|
Other items that have been in the news this month...
Paving the Way to Cut Pollution Run-Off.
Storm water run-off from impermeable surfaces, such as driveways, rooftops and parking lots, can lead to the collection and build-up of pollutants. Without normal ground filtration these pollutants end up in waterways; resulting in water quality deterioration.
The US Environmental Protection Agency (EPA) is embarking on decade long research to assess the merits of permeable pavements. During the summer, they replaced a 43,000 square foot portion of their parking lot with three different types of permeable pavement. The parking lot will remain in use, in order to examine how each material copes with vehicle related pollution, such as leaking oil. Rain gardens, with varying amounts of vegetation, were also introduced. The study hopes to establish how effective these features can be for filtering pollutants and storm water management.
Bringing the Outdoors, Indoors.
The thin film of dust that appears to renew itself on household objects has been shown to originate from outdoor sources. Contaminated soil (tracked in by footwear) and particulate matter (infiltrated from outdoor air) are said to be the main culprits in addition to other known sources, such as dead skin shedding and fibres from soft furnishings.
The study reports that arsenic, lead and other harmful substances can migrate indoors in this manner.
North Carolina in Deep.
Sea-level rise in North Carolina is accelerating. It was found to be three times higher in the 20th century than it has been over the past 500 years; ranging from 3 to 3.3mm higher compared to previous values of around 1mm. Much of this rise occurred between 1879 and 1915, which coincides with major industrialisation.
The drastic change in sea level may have resulted from the melting of the Greenland ice sheet.
Cost of Coral.
Analysis of 80 coral reef valuation studies has revealed that coral reef ‘services’, worldwide, are worth an estimated $172 billion per year.
Coral reef services include; the supply of food, raw materials, climate regulation, water purification, tourism and maintaining genetic diversity.
Meanwhile there is growing consensus that coral reefs are unlikely to survive if carbon dioxide levels, in the atmosphere, reach 350 ppm (parts per million). Earlier this week, scientists proposed freezing samples to re-introduce coral in the future if global temperatures can be stabilized.
Simple Steps for Greener Living.
Individuals in the USA can help in the fight against global warming by adjusting their own behaviour. 38% of carbon dioxide emissions in the USA are generated by household energy consumption, which amounts to 8% of global emissions.
Simple steps such as hanging clothes outside to dry instead of using a dryer could make a big difference, especially if, as the researchers suggest, this behaviour is then copied by peers to become the norm rather than the exception.
|
|
Ocean Acidification Makes Shellfish Clam Up.
10/26/2009 8:59:19 PM
|
Relatively minor increases in ocean acidity brought about by high levels of carbon dioxide have significant detrimental effects on the growth, development, and survival of hard clams, bay scallops, and Eastern oysters, according to new research to be published, next month, in the journal Limnology and Oceanography.
Over the last century, the oceans absorbed almost half of the atmospheric carbon dioxide that was generated by human activities such as burning fossil fuels. Oceans become more acidic as they absorb carbon dioxide, they also have reduced concentrations of carbonate, which shell-making organisms use to produce their calcium carbonate structures, such as the shells of shellfish.
How?
The research examined the growth and survival of larvae, from three different species of shellfish. The larvae were raised in containers through which different levels of carbon dioxide were bubbled through. Carbon dioxide concentrations used in the study were based on a range of projected values expected to occur in the 21st century and beyond.
Findings?
Carbon dioxide levels expected later this century:
Clam and scallop larvae were smaller, took longer to develop in the larval stage and showed more than a 50% drop in survival. Oysters grew more slowly but survival was not affected.
Carbon dioxide levels expected next century:
Oyster survival also diminished. Repercussions?
The authors of the report are concerned that rising levels of carbon dioxide could drastically alter the composition of the entire population. Slower development means the larval stage is extended and because larvae are free swimming, this leaves them open to predators.
The scientists suggest that the present decline in shellfish stock, experienced in some localized regions, could be explained as resulting from higher levels of carbon dioxide.
|
|
Coral - Frozen Out of Extinction.
10/25/2009 9:07:36 PM
|
Coral reefs make up less than 0.25% of the ocean floor, yet provide a source of food, income and coastal protection for around 500 million people worldwide. Researchers gathered evidence to show that most coral reefs will not survive even if greenhouse gas emissions are strictly controlled. Recent research indicates that the Coral Triangle (in the Indo-Pacific Ocean), which is believed to harbour around 75% of the world’s coral species, could be completely destroyed by the end of the century. In an effort to save biodiversity; the experts consider it will be necessary to store samples of coral species in liquid nitrogen to enable re-introduction to the oceans in the future, if global temperatures can be stabilized. It is hoped that the reefs could eventually be rebuilt.
The evidence was presented to legislators, from 16 major economies, at a meeting in Copenhagen ahead of the Climate Change Summit in December.
Source: BBC News
|
All of this could be lost to climate change.|
New Evidence Shows Global Warming Today is Not Natural.
10/25/2009 9:48:12 AM
|
Sediments that were retrieved from a remote Arctic lake1 are unique because they contain raw paleoclimate information about the past 200,000 years. Typically, most finds, uncovered in the glaciated portion of the Arctic, only reveal clues about the past 10,000 years.
Despite the fact that glaciers did cover the lake, for various reasons, the ice cores were not eroded. These ice cores represent the most extensive historical record of data that has ever been uncovered; a span which includes two ice ages and three interglacial periods.
The study suggests that global warming seen in the 20th century has not been due to natural causes; a view supported by preceding research in this field.
The data showed that there have been periods in history when the climate was as warm as today. However, these warm periods were directly related to patterns of the Earth’s orbit around the sun. Sediments from the mid 20th century were described as being similar to past warm periods, but stark differences were observed in sediments dated after the mid 20th century.
The sediments showed that several species of 'cold-adapted' mosquito-like midges inhabited the region, in strong numbers, for thousands of years but declined rapidly around 1950. Two species, that were adapted for the coldest temperatures, completely disappeared from the lake. The amount of lake algae, a species of diatom, which was a rarity before the 20th century, has also increased rapidly over the last few decades. The paper’s lead author, Yarrow Axford, concluded that, “The 20th century is the only period during the past 200 millennia in which aquatic indicators reflect increased warming, despite the declining effect of slow changes in the tilt of the Earth's axis which, under natural conditions, would lead to climatic cooling.”
1The sediment cores were extracted from the bottom of a 30-foot-deep lake near the village of Clyde River on the east coast of Baffin Island, which is several hundred miles west of Greenland. Related Articles: Global warming sees off Arctic chill.
|
| 66 items total | 1 2 3 4 5 |
